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Subject[PATCH 41/49] ext4: Add multi block allocator for ext4
Date
From: Alex Tomas <alex@clusterfs.com>

Signed-off-by: Alex Tomas <alex@clusterfs.com>
Signed-off-by: Andreas Dilger <adilger@clusterfs.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---
fs/ext4/Makefile | 2 +-
fs/ext4/balloc.c | 67 +-
fs/ext4/extents.c | 45 +-
fs/ext4/inode.c | 15 +-
fs/ext4/mballoc.c | 4551 ++++++++++++++++++++++++++++++++++++++++++++
fs/ext4/migrate.c | 10 +-
fs/ext4/super.c | 61 +-
fs/ext4/xattr.c | 4 +-
include/linux/ext4_fs.h | 76 +-
include/linux/ext4_fs_i.h | 4 +
include/linux/ext4_fs_sb.h | 52 +
11 files changed, 4850 insertions(+), 37 deletions(-)
create mode 100644 fs/ext4/mballoc.c
diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile
index d5fd80b..ac6fa8c 100644
--- a/fs/ext4/Makefile
+++ b/fs/ext4/Makefile
@@ -6,7 +6,7 @@ obj-$(CONFIG_EXT4DEV_FS) += ext4dev.o

ext4dev-y := balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o \
ioctl.o namei.o super.o symlink.o hash.o resize.o extents.o \
- ext4_jbd2.o migrate.o
+ ext4_jbd2.o migrate.o mballoc.o

ext4dev-$(CONFIG_EXT4DEV_FS_XATTR) += xattr.o xattr_user.o xattr_trusted.o
ext4dev-$(CONFIG_EXT4DEV_FS_POSIX_ACL) += acl.o
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 54d3da7..643046b 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -577,6 +577,8 @@ void ext4_discard_reservation(struct inode *inode)
struct ext4_reserve_window_node *rsv;
spinlock_t *rsv_lock = &EXT4_SB(inode->i_sb)->s_rsv_window_lock;

+ ext4_mb_discard_inode_preallocations(inode);
+
if (!block_i)
return;

@@ -785,19 +787,29 @@ error_return:
* @inode: inode
* @block: start physical block to free
* @count: number of blocks to count
+ * @metadata: Are these metadata blocks
*/
void ext4_free_blocks(handle_t *handle, struct inode *inode,
- ext4_fsblk_t block, unsigned long count)
+ ext4_fsblk_t block, unsigned long count,
+ int metadata)
{
struct super_block * sb;
unsigned long dquot_freed_blocks;

+ /* this isn't the right place to decide whether block is metadata
+ * inode.c/extents.c knows better, but for safety ... */
+ if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode) ||
+ ext4_should_journal_data(inode))
+ metadata = 1;
+
sb = inode->i_sb;
- if (!sb) {
- printk ("ext4_free_blocks: nonexistent device");
- return;
- }
- ext4_free_blocks_sb(handle, sb, block, count, &dquot_freed_blocks);
+
+ if (!test_opt(sb, MBALLOC) || !EXT4_SB(sb)->s_group_info)
+ ext4_free_blocks_sb(handle, sb, block, count,
+ &dquot_freed_blocks);
+ else
+ ext4_mb_free_blocks(handle, inode, block, count,
+ metadata, &dquot_freed_blocks);
if (dquot_freed_blocks)
DQUOT_FREE_BLOCK(inode, dquot_freed_blocks);
return;
@@ -1576,7 +1588,7 @@ int ext4_should_retry_alloc(struct super_block *sb, int *retries)
}

/**
- * ext4_new_blocks() -- core block(s) allocation function
+ * ext4_new_blocks_old() -- core block(s) allocation function
* @handle: handle to this transaction
* @inode: file inode
* @goal: given target block(filesystem wide)
@@ -1589,7 +1601,7 @@ int ext4_should_retry_alloc(struct super_block *sb, int *retries)
* any specific goal block.
*
*/
-ext4_fsblk_t ext4_new_blocks(handle_t *handle, struct inode *inode,
+ext4_fsblk_t ext4_new_blocks_old(handle_t *handle, struct inode *inode,
ext4_fsblk_t goal, unsigned long *count, int *errp)
{
struct buffer_head *bitmap_bh = NULL;
@@ -1849,13 +1861,46 @@ out:
}

ext4_fsblk_t ext4_new_block(handle_t *handle, struct inode *inode,
- ext4_fsblk_t goal, int *errp)
+ ext4_fsblk_t goal, int *errp)
+{
+ struct ext4_allocation_request ar;
+ ext4_fsblk_t ret;
+
+ if (!test_opt(inode->i_sb, MBALLOC)) {
+ unsigned long count = 1;
+ ret = ext4_new_blocks_old(handle, inode, goal, &count, errp);
+ return ret;
+ }
+
+ memset(&ar, 0, sizeof(ar));
+ ar.inode = inode;
+ ar.goal = goal;
+ ar.len = 1;
+ ret = ext4_mb_new_blocks(handle, &ar, errp);
+ return ret;
+}
+
+ext4_fsblk_t ext4_new_blocks(handle_t *handle, struct inode *inode,
+ ext4_fsblk_t goal, unsigned long *count, int *errp)
{
- unsigned long count = 1;
+ struct ext4_allocation_request ar;
+ ext4_fsblk_t ret;

- return ext4_new_blocks(handle, inode, goal, &count, errp);
+ if (!test_opt(inode->i_sb, MBALLOC)) {
+ ret = ext4_new_blocks_old(handle, inode, goal, count, errp);
+ return ret;
+ }
+
+ memset(&ar, 0, sizeof(ar));
+ ar.inode = inode;
+ ar.goal = goal;
+ ar.len = *count;
+ ret = ext4_mb_new_blocks(handle, &ar, errp);
+ *count = ar.len;
+ return ret;
}

+
/**
* ext4_count_free_blocks() -- count filesystem free blocks
* @sb: superblock
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index a60227c..8cf5545 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -853,7 +853,7 @@ cleanup:
for (i = 0; i < depth; i++) {
if (!ablocks[i])
continue;
- ext4_free_blocks(handle, inode, ablocks[i], 1);
+ ext4_free_blocks(handle, inode, ablocks[i], 1, 1);
}
}
kfree(ablocks);
@@ -1698,7 +1698,7 @@ static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
ext_debug("index is empty, remove it, free block %llu\n", leaf);
bh = sb_find_get_block(inode->i_sb, leaf);
ext4_forget(handle, 1, inode, bh, leaf);
- ext4_free_blocks(handle, inode, leaf, 1);
+ ext4_free_blocks(handle, inode, leaf, 1, 1);
return err;
}

@@ -1759,8 +1759,10 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
{
struct buffer_head *bh;
unsigned short ee_len = ext4_ext_get_actual_len(ex);
- int i;
+ int i, metadata = 0;

+ if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
+ metadata = 1;
#ifdef EXTENTS_STATS
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
@@ -1789,7 +1791,7 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
bh = sb_find_get_block(inode->i_sb, start + i);
ext4_forget(handle, 0, inode, bh, start + i);
}
- ext4_free_blocks(handle, inode, start, num);
+ ext4_free_blocks(handle, inode, start, num, metadata);
} else if (from == le32_to_cpu(ex->ee_block)
&& to <= le32_to_cpu(ex->ee_block) + ee_len - 1) {
printk(KERN_INFO "strange request: removal %u-%u from %u:%u\n",
@@ -2287,6 +2289,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
ext4_fsblk_t goal, newblock;
int err = 0, depth, ret;
unsigned long allocated = 0;
+ struct ext4_allocation_request ar;

__clear_bit(BH_New, &bh_result->b_state);
ext_debug("blocks %u/%lu requested for inode %u\n",
@@ -2397,8 +2400,15 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
if (S_ISREG(inode->i_mode) && (!EXT4_I(inode)->i_block_alloc_info))
ext4_init_block_alloc_info(inode);

- /* allocate new block */
- goal = ext4_ext_find_goal(inode, path, iblock);
+ /* find neighbour allocated blocks */
+ ar.lleft = iblock;
+ err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
+ if (err)
+ goto out2;
+ ar.lright = iblock;
+ err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright);
+ if (err)
+ goto out2;

/*
* See if request is beyond maximum number of blocks we can have in
@@ -2421,7 +2431,18 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
allocated = le16_to_cpu(newex.ee_len);
else
allocated = max_blocks;
- newblock = ext4_new_blocks(handle, inode, goal, &allocated, &err);
+
+ /* allocate new block */
+ ar.inode = inode;
+ ar.goal = ext4_ext_find_goal(inode, path, iblock);
+ ar.logical = iblock;
+ ar.len = allocated;
+ if (S_ISREG(inode->i_mode))
+ ar.flags = EXT4_MB_HINT_DATA;
+ else
+ /* disable in-core preallocation for non-regular files */
+ ar.flags = 0;
+ newblock = ext4_mb_new_blocks(handle, &ar, &err);
if (!newblock)
goto out2;
ext_debug("allocate new block: goal %llu, found %llu/%lu\n",
@@ -2429,14 +2450,17 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,

/* try to insert new extent into found leaf and return */
ext4_ext_store_pblock(&newex, newblock);
- newex.ee_len = cpu_to_le16(allocated);
+ newex.ee_len = cpu_to_le16(ar.len);
if (create == EXT4_CREATE_UNINITIALIZED_EXT) /* Mark uninitialized */
ext4_ext_mark_uninitialized(&newex);
err = ext4_ext_insert_extent(handle, inode, path, &newex);
if (err) {
/* free data blocks we just allocated */
+ /* not a good idea to call discard here directly,
+ * but otherwise we'd need to call it every free() */
+ ext4_mb_discard_inode_preallocations(inode);
ext4_free_blocks(handle, inode, ext_pblock(&newex),
- le16_to_cpu(newex.ee_len));
+ le16_to_cpu(newex.ee_len), 0);
goto out2;
}

@@ -2445,6 +2469,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,

/* previous routine could use block we allocated */
newblock = ext_pblock(&newex);
+ allocated = le16_to_cpu(newex.ee_len);
outnew:
__set_bit(BH_New, &bh_result->b_state);

@@ -2496,6 +2521,8 @@ void ext4_ext_truncate(struct inode * inode, struct page *page)
down_write(&EXT4_I(inode)->i_data_sem);
ext4_ext_invalidate_cache(inode);

+ ext4_mb_discard_inode_preallocations(inode);
+
/*
* TODO: optimization is possible here.
* Probably we need not scan at all,
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 3c013e5..2947800 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -551,7 +551,7 @@ static int ext4_alloc_blocks(handle_t *handle, struct inode *inode,
return ret;
failed_out:
for (i = 0; i <index; i++)
- ext4_free_blocks(handle, inode, new_blocks[i], 1);
+ ext4_free_blocks(handle, inode, new_blocks[i], 1, 0);
return ret;
}

@@ -650,9 +650,9 @@ failed:
ext4_journal_forget(handle, branch[i].bh);
}
for (i = 0; i <indirect_blks; i++)
- ext4_free_blocks(handle, inode, new_blocks[i], 1);
+ ext4_free_blocks(handle, inode, new_blocks[i], 1, 0);

- ext4_free_blocks(handle, inode, new_blocks[i], num);
+ ext4_free_blocks(handle, inode, new_blocks[i], num, 0);

return err;
}
@@ -749,9 +749,10 @@ err_out:
for (i = 1; i <= num; i++) {
BUFFER_TRACE(where[i].bh, "call jbd2_journal_forget");
ext4_journal_forget(handle, where[i].bh);
- ext4_free_blocks(handle,inode,le32_to_cpu(where[i-1].key),1);
+ ext4_free_blocks(handle, inode,
+ le32_to_cpu(where[i-1].key), 1, 0);
}
- ext4_free_blocks(handle, inode, le32_to_cpu(where[num].key), blks);
+ ext4_free_blocks(handle, inode, le32_to_cpu(where[num].key), blks, 0);

return err;
}
@@ -2051,7 +2052,7 @@ static void ext4_clear_blocks(handle_t *handle, struct inode *inode,
}
}

- ext4_free_blocks(handle, inode, block_to_free, count);
+ ext4_free_blocks(handle, inode, block_to_free, count, 0);
}

/**
@@ -2224,7 +2225,7 @@ static void ext4_free_branches(handle_t *handle, struct inode *inode,
ext4_journal_test_restart(handle, inode);
}

- ext4_free_blocks(handle, inode, nr, 1);
+ ext4_free_blocks(handle, inode, nr, 1, 1);

if (parent_bh) {
/*
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
new file mode 100644
index 0000000..0398aa0
--- /dev/null
+++ b/fs/ext4/mballoc.c
@@ -0,0 +1,4551 @@
+/*
+ * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
+ * Written by Alex Tomas <alex@clusterfs.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public Licens
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
+ */
+
+
+/*
+ * mballoc.c contains the multiblocks allocation routines
+ */
+
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/ext4_jbd2.h>
+#include <linux/ext4_fs.h>
+#include <linux/quotaops.h>
+#include <linux/buffer_head.h>
+#include <linux/module.h>
+#include <linux/swap.h>
+#include <linux/proc_fs.h>
+#include <linux/pagemap.h>
+#include <linux/seq_file.h>
+#include <linux/version.h>
+#include "group.h"
+
+/*
+ * MUSTDO:
+ * - test ext4_ext_search_left() and ext4_ext_search_right()
+ * - search for metadata in few groups
+ *
+ * TODO v4:
+ * - normalization should take into account whether file is still open
+ * - discard preallocations if no free space left (policy?)
+ * - don't normalize tails
+ * - quota
+ * - reservation for superuser
+ *
+ * TODO v3:
+ * - bitmap read-ahead (proposed by Oleg Drokin aka green)
+ * - track min/max extents in each group for better group selection
+ * - mb_mark_used() may allocate chunk right after splitting buddy
+ * - tree of groups sorted by number of free blocks
+ * - error handling
+ */
+
+/*
+ * The allocation request involve request for multiple number of blocks
+ * near to the goal(block) value specified.
+ *
+ * During initialization phase of the allocator we decide to use the group
+ * preallocation or inode preallocation depending on the size file. The
+ * size of the file could be the resulting file size we would have after
+ * allocation or the current file size which ever is larger. If the size is
+ * less that sbi->s_mb_stream_request we select the group
+ * preallocation. The default value of s_mb_stream_request is 16
+ * blocks. This can also be tuned via
+ * /proc/fs/ext4/<partition>/stream_req. The value is represented in terms
+ * of number of blocks.
+ *
+ * The main motivation for having small file use group preallocation is to
+ * ensure that we have small file closer in the disk.
+ *
+ * First stage the allocator looks at the inode prealloc list
+ * ext4_inode_info->i_prealloc_list contain list of prealloc spaces for
+ * this particular inode. The inode prealloc space is represented as:
+ *
+ * pa_lstart -> the logical start block for this prealloc space
+ * pa_pstart -> the physical start block for this prealloc space
+ * pa_len -> lenght for this prealloc space
+ * pa_free -> free space available in this prealloc space
+ *
+ * The inode preallocation space is used looking at the _logical_ start
+ * block. If only the logical file block falls within the range of prealloc
+ * space we will consume the particular prealloc space. This make sure that
+ * that the we have contiguous physical blocks representing the file blocks
+ *
+ * The important thing to be noted in case of inode prealloc space is that
+ * we don't modify the values associated to inode prealloc space except
+ * pa_free.
+ *
+ * If we are not able to find blocks in the inode prealloc space and if we
+ * have the group allocation flag set then we look at the locality group
+ * prealloc space. These are per CPU prealloc list repreasented as
+ *
+ * ext4_sb_info.s_locality_groups[smp_processor_id()]
+ *
+ * The reason for having a per cpu locality group is to reduce the contention
+ * between CPUs. It is possible to get scheduled at this point.
+ *
+ * The locality group prealloc space is used looking at whether we have
+ * enough free space (pa_free) withing the prealloc space.
+ *
+ * If we can't allocate blocks via inode prealloc or/and locality group
+ * prealloc then we look at the buddy cache. The buddy cache is represented
+ * by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets
+ * mapped to the buddy and bitmap information regarding different
+ * groups. The buddy information is attached to buddy cache inode so that
+ * we can access them through the page cache. The information regarding
+ * each group is loaded via ext4_mb_load_buddy. The information involve
+ * block bitmap and buddy information. The information are stored in the
+ * inode as:
+ *
+ * { page }
+ * [ group 0 buddy][ group 0 bitmap] [group 1][ group 1]...
+ *
+ *
+ * one block each for bitmap and buddy information. So for each group we
+ * take up 2 blocks. A page can contain blocks_per_page (PAGE_CACHE_SIZE /
+ * blocksize) blocks. So it can have information regarding groups_per_page
+ * which is blocks_per_page/2
+ *
+ * The buddy cache inode is not stored on disk. The inode is thrown
+ * away when the filesystem is unmounted.
+ *
+ * We look for count number of blocks in the buddy cache. If we were able
+ * to locate that many free blocks we return with additional information
+ * regarding rest of the contiguous physical block available
+ *
+ * Before allocating blocks via buddy cache we normalize the request
+ * blocks. This ensure we ask for more blocks that we needed. The extra
+ * blocks that we get after allocation is added to the respective prealloc
+ * list. In case of inode preallocation we follow a list of heuristics
+ * based on file size. This can be found in ext4_mb_normalize_request. If
+ * we are doing a group prealloc we try to normalize the request to
+ * sbi->s_mb_group_prealloc. Default value of s_mb_group_prealloc is set to
+ * 512 blocks. This can be tuned via
+ * /proc/fs/ext4/<partition/group_prealloc. The value is represented in
+ * terms of number of blocks. If we have mounted the file system with -O
+ * stripe=<value> option the group prealloc request is normalized to the
+ * stripe value (sbi->s_stripe)
+ *
+ * The regular allocator(using the buddy cache) support few tunables.
+ *
+ * /proc/fs/ext4/<partition>/min_to_scan
+ * /proc/fs/ext4/<partition>/max_to_scan
+ * /proc/fs/ext4/<partition>/order2_req
+ *
+ * The regular allocator use buddy scan only if the request len is power of
+ * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
+ * value of s_mb_order2_reqs can be tuned via
+ * /proc/fs/ext4/<partition>/order2_req. If the request len is equal to
+ * stripe size (sbi->s_stripe), we try to search for contigous block in
+ * stripe size. This should result in better allocation on RAID setup. If
+ * not we search in the specific group using bitmap for best extents. The
+ * tunable min_to_scan and max_to_scan controll the behaviour here.
+ * min_to_scan indicate how long the mballoc __must__ look for a best
+ * extent and max_to_scanindicate how long the mballoc __can__ look for a
+ * best extent in the found extents. Searching for the blocks starts with
+ * the group specified as the goal value in allocation context via
+ * ac_g_ex. Each group is first checked based on the criteria whether it
+ * can used for allocation. ext4_mb_good_group explains how the groups are
+ * checked.
+ *
+ * Both the prealloc space are getting populated as above. So for the first
+ * request we will hit the buddy cache which will result in this prealloc
+ * space getting filled. The prealloc space is then later used for the
+ * subsequent request.
+ */
+
+/*
+ * mballoc operates on the following data:
+ * - on-disk bitmap
+ * - in-core buddy (actually includes buddy and bitmap)
+ * - preallocation descriptors (PAs)
+ *
+ * there are two types of preallocations:
+ * - inode
+ * assiged to specific inode and can be used for this inode only.
+ * it describes part of inode's space preallocated to specific
+ * physical blocks. any block from that preallocated can be used
+ * independent. the descriptor just tracks number of blocks left
+ * unused. so, before taking some block from descriptor, one must
+ * make sure corresponded logical block isn't allocated yet. this
+ * also means that freeing any block within descriptor's range
+ * must discard all preallocated blocks.
+ * - locality group
+ * assigned to specific locality group which does not translate to
+ * permanent set of inodes: inode can join and leave group. space
+ * from this type of preallocation can be used for any inode. thus
+ * it's consumed from the beginning to the end.
+ *
+ * relation between them can be expressed as:
+ * in-core buddy = on-disk bitmap + preallocation descriptors
+ *
+ * this mean blocks mballoc considers used are:
+ * - allocated blocks (persistent)
+ * - preallocated blocks (non-persistent)
+ *
+ * consistency in mballoc world means that at any time a block is either
+ * free or used in ALL structures. notice: "any time" should not be read
+ * literally -- time is discrete and delimited by locks.
+ *
+ * to keep it simple, we don't use block numbers, instead we count number of
+ * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA.
+ *
+ * all operations can be expressed as:
+ * - init buddy: buddy = on-disk + PAs
+ * - new PA: buddy += N; PA = N
+ * - use inode PA: on-disk += N; PA -= N
+ * - discard inode PA buddy -= on-disk - PA; PA = 0
+ * - use locality group PA on-disk += N; PA -= N
+ * - discard locality group PA buddy -= PA; PA = 0
+ * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap
+ * is used in real operation because we can't know actual used
+ * bits from PA, only from on-disk bitmap
+ *
+ * if we follow this strict logic, then all operations above should be atomic.
+ * given some of them can block, we'd have to use something like semaphores
+ * killing performance on high-end SMP hardware. let's try to relax it using
+ * the following knowledge:
+ * 1) if buddy is referenced, it's already initialized
+ * 2) while block is used in buddy and the buddy is referenced,
+ * nobody can re-allocate that block
+ * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has
+ * bit set and PA claims same block, it's OK. IOW, one can set bit in
+ * on-disk bitmap if buddy has same bit set or/and PA covers corresponded
+ * block
+ *
+ * so, now we're building a concurrency table:
+ * - init buddy vs.
+ * - new PA
+ * blocks for PA are allocated in the buddy, buddy must be referenced
+ * until PA is linked to allocation group to avoid concurrent buddy init
+ * - use inode PA
+ * we need to make sure that either on-disk bitmap or PA has uptodate data
+ * given (3) we care that PA-=N operation doesn't interfere with init
+ * - discard inode PA
+ * the simplest way would be to have buddy initialized by the discard
+ * - use locality group PA
+ * again PA-=N must be serialized with init
+ * - discard locality group PA
+ * the simplest way would be to have buddy initialized by the discard
+ * - new PA vs.
+ * - use inode PA
+ * i_data_sem serializes them
+ * - discard inode PA
+ * discard process must wait until PA isn't used by another process
+ * - use locality group PA
+ * some mutex should serialize them
+ * - discard locality group PA
+ * discard process must wait until PA isn't used by another process
+ * - use inode PA
+ * - use inode PA
+ * i_data_sem or another mutex should serializes them
+ * - discard inode PA
+ * discard process must wait until PA isn't used by another process
+ * - use locality group PA
+ * nothing wrong here -- they're different PAs covering different blocks
+ * - discard locality group PA
+ * discard process must wait until PA isn't used by another process
+ *
+ * now we're ready to make few consequences:
+ * - PA is referenced and while it is no discard is possible
+ * - PA is referenced until block isn't marked in on-disk bitmap
+ * - PA changes only after on-disk bitmap
+ * - discard must not compete with init. either init is done before
+ * any discard or they're serialized somehow
+ * - buddy init as sum of on-disk bitmap and PAs is done atomically
+ *
+ * a special case when we've used PA to emptiness. no need to modify buddy
+ * in this case, but we should care about concurrent init
+ *
+ */
+
+ /*
+ * Logic in few words:
+ *
+ * - allocation:
+ * load group
+ * find blocks
+ * mark bits in on-disk bitmap
+ * release group
+ *
+ * - use preallocation:
+ * find proper PA (per-inode or group)
+ * load group
+ * mark bits in on-disk bitmap
+ * release group
+ * release PA
+ *
+ * - free:
+ * load group
+ * mark bits in on-disk bitmap
+ * release group
+ *
+ * - discard preallocations in group:
+ * mark PAs deleted
+ * move them onto local list
+ * load on-disk bitmap
+ * load group
+ * remove PA from object (inode or locality group)
+ * mark free blocks in-core
+ *
+ * - discard inode's preallocations:
+ */
+
+/*
+ * Locking rules
+ *
+ * Locks:
+ * - bitlock on a group (group)
+ * - object (inode/locality) (object)
+ * - per-pa lock (pa)
+ *
+ * Paths:
+ * - new pa
+ * object
+ * group
+ *
+ * - find and use pa:
+ * pa
+ *
+ * - release consumed pa:
+ * pa
+ * group
+ * object
+ *
+ * - generate in-core bitmap:
+ * group
+ * pa
+ *
+ * - discard all for given object (inode, locality group):
+ * object
+ * pa
+ * group
+ *
+ * - discard all for given group:
+ * group
+ * pa
+ * group
+ * object
+ *
+ */
+
+/*
+ * with AGGRESSIVE_CHECK allocator runs consistency checks over
+ * structures. these checks slow things down a lot
+ */
+#define AGGRESSIVE_CHECK__
+
+/*
+ * with DOUBLE_CHECK defined mballoc creates persistent in-core
+ * bitmaps, maintains and uses them to check for double allocations
+ */
+#define DOUBLE_CHECK__
+
+/*
+ */
+#define MB_DEBUG__
+#ifdef MB_DEBUG
+#define mb_debug(fmt, a...) printk(fmt, ##a)
+#else
+#define mb_debug(fmt, a...)
+#endif
+
+/*
+ * with EXT4_MB_HISTORY mballoc stores last N allocations in memory
+ * and you can monitor it in /proc/fs/ext4/<dev>/mb_history
+ */
+#define EXT4_MB_HISTORY
+#define EXT4_MB_HISTORY_ALLOC 1 /* allocation */
+#define EXT4_MB_HISTORY_PREALLOC 2 /* preallocated blocks used */
+#define EXT4_MB_HISTORY_DISCARD 4 /* preallocation discarded */
+#define EXT4_MB_HISTORY_FREE 8 /* free */
+
+#define EXT4_MB_HISTORY_DEFAULT (EXT4_MB_HISTORY_ALLOC | \
+ EXT4_MB_HISTORY_PREALLOC)
+
+/*
+ * How long mballoc can look for a best extent (in found extents)
+ */
+#define MB_DEFAULT_MAX_TO_SCAN 200
+
+/*
+ * How long mballoc must look for a best extent
+ */
+#define MB_DEFAULT_MIN_TO_SCAN 10
+
+/*
+ * How many groups mballoc will scan looking for the best chunk
+ */
+#define MB_DEFAULT_MAX_GROUPS_TO_SCAN 5
+
+/*
+ * with 'ext4_mb_stats' allocator will collect stats that will be
+ * shown at umount. The collecting costs though!
+ */
+#define MB_DEFAULT_STATS 1
+
+/*
+ * files smaller than MB_DEFAULT_STREAM_THRESHOLD are served
+ * by the stream allocator, which purpose is to pack requests
+ * as close each to other as possible to produce smooth I/O traffic
+ * We use locality group prealloc space for stream request.
+ * We can tune the same via /proc/fs/ext4/<parition>/stream_req
+ */
+#define MB_DEFAULT_STREAM_THRESHOLD 16 /* 64K */
+
+/*
+ * for which requests use 2^N search using buddies
+ */
+#define MB_DEFAULT_ORDER2_REQS 2
+
+/*
+ * default group prealloc size 512 blocks
+ */
+#define MB_DEFAULT_GROUP_PREALLOC 512
+
+static struct kmem_cache *ext4_pspace_cachep;
+
+#ifdef EXT4_BB_MAX_BLOCKS
+#undef EXT4_BB_MAX_BLOCKS
+#endif
+#define EXT4_BB_MAX_BLOCKS 30
+
+struct ext4_free_metadata {
+ ext4_group_t group;
+ unsigned short num;
+ ext4_grpblk_t blocks[EXT4_BB_MAX_BLOCKS];
+ struct list_head list;
+};
+
+struct ext4_group_info {
+ unsigned long bb_state;
+ unsigned long bb_tid;
+ struct ext4_free_metadata *bb_md_cur;
+ unsigned short bb_first_free;
+ unsigned short bb_free;
+ unsigned short bb_fragments;
+ struct list_head bb_prealloc_list;
+#ifdef DOUBLE_CHECK
+ void *bb_bitmap;
+#endif
+ unsigned short bb_counters[];
+};
+
+#define EXT4_GROUP_INFO_NEED_INIT_BIT 0
+#define EXT4_GROUP_INFO_LOCKED_BIT 1
+
+#define EXT4_MB_GRP_NEED_INIT(grp) \
+ (test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
+
+
+struct ext4_prealloc_space {
+ struct list_head pa_inode_list;
+ struct list_head pa_group_list;
+ union {
+ struct list_head pa_tmp_list;
+ struct rcu_head pa_rcu;
+ } u;
+ spinlock_t pa_lock;
+ atomic_t pa_count;
+ unsigned pa_deleted;
+ ext4_fsblk_t pa_pstart; /* phys. block */
+ ext4_lblk_t pa_lstart; /* log. block */
+ unsigned short pa_len; /* len of preallocated chunk */
+ unsigned short pa_free; /* how many blocks are free */
+ unsigned short pa_linear; /* consumed in one direction
+ * strictly, for grp prealloc */
+ spinlock_t *pa_obj_lock;
+ struct inode *pa_inode; /* hack, for history only */
+};
+
+
+struct ext4_free_extent {
+ ext4_lblk_t fe_logical;
+ ext4_grpblk_t fe_start;
+ ext4_group_t fe_group;
+ int fe_len;
+};
+
+/*
+ * Locality group:
+ * we try to group all related changes together
+ * so that writeback can flush/allocate them together as well
+ */
+struct ext4_locality_group {
+ /* for allocator */
+ struct semaphore lg_sem; /* to serialize allocates */
+ struct list_head lg_prealloc_list;/* list of preallocations */
+ spinlock_t lg_prealloc_lock;
+};
+
+struct ext4_allocation_context {
+ struct inode *ac_inode;
+ struct super_block *ac_sb;
+
+ /* original request */
+ struct ext4_free_extent ac_o_ex;
+
+ /* goal request (after normalization) */
+ struct ext4_free_extent ac_g_ex;
+
+ /* the best found extent */
+ struct ext4_free_extent ac_b_ex;
+
+ /* copy of the bext found extent taken before preallocation efforts */
+ struct ext4_free_extent ac_f_ex;
+
+ /* number of iterations done. we have to track to limit searching */
+ unsigned long ac_ex_scanned;
+ __u16 ac_groups_scanned;
+ __u16 ac_found;
+ __u16 ac_tail;
+ __u16 ac_buddy;
+ __u16 ac_flags; /* allocation hints */
+ __u8 ac_status;
+ __u8 ac_criteria;
+ __u8 ac_repeats;
+ __u8 ac_2order; /* if request is to allocate 2^N blocks and
+ * N > 0, the field stores N, otherwise 0 */
+ __u8 ac_op; /* operation, for history only */
+ struct page *ac_bitmap_page;
+ struct page *ac_buddy_page;
+ struct ext4_prealloc_space *ac_pa;
+ struct ext4_locality_group *ac_lg;
+};
+
+#define AC_STATUS_CONTINUE 1
+#define AC_STATUS_FOUND 2
+#define AC_STATUS_BREAK 3
+
+struct ext4_mb_history {
+ struct ext4_free_extent orig; /* orig allocation */
+ struct ext4_free_extent goal; /* goal allocation */
+ struct ext4_free_extent result; /* result allocation */
+ unsigned pid;
+ unsigned ino;
+ __u16 found; /* how many extents have been found */
+ __u16 groups; /* how many groups have been scanned */
+ __u16 tail; /* what tail broke some buddy */
+ __u16 buddy; /* buddy the tail ^^^ broke */
+ __u16 flags;
+ __u8 cr:3; /* which phase the result extent was found at */
+ __u8 op:4;
+ __u8 merged:1;
+};
+
+struct ext4_buddy {
+ struct page *bd_buddy_page;
+ void *bd_buddy;
+ struct page *bd_bitmap_page;
+ void *bd_bitmap;
+ struct ext4_group_info *bd_info;
+ struct super_block *bd_sb;
+ __u16 bd_blkbits;
+ ext4_group_t bd_group;
+};
+#define EXT4_MB_BITMAP(e4b) ((e4b)->bd_bitmap)
+#define EXT4_MB_BUDDY(e4b) ((e4b)->bd_buddy)
+
+#ifndef EXT4_MB_HISTORY
+#define ext4_mb_store_history(ac)
+#else
+static void ext4_mb_store_history(struct ext4_allocation_context *ac);
+#endif
+
+#define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
+
+static struct proc_dir_entry *proc_root_ext4;
+struct buffer_head *read_block_bitmap(struct super_block *, ext4_group_t);
+ext4_fsblk_t ext4_new_blocks_old(handle_t *handle, struct inode *inode,
+ ext4_fsblk_t goal, unsigned long *count, int *errp);
+
+static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
+ ext4_group_t group);
+static void ext4_mb_poll_new_transaction(struct super_block *, handle_t *);
+static void ext4_mb_free_committed_blocks(struct super_block *);
+static void ext4_mb_return_to_preallocation(struct inode *inode,
+ struct ext4_buddy *e4b, sector_t block,
+ int count);
+static void ext4_mb_put_pa(struct ext4_allocation_context *,
+ struct super_block *, struct ext4_prealloc_space *pa);
+static int ext4_mb_init_per_dev_proc(struct super_block *sb);
+static int ext4_mb_destroy_per_dev_proc(struct super_block *sb);
+
+
+static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
+{
+ struct ext4_group_info *grinfo = ext4_get_group_info(sb, group);
+
+ bit_spin_lock(EXT4_GROUP_INFO_LOCKED_BIT, &(grinfo->bb_state));
+}
+
+static inline void ext4_unlock_group(struct super_block *sb,
+ ext4_group_t group)
+{
+ struct ext4_group_info *grinfo = ext4_get_group_info(sb, group);
+
+ bit_spin_unlock(EXT4_GROUP_INFO_LOCKED_BIT, &(grinfo->bb_state));
+}
+
+static inline int ext4_is_group_locked(struct super_block *sb,
+ ext4_group_t group)
+{
+ struct ext4_group_info *grinfo = ext4_get_group_info(sb, group);
+
+ return bit_spin_is_locked(EXT4_GROUP_INFO_LOCKED_BIT,
+ &(grinfo->bb_state));
+}
+
+static ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb,
+ struct ext4_free_extent *fex)
+{
+ ext4_fsblk_t block;
+
+ block = (ext4_fsblk_t) fex->fe_group * EXT4_BLOCKS_PER_GROUP(sb)
+ + fex->fe_start
+ + le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
+ return block;
+}
+
+#if BITS_PER_LONG == 64
+#define mb_correct_addr_and_bit(bit, addr) \
+{ \
+ bit += ((unsigned long) addr & 7UL) << 3; \
+ addr = (void *) ((unsigned long) addr & ~7UL); \
+}
+#elif BITS_PER_LONG == 32
+#define mb_correct_addr_and_bit(bit, addr) \
+{ \
+ bit += ((unsigned long) addr & 3UL) << 3; \
+ addr = (void *) ((unsigned long) addr & ~3UL); \
+}
+#else
+#error "how many bits you are?!"
+#endif
+
+static inline int mb_test_bit(int bit, void *addr)
+{
+ mb_correct_addr_and_bit(bit, addr);
+ return ext4_test_bit(bit, addr);
+}
+
+static inline void mb_set_bit(int bit, void *addr)
+{
+ mb_correct_addr_and_bit(bit, addr);
+ ext4_set_bit(bit, addr);
+}
+
+static inline void mb_set_bit_atomic(spinlock_t *lock, int bit, void *addr)
+{
+ mb_correct_addr_and_bit(bit, addr);
+ ext4_set_bit_atomic(lock, bit, addr);
+}
+
+static inline void mb_clear_bit(int bit, void *addr)
+{
+ mb_correct_addr_and_bit(bit, addr);
+ ext4_clear_bit(bit, addr);
+}
+
+static inline void mb_clear_bit_atomic(spinlock_t *lock, int bit, void *addr)
+{
+ mb_correct_addr_and_bit(bit, addr);
+ ext4_clear_bit_atomic(lock, bit, addr);
+}
+
+static inline void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max)
+{
+ char *bb;
+
+ /* FIXME!! is this needed */
+ BUG_ON(EXT4_MB_BITMAP(e4b) == EXT4_MB_BUDDY(e4b));
+ BUG_ON(max == NULL);
+
+ if (order > e4b->bd_blkbits + 1) {
+ *max = 0;
+ return NULL;
+ }
+
+ /* at order 0 we see each particular block */
+ *max = 1 << (e4b->bd_blkbits + 3);
+ if (order == 0)
+ return EXT4_MB_BITMAP(e4b);
+
+ bb = EXT4_MB_BUDDY(e4b) + EXT4_SB(e4b->bd_sb)->s_mb_offsets[order];
+ *max = EXT4_SB(e4b->bd_sb)->s_mb_maxs[order];
+
+ return bb;
+}
+
+#ifdef DOUBLE_CHECK
+static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b,
+ int first, int count)
+{
+ int i;
+ struct super_block *sb = e4b->bd_sb;
+
+ if (unlikely(e4b->bd_info->bb_bitmap == NULL))
+ return;
+ BUG_ON(!ext4_is_group_locked(sb, e4b->bd_group));
+ for (i = 0; i < count; i++) {
+ if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) {
+ ext4_fsblk_t blocknr;
+ blocknr = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb);
+ blocknr += first + i;
+ blocknr +=
+ le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
+
+ ext4_error(sb, __FUNCTION__, "double-free of inode"
+ " %lu's block %llu(bit %u in group %lu)\n",
+ inode ? inode->i_ino : 0, blocknr,
+ first + i, e4b->bd_group);
+ }
+ mb_clear_bit(first + i, e4b->bd_info->bb_bitmap);
+ }
+}
+
+static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count)
+{
+ int i;
+
+ if (unlikely(e4b->bd_info->bb_bitmap == NULL))
+ return;
+ BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group));
+ for (i = 0; i < count; i++) {
+ BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap));
+ mb_set_bit(first + i, e4b->bd_info->bb_bitmap);
+ }
+}
+
+static void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
+{
+ if (memcmp(e4b->bd_info->bb_bitmap, bitmap, e4b->bd_sb->s_blocksize)) {
+ unsigned char *b1, *b2;
+ int i;
+ b1 = (unsigned char *) e4b->bd_info->bb_bitmap;
+ b2 = (unsigned char *) bitmap;
+ for (i = 0; i < e4b->bd_sb->s_blocksize; i++) {
+ if (b1[i] != b2[i]) {
+ printk("corruption in group %lu at byte %u(%u):"
+ " %x in copy != %x on disk/prealloc\n",
+ e4b->bd_group, i, i * 8, b1[i], b2[i]);
+ BUG();
+ }
+ }
+ }
+}
+
+#else
+#define mb_free_blocks_double(a, b, c, d)
+#define mb_mark_used_double(a, b, c)
+#define mb_cmp_bitmaps(a, b)
+#endif
+
+#ifdef AGGRESSIVE_CHECK
+
+#define MB_CHECK_ASSERT(assert) \
+do { \
+ if (!(assert)) { \
+ printk(KERN_EMERG \
+ "Assertion failure in %s() at %s:%d: \"%s\"\n", \
+ function, file, line, # assert); \
+ BUG(); \
+ } \
+} while (0)
+
+static int __mb_check_buddy(struct ext4_buddy *e4b, char *file,
+ const char *function, int line)
+{
+ struct super_block *sb = e4b->bd_sb;
+ int order = e4b->bd_blkbits + 1;
+ int max;
+ int max2;
+ int i;
+ int j;
+ int k;
+ int count;
+ struct ext4_group_info *grp;
+ int fragments = 0;
+ int fstart;
+ struct list_head *cur;
+ void *buddy;
+ void *buddy2;
+
+ if (!test_opt(sb, MBALLOC))
+ return 0;
+
+ {
+ static int mb_check_counter;
+ if (mb_check_counter++ % 100 != 0)
+ return 0;
+ }
+
+ while (order > 1) {
+ buddy = mb_find_buddy(e4b, order, &max);
+ MB_CHECK_ASSERT(buddy);
+ buddy2 = mb_find_buddy(e4b, order - 1, &max2);
+ MB_CHECK_ASSERT(buddy2);
+ MB_CHECK_ASSERT(buddy != buddy2);
+ MB_CHECK_ASSERT(max * 2 == max2);
+
+ count = 0;
+ for (i = 0; i < max; i++) {
+
+ if (mb_test_bit(i, buddy)) {
+ /* only single bit in buddy2 may be 1 */
+ if (!mb_test_bit(i << 1, buddy2)) {
+ MB_CHECK_ASSERT(
+ mb_test_bit((i<<1)+1, buddy2));
+ } else if (!mb_test_bit((i << 1) + 1, buddy2)) {
+ MB_CHECK_ASSERT(
+ mb_test_bit(i << 1, buddy2));
+ }
+ continue;
+ }
+
+ /* both bits in buddy2 must be 0 */
+ MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2));
+ MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2));
+
+ for (j = 0; j < (1 << order); j++) {
+ k = (i * (1 << order)) + j;
+ MB_CHECK_ASSERT(
+ !mb_test_bit(k, EXT4_MB_BITMAP(e4b)));
+ }
+ count++;
+ }
+ MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count);
+ order--;
+ }
+
+ fstart = -1;
+ buddy = mb_find_buddy(e4b, 0, &max);
+ for (i = 0; i < max; i++) {
+ if (!mb_test_bit(i, buddy)) {
+ MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free);
+ if (fstart == -1) {
+ fragments++;
+ fstart = i;
+ }
+ continue;
+ }
+ fstart = -1;
+ /* check used bits only */
+ for (j = 0; j < e4b->bd_blkbits + 1; j++) {
+ buddy2 = mb_find_buddy(e4b, j, &max2);
+ k = i >> j;
+ MB_CHECK_ASSERT(k < max2);
+ MB_CHECK_ASSERT(mb_test_bit(k, buddy2));
+ }
+ }
+ MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info));
+ MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments);
+
+ grp = ext4_get_group_info(sb, e4b->bd_group);
+ buddy = mb_find_buddy(e4b, 0, &max);
+ list_for_each(cur, &grp->bb_prealloc_list) {
+ ext4_group_t groupnr;
+ struct ext4_prealloc_space *pa;
+ pa = list_entry(cur, struct ext4_prealloc_space, group_list);
+ ext4_get_group_no_and_offset(sb, pa->pstart, &groupnr, &k);
+ MB_CHECK_ASSERT(groupnr == e4b->bd_group);
+ for (i = 0; i < pa->len; i++)
+ MB_CHECK_ASSERT(mb_test_bit(k + i, buddy));
+ }
+ return 0;
+}
+#undef MB_CHECK_ASSERT
+#define mb_check_buddy(e4b) __mb_check_buddy(e4b, \
+ __FILE__, __FUNCTION__, __LINE__)
+#else
+#define mb_check_buddy(e4b)
+#endif
+
+/* find most significant bit */
+static int fmsb(unsigned short word)
+{
+ int order;
+
+ if (word > 255) {
+ order = 7;
+ word >>= 8;
+ } else {
+ order = -1;
+ }
+
+ do {
+ order++;
+ word >>= 1;
+ } while (word != 0);
+
+ return order;
+}
+
+/* FIXME!! need more doc */
+static void ext4_mb_mark_free_simple(struct super_block *sb,
+ void *buddy, unsigned first, int len,
+ struct ext4_group_info *grp)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ unsigned short min;
+ unsigned short max;
+ unsigned short chunk;
+ unsigned short border;
+
+ BUG_ON(len >= EXT4_BLOCKS_PER_GROUP(sb));
+
+ border = 2 << sb->s_blocksize_bits;
+
+ while (len > 0) {
+ /* find how many blocks can be covered since this position */
+ max = ffs(first | border) - 1;
+
+ /* find how many blocks of power 2 we need to mark */
+ min = fmsb(len);
+
+ if (max < min)
+ min = max;
+ chunk = 1 << min;
+
+ /* mark multiblock chunks only */
+ grp->bb_counters[min]++;
+ if (min > 0)
+ mb_clear_bit(first >> min,
+ buddy + sbi->s_mb_offsets[min]);
+
+ len -= chunk;
+ first += chunk;
+ }
+}
+
+static void ext4_mb_generate_buddy(struct super_block *sb,
+ void *buddy, void *bitmap, ext4_group_t group)
+{
+ struct ext4_group_info *grp = ext4_get_group_info(sb, group);
+ unsigned short max = EXT4_BLOCKS_PER_GROUP(sb);
+ unsigned short i = 0;
+ unsigned short first;
+ unsigned short len;
+ unsigned free = 0;
+ unsigned fragments = 0;
+ unsigned long long period = get_cycles();
+
+ /* initialize buddy from bitmap which is aggregation
+ * of on-disk bitmap and preallocations */
+ i = ext4_find_next_zero_bit(bitmap, max, 0);
+ grp->bb_first_free = i;
+ while (i < max) {
+ fragments++;
+ first = i;
+ i = ext4_find_next_bit(bitmap, max, i);
+ len = i - first;
+ free += len;
+ if (len > 1)
+ ext4_mb_mark_free_simple(sb, buddy, first, len, grp);
+ else
+ grp->bb_counters[0]++;
+ if (i < max)
+ i = ext4_find_next_zero_bit(bitmap, max, i);
+ }
+ grp->bb_fragments = fragments;
+
+ if (free != grp->bb_free) {
+ printk(KERN_DEBUG
+ "EXT4-fs: group %lu: %u blocks in bitmap, %u in gd\n",
+ group, free, grp->bb_free);
+ grp->bb_free = free;
+ }
+
+ clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state));
+
+ period = get_cycles() - period;
+ spin_lock(&EXT4_SB(sb)->s_bal_lock);
+ EXT4_SB(sb)->s_mb_buddies_generated++;
+ EXT4_SB(sb)->s_mb_generation_time += period;
+ spin_unlock(&EXT4_SB(sb)->s_bal_lock);
+}
+
+/* The buddy information is attached the buddy cache inode
+ * for convenience. The information regarding each group
+ * is loaded via ext4_mb_load_buddy. The information involve
+ * block bitmap and buddy information. The information are
+ * stored in the inode as
+ *
+ * { page }
+ * [ group 0 buddy][ group 0 bitmap] [group 1][ group 1]...
+ *
+ *
+ * one block each for bitmap and buddy information.
+ * So for each group we take up 2 blocks. A page can
+ * contain blocks_per_page (PAGE_CACHE_SIZE / blocksize) blocks.
+ * So it can have information regarding groups_per_page which
+ * is blocks_per_page/2
+ */
+
+static int ext4_mb_init_cache(struct page *page, char *incore)
+{
+ int blocksize;
+ int blocks_per_page;
+ int groups_per_page;
+ int err = 0;
+ int i;
+ ext4_group_t first_group;
+ int first_block;
+ struct super_block *sb;
+ struct buffer_head *bhs;
+ struct buffer_head **bh;
+ struct inode *inode;
+ char *data;
+ char *bitmap;
+
+ mb_debug("init page %lu\n", page->index);
+
+ inode = page->mapping->host;
+ sb = inode->i_sb;
+ blocksize = 1 << inode->i_blkbits;
+ blocks_per_page = PAGE_CACHE_SIZE / blocksize;
+
+ groups_per_page = blocks_per_page >> 1;
+ if (groups_per_page == 0)
+ groups_per_page = 1;
+
+ /* allocate buffer_heads to read bitmaps */
+ if (groups_per_page > 1) {
+ err = -ENOMEM;
+ i = sizeof(struct buffer_head *) * groups_per_page;
+ bh = kmalloc(i, GFP_NOFS);
+ if (bh == NULL)
+ goto out;
+ memset(bh, 0, i);
+ } else
+ bh = &bhs;
+
+ first_group = page->index * blocks_per_page / 2;
+
+ /* read all groups the page covers into the cache */
+ for (i = 0; i < groups_per_page; i++) {
+ struct ext4_group_desc *desc;
+
+ if (first_group + i >= EXT4_SB(sb)->s_groups_count)
+ break;
+
+ err = -EIO;
+ desc = ext4_get_group_desc(sb, first_group + i, NULL);
+ if (desc == NULL)
+ goto out;
+
+ err = -ENOMEM;
+ bh[i] = sb_getblk(sb, ext4_block_bitmap(sb, desc));
+ if (bh[i] == NULL)
+ goto out;
+
+ if (buffer_uptodate(bh[i]))
+ continue;
+
+ lock_buffer(bh[i]);
+ if (buffer_uptodate(bh[i])) {
+ unlock_buffer(bh[i]);
+ continue;
+ }
+
+ if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
+ ext4_init_block_bitmap(sb, bh[i],
+ first_group + i, desc);
+ set_buffer_uptodate(bh[i]);
+ unlock_buffer(bh[i]);
+ continue;
+ }
+ get_bh(bh[i]);
+ bh[i]->b_end_io = end_buffer_read_sync;
+ submit_bh(READ, bh[i]);
+ mb_debug("read bitmap for group %lu\n", first_group + i);
+ }
+
+ /* wait for I/O completion */
+ for (i = 0; i < groups_per_page && bh[i]; i++)
+ wait_on_buffer(bh[i]);
+
+ err = -EIO;
+ for (i = 0; i < groups_per_page && bh[i]; i++)
+ if (!buffer_uptodate(bh[i]))
+ goto out;
+
+ first_block = page->index * blocks_per_page;
+ for (i = 0; i < blocks_per_page; i++) {
+ int group;
+ struct ext4_group_info *grinfo;
+
+ group = (first_block + i) >> 1;
+ if (group >= EXT4_SB(sb)->s_groups_count)
+ break;
+
+ /*
+ * data carry information regarding this
+ * particular group in the format specified
+ * above
+ *
+ */
+ data = page_address(page) + (i * blocksize);
+ bitmap = bh[group - first_group]->b_data;
+
+ /*
+ * We place the buddy block and bitmap block
+ * close together
+ */
+ if ((first_block + i) & 1) {
+ /* this is block of buddy */
+ BUG_ON(incore == NULL);
+ mb_debug("put buddy for group %u in page %lu/%x\n",
+ group, page->index, i * blocksize);
+ memset(data, 0xff, blocksize);
+ grinfo = ext4_get_group_info(sb, group);
+ grinfo->bb_fragments = 0;
+ memset(grinfo->bb_counters, 0,
+ sizeof(unsigned short)*(sb->s_blocksize_bits+2));
+ /*
+ * incore got set to the group block bitmap below
+ */
+ ext4_mb_generate_buddy(sb, data, incore, group);
+ incore = NULL;
+ } else {
+ /* this is block of bitmap */
+ BUG_ON(incore != NULL);
+ mb_debug("put bitmap for group %u in page %lu/%x\n",
+ group, page->index, i * blocksize);
+
+ /* see comments in ext4_mb_put_pa() */
+ ext4_lock_group(sb, group);
+ memcpy(data, bitmap, blocksize);
+
+ /* mark all preallocated blks used in in-core bitmap */
+ ext4_mb_generate_from_pa(sb, data, group);
+ ext4_unlock_group(sb, group);
+
+ /* set incore so that the buddy information can be
+ * generated using this
+ */
+ incore = data;
+ }
+ }
+ SetPageUptodate(page);
+
+out:
+ if (bh) {
+ for (i = 0; i < groups_per_page && bh[i]; i++)
+ brelse(bh[i]);
+ if (bh != &bhs)
+ kfree(bh);
+ }
+ return err;
+}
+
+static int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
+ struct ext4_buddy *e4b)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct inode *inode = sbi->s_buddy_cache;
+ int blocks_per_page;
+ int block;
+ int pnum;
+ int poff;
+ struct page *page;
+
+ mb_debug("load group %lu\n", group);
+
+ blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize;
+
+ e4b->bd_blkbits = sb->s_blocksize_bits;
+ e4b->bd_info = ext4_get_group_info(sb, group);
+ e4b->bd_sb = sb;
+ e4b->bd_group = group;
+ e4b->bd_buddy_page = NULL;
+ e4b->bd_bitmap_page = NULL;
+
+ /*
+ * the buddy cache inode stores the block bitmap
+ * and buddy information in consecutive blocks.
+ * So for each group we need two blocks.
+ */
+ block = group * 2;
+ pnum = block / blocks_per_page;
+ poff = block % blocks_per_page;
+
+ /* we could use find_or_create_page(), but it locks page
+ * what we'd like to avoid in fast path ... */
+ page = find_get_page(inode->i_mapping, pnum);
+ if (page == NULL || !PageUptodate(page)) {
+ if (page)
+ page_cache_release(page);
+ page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS);
+ if (page) {
+ BUG_ON(page->mapping != inode->i_mapping);
+ if (!PageUptodate(page)) {
+ ext4_mb_init_cache(page, NULL);
+ mb_cmp_bitmaps(e4b, page_address(page) +
+ (poff * sb->s_blocksize));
+ }
+ unlock_page(page);
+ }
+ }
+ if (page == NULL || !PageUptodate(page))
+ goto err;
+ e4b->bd_bitmap_page = page;
+ e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
+ mark_page_accessed(page);
+
+ block++;
+ pnum = block / blocks_per_page;
+ poff = block % blocks_per_page;
+
+ page = find_get_page(inode->i_mapping, pnum);
+ if (page == NULL || !PageUptodate(page)) {
+ if (page)
+ page_cache_release(page);
+ page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS);
+ if (page) {
+ BUG_ON(page->mapping != inode->i_mapping);
+ if (!PageUptodate(page))
+ ext4_mb_init_cache(page, e4b->bd_bitmap);
+
+ unlock_page(page);
+ }
+ }
+ if (page == NULL || !PageUptodate(page))
+ goto err;
+ e4b->bd_buddy_page = page;
+ e4b->bd_buddy = page_address(page) + (poff * sb->s_blocksize);
+ mark_page_accessed(page);
+
+ BUG_ON(e4b->bd_bitmap_page == NULL);
+ BUG_ON(e4b->bd_buddy_page == NULL);
+
+ return 0;
+
+err:
+ if (e4b->bd_bitmap_page)
+ page_cache_release(e4b->bd_bitmap_page);
+ if (e4b->bd_buddy_page)
+ page_cache_release(e4b->bd_buddy_page);
+ e4b->bd_buddy = NULL;
+ e4b->bd_bitmap = NULL;
+ return -EIO;
+}
+
+static void ext4_mb_release_desc(struct ext4_buddy *e4b)
+{
+ if (e4b->bd_bitmap_page)
+ page_cache_release(e4b->bd_bitmap_page);
+ if (e4b->bd_buddy_page)
+ page_cache_release(e4b->bd_buddy_page);
+}
+
+
+static int mb_find_order_for_block(struct ext4_buddy *e4b, int block)
+{
+ int order = 1;
+ void *bb;
+
+ BUG_ON(EXT4_MB_BITMAP(e4b) == EXT4_MB_BUDDY(e4b));
+ BUG_ON(block >= (1 << (e4b->bd_blkbits + 3)));
+
+ bb = EXT4_MB_BUDDY(e4b);
+ while (order <= e4b->bd_blkbits + 1) {
+ block = block >> 1;
+ if (!mb_test_bit(block, bb)) {
+ /* this block is part of buddy of order 'order' */
+ return order;
+ }
+ bb += 1 << (e4b->bd_blkbits - order);
+ order++;
+ }
+ return 0;
+}
+
+static void mb_clear_bits(spinlock_t *lock, void *bm, int cur, int len)
+{
+ __u32 *addr;
+
+ len = cur + len;
+ while (cur < len) {
+ if ((cur & 31) == 0 && (len - cur) >= 32) {
+ /* fast path: clear whole word at once */
+ addr = bm + (cur >> 3);
+ *addr = 0;
+ cur += 32;
+ continue;
+ }
+ mb_clear_bit_atomic(lock, cur, bm);
+ cur++;
+ }
+}
+
+static void mb_set_bits(spinlock_t *lock, void *bm, int cur, int len)
+{
+ __u32 *addr;
+
+ len = cur + len;
+ while (cur < len) {
+ if ((cur & 31) == 0 && (len - cur) >= 32) {
+ /* fast path: clear whole word at once */
+ addr = bm + (cur >> 3);
+ *addr = 0xffffffff;
+ cur += 32;
+ continue;
+ }
+ mb_set_bit_atomic(lock, cur, bm);
+ cur++;
+ }
+}
+
+static int mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
+ int first, int count)
+{
+ int block = 0;
+ int max = 0;
+ int order;
+ void *buddy;
+ void *buddy2;
+ struct super_block *sb = e4b->bd_sb;
+
+ BUG_ON(first + count > (sb->s_blocksize << 3));
+ BUG_ON(!ext4_is_group_locked(sb, e4b->bd_group));
+ mb_check_buddy(e4b);
+ mb_free_blocks_double(inode, e4b, first, count);
+
+ e4b->bd_info->bb_free += count;
+ if (first < e4b->bd_info->bb_first_free)
+ e4b->bd_info->bb_first_free = first;
+
+ /* let's maintain fragments counter */
+ if (first != 0)
+ block = !mb_test_bit(first - 1, EXT4_MB_BITMAP(e4b));
+ if (first + count < EXT4_SB(sb)->s_mb_maxs[0])
+ max = !mb_test_bit(first + count, EXT4_MB_BITMAP(e4b));
+ if (block && max)
+ e4b->bd_info->bb_fragments--;
+ else if (!block && !max)
+ e4b->bd_info->bb_fragments++;
+
+ /* let's maintain buddy itself */
+ while (count-- > 0) {
+ block = first++;
+ order = 0;
+
+ if (!mb_test_bit(block, EXT4_MB_BITMAP(e4b))) {
+ ext4_fsblk_t blocknr;
+ blocknr = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb);
+ blocknr += block;
+ blocknr +=
+ le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
+
+ ext4_error(sb, __FUNCTION__, "double-free of inode"
+ " %lu's block %llu(bit %u in group %lu)\n",
+ inode ? inode->i_ino : 0, blocknr, block,
+ e4b->bd_group);
+ }
+ mb_clear_bit(block, EXT4_MB_BITMAP(e4b));
+ e4b->bd_info->bb_counters[order]++;
+
+ /* start of the buddy */
+ buddy = mb_find_buddy(e4b, order, &max);
+
+ do {
+ block &= ~1UL;
+ if (mb_test_bit(block, buddy) ||
+ mb_test_bit(block + 1, buddy))
+ break;
+
+ /* both the buddies are free, try to coalesce them */
+ buddy2 = mb_find_buddy(e4b, order + 1, &max);
+
+ if (!buddy2)
+ break;
+
+ if (order > 0) {
+ /* for special purposes, we don't set
+ * free bits in bitmap */
+ mb_set_bit(block, buddy);
+ mb_set_bit(block + 1, buddy);
+ }
+ e4b->bd_info->bb_counters[order]--;
+ e4b->bd_info->bb_counters[order]--;
+
+ block = block >> 1;
+ order++;
+ e4b->bd_info->bb_counters[order]++;
+
+ mb_clear_bit(block, buddy2);
+ buddy = buddy2;
+ } while (1);
+ }
+ mb_check_buddy(e4b);
+
+ return 0;
+}
+
+static int mb_find_extent(struct ext4_buddy *e4b, int order, int block,
+ int needed, struct ext4_free_extent *ex)
+{
+ int next = block;
+ int max;
+ int ord;
+ void *buddy;
+
+ BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group));
+ BUG_ON(ex == NULL);
+
+ buddy = mb_find_buddy(e4b, order, &max);
+ BUG_ON(buddy == NULL);
+ BUG_ON(block >= max);
+ if (mb_test_bit(block, buddy)) {
+ ex->fe_len = 0;
+ ex->fe_start = 0;
+ ex->fe_group = 0;
+ return 0;
+ }
+
+ /* FIXME dorp order completely ? */
+ if (likely(order == 0)) {
+ /* find actual order */
+ order = mb_find_order_for_block(e4b, block);
+ block = block >> order;
+ }
+
+ ex->fe_len = 1 << order;
+ ex->fe_start = block << order;
+ ex->fe_group = e4b->bd_group;
+
+ /* calc difference from given start */
+ next = next - ex->fe_start;
+ ex->fe_len -= next;
+ ex->fe_start += next;
+
+ while (needed > ex->fe_len &&
+ (buddy = mb_find_buddy(e4b, order, &max))) {
+
+ if (block + 1 >= max)
+ break;
+
+ next = (block + 1) * (1 << order);
+ if (mb_test_bit(next, EXT4_MB_BITMAP(e4b)))
+ break;
+
+ ord = mb_find_order_for_block(e4b, next);
+
+ order = ord;
+ block = next >> order;
+ ex->fe_len += 1 << order;
+ }
+
+ BUG_ON(ex->fe_start + ex->fe_len > (1 << (e4b->bd_blkbits + 3)));
+ return ex->fe_len;
+}
+
+static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
+{
+ int ord;
+ int mlen = 0;
+ int max = 0;
+ int cur;
+ int start = ex->fe_start;
+ int len = ex->fe_len;
+ unsigned ret = 0;
+ int len0 = len;
+ void *buddy;
+
+ BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3));
+ BUG_ON(e4b->bd_group != ex->fe_group);
+ BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group));
+ mb_check_buddy(e4b);
+ mb_mark_used_double(e4b, start, len);
+
+ e4b->bd_info->bb_free -= len;
+ if (e4b->bd_info->bb_first_free == start)
+ e4b->bd_info->bb_first_free += len;
+
+ /* let's maintain fragments counter */
+ if (start != 0)
+ mlen = !mb_test_bit(start - 1, EXT4_MB_BITMAP(e4b));
+ if (start + len < EXT4_SB(e4b->bd_sb)->s_mb_maxs[0])
+ max = !mb_test_bit(start + len, EXT4_MB_BITMAP(e4b));
+ if (mlen && max)
+ e4b->bd_info->bb_fragments++;
+ else if (!mlen && !max)
+ e4b->bd_info->bb_fragments--;
+
+ /* let's maintain buddy itself */
+ while (len) {
+ ord = mb_find_order_for_block(e4b, start);
+
+ if (((start >> ord) << ord) == start && len >= (1 << ord)) {
+ /* the whole chunk may be allocated at once! */
+ mlen = 1 << ord;
+ buddy = mb_find_buddy(e4b, ord, &max);
+ BUG_ON((start >> ord) >= max);
+ mb_set_bit(start >> ord, buddy);
+ e4b->bd_info->bb_counters[ord]--;
+ start += mlen;
+ len -= mlen;
+ BUG_ON(len < 0);
+ continue;
+ }
+
+ /* store for history */
+ if (ret == 0)
+ ret = len | (ord << 16);
+
+ /* we have to split large buddy */
+ BUG_ON(ord <= 0);
+ buddy = mb_find_buddy(e4b, ord, &max);
+ mb_set_bit(start >> ord, buddy);
+ e4b->bd_info->bb_counters[ord]--;
+
+ ord--;
+ cur = (start >> ord) & ~1U;
+ buddy = mb_find_buddy(e4b, ord, &max);
+ mb_clear_bit(cur, buddy);
+ mb_clear_bit(cur + 1, buddy);
+ e4b->bd_info->bb_counters[ord]++;
+ e4b->bd_info->bb_counters[ord]++;
+ }
+
+ mb_set_bits(sb_bgl_lock(EXT4_SB(e4b->bd_sb), ex->fe_group),
+ EXT4_MB_BITMAP(e4b), ex->fe_start, len0);
+ mb_check_buddy(e4b);
+
+ return ret;
+}
+
+/*
+ * Must be called under group lock!
+ */
+static void ext4_mb_use_best_found(struct ext4_allocation_context *ac,
+ struct ext4_buddy *e4b)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
+ int ret;
+
+ BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group);
+ BUG_ON(ac->ac_status == AC_STATUS_FOUND);
+
+ ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len);
+ ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical;
+ ret = mb_mark_used(e4b, &ac->ac_b_ex);
+
+ /* preallocation can change ac_b_ex, thus we store actually
+ * allocated blocks for history */
+ ac->ac_f_ex = ac->ac_b_ex;
+
+ ac->ac_status = AC_STATUS_FOUND;
+ ac->ac_tail = ret & 0xffff;
+ ac->ac_buddy = ret >> 16;
+
+ /* XXXXXXX: SUCH A HORRIBLE **CK */
+ /*FIXME!! Why ? */
+ ac->ac_bitmap_page = e4b->bd_bitmap_page;
+ get_page(ac->ac_bitmap_page);
+ ac->ac_buddy_page = e4b->bd_buddy_page;
+ get_page(ac->ac_buddy_page);
+
+ /* store last allocated for subsequent stream allocation */
+ if ((ac->ac_flags & EXT4_MB_HINT_DATA)) {
+ spin_lock(&sbi->s_md_lock);
+ sbi->s_mb_last_group = ac->ac_f_ex.fe_group;
+ sbi->s_mb_last_start = ac->ac_f_ex.fe_start;
+ spin_unlock(&sbi->s_md_lock);
+ }
+}
+
+/*
+ * regular allocator, for general purposes allocation
+ */
+
+static void ext4_mb_check_limits(struct ext4_allocation_context *ac,
+ struct ext4_buddy *e4b,
+ int finish_group)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
+ struct ext4_free_extent *bex = &ac->ac_b_ex;
+ struct ext4_free_extent *gex = &ac->ac_g_ex;
+ struct ext4_free_extent ex;
+ int max;
+
+ /*
+ * We don't want to scan for a whole year
+ */
+ if (ac->ac_found > sbi->s_mb_max_to_scan &&
+ !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
+ ac->ac_status = AC_STATUS_BREAK;
+ return;
+ }
+
+ /*
+ * Haven't found good chunk so far, let's continue
+ */
+ if (bex->fe_len < gex->fe_len)
+ return;
+
+ if ((finish_group || ac->ac_found > sbi->s_mb_min_to_scan)
+ && bex->fe_group == e4b->bd_group) {
+ /* recheck chunk's availability - we don't know
+ * when it was found (within this lock-unlock
+ * period or not) */
+ max = mb_find_extent(e4b, 0, bex->fe_start, gex->fe_len, &ex);
+ if (max >= gex->fe_len) {
+ ext4_mb_use_best_found(ac, e4b);
+ return;
+ }
+ }
+}
+
+/*
+ * The routine checks whether found extent is good enough. If it is,
+ * then the extent gets marked used and flag is set to the context
+ * to stop scanning. Otherwise, the extent is compared with the
+ * previous found extent and if new one is better, then it's stored
+ * in the context. Later, the best found extent will be used, if
+ * mballoc can't find good enough extent.
+ *
+ * FIXME: real allocation policy is to be designed yet!
+ */
+static void ext4_mb_measure_extent(struct ext4_allocation_context *ac,
+ struct ext4_free_extent *ex,
+ struct ext4_buddy *e4b)
+{
+ struct ext4_free_extent *bex = &ac->ac_b_ex;
+ struct ext4_free_extent *gex = &ac->ac_g_ex;
+
+ BUG_ON(ex->fe_len <= 0);
+ BUG_ON(ex->fe_len >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
+ BUG_ON(ex->fe_start >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
+ BUG_ON(ac->ac_status != AC_STATUS_CONTINUE);
+
+ ac->ac_found++;
+
+ /*
+ * The special case - take what you catch first
+ */
+ if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
+ *bex = *ex;
+ ext4_mb_use_best_found(ac, e4b);
+ return;
+ }
+
+ /*
+ * Let's check whether the chuck is good enough
+ */
+ if (ex->fe_len == gex->fe_len) {
+ *bex = *ex;
+ ext4_mb_use_best_found(ac, e4b);
+ return;
+ }
+
+ /*
+ * If this is first found extent, just store it in the context
+ */
+ if (bex->fe_len == 0) {
+ *bex = *ex;
+ return;
+ }
+
+ /*
+ * If new found extent is better, store it in the context
+ */
+ if (bex->fe_len < gex->fe_len) {
+ /* if the request isn't satisfied, any found extent
+ * larger than previous best one is better */
+ if (ex->fe_len > bex->fe_len)
+ *bex = *ex;
+ } else if (ex->fe_len > gex->fe_len) {
+ /* if the request is satisfied, then we try to find
+ * an extent that still satisfy the request, but is
+ * smaller than previous one */
+ if (ex->fe_len < bex->fe_len)
+ *bex = *ex;
+ }
+
+ ext4_mb_check_limits(ac, e4b, 0);
+}
+
+static int ext4_mb_try_best_found(struct ext4_allocation_context *ac,
+ struct ext4_buddy *e4b)
+{
+ struct ext4_free_extent ex = ac->ac_b_ex;
+ ext4_group_t group = ex.fe_group;
+ int max;
+ int err;
+
+ BUG_ON(ex.fe_len <= 0);
+ err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
+ if (err)
+ return err;
+
+ ext4_lock_group(ac->ac_sb, group);
+ max = mb_find_extent(e4b, 0, ex.fe_start, ex.fe_len, &ex);
+
+ if (max > 0) {
+ ac->ac_b_ex = ex;
+ ext4_mb_use_best_found(ac, e4b);
+ }
+
+ ext4_unlock_group(ac->ac_sb, group);
+ ext4_mb_release_desc(e4b);
+
+ return 0;
+}
+
+static int ext4_mb_find_by_goal(struct ext4_allocation_context *ac,
+ struct ext4_buddy *e4b)
+{
+ ext4_group_t group = ac->ac_g_ex.fe_group;
+ int max;
+ int err;
+ struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
+ struct ext4_super_block *es = sbi->s_es;
+ struct ext4_free_extent ex;
+
+ if (!(ac->ac_flags & EXT4_MB_HINT_TRY_GOAL))
+ return 0;
+
+ err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
+ if (err)
+ return err;
+
+ ext4_lock_group(ac->ac_sb, group);
+ max = mb_find_extent(e4b, 0, ac->ac_g_ex.fe_start,
+ ac->ac_g_ex.fe_len, &ex);
+
+ if (max >= ac->ac_g_ex.fe_len && ac->ac_g_ex.fe_len == sbi->s_stripe) {
+ ext4_fsblk_t start;
+
+ start = (e4b->bd_group * EXT4_BLOCKS_PER_GROUP(ac->ac_sb)) +
+ ex.fe_start + le32_to_cpu(es->s_first_data_block);
+ /* use do_div to get remainder (would be 64-bit modulo) */
+ if (do_div(start, sbi->s_stripe) == 0) {
+ ac->ac_found++;
+ ac->ac_b_ex = ex;
+ ext4_mb_use_best_found(ac, e4b);
+ }
+ } else if (max >= ac->ac_g_ex.fe_len) {
+ BUG_ON(ex.fe_len <= 0);
+ BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
+ BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
+ ac->ac_found++;
+ ac->ac_b_ex = ex;
+ ext4_mb_use_best_found(ac, e4b);
+ } else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) {
+ /* Sometimes, caller may want to merge even small
+ * number of blocks to an existing extent */
+ BUG_ON(ex.fe_len <= 0);
+ BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
+ BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
+ ac->ac_found++;
+ ac->ac_b_ex = ex;
+ ext4_mb_use_best_found(ac, e4b);
+ }
+ ext4_unlock_group(ac->ac_sb, group);
+ ext4_mb_release_desc(e4b);
+
+ return 0;
+}
+
+/*
+ * The routine scans buddy structures (not bitmap!) from given order
+ * to max order and tries to find big enough chunk to satisfy the req
+ */
+static void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac,
+ struct ext4_buddy *e4b)
+{
+ struct super_block *sb = ac->ac_sb;
+ struct ext4_group_info *grp = e4b->bd_info;
+ void *buddy;
+ int i;
+ int k;
+ int max;
+
+ BUG_ON(ac->ac_2order <= 0);
+ for (i = ac->ac_2order; i <= sb->s_blocksize_bits + 1; i++) {
+ if (grp->bb_counters[i] == 0)
+ continue;
+
+ buddy = mb_find_buddy(e4b, i, &max);
+ BUG_ON(buddy == NULL);
+
+ k = ext4_find_next_zero_bit(buddy, max, 0);
+ BUG_ON(k >= max);
+
+ ac->ac_found++;
+
+ ac->ac_b_ex.fe_len = 1 << i;
+ ac->ac_b_ex.fe_start = k << i;
+ ac->ac_b_ex.fe_group = e4b->bd_group;
+
+ ext4_mb_use_best_found(ac, e4b);
+
+ BUG_ON(ac->ac_b_ex.fe_len != ac->ac_g_ex.fe_len);
+
+ if (EXT4_SB(sb)->s_mb_stats)
+ atomic_inc(&EXT4_SB(sb)->s_bal_2orders);
+
+ break;
+ }
+}
+
+/*
+ * The routine scans the group and measures all found extents.
+ * In order to optimize scanning, caller must pass number of
+ * free blocks in the group, so the routine can know upper limit.
+ */
+static void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac,
+ struct ext4_buddy *e4b)
+{
+ struct super_block *sb = ac->ac_sb;
+ void *bitmap = EXT4_MB_BITMAP(e4b);
+ struct ext4_free_extent ex;
+ int i;
+ int free;
+
+ free = e4b->bd_info->bb_free;
+ BUG_ON(free <= 0);
+
+ i = e4b->bd_info->bb_first_free;
+
+ while (free && ac->ac_status == AC_STATUS_CONTINUE) {
+ i = ext4_find_next_zero_bit(bitmap,
+ EXT4_BLOCKS_PER_GROUP(sb), i);
+ if (i >= EXT4_BLOCKS_PER_GROUP(sb)) {
+ BUG_ON(free != 0);
+ break;
+ }
+
+ mb_find_extent(e4b, 0, i, ac->ac_g_ex.fe_len, &ex);
+ BUG_ON(ex.fe_len <= 0);
+ BUG_ON(free < ex.fe_len);
+
+ ext4_mb_measure_extent(ac, &ex, e4b);
+
+ i += ex.fe_len;
+ free -= ex.fe_len;
+ }
+
+ ext4_mb_check_limits(ac, e4b, 1);
+}
+
+/*
+ * This is a special case for storages like raid5
+ * we try to find stripe-aligned chunks for stripe-size requests
+ * XXX should do so at least for multiples of stripe size as well
+ */
+static void ext4_mb_scan_aligned(struct ext4_allocation_context *ac,
+ struct ext4_buddy *e4b)
+{
+ struct super_block *sb = ac->ac_sb;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ void *bitmap = EXT4_MB_BITMAP(e4b);
+ struct ext4_free_extent ex;
+ ext4_fsblk_t first_group_block;
+ ext4_fsblk_t a;
+ ext4_grpblk_t i;
+ int max;
+
+ BUG_ON(sbi->s_stripe == 0);
+
+ /* find first stripe-aligned block in group */
+ first_group_block = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb)
+ + le32_to_cpu(sbi->s_es->s_first_data_block);
+ a = first_group_block + sbi->s_stripe - 1;
+ do_div(a, sbi->s_stripe);
+ i = (a * sbi->s_stripe) - first_group_block;
+
+ while (i < EXT4_BLOCKS_PER_GROUP(sb)) {
+ if (!mb_test_bit(i, bitmap)) {
+ max = mb_find_extent(e4b, 0, i, sbi->s_stripe, &ex);
+ if (max >= sbi->s_stripe) {
+ ac->ac_found++;
+ ac->ac_b_ex = ex;
+ ext4_mb_use_best_found(ac, e4b);
+ break;
+ }
+ }
+ i += sbi->s_stripe;
+ }
+}
+
+static int ext4_mb_good_group(struct ext4_allocation_context *ac,
+ ext4_group_t group, int cr)
+{
+ unsigned free, fragments;
+ unsigned i, bits;
+ struct ext4_group_desc *desc;
+ struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
+
+ BUG_ON(cr < 0 || cr >= 4);
+ BUG_ON(EXT4_MB_GRP_NEED_INIT(grp));
+
+ free = grp->bb_free;
+ fragments = grp->bb_fragments;
+ if (free == 0)
+ return 0;
+ if (fragments == 0)
+ return 0;
+
+ switch (cr) {
+ case 0:
+ BUG_ON(ac->ac_2order == 0);
+ /* If this group is uninitialized, skip it initially */
+ desc = ext4_get_group_desc(ac->ac_sb, group, NULL);
+ if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))
+ return 0;
+
+ bits = ac->ac_sb->s_blocksize_bits + 1;
+ for (i = ac->ac_2order; i <= bits; i++)
+ if (grp->bb_counters[i] > 0)
+ return 1;
+ break;
+ case 1:
+ if ((free / fragments) >= ac->ac_g_ex.fe_len)
+ return 1;
+ break;
+ case 2:
+ if (free >= ac->ac_g_ex.fe_len)
+ return 1;
+ break;
+ case 3:
+ return 1;
+ default:
+ BUG();
+ }
+
+ return 0;
+}
+
+static int ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
+{
+ ext4_group_t group;
+ ext4_group_t i;
+ int cr;
+ int err = 0;
+ int bsbits;
+ struct ext4_sb_info *sbi;
+ struct super_block *sb;
+ struct ext4_buddy e4b;
+ loff_t size, isize;
+
+ sb = ac->ac_sb;
+ sbi = EXT4_SB(sb);
+ BUG_ON(ac->ac_status == AC_STATUS_FOUND);
+
+ /* first, try the goal */
+ err = ext4_mb_find_by_goal(ac, &e4b);
+ if (err || ac->ac_status == AC_STATUS_FOUND)
+ goto out;
+
+ if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
+ goto out;
+
+ /*
+ * ac->ac2_order is set only if the fe_len is a power of 2
+ * if ac2_order is set we also set criteria to 0 so that we
+ * try exact allocation using buddy.
+ */
+ i = fls(ac->ac_g_ex.fe_len);
+ ac->ac_2order = 0;
+ /*
+ * We search using buddy data only if the order of the request
+ * is greater than equal to the sbi_s_mb_order2_reqs
+ * You can tune it via /proc/fs/ext4/<partition>/order2_req
+ */
+ if (i >= sbi->s_mb_order2_reqs) {
+ /*
+ * This should tell if fe_len is exactly power of 2
+ */
+ if ((ac->ac_g_ex.fe_len & (~(1 << (i - 1)))) == 0)
+ ac->ac_2order = i - 1;
+ }
+
+ bsbits = ac->ac_sb->s_blocksize_bits;
+ /* if stream allocation is enabled, use global goal */
+ size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len;
+ isize = i_size_read(ac->ac_inode) >> bsbits;
+ if (size < isize)
+ size = isize;
+
+ if (size < sbi->s_mb_stream_request &&
+ (ac->ac_flags & EXT4_MB_HINT_DATA)) {
+ /* TBD: may be hot point */
+ spin_lock(&sbi->s_md_lock);
+ ac->ac_g_ex.fe_group = sbi->s_mb_last_group;
+ ac->ac_g_ex.fe_start = sbi->s_mb_last_start;
+ spin_unlock(&sbi->s_md_lock);
+ }
+
+ /* searching for the right group start from the goal value specified */
+ group = ac->ac_g_ex.fe_group;
+
+ /* Let's just scan groups to find more-less suitable blocks */
+ cr = ac->ac_2order ? 0 : 1;
+ /*
+ * cr == 0 try to get exact allocation,
+ * cr == 3 try to get anything
+ */
+repeat:
+ for (; cr < 4 && ac->ac_status == AC_STATUS_CONTINUE; cr++) {
+ ac->ac_criteria = cr;
+ for (i = 0; i < EXT4_SB(sb)->s_groups_count; group++, i++) {
+ struct ext4_group_info *grp;
+ struct ext4_group_desc *desc;
+
+ if (group == EXT4_SB(sb)->s_groups_count)
+ group = 0;
+
+ /* quick check to skip empty groups */
+ grp = ext4_get_group_info(ac->ac_sb, group);
+ if (grp->bb_free == 0)
+ continue;
+
+ /*
+ * if the group is already init we check whether it is
+ * a good group and if not we don't load the buddy
+ */
+ if (EXT4_MB_GRP_NEED_INIT(grp)) {
+ /*
+ * we need full data about the group
+ * to make a good selection
+ */
+ err = ext4_mb_load_buddy(sb, group, &e4b);
+ if (err)
+ goto out;
+ ext4_mb_release_desc(&e4b);
+ }
+
+ /*
+ * If the particular group doesn't satisfy our
+ * criteria we continue with the next group
+ */
+ if (!ext4_mb_good_group(ac, group, cr))
+ continue;
+
+ err = ext4_mb_load_buddy(sb, group, &e4b);
+ if (err)
+ goto out;
+
+ ext4_lock_group(sb, group);
+ if (!ext4_mb_good_group(ac, group, cr)) {
+ /* someone did allocation from this group */
+ ext4_unlock_group(sb, group);
+ ext4_mb_release_desc(&e4b);
+ continue;
+ }
+
+ ac->ac_groups_scanned++;
+ desc = ext4_get_group_desc(sb, group, NULL);
+ if (cr == 0 || (desc->bg_flags &
+ cpu_to_le16(EXT4_BG_BLOCK_UNINIT) &&
+ ac->ac_2order != 0))
+ ext4_mb_simple_scan_group(ac, &e4b);
+ else if (cr == 1 &&
+ ac->ac_g_ex.fe_len == sbi->s_stripe)
+ ext4_mb_scan_aligned(ac, &e4b);
+ else
+ ext4_mb_complex_scan_group(ac, &e4b);
+
+ ext4_unlock_group(sb, group);
+ ext4_mb_release_desc(&e4b);
+
+ if (ac->ac_status != AC_STATUS_CONTINUE)
+ break;
+ }
+ }
+
+ if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND &&
+ !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
+ /*
+ * We've been searching too long. Let's try to allocate
+ * the best chunk we've found so far
+ */
+
+ ext4_mb_try_best_found(ac, &e4b);
+ if (ac->ac_status != AC_STATUS_FOUND) {
+ /*
+ * Someone more lucky has already allocated it.
+ * The only thing we can do is just take first
+ * found block(s)
+ printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n");
+ */
+ ac->ac_b_ex.fe_group = 0;
+ ac->ac_b_ex.fe_start = 0;
+ ac->ac_b_ex.fe_len = 0;
+ ac->ac_status = AC_STATUS_CONTINUE;
+ ac->ac_flags |= EXT4_MB_HINT_FIRST;
+ cr = 3;
+ atomic_inc(&sbi->s_mb_lost_chunks);
+ goto repeat;
+ }
+ }
+out:
+ return err;
+}
+
+#ifdef EXT4_MB_HISTORY
+struct ext4_mb_proc_session {
+ struct ext4_mb_history *history;
+ struct super_block *sb;
+ int start;
+ int max;
+};
+
+static void *ext4_mb_history_skip_empty(struct ext4_mb_proc_session *s,
+ struct ext4_mb_history *hs,
+ int first)
+{
+ if (hs == s->history + s->max)
+ hs = s->history;
+ if (!first && hs == s->history + s->start)
+ return NULL;
+ while (hs->orig.fe_len == 0) {
+ hs++;
+ if (hs == s->history + s->max)
+ hs = s->history;
+ if (hs == s->history + s->start)
+ return NULL;
+ }
+ return hs;
+}
+
+static void *ext4_mb_seq_history_start(struct seq_file *seq, loff_t *pos)
+{
+ struct ext4_mb_proc_session *s = seq->private;
+ struct ext4_mb_history *hs;
+ int l = *pos;
+
+ if (l == 0)
+ return SEQ_START_TOKEN;
+ hs = ext4_mb_history_skip_empty(s, s->history + s->start, 1);
+ if (!hs)
+ return NULL;
+ while (--l && (hs = ext4_mb_history_skip_empty(s, ++hs, 0)) != NULL);
+ return hs;
+}
+
+static void *ext4_mb_seq_history_next(struct seq_file *seq, void *v,
+ loff_t *pos)
+{
+ struct ext4_mb_proc_session *s = seq->private;
+ struct ext4_mb_history *hs = v;
+
+ ++*pos;
+ if (v == SEQ_START_TOKEN)
+ return ext4_mb_history_skip_empty(s, s->history + s->start, 1);
+ else
+ return ext4_mb_history_skip_empty(s, ++hs, 0);
+}
+
+static int ext4_mb_seq_history_show(struct seq_file *seq, void *v)
+{
+ char buf[25], buf2[25], buf3[25], *fmt;
+ struct ext4_mb_history *hs = v;
+
+ if (v == SEQ_START_TOKEN) {
+ seq_printf(seq, "%-5s %-8s %-23s %-23s %-23s %-5s "
+ "%-5s %-2s %-5s %-5s %-5s %-6s\n",
+ "pid", "inode", "original", "goal", "result", "found",
+ "grps", "cr", "flags", "merge", "tail", "broken");
+ return 0;
+ }
+
+ if (hs->op == EXT4_MB_HISTORY_ALLOC) {
+ fmt = "%-5u %-8u %-23s %-23s %-23s %-5u %-5u %-2u "
+ "%-5u %-5s %-5u %-6u\n";
+ sprintf(buf2, "%lu/%d/%u@%u", hs->result.fe_group,
+ hs->result.fe_start, hs->result.fe_len,
+ hs->result.fe_logical);
+ sprintf(buf, "%lu/%d/%u@%u", hs->orig.fe_group,
+ hs->orig.fe_start, hs->orig.fe_len,
+ hs->orig.fe_logical);
+ sprintf(buf3, "%lu/%d/%u@%u", hs->goal.fe_group,
+ hs->goal.fe_start, hs->goal.fe_len,
+ hs->goal.fe_logical);
+ seq_printf(seq, fmt, hs->pid, hs->ino, buf, buf3, buf2,
+ hs->found, hs->groups, hs->cr, hs->flags,
+ hs->merged ? "M" : "", hs->tail,
+ hs->buddy ? 1 << hs->buddy : 0);
+ } else if (hs->op == EXT4_MB_HISTORY_PREALLOC) {
+ fmt = "%-5u %-8u %-23s %-23s %-23s\n";
+ sprintf(buf2, "%lu/%d/%u@%u", hs->result.fe_group,
+ hs->result.fe_start, hs->result.fe_len,
+ hs->result.fe_logical);
+ sprintf(buf, "%lu/%d/%u@%u", hs->orig.fe_group,
+ hs->orig.fe_start, hs->orig.fe_len,
+ hs->orig.fe_logical);
+ seq_printf(seq, fmt, hs->pid, hs->ino, buf, "", buf2);
+ } else if (hs->op == EXT4_MB_HISTORY_DISCARD) {
+ sprintf(buf2, "%lu/%d/%u", hs->result.fe_group,
+ hs->result.fe_start, hs->result.fe_len);
+ seq_printf(seq, "%-5u %-8u %-23s discard\n",
+ hs->pid, hs->ino, buf2);
+ } else if (hs->op == EXT4_MB_HISTORY_FREE) {
+ sprintf(buf2, "%lu/%d/%u", hs->result.fe_group,
+ hs->result.fe_start, hs->result.fe_len);
+ seq_printf(seq, "%-5u %-8u %-23s free\n",
+ hs->pid, hs->ino, buf2);
+ }
+ return 0;
+}
+
+static void ext4_mb_seq_history_stop(struct seq_file *seq, void *v)
+{
+}
+
+static struct seq_operations ext4_mb_seq_history_ops = {
+ .start = ext4_mb_seq_history_start,
+ .next = ext4_mb_seq_history_next,
+ .stop = ext4_mb_seq_history_stop,
+ .show = ext4_mb_seq_history_show,
+};
+
+static int ext4_mb_seq_history_open(struct inode *inode, struct file *file)
+{
+ struct super_block *sb = PDE(inode)->data;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_mb_proc_session *s;
+ int rc;
+ int size;
+
+ s = kmalloc(sizeof(*s), GFP_KERNEL);
+ if (s == NULL)
+ return -ENOMEM;
+ s->sb = sb;
+ size = sizeof(struct ext4_mb_history) * sbi->s_mb_history_max;
+ s->history = kmalloc(size, GFP_KERNEL);
+ if (s->history == NULL) {
+ kfree(s);
+ return -ENOMEM;
+ }
+
+ spin_lock(&sbi->s_mb_history_lock);
+ memcpy(s->history, sbi->s_mb_history, size);
+ s->max = sbi->s_mb_history_max;
+ s->start = sbi->s_mb_history_cur % s->max;
+ spin_unlock(&sbi->s_mb_history_lock);
+
+ rc = seq_open(file, &ext4_mb_seq_history_ops);
+ if (rc == 0) {
+ struct seq_file *m = (struct seq_file *)file->private_data;
+ m->private = s;
+ } else {
+ kfree(s->history);
+ kfree(s);
+ }
+ return rc;
+
+}
+
+static int ext4_mb_seq_history_release(struct inode *inode, struct file *file)
+{
+ struct seq_file *seq = (struct seq_file *)file->private_data;
+ struct ext4_mb_proc_session *s = seq->private;
+ kfree(s->history);
+ kfree(s);
+ return seq_release(inode, file);
+}
+
+static ssize_t ext4_mb_seq_history_write(struct file *file,
+ const char __user *buffer,
+ size_t count, loff_t *ppos)
+{
+ struct seq_file *seq = (struct seq_file *)file->private_data;
+ struct ext4_mb_proc_session *s = seq->private;
+ struct super_block *sb = s->sb;
+ char str[32];
+ int value;
+
+ if (count >= sizeof(str)) {
+ printk(KERN_ERR "EXT4-fs: %s string too long, max %u bytes\n",
+ "mb_history", (int)sizeof(str));
+ return -EOVERFLOW;
+ }
+
+ if (copy_from_user(str, buffer, count))
+ return -EFAULT;
+
+ value = simple_strtol(str, NULL, 0);
+ if (value < 0)
+ return -ERANGE;
+ EXT4_SB(sb)->s_mb_history_filter = value;
+
+ return count;
+}
+
+static struct file_operations ext4_mb_seq_history_fops = {
+ .owner = THIS_MODULE,
+ .open = ext4_mb_seq_history_open,
+ .read = seq_read,
+ .write = ext4_mb_seq_history_write,
+ .llseek = seq_lseek,
+ .release = ext4_mb_seq_history_release,
+};
+
+static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos)
+{
+ struct super_block *sb = seq->private;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ ext4_group_t group;
+
+ if (*pos < 0 || *pos >= sbi->s_groups_count)
+ return NULL;
+
+ group = *pos + 1;
+ return (void *) group;
+}
+
+static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+ struct super_block *sb = seq->private;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ ext4_group_t group;
+
+ ++*pos;
+ if (*pos < 0 || *pos >= sbi->s_groups_count)
+ return NULL;
+ group = *pos + 1;
+ return (void *) group;;
+}
+
+static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
+{
+ struct super_block *sb = seq->private;
+ long group = (long) v;
+ int i;
+ int err;
+ struct ext4_buddy e4b;
+ struct sg {
+ struct ext4_group_info info;
+ unsigned short counters[16];
+ } sg;
+
+ group--;
+ if (group == 0)
+ seq_printf(seq, "#%-5s: %-5s %-5s %-5s "
+ "[ %-5s %-5s %-5s %-5s %-5s %-5s %-5s "
+ "%-5s %-5s %-5s %-5s %-5s %-5s %-5s ]\n",
+ "group", "free", "frags", "first",
+ "2^0", "2^1", "2^2", "2^3", "2^4", "2^5", "2^6",
+ "2^7", "2^8", "2^9", "2^10", "2^11", "2^12", "2^13");
+
+ i = (sb->s_blocksize_bits + 2) * sizeof(sg.info.bb_counters[0]) +
+ sizeof(struct ext4_group_info);
+ err = ext4_mb_load_buddy(sb, group, &e4b);
+ if (err) {
+ seq_printf(seq, "#%-5lu: I/O error\n", group);
+ return 0;
+ }
+ ext4_lock_group(sb, group);
+ memcpy(&sg, ext4_get_group_info(sb, group), i);
+ ext4_unlock_group(sb, group);
+ ext4_mb_release_desc(&e4b);
+
+ seq_printf(seq, "#%-5lu: %-5u %-5u %-5u [", group, sg.info.bb_free,
+ sg.info.bb_fragments, sg.info.bb_first_free);
+ for (i = 0; i <= 13; i++)
+ seq_printf(seq, " %-5u", i <= sb->s_blocksize_bits + 1 ?
+ sg.info.bb_counters[i] : 0);
+ seq_printf(seq, " ]\n");
+
+ return 0;
+}
+
+static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v)
+{
+}
+
+static struct seq_operations ext4_mb_seq_groups_ops = {
+ .start = ext4_mb_seq_groups_start,
+ .next = ext4_mb_seq_groups_next,
+ .stop = ext4_mb_seq_groups_stop,
+ .show = ext4_mb_seq_groups_show,
+};
+
+static int ext4_mb_seq_groups_open(struct inode *inode, struct file *file)
+{
+ struct super_block *sb = PDE(inode)->data;
+ int rc;
+
+ rc = seq_open(file, &ext4_mb_seq_groups_ops);
+ if (rc == 0) {
+ struct seq_file *m = (struct seq_file *)file->private_data;
+ m->private = sb;
+ }
+ return rc;
+
+}
+
+static struct file_operations ext4_mb_seq_groups_fops = {
+ .owner = THIS_MODULE,
+ .open = ext4_mb_seq_groups_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static void ext4_mb_history_release(struct super_block *sb)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+ remove_proc_entry("mb_groups", sbi->s_mb_proc);
+ remove_proc_entry("mb_history", sbi->s_mb_proc);
+
+ kfree(sbi->s_mb_history);
+}
+
+static void ext4_mb_history_init(struct super_block *sb)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ int i;
+
+ if (sbi->s_mb_proc != NULL) {
+ struct proc_dir_entry *p;
+ p = create_proc_entry("mb_history", S_IRUGO, sbi->s_mb_proc);
+ if (p) {
+ p->proc_fops = &ext4_mb_seq_history_fops;
+ p->data = sb;
+ }
+ p = create_proc_entry("mb_groups", S_IRUGO, sbi->s_mb_proc);
+ if (p) {
+ p->proc_fops = &ext4_mb_seq_groups_fops;
+ p->data = sb;
+ }
+ }
+
+ sbi->s_mb_history_max = 1000;
+ sbi->s_mb_history_cur = 0;
+ spin_lock_init(&sbi->s_mb_history_lock);
+ i = sbi->s_mb_history_max * sizeof(struct ext4_mb_history);
+ sbi->s_mb_history = kmalloc(i, GFP_KERNEL);
+ if (likely(sbi->s_mb_history != NULL))
+ memset(sbi->s_mb_history, 0, i);
+ /* if we can't allocate history, then we simple won't use it */
+}
+
+static void ext4_mb_store_history(struct ext4_allocation_context *ac)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
+ struct ext4_mb_history h;
+
+ if (unlikely(sbi->s_mb_history == NULL))
+ return;
+
+ if (!(ac->ac_op & sbi->s_mb_history_filter))
+ return;
+
+ h.op = ac->ac_op;
+ h.pid = current->pid;
+ h.ino = ac->ac_inode ? ac->ac_inode->i_ino : 0;
+ h.orig = ac->ac_o_ex;
+ h.result = ac->ac_b_ex;
+ h.flags = ac->ac_flags;
+ h.found = ac->ac_found;
+ h.groups = ac->ac_groups_scanned;
+ h.cr = ac->ac_criteria;
+ h.tail = ac->ac_tail;
+ h.buddy = ac->ac_buddy;
+ h.merged = 0;
+ if (ac->ac_op == EXT4_MB_HISTORY_ALLOC) {
+ if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
+ ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
+ h.merged = 1;
+ h.goal = ac->ac_g_ex;
+ h.result = ac->ac_f_ex;
+ }
+
+ spin_lock(&sbi->s_mb_history_lock);
+ memcpy(sbi->s_mb_history + sbi->s_mb_history_cur, &h, sizeof(h));
+ if (++sbi->s_mb_history_cur >= sbi->s_mb_history_max)
+ sbi->s_mb_history_cur = 0;
+ spin_unlock(&sbi->s_mb_history_lock);
+}
+
+#else
+#define ext4_mb_history_release(sb)
+#define ext4_mb_history_init(sb)
+#endif
+
+static int ext4_mb_init_backend(struct super_block *sb)
+{
+ ext4_group_t i;
+ int j, len, metalen;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ int num_meta_group_infos =
+ (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) >>
+ EXT4_DESC_PER_BLOCK_BITS(sb);
+ struct ext4_group_info **meta_group_info;
+
+ /* An 8TB filesystem with 64-bit pointers requires a 4096 byte
+ * kmalloc. A 128kb malloc should suffice for a 256TB filesystem.
+ * So a two level scheme suffices for now. */
+ sbi->s_group_info = kmalloc(sizeof(*sbi->s_group_info) *
+ num_meta_group_infos, GFP_KERNEL);
+ if (sbi->s_group_info == NULL) {
+ printk(KERN_ERR "EXT4-fs: can't allocate buddy meta group\n");
+ return -ENOMEM;
+ }
+ sbi->s_buddy_cache = new_inode(sb);
+ if (sbi->s_buddy_cache == NULL) {
+ printk(KERN_ERR "EXT4-fs: can't get new inode\n");
+ goto err_freesgi;
+ }
+ EXT4_I(sbi->s_buddy_cache)->i_disksize = 0;
+
+ metalen = sizeof(*meta_group_info) << EXT4_DESC_PER_BLOCK_BITS(sb);
+ for (i = 0; i < num_meta_group_infos; i++) {
+ if ((i + 1) == num_meta_group_infos)
+ metalen = sizeof(*meta_group_info) *
+ (sbi->s_groups_count -
+ (i << EXT4_DESC_PER_BLOCK_BITS(sb)));
+ meta_group_info = kmalloc(metalen, GFP_KERNEL);
+ if (meta_group_info == NULL) {
+ printk(KERN_ERR "EXT4-fs: can't allocate mem for a "
+ "buddy group\n");
+ goto err_freemeta;
+ }
+ sbi->s_group_info[i] = meta_group_info;
+ }
+
+ /*
+ * calculate needed size. if change bb_counters size,
+ * don't forget about ext4_mb_generate_buddy()
+ */
+ len = sizeof(struct ext4_group_info);
+ len += sizeof(unsigned short) * (sb->s_blocksize_bits + 2);
+ for (i = 0; i < sbi->s_groups_count; i++) {
+ struct ext4_group_desc *desc;
+
+ meta_group_info =
+ sbi->s_group_info[i >> EXT4_DESC_PER_BLOCK_BITS(sb)];
+ j = i & (EXT4_DESC_PER_BLOCK(sb) - 1);
+
+ meta_group_info[j] = kzalloc(len, GFP_KERNEL);
+ if (meta_group_info[j] == NULL) {
+ printk(KERN_ERR "EXT4-fs: can't allocate buddy mem\n");
+ i--;
+ goto err_freebuddy;
+ }
+ desc = ext4_get_group_desc(sb, i, NULL);
+ if (desc == NULL) {
+ printk(KERN_ERR
+ "EXT4-fs: can't read descriptor %lu\n", i);
+ goto err_freebuddy;
+ }
+ memset(meta_group_info[j], 0, len);
+ set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
+ &(meta_group_info[j]->bb_state));
+
+ /*
+ * initialize bb_free to be able to skip
+ * empty groups without initialization
+ */
+ if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
+ meta_group_info[j]->bb_free =
+ ext4_free_blocks_after_init(sb, i, desc);
+ } else {
+ meta_group_info[j]->bb_free =
+ le16_to_cpu(desc->bg_free_blocks_count);
+ }
+
+ INIT_LIST_HEAD(&meta_group_info[j]->bb_prealloc_list);
+
+#ifdef DOUBLE_CHECK
+ {
+ struct buffer_head *bh;
+ meta_group_info[j]->bb_bitmap =
+ kmalloc(sb->s_blocksize, GFP_KERNEL);
+ BUG_ON(meta_group_info[j]->bb_bitmap == NULL);
+ bh = read_block_bitmap(sb, i);
+ BUG_ON(bh == NULL);
+ memcpy(meta_group_info[j]->bb_bitmap, bh->b_data,
+ sb->s_blocksize);
+ brelse(bh);
+ }
+#endif
+
+ }
+
+ return 0;
+
+err_freebuddy:
+ while (i >= 0) {
+ kfree(ext4_get_group_info(sb, i));
+ i--;
+ }
+ i = num_meta_group_infos;
+err_freemeta:
+ while (--i >= 0)
+ kfree(sbi->s_group_info[i]);
+ iput(sbi->s_buddy_cache);
+err_freesgi:
+ kfree(sbi->s_group_info);
+ return -ENOMEM;
+}
+
+int ext4_mb_init(struct super_block *sb, int needs_recovery)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ unsigned i;
+ unsigned offset;
+ unsigned max;
+
+ if (!test_opt(sb, MBALLOC))
+ return 0;
+
+ i = (sb->s_blocksize_bits + 2) * sizeof(unsigned short);
+
+ sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL);
+ if (sbi->s_mb_offsets == NULL) {
+ clear_opt(sbi->s_mount_opt, MBALLOC);
+ return -ENOMEM;
+ }
+ sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL);
+ if (sbi->s_mb_maxs == NULL) {
+ clear_opt(sbi->s_mount_opt, MBALLOC);
+ kfree(sbi->s_mb_maxs);
+ return -ENOMEM;
+ }
+
+ /* order 0 is regular bitmap */
+ sbi->s_mb_maxs[0] = sb->s_blocksize << 3;
+ sbi->s_mb_offsets[0] = 0;
+
+ i = 1;
+ offset = 0;
+ max = sb->s_blocksize << 2;
+ do {
+ sbi->s_mb_offsets[i] = offset;
+ sbi->s_mb_maxs[i] = max;
+ offset += 1 << (sb->s_blocksize_bits - i);
+ max = max >> 1;
+ i++;
+ } while (i <= sb->s_blocksize_bits + 1);
+
+ /* init file for buddy data */
+ i = ext4_mb_init_backend(sb);
+ if (i) {
+ clear_opt(sbi->s_mount_opt, MBALLOC);
+ kfree(sbi->s_mb_offsets);
+ kfree(sbi->s_mb_maxs);
+ return i;
+ }
+
+ spin_lock_init(&sbi->s_md_lock);
+ INIT_LIST_HEAD(&sbi->s_active_transaction);
+ INIT_LIST_HEAD(&sbi->s_closed_transaction);
+ INIT_LIST_HEAD(&sbi->s_committed_transaction);
+ spin_lock_init(&sbi->s_bal_lock);
+
+ sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN;
+ sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN;
+ sbi->s_mb_stats = MB_DEFAULT_STATS;
+ sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD;
+ sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS;
+ sbi->s_mb_history_filter = EXT4_MB_HISTORY_DEFAULT;
+ sbi->s_mb_group_prealloc = MB_DEFAULT_GROUP_PREALLOC;
+
+ i = sizeof(struct ext4_locality_group) * NR_CPUS;
+ sbi->s_locality_groups = kmalloc(i, GFP_NOFS);
+ if (sbi->s_locality_groups == NULL) {
+ clear_opt(sbi->s_mount_opt, MBALLOC);
+ kfree(sbi->s_mb_offsets);
+ kfree(sbi->s_mb_maxs);
+ return -ENOMEM;
+ }
+ for (i = 0; i < NR_CPUS; i++) {
+ struct ext4_locality_group *lg;
+ lg = &sbi->s_locality_groups[i];
+ sema_init(&lg->lg_sem, 1);
+ INIT_LIST_HEAD(&lg->lg_prealloc_list);
+ spin_lock_init(&lg->lg_prealloc_lock);
+ }
+
+ ext4_mb_init_per_dev_proc(sb);
+ ext4_mb_history_init(sb);
+
+ printk("EXT4-fs: mballoc enabled\n");
+ return 0;
+}
+
+static void ext4_mb_cleanup_pa(struct ext4_group_info *grp)
+{
+ struct ext4_prealloc_space *pa;
+ struct list_head *cur, *tmp;
+ int count = 0;
+
+ list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) {
+ pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
+ list_del_rcu(&pa->pa_group_list);
+ count++;
+ kfree(pa);
+ }
+ if (count)
+ mb_debug("mballoc: %u PAs left\n", count);
+
+}
+
+int ext4_mb_release(struct super_block *sb)
+{
+ ext4_group_t i;
+ int num_meta_group_infos;
+ struct ext4_group_info *grinfo;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+ if (!test_opt(sb, MBALLOC))
+ return 0;
+
+ /* release freed, non-committed blocks */
+ spin_lock(&sbi->s_md_lock);
+ list_splice_init(&sbi->s_closed_transaction,
+ &sbi->s_committed_transaction);
+ list_splice_init(&sbi->s_active_transaction,
+ &sbi->s_committed_transaction);
+ spin_unlock(&sbi->s_md_lock);
+ ext4_mb_free_committed_blocks(sb);
+
+ if (sbi->s_group_info) {
+ for (i = 0; i < sbi->s_groups_count; i++) {
+ grinfo = ext4_get_group_info(sb, i);
+#ifdef DOUBLE_CHECK
+ kfree(grinfo->bb_bitmap);
+#endif
+ ext4_mb_cleanup_pa(grinfo);
+ kfree(grinfo);
+ }
+ num_meta_group_infos = (sbi->s_groups_count +
+ EXT4_DESC_PER_BLOCK(sb) - 1) >>
+ EXT4_DESC_PER_BLOCK_BITS(sb);
+ for (i = 0; i < num_meta_group_infos; i++)
+ kfree(sbi->s_group_info[i]);
+ kfree(sbi->s_group_info);
+ }
+ kfree(sbi->s_mb_offsets);
+ kfree(sbi->s_mb_maxs);
+ if (sbi->s_buddy_cache)
+ iput(sbi->s_buddy_cache);
+ if (sbi->s_mb_stats) {
+ printk(KERN_INFO
+ "EXT4-fs: mballoc: %u blocks %u reqs (%u success)\n",
+ atomic_read(&sbi->s_bal_allocated),
+ atomic_read(&sbi->s_bal_reqs),
+ atomic_read(&sbi->s_bal_success));
+ printk(KERN_INFO
+ "EXT4-fs: mballoc: %u extents scanned, %u goal hits, "
+ "%u 2^N hits, %u breaks, %u lost\n",
+ atomic_read(&sbi->s_bal_ex_scanned),
+ atomic_read(&sbi->s_bal_goals),
+ atomic_read(&sbi->s_bal_2orders),
+ atomic_read(&sbi->s_bal_breaks),
+ atomic_read(&sbi->s_mb_lost_chunks));
+ printk(KERN_INFO
+ "EXT4-fs: mballoc: %lu generated and it took %Lu\n",
+ sbi->s_mb_buddies_generated++,
+ sbi->s_mb_generation_time);
+ printk(KERN_INFO
+ "EXT4-fs: mballoc: %u preallocated, %u discarded\n",
+ atomic_read(&sbi->s_mb_preallocated),
+ atomic_read(&sbi->s_mb_discarded));
+ }
+
+ kfree(sbi->s_locality_groups);
+
+ ext4_mb_history_release(sb);
+ ext4_mb_destroy_per_dev_proc(sb);
+
+ return 0;
+}
+
+static void ext4_mb_free_committed_blocks(struct super_block *sb)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ int err;
+ int i;
+ int count = 0;
+ int count2 = 0;
+ struct ext4_free_metadata *md;
+ struct ext4_buddy e4b;
+
+ if (list_empty(&sbi->s_committed_transaction))
+ return;
+
+ /* there is committed blocks to be freed yet */
+ do {
+ /* get next array of blocks */
+ md = NULL;
+ spin_lock(&sbi->s_md_lock);
+ if (!list_empty(&sbi->s_committed_transaction)) {
+ md = list_entry(sbi->s_committed_transaction.next,
+ struct ext4_free_metadata, list);
+ list_del(&md->list);
+ }
+ spin_unlock(&sbi->s_md_lock);
+
+ if (md == NULL)
+ break;
+
+ mb_debug("gonna free %u blocks in group %lu (0x%p):",
+ md->num, md->group, md);
+
+ err = ext4_mb_load_buddy(sb, md->group, &e4b);
+ /* we expect to find existing buddy because it's pinned */
+ BUG_ON(err != 0);
+
+ /* there are blocks to put in buddy to make them really free */
+ count += md->num;
+ count2++;
+ ext4_lock_group(sb, md->group);
+ for (i = 0; i < md->num; i++) {
+ mb_debug(" %u", md->blocks[i]);
+ err = mb_free_blocks(NULL, &e4b, md->blocks[i], 1);
+ BUG_ON(err != 0);
+ }
+ mb_debug("\n");
+ ext4_unlock_group(sb, md->group);
+
+ /* balance refcounts from ext4_mb_free_metadata() */
+ page_cache_release(e4b.bd_buddy_page);
+ page_cache_release(e4b.bd_bitmap_page);
+
+ kfree(md);
+ ext4_mb_release_desc(&e4b);
+
+ } while (md);
+
+ mb_debug("freed %u blocks in %u structures\n", count, count2);
+}
+
+#define EXT4_ROOT "ext4"
+#define EXT4_MB_STATS_NAME "stats"
+#define EXT4_MB_MAX_TO_SCAN_NAME "max_to_scan"
+#define EXT4_MB_MIN_TO_SCAN_NAME "min_to_scan"
+#define EXT4_MB_ORDER2_REQ "order2_req"
+#define EXT4_MB_STREAM_REQ "stream_req"
+#define EXT4_MB_GROUP_PREALLOC "group_prealloc"
+
+
+
+#define MB_PROC_VALUE_READ(name) \
+static int ext4_mb_read_##name(char *page, char **start, \
+ off_t off, int count, int *eof, void *data) \
+{ \
+ struct ext4_sb_info *sbi = data; \
+ int len; \
+ *eof = 1; \
+ if (off != 0) \
+ return 0; \
+ len = sprintf(page, "%ld\n", sbi->s_mb_##name); \
+ *start = page; \
+ return len; \
+}
+
+#define MB_PROC_VALUE_WRITE(name) \
+static int ext4_mb_write_##name(struct file *file, \
+ const char __user *buf, unsigned long cnt, void *data) \
+{ \
+ struct ext4_sb_info *sbi = data; \
+ char str[32]; \
+ long value; \
+ if (cnt >= sizeof(str)) \
+ return -EINVAL; \
+ if (copy_from_user(str, buf, cnt)) \
+ return -EFAULT; \
+ value = simple_strtol(str, NULL, 0); \
+ if (value <= 0) \
+ return -ERANGE; \
+ sbi->s_mb_##name = value; \
+ return cnt; \
+}
+
+MB_PROC_VALUE_READ(stats);
+MB_PROC_VALUE_WRITE(stats);
+MB_PROC_VALUE_READ(max_to_scan);
+MB_PROC_VALUE_WRITE(max_to_scan);
+MB_PROC_VALUE_READ(min_to_scan);
+MB_PROC_VALUE_WRITE(min_to_scan);
+MB_PROC_VALUE_READ(order2_reqs);
+MB_PROC_VALUE_WRITE(order2_reqs);
+MB_PROC_VALUE_READ(stream_request);
+MB_PROC_VALUE_WRITE(stream_request);
+MB_PROC_VALUE_READ(group_prealloc);
+MB_PROC_VALUE_WRITE(group_prealloc);
+
+#define MB_PROC_HANDLER(name, var) \
+do { \
+ proc = create_proc_entry(name, mode, sbi->s_mb_proc); \
+ if (proc == NULL) { \
+ printk(KERN_ERR "EXT4-fs: can't to create %s\n", name); \
+ goto err_out; \
+ } \
+ proc->data = sbi; \
+ proc->read_proc = ext4_mb_read_##var ; \
+ proc->write_proc = ext4_mb_write_##var; \
+} while (0)
+
+static int ext4_mb_init_per_dev_proc(struct super_block *sb)
+{
+ mode_t mode = S_IFREG | S_IRUGO | S_IWUSR;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct proc_dir_entry *proc;
+ char devname[64];
+
+ snprintf(devname, sizeof(devname) - 1, "%s",
+ bdevname(sb->s_bdev, devname));
+ sbi->s_mb_proc = proc_mkdir(devname, proc_root_ext4);
+
+ MB_PROC_HANDLER(EXT4_MB_STATS_NAME, stats);
+ MB_PROC_HANDLER(EXT4_MB_MAX_TO_SCAN_NAME, max_to_scan);
+ MB_PROC_HANDLER(EXT4_MB_MIN_TO_SCAN_NAME, min_to_scan);
+ MB_PROC_HANDLER(EXT4_MB_ORDER2_REQ, order2_reqs);
+ MB_PROC_HANDLER(EXT4_MB_STREAM_REQ, stream_request);
+ MB_PROC_HANDLER(EXT4_MB_GROUP_PREALLOC, group_prealloc);
+
+ return 0;
+
+err_out:
+ printk(KERN_ERR "EXT4-fs: Unable to create %s\n", devname);
+ remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_mb_proc);
+ remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_mb_proc);
+ remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_mb_proc);
+ remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME, sbi->s_mb_proc);
+ remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME, sbi->s_mb_proc);
+ remove_proc_entry(EXT4_MB_STATS_NAME, sbi->s_mb_proc);
+ remove_proc_entry(devname, proc_root_ext4);
+ sbi->s_mb_proc = NULL;
+
+ return -ENOMEM;
+}
+
+static int ext4_mb_destroy_per_dev_proc(struct super_block *sb)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ char devname[64];
+
+ if (sbi->s_mb_proc == NULL)
+ return -EINVAL;
+
+ snprintf(devname, sizeof(devname) - 1, "%s",
+ bdevname(sb->s_bdev, devname));
+ remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_mb_proc);
+ remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_mb_proc);
+ remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_mb_proc);
+ remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME, sbi->s_mb_proc);
+ remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME, sbi->s_mb_proc);
+ remove_proc_entry(EXT4_MB_STATS_NAME, sbi->s_mb_proc);
+ remove_proc_entry(devname, proc_root_ext4);
+
+ return 0;
+}
+
+int __init init_ext4_mballoc(void)
+{
+ ext4_pspace_cachep =
+ kmem_cache_create("ext4_prealloc_space",
+ sizeof(struct ext4_prealloc_space),
+ 0, SLAB_RECLAIM_ACCOUNT, NULL);
+ if (ext4_pspace_cachep == NULL)
+ return -ENOMEM;
+
+#ifdef CONFIG_PROC_FS
+ proc_root_ext4 = proc_mkdir(EXT4_ROOT, proc_root_fs);
+ if (proc_root_ext4 == NULL)
+ printk(KERN_ERR "EXT4-fs: Unable to create %s\n", EXT4_ROOT);
+#endif
+
+ return 0;
+}
+
+void exit_ext4_mballoc(void)
+{
+ /* XXX: synchronize_rcu(); */
+ kmem_cache_destroy(ext4_pspace_cachep);
+#ifdef CONFIG_PROC_FS
+ remove_proc_entry(EXT4_ROOT, proc_root_fs);
+#endif
+}
+
+
+/*
+ * Check quota and mark choosed space (ac->ac_b_ex) non-free in bitmaps
+ * Returns 0 if success or error code
+ */
+static int ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
+ handle_t *handle)
+{
+ struct buffer_head *bitmap_bh = NULL;
+ struct ext4_super_block *es;
+ struct ext4_group_desc *gdp;
+ struct buffer_head *gdp_bh;
+ struct ext4_sb_info *sbi;
+ struct super_block *sb;
+ ext4_fsblk_t block;
+ int err;
+
+ BUG_ON(ac->ac_status != AC_STATUS_FOUND);
+ BUG_ON(ac->ac_b_ex.fe_len <= 0);
+
+ sb = ac->ac_sb;
+ sbi = EXT4_SB(sb);
+ es = sbi->s_es;
+
+ ext4_debug("using block group %lu(%d)\n", ac->ac_b_ex.fe_group,
+ gdp->bg_free_blocks_count);
+
+ err = -EIO;
+ bitmap_bh = read_block_bitmap(sb, ac->ac_b_ex.fe_group);
+ if (!bitmap_bh)
+ goto out_err;
+
+ err = ext4_journal_get_write_access(handle, bitmap_bh);
+ if (err)
+ goto out_err;
+
+ err = -EIO;
+ gdp = ext4_get_group_desc(sb, ac->ac_b_ex.fe_group, &gdp_bh);
+ if (!gdp)
+ goto out_err;
+
+ err = ext4_journal_get_write_access(handle, gdp_bh);
+ if (err)
+ goto out_err;
+
+ block = ac->ac_b_ex.fe_group * EXT4_BLOCKS_PER_GROUP(sb)
+ + ac->ac_b_ex.fe_start
+ + le32_to_cpu(es->s_first_data_block);
+
+ if (block == ext4_block_bitmap(sb, gdp) ||
+ block == ext4_inode_bitmap(sb, gdp) ||
+ in_range(block, ext4_inode_table(sb, gdp),
+ EXT4_SB(sb)->s_itb_per_group)) {
+
+ ext4_error(sb, __FUNCTION__,
+ "Allocating block in system zone - block = %llu",
+ block);
+ }
+#ifdef AGGRESSIVE_CHECK
+ {
+ int i;
+ for (i = 0; i < ac->ac_b_ex.fe_len; i++) {
+ BUG_ON(mb_test_bit(ac->ac_b_ex.fe_start + i,
+ bitmap_bh->b_data));
+ }
+ }
+#endif
+ mb_set_bits(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group), bitmap_bh->b_data,
+ ac->ac_b_ex.fe_start, ac->ac_b_ex.fe_len);
+
+ spin_lock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group));
+ if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
+ gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
+ gdp->bg_free_blocks_count =
+ cpu_to_le16(ext4_free_blocks_after_init(sb,
+ ac->ac_b_ex.fe_group,
+ gdp));
+ }
+ gdp->bg_free_blocks_count =
+ cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count)
+ - ac->ac_b_ex.fe_len);
+ gdp->bg_checksum = ext4_group_desc_csum(sbi, ac->ac_b_ex.fe_group, gdp);
+ spin_unlock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group));
+ percpu_counter_sub(&sbi->s_freeblocks_counter, ac->ac_b_ex.fe_len);
+
+ err = ext4_journal_dirty_metadata(handle, bitmap_bh);
+ if (err)
+ goto out_err;
+ err = ext4_journal_dirty_metadata(handle, gdp_bh);
+
+out_err:
+ sb->s_dirt = 1;
+ brelse(bitmap_bh);
+ return err;
+}
+
+/*
+ * here we normalize request for locality group
+ * Group request are normalized to s_strip size if we set the same via mount
+ * option. If not we set it to s_mb_group_prealloc which can be configured via
+ * /proc/fs/ext4/<partition>/group_prealloc
+ *
+ * XXX: should we try to preallocate more than the group has now?
+ */
+static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac)
+{
+ struct super_block *sb = ac->ac_sb;
+ struct ext4_locality_group *lg = ac->ac_lg;
+
+ BUG_ON(lg == NULL);
+ if (EXT4_SB(sb)->s_stripe)
+ ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_stripe;
+ else
+ ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc;
+ mb_debug("#%u: goal %lu blocks for locality group\n",
+ current->pid, ac->ac_g_ex.fe_len);
+}
+
+/*
+ * Normalization means making request better in terms of
+ * size and alignment
+ */
+static void ext4_mb_normalize_request(struct ext4_allocation_context *ac,
+ struct ext4_allocation_request *ar)
+{
+ int bsbits, max;
+ ext4_lblk_t end;
+ struct list_head *cur;
+ loff_t size, orig_size, start_off;
+ ext4_lblk_t start, orig_start;
+ struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
+
+ /* do normalize only data requests, metadata requests
+ do not need preallocation */
+ if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
+ return;
+
+ /* sometime caller may want exact blocks */
+ if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
+ return;
+
+ /* caller may indicate that preallocation isn't
+ * required (it's a tail, for example) */
+ if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC)
+ return;
+
+ if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) {
+ ext4_mb_normalize_group_request(ac);
+ return ;
+ }
+
+ bsbits = ac->ac_sb->s_blocksize_bits;
+
+ /* first, let's learn actual file size
+ * given current request is allocated */
+ size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len;
+ size = size << bsbits;
+ if (size < i_size_read(ac->ac_inode))
+ size = i_size_read(ac->ac_inode);
+
+ /* max available blocks in a free group */
+ max = EXT4_BLOCKS_PER_GROUP(ac->ac_sb) - 1 - 1 -
+ EXT4_SB(ac->ac_sb)->s_itb_per_group;
+
+#define NRL_CHECK_SIZE(req, size, max,bits) \
+ (req <= (size) || max <= ((size) >> bits))
+
+ /* first, try to predict filesize */
+ /* XXX: should this table be tunable? */
+ start_off = 0;
+ if (size <= 16 * 1024) {
+ size = 16 * 1024;
+ } else if (size <= 32 * 1024) {
+ size = 32 * 1024;
+ } else if (size <= 64 * 1024) {
+ size = 64 * 1024;
+ } else if (size <= 128 * 1024) {
+ size = 128 * 1024;
+ } else if (size <= 256 * 1024) {
+ size = 256 * 1024;
+ } else if (size <= 512 * 1024) {
+ size = 512 * 1024;
+ } else if (size <= 1024 * 1024) {
+ size = 1024 * 1024;
+ } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, bsbits)) {
+ start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
+ (20 - bsbits)) << 20;
+ size = 1024 * 1024;
+ } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, bsbits)) {
+ start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
+ (22 - bsbits)) << 22;
+ size = 4 * 1024 * 1024;
+ } else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len,
+ (8<<20)>>bsbits, max, bsbits)) {
+ start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
+ (23 - bsbits)) << 23;
+ size = 8 * 1024 * 1024;
+ } else {
+ start_off = (loff_t)ac->ac_o_ex.fe_logical << bsbits;
+ size = ac->ac_o_ex.fe_len << bsbits;
+ }
+ orig_size = size = size >> bsbits;
+ orig_start = start = start_off >> bsbits;
+
+ /* don't cover already allocated blocks in selected range */
+ if (ar->pleft && start <= ar->lleft) {
+ size -= ar->lleft + 1 - start;
+ start = ar->lleft + 1;
+ }
+ if (ar->pright && start + size - 1 >= ar->lright)
+ size -= start + size - ar->lright;
+
+ end = start + size;
+
+ /* check we don't cross already preallocated blocks */
+ rcu_read_lock();
+ list_for_each_rcu(cur, &ei->i_prealloc_list) {
+ struct ext4_prealloc_space *pa;
+ unsigned long pa_end;
+
+ pa = list_entry(cur, struct ext4_prealloc_space, pa_inode_list);
+
+ if (pa->pa_deleted)
+ continue;
+ spin_lock(&pa->pa_lock);
+ if (pa->pa_deleted) {
+ spin_unlock(&pa->pa_lock);
+ continue;
+ }
+
+ pa_end = pa->pa_lstart + pa->pa_len;
+
+ /* PA must not overlap original request */
+ BUG_ON(!(ac->ac_o_ex.fe_logical >= pa_end ||
+ ac->ac_o_ex.fe_logical < pa->pa_lstart));
+
+ /* skip PA normalized request doesn't overlap with */
+ if (pa->pa_lstart >= end) {
+ spin_unlock(&pa->pa_lock);
+ continue;
+ }
+ if (pa_end <= start) {
+ spin_unlock(&pa->pa_lock);
+ continue;
+ }
+ BUG_ON(pa->pa_lstart <= start && pa_end >= end);
+
+ if (pa_end <= ac->ac_o_ex.fe_logical) {
+ BUG_ON(pa_end < start);
+ start = pa_end;
+ }
+
+ if (pa->pa_lstart > ac->ac_o_ex.fe_logical) {
+ BUG_ON(pa->pa_lstart > end);
+ end = pa->pa_lstart;
+ }
+ spin_unlock(&pa->pa_lock);
+ }
+ rcu_read_unlock();
+ size = end - start;
+
+ /* XXX: extra loop to check we really don't overlap preallocations */
+ rcu_read_lock();
+ list_for_each_rcu(cur, &ei->i_prealloc_list) {
+ struct ext4_prealloc_space *pa;
+ unsigned long pa_end;
+ pa = list_entry(cur, struct ext4_prealloc_space, pa_inode_list);
+ spin_lock(&pa->pa_lock);
+ if (pa->pa_deleted == 0) {
+ pa_end = pa->pa_lstart + pa->pa_len;
+ BUG_ON(!(start >= pa_end || end <= pa->pa_lstart));
+ }
+ spin_unlock(&pa->pa_lock);
+ }
+ rcu_read_unlock();
+
+ if (start + size <= ac->ac_o_ex.fe_logical &&
+ start > ac->ac_o_ex.fe_logical) {
+ printk(KERN_ERR "start %lu, size %lu, fe_logical %lu\n",
+ (unsigned long) start, (unsigned long) size,
+ (unsigned long) ac->ac_o_ex.fe_logical);
+ }
+ BUG_ON(start + size <= ac->ac_o_ex.fe_logical &&
+ start > ac->ac_o_ex.fe_logical);
+ BUG_ON(size <= 0 || size >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
+
+ /* now prepare goal request */
+
+ /* XXX: is it better to align blocks WRT to logical
+ * placement or satisfy big request as is */
+ ac->ac_g_ex.fe_logical = start;
+ ac->ac_g_ex.fe_len = size;
+
+ /* define goal start in order to merge */
+ if (ar->pright && (ar->lright == (start + size))) {
+ /* merge to the right */
+ ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size,
+ &ac->ac_f_ex.fe_group,
+ &ac->ac_f_ex.fe_start);
+ ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
+ }
+ if (ar->pleft && (ar->lleft + 1 == start)) {
+ /* merge to the left */
+ ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1,
+ &ac->ac_f_ex.fe_group,
+ &ac->ac_f_ex.fe_start);
+ ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
+ }
+
+ mb_debug("goal: %u(was %u) blocks at %u\n", (unsigned) size,
+ (unsigned) orig_size, (unsigned) start);
+}
+
+static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
+
+ if (sbi->s_mb_stats && ac->ac_g_ex.fe_len > 1) {
+ atomic_inc(&sbi->s_bal_reqs);
+ atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated);
+ if (ac->ac_o_ex.fe_len >= ac->ac_g_ex.fe_len)
+ atomic_inc(&sbi->s_bal_success);
+ atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned);
+ if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
+ ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
+ atomic_inc(&sbi->s_bal_goals);
+ if (ac->ac_found > sbi->s_mb_max_to_scan)
+ atomic_inc(&sbi->s_bal_breaks);
+ }
+
+ ext4_mb_store_history(ac);
+}
+
+/*
+ * use blocks preallocated to inode
+ */
+static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac,
+ struct ext4_prealloc_space *pa)
+{
+ ext4_fsblk_t start;
+ ext4_fsblk_t end;
+ int len;
+
+ /* found preallocated blocks, use them */
+ start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart);
+ end = min(pa->pa_pstart + pa->pa_len, start + ac->ac_o_ex.fe_len);
+ len = end - start;
+ ext4_get_group_no_and_offset(ac->ac_sb, start, &ac->ac_b_ex.fe_group,
+ &ac->ac_b_ex.fe_start);
+ ac->ac_b_ex.fe_len = len;
+ ac->ac_status = AC_STATUS_FOUND;
+ ac->ac_pa = pa;
+
+ BUG_ON(start < pa->pa_pstart);
+ BUG_ON(start + len > pa->pa_pstart + pa->pa_len);
+ BUG_ON(pa->pa_free < len);
+ pa->pa_free -= len;
+
+ mb_debug("use %llu/%lu from inode pa %p\n", start, len, pa);
+}
+
+/*
+ * use blocks preallocated to locality group
+ */
+static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac,
+ struct ext4_prealloc_space *pa)
+{
+ unsigned len = ac->ac_o_ex.fe_len;
+
+ ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart,
+ &ac->ac_b_ex.fe_group,
+ &ac->ac_b_ex.fe_start);
+ ac->ac_b_ex.fe_len = len;
+ ac->ac_status = AC_STATUS_FOUND;
+ ac->ac_pa = pa;
+
+ /* we don't correct pa_pstart or pa_plen here to avoid
+ * possible race when tte group is being loaded concurrently
+ * instead we correct pa later, after blocks are marked
+ * in on-disk bitmap -- see ext4_mb_release_context() */
+ /*
+ * FIXME!! but the other CPUs can look at this particular
+ * pa and think that it have enought free blocks if we
+ * don't update pa_free here right ?
+ */
+ mb_debug("use %u/%u from group pa %p\n", pa->pa_lstart-len, len, pa);
+}
+
+/*
+ * search goal blocks in preallocated space
+ */
+static int ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
+{
+ struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
+ struct ext4_locality_group *lg;
+ struct ext4_prealloc_space *pa;
+ struct list_head *cur;
+
+ /* only data can be preallocated */
+ if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
+ return 0;
+
+ /* first, try per-file preallocation */
+ rcu_read_lock();
+ list_for_each_rcu(cur, &ei->i_prealloc_list) {
+ pa = list_entry(cur, struct ext4_prealloc_space, pa_inode_list);
+
+ /* all fields in this condition don't change,
+ * so we can skip locking for them */
+ if (ac->ac_o_ex.fe_logical < pa->pa_lstart ||
+ ac->ac_o_ex.fe_logical >= pa->pa_lstart + pa->pa_len)
+ continue;
+
+ /* found preallocated blocks, use them */
+ spin_lock(&pa->pa_lock);
+ if (pa->pa_deleted == 0 && pa->pa_free) {
+ atomic_inc(&pa->pa_count);
+ ext4_mb_use_inode_pa(ac, pa);
+ spin_unlock(&pa->pa_lock);
+ ac->ac_criteria = 10;
+ rcu_read_unlock();
+ return 1;
+ }
+ spin_unlock(&pa->pa_lock);
+ }
+ rcu_read_unlock();
+
+ /* can we use group allocation? */
+ if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC))
+ return 0;
+
+ /* inode may have no locality group for some reason */
+ lg = ac->ac_lg;
+ if (lg == NULL)
+ return 0;
+
+ rcu_read_lock();
+ list_for_each_rcu(cur, &lg->lg_prealloc_list) {
+ pa = list_entry(cur, struct ext4_prealloc_space, pa_inode_list);
+ spin_lock(&pa->pa_lock);
+ if (pa->pa_deleted == 0 && pa->pa_free >= ac->ac_o_ex.fe_len) {
+ atomic_inc(&pa->pa_count);
+ ext4_mb_use_group_pa(ac, pa);
+ spin_unlock(&pa->pa_lock);
+ ac->ac_criteria = 20;
+ rcu_read_unlock();
+ return 1;
+ }
+ spin_unlock(&pa->pa_lock);
+ }
+ rcu_read_unlock();
+
+ return 0;
+}
+
+/*
+ * the function goes through all preallocation in this group and marks them
+ * used in in-core bitmap. buddy must be generated from this bitmap
+ */
+static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
+ ext4_group_t group)
+{
+ struct ext4_group_info *grp = ext4_get_group_info(sb, group);
+ struct ext4_prealloc_space *pa;
+ struct list_head *cur;
+ ext4_group_t groupnr;
+ ext4_grpblk_t start;
+ int preallocated = 0;
+ int count = 0;
+ int len;
+
+ /* all form of preallocation discards first load group,
+ * so the only competing code is preallocation use.
+ * we don't need any locking here
+ * notice we do NOT ignore preallocations with pa_deleted
+ * otherwise we could leave used blocks available for
+ * allocation in buddy when concurrent ext4_mb_put_pa()
+ * is dropping preallocation
+ */
+ list_for_each_rcu(cur, &grp->bb_prealloc_list) {
+ pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
+ spin_lock(&pa->pa_lock);
+ ext4_get_group_no_and_offset(sb, pa->pa_pstart,
+ &groupnr, &start);
+ len = pa->pa_len;
+ spin_unlock(&pa->pa_lock);
+ if (unlikely(len == 0))
+ continue;
+ BUG_ON(groupnr != group);
+ mb_set_bits(sb_bgl_lock(EXT4_SB(sb), group),
+ bitmap, start, len);
+ preallocated += len;
+ count++;
+ }
+ mb_debug("prellocated %u for group %lu\n", preallocated, group);
+}
+
+static void ext4_mb_pa_callback(struct rcu_head *head)
+{
+ struct ext4_prealloc_space *pa;
+ pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu);
+ kmem_cache_free(ext4_pspace_cachep, pa);
+}
+#define mb_call_rcu(__pa) call_rcu(&(__pa)->u.pa_rcu, ext4_mb_pa_callback)
+
+/*
+ * drops a reference to preallocated space descriptor
+ * if this was the last reference and the space is consumed
+ */
+static void ext4_mb_put_pa(struct ext4_allocation_context *ac,
+ struct super_block *sb, struct ext4_prealloc_space *pa)
+{
+ unsigned long grp;
+
+ if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0)
+ return;
+
+ /* in this short window concurrent discard can set pa_deleted */
+ spin_lock(&pa->pa_lock);
+ if (pa->pa_deleted == 1) {
+ spin_unlock(&pa->pa_lock);
+ return;
+ }
+
+ pa->pa_deleted = 1;
+ spin_unlock(&pa->pa_lock);
+
+ /* -1 is to protect from crossing allocation group */
+ ext4_get_group_no_and_offset(sb, pa->pa_pstart - 1, &grp, NULL);
+
+ /*
+ * possible race:
+ *
+ * P1 (buddy init) P2 (regular allocation)
+ * find block B in PA
+ * copy on-disk bitmap to buddy
+ * mark B in on-disk bitmap
+ * drop PA from group
+ * mark all PAs in buddy
+ *
+ * thus, P1 initializes buddy with B available. to prevent this
+ * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
+ * against that pair
+ */
+ ext4_lock_group(sb, grp);
+ list_del_rcu(&pa->pa_group_list);
+ ext4_unlock_group(sb, grp);
+
+ spin_lock(pa->pa_obj_lock);
+ list_del_rcu(&pa->pa_inode_list);
+ spin_unlock(pa->pa_obj_lock);
+
+ mb_call_rcu(pa);
+}
+
+/*
+ * creates new preallocated space for given inode
+ */
+static int ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)
+{
+ struct super_block *sb = ac->ac_sb;
+ struct ext4_prealloc_space *pa;
+ struct ext4_group_info *grp;
+ struct ext4_inode_info *ei;
+
+ /* preallocate only when found space is larger then requested */
+ BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
+ BUG_ON(ac->ac_status != AC_STATUS_FOUND);
+ BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
+
+ pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
+ if (pa == NULL)
+ return -ENOMEM;
+
+ if (ac->ac_b_ex.fe_len < ac->ac_g_ex.fe_len) {
+ int winl;
+ int wins;
+ int win;
+ int offs;
+
+ /* we can't allocate as much as normalizer wants.
+ * so, found space must get proper lstart
+ * to cover original request */
+ BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical);
+ BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len);
+
+ /* we're limited by original request in that
+ * logical block must be covered any way
+ * winl is window we can move our chunk within */
+ winl = ac->ac_o_ex.fe_logical - ac->ac_g_ex.fe_logical;
+
+ /* also, we should cover whole original request */
+ wins = ac->ac_b_ex.fe_len - ac->ac_o_ex.fe_len;
+
+ /* the smallest one defines real window */
+ win = min(winl, wins);
+
+ offs = ac->ac_o_ex.fe_logical % ac->ac_b_ex.fe_len;
+ if (offs && offs < win)
+ win = offs;
+
+ ac->ac_b_ex.fe_logical = ac->ac_o_ex.fe_logical - win;
+ BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical);
+ BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len);
+ }
+
+ /* preallocation can change ac_b_ex, thus we store actually
+ * allocated blocks for history */
+ ac->ac_f_ex = ac->ac_b_ex;
+
+ pa->pa_lstart = ac->ac_b_ex.fe_logical;
+ pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
+ pa->pa_len = ac->ac_b_ex.fe_len;
+ pa->pa_free = pa->pa_len;
+ atomic_set(&pa->pa_count, 1);
+ spin_lock_init(&pa->pa_lock);
+ pa->pa_deleted = 0;
+ pa->pa_linear = 0;
+
+ mb_debug("new inode pa %p: %llu/%u for %u\n", pa,
+ pa->pa_pstart, pa->pa_len, pa->pa_lstart);
+
+ ext4_mb_use_inode_pa(ac, pa);
+ atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);
+
+ ei = EXT4_I(ac->ac_inode);
+ grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
+
+ pa->pa_obj_lock = &ei->i_prealloc_lock;
+ pa->pa_inode = ac->ac_inode;
+
+ ext4_lock_group(sb, ac->ac_b_ex.fe_group);
+ list_add_rcu(&pa->pa_group_list, &grp->bb_prealloc_list);
+ ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
+
+ spin_lock(pa->pa_obj_lock);
+ list_add_rcu(&pa->pa_inode_list, &ei->i_prealloc_list);
+ spin_unlock(pa->pa_obj_lock);
+
+ return 0;
+}
+
+/*
+ * creates new preallocated space for locality group inodes belongs to
+ */
+static int ext4_mb_new_group_pa(struct ext4_allocation_context *ac)
+{
+ struct super_block *sb = ac->ac_sb;
+ struct ext4_locality_group *lg;
+ struct ext4_prealloc_space *pa;
+ struct ext4_group_info *grp;
+
+ /* preallocate only when found space is larger then requested */
+ BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
+ BUG_ON(ac->ac_status != AC_STATUS_FOUND);
+ BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
+
+ BUG_ON(ext4_pspace_cachep == NULL);
+ pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
+ if (pa == NULL)
+ return -ENOMEM;
+
+ /* preallocation can change ac_b_ex, thus we store actually
+ * allocated blocks for history */
+ ac->ac_f_ex = ac->ac_b_ex;
+
+ pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
+ pa->pa_lstart = pa->pa_pstart;
+ pa->pa_len = ac->ac_b_ex.fe_len;
+ pa->pa_free = pa->pa_len;
+ atomic_set(&pa->pa_count, 1);
+ spin_lock_init(&pa->pa_lock);
+ pa->pa_deleted = 0;
+ pa->pa_linear = 1;
+
+ mb_debug("new group pa %p: %llu/%u for %u\n", pa,
+ pa->pa_pstart, pa->pa_len, pa->pa_lstart);
+
+ ext4_mb_use_group_pa(ac, pa);
+ atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);
+
+ grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
+ lg = ac->ac_lg;
+ BUG_ON(lg == NULL);
+
+ pa->pa_obj_lock = &lg->lg_prealloc_lock;
+ pa->pa_inode = NULL;
+
+ ext4_lock_group(sb, ac->ac_b_ex.fe_group);
+ list_add_rcu(&pa->pa_group_list, &grp->bb_prealloc_list);
+ ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
+
+ spin_lock(pa->pa_obj_lock);
+ list_add_tail_rcu(&pa->pa_inode_list, &lg->lg_prealloc_list);
+ spin_unlock(pa->pa_obj_lock);
+
+ return 0;
+}
+
+static int ext4_mb_new_preallocation(struct ext4_allocation_context *ac)
+{
+ int err;
+
+ if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
+ err = ext4_mb_new_group_pa(ac);
+ else
+ err = ext4_mb_new_inode_pa(ac);
+ return err;
+}
+
+/*
+ * finds all unused blocks in on-disk bitmap, frees them in
+ * in-core bitmap and buddy.
+ * @pa must be unlinked from inode and group lists, so that
+ * nobody else can find/use it.
+ * the caller MUST hold group/inode locks.
+ * TODO: optimize the case when there are no in-core structures yet
+ */
+static int ext4_mb_release_inode_pa(struct ext4_buddy *e4b,
+ struct buffer_head *bitmap_bh,
+ struct ext4_prealloc_space *pa)
+{
+ struct ext4_allocation_context ac;
+ struct super_block *sb = e4b->bd_sb;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ unsigned long end;
+ unsigned long next;
+ ext4_group_t group;
+ ext4_grpblk_t bit;
+ sector_t start;
+ int err = 0;
+ int free = 0;
+
+ BUG_ON(pa->pa_deleted == 0);
+ ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
+ BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
+ end = bit + pa->pa_len;
+
+ ac.ac_sb = sb;
+ ac.ac_inode = pa->pa_inode;
+ ac.ac_op = EXT4_MB_HISTORY_DISCARD;
+
+ while (bit < end) {
+ bit = ext4_find_next_zero_bit(bitmap_bh->b_data, end, bit);
+ if (bit >= end)
+ break;
+ next = ext4_find_next_bit(bitmap_bh->b_data, end, bit);
+ if (next > end)
+ next = end;
+ start = group * EXT4_BLOCKS_PER_GROUP(sb) + bit +
+ le32_to_cpu(sbi->s_es->s_first_data_block);
+ mb_debug(" free preallocated %u/%u in group %u\n",
+ (unsigned) start, (unsigned) next - bit,
+ (unsigned) group);
+ free += next - bit;
+
+ ac.ac_b_ex.fe_group = group;
+ ac.ac_b_ex.fe_start = bit;
+ ac.ac_b_ex.fe_len = next - bit;
+ ac.ac_b_ex.fe_logical = 0;
+ ext4_mb_store_history(&ac);
+
+ mb_free_blocks(pa->pa_inode, e4b, bit, next - bit);
+ bit = next + 1;
+ }
+ if (free != pa->pa_free) {
+ printk(KERN_ERR "pa %p: logic %lu, phys. %lu, len %lu\n",
+ pa, (unsigned long) pa->pa_lstart,
+ (unsigned long) pa->pa_pstart,
+ (unsigned long) pa->pa_len);
+ printk(KERN_ERR "free %u, pa_free %u\n", free, pa->pa_free);
+ }
+ BUG_ON(free != pa->pa_free);
+ atomic_add(free, &sbi->s_mb_discarded);
+
+ return err;
+}
+
+static int ext4_mb_release_group_pa(struct ext4_buddy *e4b,
+ struct ext4_prealloc_space *pa)
+{
+ struct ext4_allocation_context ac;
+ struct super_block *sb = e4b->bd_sb;
+ ext4_group_t group;
+ ext4_grpblk_t bit;
+
+ ac.ac_op = EXT4_MB_HISTORY_DISCARD;
+
+ BUG_ON(pa->pa_deleted == 0);
+ ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
+ BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
+ mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len);
+ atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded);
+
+ ac.ac_sb = sb;
+ ac.ac_inode = NULL;
+ ac.ac_b_ex.fe_group = group;
+ ac.ac_b_ex.fe_start = bit;
+ ac.ac_b_ex.fe_len = pa->pa_len;
+ ac.ac_b_ex.fe_logical = 0;
+ ext4_mb_store_history(&ac);
+
+ return 0;
+}
+
+/*
+ * releases all preallocations in given group
+ *
+ * first, we need to decide discard policy:
+ * - when do we discard
+ * 1) ENOSPC
+ * - how many do we discard
+ * 1) how many requested
+ */
+static int ext4_mb_discard_group_preallocations(struct super_block *sb,
+ ext4_group_t group, int needed)
+{
+ struct ext4_group_info *grp = ext4_get_group_info(sb, group);
+ struct buffer_head *bitmap_bh = NULL;
+ struct ext4_prealloc_space *pa, *tmp;
+ struct list_head list;
+ struct ext4_buddy e4b;
+ int err;
+ int busy = 0;
+ int free = 0;
+
+ mb_debug("discard preallocation for group %lu\n", group);
+
+ if (list_empty(&grp->bb_prealloc_list))
+ return 0;
+
+ bitmap_bh = read_block_bitmap(sb, group);
+ if (bitmap_bh == NULL) {
+ /* error handling here */
+ ext4_mb_release_desc(&e4b);
+ BUG_ON(bitmap_bh == NULL);
+ }
+
+ err = ext4_mb_load_buddy(sb, group, &e4b);
+ BUG_ON(err != 0); /* error handling here */
+
+ if (needed == 0)
+ needed = EXT4_BLOCKS_PER_GROUP(sb) + 1;
+
+ grp = ext4_get_group_info(sb, group);
+ INIT_LIST_HEAD(&list);
+
+repeat:
+ ext4_lock_group(sb, group);
+ list_for_each_entry_safe(pa, tmp,
+ &grp->bb_prealloc_list, pa_group_list) {
+ spin_lock(&pa->pa_lock);
+ if (atomic_read(&pa->pa_count)) {
+ spin_unlock(&pa->pa_lock);
+ busy = 1;
+ continue;
+ }
+ if (pa->pa_deleted) {
+ spin_unlock(&pa->pa_lock);
+ continue;
+ }
+
+ /* seems this one can be freed ... */
+ pa->pa_deleted = 1;
+
+ /* we can trust pa_free ... */
+ free += pa->pa_free;
+
+ spin_unlock(&pa->pa_lock);
+
+ list_del_rcu(&pa->pa_group_list);
+ list_add(&pa->u.pa_tmp_list, &list);
+ }
+
+ /* if we still need more blocks and some PAs were used, try again */
+ if (free < needed && busy) {
+ busy = 0;
+ ext4_unlock_group(sb, group);
+ /*
+ * Yield the CPU here so that we don't get soft lockup
+ * in non preempt case.
+ */
+ yield();
+ goto repeat;
+ }
+
+ /* found anything to free? */
+ if (list_empty(&list)) {
+ BUG_ON(free != 0);
+ goto out;
+ }
+
+ /* now free all selected PAs */
+ list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
+
+ /* remove from object (inode or locality group) */
+ spin_lock(pa->pa_obj_lock);
+ list_del_rcu(&pa->pa_inode_list);
+ spin_unlock(pa->pa_obj_lock);
+
+ if (pa->pa_linear)
+ ext4_mb_release_group_pa(&e4b, pa);
+ else
+ ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
+
+ list_del(&pa->u.pa_tmp_list);
+ mb_call_rcu(pa);
+ }
+
+out:
+ ext4_unlock_group(sb, group);
+ ext4_mb_release_desc(&e4b);
+ brelse(bitmap_bh);
+ return free;
+}
+
+/*
+ * releases all non-used preallocated blocks for given inode
+ *
+ * It's important to discard preallocations under i_data_sem
+ * We don't want another block to be served from the prealloc
+ * space when we are discarding the inode prealloc space.
+ *
+ * FIXME!! Make sure it is valid at all the call sites
+ */
+void ext4_mb_discard_inode_preallocations(struct inode *inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ struct super_block *sb = inode->i_sb;
+ struct buffer_head *bitmap_bh = NULL;
+ struct ext4_prealloc_space *pa, *tmp;
+ ext4_group_t group = 0;
+ struct list_head list;
+ struct ext4_buddy e4b;
+ int err;
+
+ if (!test_opt(sb, MBALLOC) || !S_ISREG(inode->i_mode)) {
+ /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
+ return;
+ }
+
+ mb_debug("discard preallocation for inode %lu\n", inode->i_ino);
+
+ INIT_LIST_HEAD(&list);
+
+repeat:
+ /* first, collect all pa's in the inode */
+ spin_lock(&ei->i_prealloc_lock);
+ while (!list_empty(&ei->i_prealloc_list)) {
+ pa = list_entry(ei->i_prealloc_list.next,
+ struct ext4_prealloc_space, pa_inode_list);
+ BUG_ON(pa->pa_obj_lock != &ei->i_prealloc_lock);
+ spin_lock(&pa->pa_lock);
+ if (atomic_read(&pa->pa_count)) {
+ /* this shouldn't happen often - nobody should
+ * use preallocation while we're discarding it */
+ spin_unlock(&pa->pa_lock);
+ spin_unlock(&ei->i_prealloc_lock);
+ printk(KERN_ERR "uh-oh! used pa while discarding\n");
+ dump_stack();
+ current->state = TASK_UNINTERRUPTIBLE;
+ schedule_timeout(HZ);
+ goto repeat;
+
+ }
+ if (pa->pa_deleted == 0) {
+ pa->pa_deleted = 1;
+ spin_unlock(&pa->pa_lock);
+ list_del_rcu(&pa->pa_inode_list);
+ list_add(&pa->u.pa_tmp_list, &list);
+ continue;
+ }
+
+ /* someone is deleting pa right now */
+ spin_unlock(&pa->pa_lock);
+ spin_unlock(&ei->i_prealloc_lock);
+
+ /* we have to wait here because pa_deleted
+ * doesn't mean pa is already unlinked from
+ * the list. as we might be called from
+ * ->clear_inode() the inode will get freed
+ * and concurrent thread which is unlinking
+ * pa from inode's list may access already
+ * freed memory, bad-bad-bad */
+
+ /* XXX: if this happens too often, we can
+ * add a flag to force wait only in case
+ * of ->clear_inode(), but not in case of
+ * regular truncate */
+ current->state = TASK_UNINTERRUPTIBLE;
+ schedule_timeout(HZ);
+ goto repeat;
+ }
+ spin_unlock(&ei->i_prealloc_lock);
+
+ list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
+ BUG_ON(pa->pa_linear != 0);
+ ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, NULL);
+
+ err = ext4_mb_load_buddy(sb, group, &e4b);
+ BUG_ON(err != 0); /* error handling here */
+
+ bitmap_bh = read_block_bitmap(sb, group);
+ if (bitmap_bh == NULL) {
+ /* error handling here */
+ ext4_mb_release_desc(&e4b);
+ BUG_ON(bitmap_bh == NULL);
+ }
+
+ ext4_lock_group(sb, group);
+ list_del_rcu(&pa->pa_group_list);
+ ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
+ ext4_unlock_group(sb, group);
+
+ ext4_mb_release_desc(&e4b);
+ brelse(bitmap_bh);
+
+ list_del(&pa->u.pa_tmp_list);
+ mb_call_rcu(pa);
+ }
+}
+
+/*
+ * finds all preallocated spaces and return blocks being freed to them
+ * if preallocated space becomes full (no block is used from the space)
+ * then the function frees space in buddy
+ * XXX: at the moment, truncate (which is the only way to free blocks)
+ * discards all preallocations
+ */
+static void ext4_mb_return_to_preallocation(struct inode *inode,
+ struct ext4_buddy *e4b,
+ sector_t block, int count)
+{
+ BUG_ON(!list_empty(&EXT4_I(inode)->i_prealloc_list));
+}
+#ifdef MB_DEBUG
+static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
+{
+ struct super_block *sb = ac->ac_sb;
+ ext4_group_t i;
+
+ printk(KERN_ERR "EXT4-fs: Can't allocate:"
+ " Allocation context details:\n");
+ printk(KERN_ERR "EXT4-fs: status %d flags %d\n",
+ ac->ac_status, ac->ac_flags);
+ printk(KERN_ERR "EXT4-fs: orig %lu/%lu/%lu@%lu, goal %lu/%lu/%lu@%lu, "
+ "best %lu/%lu/%lu@%lu cr %d\n",
+ (unsigned long)ac->ac_o_ex.fe_group,
+ (unsigned long)ac->ac_o_ex.fe_start,
+ (unsigned long)ac->ac_o_ex.fe_len,
+ (unsigned long)ac->ac_o_ex.fe_logical,
+ (unsigned long)ac->ac_g_ex.fe_group,
+ (unsigned long)ac->ac_g_ex.fe_start,
+ (unsigned long)ac->ac_g_ex.fe_len,
+ (unsigned long)ac->ac_g_ex.fe_logical,
+ (unsigned long)ac->ac_b_ex.fe_group,
+ (unsigned long)ac->ac_b_ex.fe_start,
+ (unsigned long)ac->ac_b_ex.fe_len,
+ (unsigned long)ac->ac_b_ex.fe_logical,
+ (int)ac->ac_criteria);
+ printk(KERN_ERR "EXT4-fs: %lu scanned, %d found\n", ac->ac_ex_scanned,
+ ac->ac_found);
+ printk(KERN_ERR "EXT4-fs: groups: \n");
+ for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
+ struct ext4_group_info *grp = ext4_get_group_info(sb, i);
+ struct ext4_prealloc_space *pa;
+ ext4_grpblk_t start;
+ struct list_head *cur;
+ list_for_each_rcu(cur, &grp->bb_prealloc_list) {
+ pa = list_entry(cur, struct ext4_prealloc_space,
+ pa_group_list);
+ spin_lock(&pa->pa_lock);
+ ext4_get_group_no_and_offset(sb, pa->pa_pstart,
+ NULL, &start);
+ spin_unlock(&pa->pa_lock);
+ printk(KERN_ERR "PA:%lu:%d:%u \n", i,
+ start, pa->pa_len);
+ }
+
+ if (grp->bb_free == 0)
+ continue;
+ printk(KERN_ERR "%lu: %d/%d \n",
+ i, grp->bb_free, grp->bb_fragments);
+ }
+ printk(KERN_ERR "\n");
+}
+#else
+#define ext4_mb_show_ac(x)
+#endif
+
+/*
+ * We use locality group preallocation for small size file. The size of the
+ * file is determined by the current size or the resulting size after
+ * allocation which ever is larger
+ *
+ * One can tune this size via /proc/fs/ext4/<partition>/stream_req
+ */
+static void ext4_mb_group_or_file(struct ext4_allocation_context *ac)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
+ int bsbits = ac->ac_sb->s_blocksize_bits;
+ loff_t size, isize;
+
+ if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
+ return;
+
+ size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len;
+ isize = i_size_read(ac->ac_inode) >> bsbits;
+ if (size < isize)
+ size = isize;
+
+ /* don't use group allocation for large files */
+ if (size >= sbi->s_mb_stream_request)
+ return;
+
+ if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
+ return;
+
+ BUG_ON(ac->ac_lg != NULL);
+ ac->ac_lg = &sbi->s_locality_groups[get_cpu()];
+ put_cpu();
+
+ /* we're going to use group allocation */
+ ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC;
+
+ /* serialize all allocations in the group */
+ down(&ac->ac_lg->lg_sem);
+}
+
+static int ext4_mb_initialize_context(struct ext4_allocation_context *ac,
+ struct ext4_allocation_request *ar)
+{
+ struct super_block *sb = ar->inode->i_sb;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_super_block *es = sbi->s_es;
+ ext4_group_t group;
+ unsigned long len;
+ unsigned long goal;
+ ext4_grpblk_t block;
+
+ /* we can't allocate > group size */
+ len = ar->len;
+
+ /* just a dirty hack to filter too big requests */
+ if (len >= EXT4_BLOCKS_PER_GROUP(sb) - 10)
+ len = EXT4_BLOCKS_PER_GROUP(sb) - 10;
+
+ /* start searching from the goal */
+ goal = ar->goal;
+ if (goal < le32_to_cpu(es->s_first_data_block) ||
+ goal >= ext4_blocks_count(es))
+ goal = le32_to_cpu(es->s_first_data_block);
+ ext4_get_group_no_and_offset(sb, goal, &group, &block);
+
+ /* set up allocation goals */
+ ac->ac_b_ex.fe_logical = ar->logical;
+ ac->ac_b_ex.fe_group = 0;
+ ac->ac_b_ex.fe_start = 0;
+ ac->ac_b_ex.fe_len = 0;
+ ac->ac_status = AC_STATUS_CONTINUE;
+ ac->ac_groups_scanned = 0;
+ ac->ac_ex_scanned = 0;
+ ac->ac_found = 0;
+ ac->ac_sb = sb;
+ ac->ac_inode = ar->inode;
+ ac->ac_o_ex.fe_logical = ar->logical;
+ ac->ac_o_ex.fe_group = group;
+ ac->ac_o_ex.fe_start = block;
+ ac->ac_o_ex.fe_len = len;
+ ac->ac_g_ex.fe_logical = ar->logical;
+ ac->ac_g_ex.fe_group = group;
+ ac->ac_g_ex.fe_start = block;
+ ac->ac_g_ex.fe_len = len;
+ ac->ac_f_ex.fe_len = 0;
+ ac->ac_flags = ar->flags;
+ ac->ac_2order = 0;
+ ac->ac_criteria = 0;
+ ac->ac_pa = NULL;
+ ac->ac_bitmap_page = NULL;
+ ac->ac_buddy_page = NULL;
+ ac->ac_lg = NULL;
+
+ /* we have to define context: we'll we work with a file or
+ * locality group. this is a policy, actually */
+ ext4_mb_group_or_file(ac);
+
+ mb_debug("init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
+ "left: %u/%u, right %u/%u to %swritable\n",
+ (unsigned) ar->len, (unsigned) ar->logical,
+ (unsigned) ar->goal, ac->ac_flags, ac->ac_2order,
+ (unsigned) ar->lleft, (unsigned) ar->pleft,
+ (unsigned) ar->lright, (unsigned) ar->pright,
+ atomic_read(&ar->inode->i_writecount) ? "" : "non-");
+ return 0;
+
+}
+
+/*
+ * release all resource we used in allocation
+ */
+static int ext4_mb_release_context(struct ext4_allocation_context *ac)
+{
+ if (ac->ac_pa) {
+ if (ac->ac_pa->pa_linear) {
+ /* see comment in ext4_mb_use_group_pa() */
+ spin_lock(&ac->ac_pa->pa_lock);
+ ac->ac_pa->pa_pstart += ac->ac_b_ex.fe_len;
+ ac->ac_pa->pa_lstart += ac->ac_b_ex.fe_len;
+ ac->ac_pa->pa_free -= ac->ac_b_ex.fe_len;
+ ac->ac_pa->pa_len -= ac->ac_b_ex.fe_len;
+ spin_unlock(&ac->ac_pa->pa_lock);
+ }
+ ext4_mb_put_pa(ac, ac->ac_sb, ac->ac_pa);
+ }
+ if (ac->ac_bitmap_page)
+ page_cache_release(ac->ac_bitmap_page);
+ if (ac->ac_buddy_page)
+ page_cache_release(ac->ac_buddy_page);
+ if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
+ up(&ac->ac_lg->lg_sem);
+ ext4_mb_collect_stats(ac);
+ return 0;
+}
+
+static int ext4_mb_discard_preallocations(struct super_block *sb, int needed)
+{
+ ext4_group_t i;
+ int ret;
+ int freed = 0;
+
+ for (i = 0; i < EXT4_SB(sb)->s_groups_count && needed > 0; i++) {
+ ret = ext4_mb_discard_group_preallocations(sb, i, needed);
+ freed += ret;
+ needed -= ret;
+ }
+
+ return freed;
+}
+
+/*
+ * Main entry point into mballoc to allocate blocks
+ * it tries to use preallocation first, then falls back
+ * to usual allocation
+ */
+ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
+ struct ext4_allocation_request *ar, int *errp)
+{
+ struct ext4_allocation_context ac;
+ struct ext4_sb_info *sbi;
+ struct super_block *sb;
+ ext4_fsblk_t block = 0;
+ int freed;
+ int inquota;
+
+ sb = ar->inode->i_sb;
+ sbi = EXT4_SB(sb);
+
+ if (!test_opt(sb, MBALLOC)) {
+ block = ext4_new_blocks_old(handle, ar->inode, ar->goal,
+ &(ar->len), errp);
+ return block;
+ }
+
+ while (ar->len && DQUOT_ALLOC_BLOCK(ar->inode, ar->len)) {
+ ar->flags |= EXT4_MB_HINT_NOPREALLOC;
+ ar->len--;
+ }
+ if (ar->len == 0) {
+ *errp = -EDQUOT;
+ return 0;
+ }
+ inquota = ar->len;
+
+ ext4_mb_poll_new_transaction(sb, handle);
+
+ *errp = ext4_mb_initialize_context(&ac, ar);
+ if (*errp) {
+ ar->len = 0;
+ goto out;
+ }
+
+ ac.ac_op = EXT4_MB_HISTORY_PREALLOC;
+ if (!ext4_mb_use_preallocated(&ac)) {
+
+ ac.ac_op = EXT4_MB_HISTORY_ALLOC;
+ ext4_mb_normalize_request(&ac, ar);
+
+repeat:
+ /* allocate space in core */
+ ext4_mb_regular_allocator(&ac);
+
+ /* as we've just preallocated more space than
+ * user requested orinally, we store allocated
+ * space in a special descriptor */
+ if (ac.ac_status == AC_STATUS_FOUND &&
+ ac.ac_o_ex.fe_len < ac.ac_b_ex.fe_len)
+ ext4_mb_new_preallocation(&ac);
+ }
+
+ if (likely(ac.ac_status == AC_STATUS_FOUND)) {
+ ext4_mb_mark_diskspace_used(&ac, handle);
+ *errp = 0;
+ block = ext4_grp_offs_to_block(sb, &ac.ac_b_ex);
+ ar->len = ac.ac_b_ex.fe_len;
+ } else {
+ freed = ext4_mb_discard_preallocations(sb, ac.ac_o_ex.fe_len);
+ if (freed)
+ goto repeat;
+ *errp = -ENOSPC;
+ ac.ac_b_ex.fe_len = 0;
+ ar->len = 0;
+ ext4_mb_show_ac(&ac);
+ }
+
+ ext4_mb_release_context(&ac);
+
+out:
+ if (ar->len < inquota)
+ DQUOT_FREE_BLOCK(ar->inode, inquota - ar->len);
+
+ return block;
+}
+static void ext4_mb_poll_new_transaction(struct super_block *sb,
+ handle_t *handle)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+ if (sbi->s_last_transaction == handle->h_transaction->t_tid)
+ return;
+
+ /* new transaction! time to close last one and free blocks for
+ * committed transaction. we know that only transaction can be
+ * active, so previos transaction can be being logged and we
+ * know that transaction before previous is known to be already
+ * logged. this means that now we may free blocks freed in all
+ * transactions before previous one. hope I'm clear enough ... */
+
+ spin_lock(&sbi->s_md_lock);
+ if (sbi->s_last_transaction != handle->h_transaction->t_tid) {
+ mb_debug("new transaction %lu, old %lu\n",
+ (unsigned long) handle->h_transaction->t_tid,
+ (unsigned long) sbi->s_last_transaction);
+ list_splice_init(&sbi->s_closed_transaction,
+ &sbi->s_committed_transaction);
+ list_splice_init(&sbi->s_active_transaction,
+ &sbi->s_closed_transaction);
+ sbi->s_last_transaction = handle->h_transaction->t_tid;
+ }
+ spin_unlock(&sbi->s_md_lock);
+
+ ext4_mb_free_committed_blocks(sb);
+}
+
+static int ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
+ ext4_group_t group, ext4_grpblk_t block, int count)
+{
+ struct ext4_group_info *db = e4b->bd_info;
+ struct super_block *sb = e4b->bd_sb;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_free_metadata *md;
+ int i;
+
+ BUG_ON(e4b->bd_bitmap_page == NULL);
+ BUG_ON(e4b->bd_buddy_page == NULL);
+
+ ext4_lock_group(sb, group);
+ for (i = 0; i < count; i++) {
+ md = db->bb_md_cur;
+ if (md && db->bb_tid != handle->h_transaction->t_tid) {
+ db->bb_md_cur = NULL;
+ md = NULL;
+ }
+
+ if (md == NULL) {
+ ext4_unlock_group(sb, group);
+ md = kmalloc(sizeof(*md), GFP_KERNEL);
+ if (md == NULL)
+ return -ENOMEM;
+ md->num = 0;
+ md->group = group;
+
+ ext4_lock_group(sb, group);
+ if (db->bb_md_cur == NULL) {
+ spin_lock(&sbi->s_md_lock);
+ list_add(&md->list, &sbi->s_active_transaction);
+ spin_unlock(&sbi->s_md_lock);
+ /* protect buddy cache from being freed,
+ * otherwise we'll refresh it from
+ * on-disk bitmap and lose not-yet-available
+ * blocks */
+ page_cache_get(e4b->bd_buddy_page);
+ page_cache_get(e4b->bd_bitmap_page);
+ db->bb_md_cur = md;
+ db->bb_tid = handle->h_transaction->t_tid;
+ mb_debug("new md 0x%p for group %lu\n",
+ md, md->group);
+ } else {
+ kfree(md);
+ md = db->bb_md_cur;
+ }
+ }
+
+ BUG_ON(md->num >= EXT4_BB_MAX_BLOCKS);
+ md->blocks[md->num] = block + i;
+ md->num++;
+ if (md->num == EXT4_BB_MAX_BLOCKS) {
+ /* no more space, put full container on a sb's list */
+ db->bb_md_cur = NULL;
+ }
+ }
+ ext4_unlock_group(sb, group);
+ return 0;
+}
+
+/*
+ * Main entry point into mballoc to free blocks
+ */
+void ext4_mb_free_blocks(handle_t *handle, struct inode *inode,
+ unsigned long block, unsigned long count,
+ int metadata, unsigned long *freed)
+{
+ struct buffer_head *bitmap_bh = NULL;
+ struct super_block *sb = inode->i_sb;
+ struct ext4_allocation_context ac;
+ struct ext4_group_desc *gdp;
+ struct ext4_super_block *es;
+ unsigned long overflow;
+ ext4_grpblk_t bit;
+ struct buffer_head *gd_bh;
+ ext4_group_t block_group;
+ struct ext4_sb_info *sbi;
+ struct ext4_buddy e4b;
+ int err = 0;
+ int ret;
+
+ *freed = 0;
+
+ ext4_mb_poll_new_transaction(sb, handle);
+
+ sbi = EXT4_SB(sb);
+ es = EXT4_SB(sb)->s_es;
+ if (block < le32_to_cpu(es->s_first_data_block) ||
+ block + count < block ||
+ block + count > ext4_blocks_count(es)) {
+ ext4_error(sb, __FUNCTION__,
+ "Freeing blocks not in datazone - "
+ "block = %lu, count = %lu", block, count);
+ goto error_return;
+ }
+
+ ext4_debug("freeing block %lu\n", block);
+
+ ac.ac_op = EXT4_MB_HISTORY_FREE;
+ ac.ac_inode = inode;
+ ac.ac_sb = sb;
+
+do_more:
+ overflow = 0;
+ ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
+
+ /*
+ * Check to see if we are freeing blocks across a group
+ * boundary.
+ */
+ if (bit + count > EXT4_BLOCKS_PER_GROUP(sb)) {
+ overflow = bit + count - EXT4_BLOCKS_PER_GROUP(sb);
+ count -= overflow;
+ }
+ brelse(bitmap_bh);
+ bitmap_bh = read_block_bitmap(sb, block_group);
+ if (!bitmap_bh)
+ goto error_return;
+ gdp = ext4_get_group_desc(sb, block_group, &gd_bh);
+ if (!gdp)
+ goto error_return;
+
+ if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
+ in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
+ in_range(block, ext4_inode_table(sb, gdp),
+ EXT4_SB(sb)->s_itb_per_group) ||
+ in_range(block + count - 1, ext4_inode_table(sb, gdp),
+ EXT4_SB(sb)->s_itb_per_group)) {
+
+ ext4_error(sb, __FUNCTION__,
+ "Freeing blocks in system zone - "
+ "Block = %lu, count = %lu", block, count);
+ }
+
+ BUFFER_TRACE(bitmap_bh, "getting write access");
+ err = ext4_journal_get_write_access(handle, bitmap_bh);
+ if (err)
+ goto error_return;
+
+ /*
+ * We are about to modify some metadata. Call the journal APIs
+ * to unshare ->b_data if a currently-committing transaction is
+ * using it
+ */
+ BUFFER_TRACE(gd_bh, "get_write_access");
+ err = ext4_journal_get_write_access(handle, gd_bh);
+ if (err)
+ goto error_return;
+
+ err = ext4_mb_load_buddy(sb, block_group, &e4b);
+ if (err)
+ goto error_return;
+
+#ifdef AGGRESSIVE_CHECK
+ {
+ int i;
+ for (i = 0; i < count; i++)
+ BUG_ON(!mb_test_bit(bit + i, bitmap_bh->b_data));
+ }
+#endif
+ mb_clear_bits(sb_bgl_lock(sbi, block_group), bitmap_bh->b_data,
+ bit, count);
+
+ /* We dirtied the bitmap block */
+ BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
+ err = ext4_journal_dirty_metadata(handle, bitmap_bh);
+
+ ac.ac_b_ex.fe_group = block_group;
+ ac.ac_b_ex.fe_start = bit;
+ ac.ac_b_ex.fe_len = count;
+ ext4_mb_store_history(&ac);
+
+ if (metadata) {
+ /* blocks being freed are metadata. these blocks shouldn't
+ * be used until this transaction is committed */
+ ext4_mb_free_metadata(handle, &e4b, block_group, bit, count);
+ } else {
+ ext4_lock_group(sb, block_group);
+ err = mb_free_blocks(inode, &e4b, bit, count);
+ ext4_mb_return_to_preallocation(inode, &e4b, block, count);
+ ext4_unlock_group(sb, block_group);
+ BUG_ON(err != 0);
+ }
+
+ spin_lock(sb_bgl_lock(sbi, block_group));
+ gdp->bg_free_blocks_count =
+ cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count) + count);
+ gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp);
+ spin_unlock(sb_bgl_lock(sbi, block_group));
+ percpu_counter_add(&sbi->s_freeblocks_counter, count);
+
+ ext4_mb_release_desc(&e4b);
+
+ *freed += count;
+
+ /* And the group descriptor block */
+ BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
+ ret = ext4_journal_dirty_metadata(handle, gd_bh);
+ if (!err)
+ err = ret;
+
+ if (overflow && !err) {
+ block += count;
+ count = overflow;
+ goto do_more;
+ }
+ sb->s_dirt = 1;
+error_return:
+ brelse(bitmap_bh);
+ ext4_std_error(sb, err);
+ return;
+}
diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index 7203d3d..6b40f55 100644
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -253,11 +253,11 @@ static int free_dind_blocks(handle_t *handle,
for (i = 0; i < max_entries; i++) {
if (tmp_idata[i]) {
ext4_free_blocks(handle, inode,
- le32_to_cpu(tmp_idata[i]), 1);
+ le32_to_cpu(tmp_idata[i]), 1, 1);
}
}
brelse(bh);
- ext4_free_blocks(handle, inode, le32_to_cpu(i_data), 1);
+ ext4_free_blocks(handle, inode, le32_to_cpu(i_data), 1, 1);

return 0;

@@ -289,7 +289,7 @@ static int free_tind_blocks(handle_t *handle,
}
}
brelse(bh);
- ext4_free_blocks(handle, inode, le32_to_cpu(i_data), 1);
+ ext4_free_blocks(handle, inode, le32_to_cpu(i_data), 1, 1);

return 0;

@@ -304,7 +304,7 @@ static int free_ind_block(handle_t *handle, struct inode *inode)
if (ei->i_data[EXT4_IND_BLOCK]) {

ext4_free_blocks(handle, inode,
- le32_to_cpu(ei->i_data[EXT4_IND_BLOCK]), 1);
+ le32_to_cpu(ei->i_data[EXT4_IND_BLOCK]), 1, 1);

}

@@ -402,7 +402,7 @@ static int free_ext_idx(handle_t *handle, struct inode *inode,
if (eh->eh_depth == 0) {

brelse(bh);
- ext4_free_blocks(handle, inode, block, 1);
+ ext4_free_blocks(handle, inode, block, 1, 1);

} else {

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 64fc7f1..136d095 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -503,6 +503,7 @@ static void ext4_put_super (struct super_block * sb)
struct ext4_super_block *es = sbi->s_es;
int i;

+ ext4_mb_release(sb);
ext4_ext_release(sb);
ext4_xattr_put_super(sb);
jbd2_journal_destroy(sbi->s_journal);
@@ -569,6 +570,8 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
ei->i_block_alloc_info = NULL;
ei->vfs_inode.i_version = 1;
memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
+ INIT_LIST_HEAD(&ei->i_prealloc_list);
+ spin_lock_init(&ei->i_prealloc_lock);
return &ei->vfs_inode;
}

@@ -881,6 +884,7 @@ enum {
Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
Opt_grpquota, Opt_extents, Opt_noextents, Opt_i_version,
+ Opt_mballoc, Opt_nomballoc, Opt_stripe,
};

static match_table_t tokens = {
@@ -935,6 +939,9 @@ static match_table_t tokens = {
{Opt_extents, "extents"},
{Opt_noextents, "noextents"},
{Opt_i_version, "i_version"},
+ {Opt_mballoc, "mballoc"},
+ {Opt_nomballoc, "nomballoc"},
+ {Opt_stripe, "stripe=%u"},
{Opt_err, NULL},
{Opt_resize, "resize"},
};
@@ -1284,6 +1291,19 @@ clear_qf_name:
set_opt(sbi->s_mount_opt, I_VERSION);
sb->s_flags |= MS_I_VERSION;
break;
+ case Opt_mballoc:
+ set_opt(sbi->s_mount_opt, MBALLOC);
+ break;
+ case Opt_nomballoc:
+ clear_opt(sbi->s_mount_opt, MBALLOC);
+ break;
+ case Opt_stripe:
+ if (match_int(&args[0], &option))
+ return 0;
+ if (option < 0)
+ return 0;
+ sbi->s_stripe = option;
+ break;
default:
printk (KERN_ERR
"EXT4-fs: Unrecognized mount option \"%s\" "
@@ -1742,6 +1762,33 @@ static ext4_fsblk_t descriptor_loc(struct super_block *sb,
return (has_super + ext4_group_first_block_no(sb, bg));
}

+/**
+ * ext4_get_stripe_size: Get the stripe size.
+ * @sbi: In memory super block info
+ *
+ * If we have specified it via mount option, then
+ * use the mount option value. If the value specified at mount time is
+ * greater than the blocks per group use the super block value.
+ * If the super block value is greater than blocks per group return 0.
+ * Allocator needs it be less than blocks per group.
+ *
+ */
+static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
+{
+ unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
+ unsigned long stripe_width =
+ le32_to_cpu(sbi->s_es->s_raid_stripe_width);
+
+ if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group) {
+ return sbi->s_stripe;
+ } else if (stripe_width <= sbi->s_blocks_per_group) {
+ return stripe_width;
+ } else if (stride <= sbi->s_blocks_per_group) {
+ return stride;
+ }
+
+ return 0;
+}

static int ext4_fill_super (struct super_block *sb, void *data, int silent)
__releases(kernel_sem)
@@ -2091,6 +2138,8 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
sbi->s_rsv_window_head.rsv_goal_size = 0;
ext4_rsv_window_add(sb, &sbi->s_rsv_window_head);

+ sbi->s_stripe = ext4_get_stripe_size(sbi);
+
/*
* set up enough so that it can read an inode
*/
@@ -2250,6 +2299,7 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
"writeback");

ext4_ext_init(sb);
+ ext4_mb_init(sb, needs_recovery);

lock_kernel();
return 0;
@@ -3232,9 +3282,15 @@ static struct file_system_type ext4dev_fs_type = {

static int __init init_ext4_fs(void)
{
- int err = init_ext4_xattr();
+ int err;
+
+ err = init_ext4_mballoc();
if (err)
return err;
+
+ err = init_ext4_xattr();
+ if (err)
+ goto out2;
err = init_inodecache();
if (err)
goto out1;
@@ -3246,6 +3302,8 @@ out:
destroy_inodecache();
out1:
exit_ext4_xattr();
+out2:
+ exit_ext4_mballoc();
return err;
}

@@ -3254,6 +3312,7 @@ static void __exit exit_ext4_fs(void)
unregister_filesystem(&ext4dev_fs_type);
destroy_inodecache();
exit_ext4_xattr();
+ exit_ext4_mballoc();
}

MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 8638730..d796213 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -480,7 +480,7 @@ ext4_xattr_release_block(handle_t *handle, struct inode *inode,
ea_bdebug(bh, "refcount now=0; freeing");
if (ce)
mb_cache_entry_free(ce);
- ext4_free_blocks(handle, inode, bh->b_blocknr, 1);
+ ext4_free_blocks(handle, inode, bh->b_blocknr, 1, 1);
get_bh(bh);
ext4_forget(handle, 1, inode, bh, bh->b_blocknr);
} else {
@@ -821,7 +821,7 @@ inserted:
new_bh = sb_getblk(sb, block);
if (!new_bh) {
getblk_failed:
- ext4_free_blocks(handle, inode, block, 1);
+ ext4_free_blocks(handle, inode, block, 1, 1);
error = -EIO;
goto cleanup;
}
diff --git a/include/linux/ext4_fs.h b/include/linux/ext4_fs.h
index d0b7ca9..1852313 100644
--- a/include/linux/ext4_fs.h
+++ b/include/linux/ext4_fs.h
@@ -20,6 +20,8 @@
#include <linux/blkdev.h>
#include <linux/magic.h>

+#include <linux/ext4_fs_i.h>
+
/*
* The second extended filesystem constants/structures
*/
@@ -51,6 +53,50 @@
#define ext4_debug(f, a...) do {} while (0)
#endif

+#define EXT4_MULTIBLOCK_ALLOCATOR 1
+
+/* prefer goal again. length */
+#define EXT4_MB_HINT_MERGE 1
+/* blocks already reserved */
+#define EXT4_MB_HINT_RESERVED 2
+/* metadata is being allocated */
+#define EXT4_MB_HINT_METADATA 4
+/* first blocks in the file */
+#define EXT4_MB_HINT_FIRST 8
+/* search for the best chunk */
+#define EXT4_MB_HINT_BEST 16
+/* data is being allocated */
+#define EXT4_MB_HINT_DATA 32
+/* don't preallocate (for tails) */
+#define EXT4_MB_HINT_NOPREALLOC 64
+/* allocate for locality group */
+#define EXT4_MB_HINT_GROUP_ALLOC 128
+/* allocate goal blocks or none */
+#define EXT4_MB_HINT_GOAL_ONLY 256
+/* goal is meaningful */
+#define EXT4_MB_HINT_TRY_GOAL 512
+
+struct ext4_allocation_request {
+ /* target inode for block we're allocating */
+ struct inode *inode;
+ /* logical block in target inode */
+ ext4_lblk_t logical;
+ /* phys. target (a hint) */
+ ext4_fsblk_t goal;
+ /* the closest logical allocated block to the left */
+ ext4_lblk_t lleft;
+ /* phys. block for ^^^ */
+ ext4_fsblk_t pleft;
+ /* the closest logical allocated block to the right */
+ ext4_lblk_t lright;
+ /* phys. block for ^^^ */
+ ext4_fsblk_t pright;
+ /* how many blocks we want to allocate */
+ unsigned long len;
+ /* flags. see above EXT4_MB_HINT_* */
+ unsigned long flags;
+};
+
/*
* Special inodes numbers
*/
@@ -474,6 +520,7 @@ do { \
#define EXT4_MOUNT_JOURNAL_CHECKSUM 0x800000 /* Journal checksums */
#define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT 0x1000000 /* Journal Async Commit */
#define EXT4_MOUNT_I_VERSION 0x2000000 /* i_version support */
+#define EXT4_MOUNT_MBALLOC 0x4000000 /* Buddy allocation support */
/* Compatibility, for having both ext2_fs.h and ext4_fs.h included at once */
#ifndef _LINUX_EXT2_FS_H
#define clear_opt(o, opt) o &= ~EXT4_MOUNT_##opt
@@ -912,7 +959,7 @@ extern ext4_fsblk_t ext4_new_blocks (handle_t *handle, struct inode *inode,
extern ext4_fsblk_t ext4_new_blocks_old(handle_t *handle, struct inode *inode,
ext4_fsblk_t goal, unsigned long *count, int *errp);
extern void ext4_free_blocks (handle_t *handle, struct inode *inode,
- ext4_fsblk_t block, unsigned long count);
+ ext4_fsblk_t block, unsigned long count, int metadata);
extern void ext4_free_blocks_sb (handle_t *handle, struct super_block *sb,
ext4_fsblk_t block, unsigned long count,
unsigned long *pdquot_freed_blocks);
@@ -950,6 +997,20 @@ extern unsigned long ext4_count_dirs (struct super_block *);
extern void ext4_check_inodes_bitmap (struct super_block *);
extern unsigned long ext4_count_free (struct buffer_head *, unsigned);

+/* mballoc.c */
+extern long ext4_mb_stats;
+extern long ext4_mb_max_to_scan;
+extern int ext4_mb_init(struct super_block *, int);
+extern int ext4_mb_release(struct super_block *);
+extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
+ struct ext4_allocation_request *, int *);
+extern int ext4_mb_reserve_blocks(struct super_block *, int);
+extern void ext4_mb_discard_inode_preallocations(struct inode *);
+extern int __init init_ext4_mballoc(void);
+extern void exit_ext4_mballoc(void);
+extern void ext4_mb_free_blocks(handle_t *, struct inode *,
+ unsigned long, unsigned long, int, unsigned long *);
+

/* inode.c */
int ext4_forget(handle_t *handle, int is_metadata, struct inode *inode,
@@ -1080,6 +1141,19 @@ static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
}

+static inline
+struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
+ ext4_group_t group)
+{
+ struct ext4_group_info ***grp_info;
+ long indexv, indexh;
+ grp_info = EXT4_SB(sb)->s_group_info;
+ indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
+ indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
+ return grp_info[indexv][indexh];
+}
+
+
#define ext4_std_error(sb, errno) \
do { \
if ((errno)) \
diff --git a/include/linux/ext4_fs_i.h b/include/linux/ext4_fs_i.h
index 4377d24..d5508d3 100644
--- a/include/linux/ext4_fs_i.h
+++ b/include/linux/ext4_fs_i.h
@@ -158,6 +158,10 @@ struct ext4_inode_info {
* struct timespec i_{a,c,m}time in the generic inode.
*/
struct timespec i_crtime;
+
+ /* mballoc */
+ struct list_head i_prealloc_list;
+ spinlock_t i_prealloc_lock;
};

#endif /* _LINUX_EXT4_FS_I */
diff --git a/include/linux/ext4_fs_sb.h b/include/linux/ext4_fs_sb.h
index 38a47ec..abaae2c 100644
--- a/include/linux/ext4_fs_sb.h
+++ b/include/linux/ext4_fs_sb.h
@@ -91,6 +91,58 @@ struct ext4_sb_info {
unsigned long s_ext_blocks;
unsigned long s_ext_extents;
#endif
+
+ /* for buddy allocator */
+ struct ext4_group_info ***s_group_info;
+ struct inode *s_buddy_cache;
+ long s_blocks_reserved;
+ spinlock_t s_reserve_lock;
+ struct list_head s_active_transaction;
+ struct list_head s_closed_transaction;
+ struct list_head s_committed_transaction;
+ spinlock_t s_md_lock;
+ tid_t s_last_transaction;
+ unsigned short *s_mb_offsets, *s_mb_maxs;
+
+ /* tunables */
+ unsigned long s_stripe;
+ unsigned long s_mb_stream_request;
+ unsigned long s_mb_max_to_scan;
+ unsigned long s_mb_min_to_scan;
+ unsigned long s_mb_stats;
+ unsigned long s_mb_order2_reqs;
+ unsigned long s_mb_group_prealloc;
+ /* where last allocation was done - for stream allocation */
+ unsigned long s_mb_last_group;
+ unsigned long s_mb_last_start;
+
+ /* history to debug policy */
+ struct ext4_mb_history *s_mb_history;
+ int s_mb_history_cur;
+ int s_mb_history_max;
+ int s_mb_history_num;
+ struct proc_dir_entry *s_mb_proc;
+ spinlock_t s_mb_history_lock;
+ int s_mb_history_filter;
+
+ /* stats for buddy allocator */
+ spinlock_t s_mb_pa_lock;
+ atomic_t s_bal_reqs; /* number of reqs with len > 1 */
+ atomic_t s_bal_success; /* we found long enough chunks */
+ atomic_t s_bal_allocated; /* in blocks */
+ atomic_t s_bal_ex_scanned; /* total extents scanned */
+ atomic_t s_bal_goals; /* goal hits */
+ atomic_t s_bal_breaks; /* too long searches */
+ atomic_t s_bal_2orders; /* 2^order hits */
+ spinlock_t s_bal_lock;
+ unsigned long s_mb_buddies_generated;
+ unsigned long long s_mb_generation_time;
+ atomic_t s_mb_lost_chunks;
+ atomic_t s_mb_preallocated;
+ atomic_t s_mb_discarded;
+
+ /* locality groups */
+ struct ext4_locality_group *s_locality_groups;
};

#endif /* _LINUX_EXT4_FS_SB */
--
1.5.4.rc3.31.g1271-dirty


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