lkml.org 
[lkml]   [2012]   [Feb]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC PATCH 18/22] ext3: add support for .read_iter and .write_iter
Date
From: Zach Brown <zab@zabbo.net>

ext3 uses the generic .read_iter and .write_iter functions.

ext3_direct_IO() is refactored in to helpers which are called by the
.direct_IO{,bvec}() methods which call __blockdev_direct_IO{,_bvec}().

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: linux-ext4@vger.kernel.org
---
drivers/block/loop.c | 55 ++++++++++++++++++-
fs/ext3/file.c | 2 +
fs/ext3/inode.c | 149 ++++++++++++++++++++++++++++++++++----------------
include/linux/loop.h | 1 +
4 files changed, 160 insertions(+), 47 deletions(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index cd50435..cdc34e1 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -76,6 +76,7 @@
#include <linux/sysfs.h>
#include <linux/miscdevice.h>
#include <linux/falloc.h>
+#include <linux/aio.h>

#include <asm/uaccess.h>

@@ -213,6 +214,46 @@ lo_do_transfer(struct loop_device *lo, int cmd,
return lo->transfer(lo, cmd, rpage, roffs, lpage, loffs, size, rblock);
}

+void lo_rw_aio_complete(u64 data, long res)
+{
+ struct bio *bio = (struct bio *)data;
+
+ if (res > 0)
+ res = 0;
+ else if (res < 0)
+ res = -EIO;
+
+ bio_endio(bio, res);
+}
+
+static int lo_rw_aio(struct loop_device *lo, struct bio *bio)
+{
+ struct file *file = lo->lo_backing_file;
+ struct kiocb *iocb;
+ unsigned short op;
+ struct iov_iter iter;
+ struct bio_vec *bvec;
+ size_t nr_segs;
+ loff_t pos = ((loff_t) bio->bi_sector << 9) + lo->lo_offset;
+
+ iocb = aio_kernel_alloc(GFP_NOIO);
+ if (!iocb)
+ return -ENOMEM;
+
+ if (bio_rw(bio) & WRITE)
+ op = IOCB_CMD_WRITE_ITER;
+ else
+ op = IOCB_CMD_READ_ITER;
+
+ bvec = bio_iovec_idx(bio, bio->bi_idx);
+ nr_segs = bio_segments(bio);
+ iov_iter_init_bvec(&iter, bvec, nr_segs, bvec_length(bvec, nr_segs), 0);
+ aio_kernel_init_iter(iocb, file, op, &iter, pos);
+ aio_kernel_init_callback(iocb, lo_rw_aio_complete, (u64)bio);
+
+ return aio_kernel_submit(iocb);
+}
+
/**
* __do_lo_send_write - helper for writing data to a loop device
*
@@ -512,7 +553,14 @@ static inline void loop_handle_bio(struct loop_device *lo, struct bio *bio)
do_loop_switch(lo, bio->bi_private);
bio_put(bio);
} else {
- int ret = do_bio_filebacked(lo, bio);
+ int ret;
+ if (lo->lo_flags & LO_FLAGS_USE_AIO &&
+ lo->transfer == transfer_none) {
+ ret = lo_rw_aio(lo, bio);
+ if (ret == 0)
+ return;
+ } else
+ ret = do_bio_filebacked(lo, bio);
bio_endio(bio, ret);
}
}
@@ -854,6 +902,11 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
!file->f_op->write)
lo_flags |= LO_FLAGS_READ_ONLY;

+ if (file->f_op->write_iter && file->f_op->read_iter) {
+ file->f_flags |= O_DIRECT;
+ lo_flags |= LO_FLAGS_USE_AIO;
+ }
+
lo_blocksize = S_ISBLK(inode->i_mode) ?
inode->i_bdev->bd_block_size : PAGE_SIZE;

diff --git a/fs/ext3/file.c b/fs/ext3/file.c
index 724df69..30447a5 100644
--- a/fs/ext3/file.c
+++ b/fs/ext3/file.c
@@ -58,6 +58,8 @@ const struct file_operations ext3_file_operations = {
.write = do_sync_write,
.aio_read = generic_file_aio_read,
.aio_write = generic_file_aio_write,
+ .read_iter = generic_file_read_iter,
+ .write_iter = generic_file_write_iter,
.unlocked_ioctl = ext3_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = ext3_compat_ioctl,
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index 2d0afec..ea414f0 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -1853,6 +1853,70 @@ static int ext3_releasepage(struct page *page, gfp_t wait)
return journal_try_to_free_buffers(journal, page, wait);
}

+static ssize_t ext3_journal_orphan_add(struct inode *inode)
+{
+ struct ext3_inode_info *ei = EXT3_I(inode);
+ handle_t *handle;
+ ssize_t ret;
+
+ /* Credits for sb + inode write */
+ handle = ext3_journal_start(inode, 2);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ goto out;
+ }
+ ret = ext3_orphan_add(handle, inode);
+ if (ret) {
+ ext3_journal_stop(handle);
+ goto out;
+ }
+ ei->i_disksize = inode->i_size;
+ ext3_journal_stop(handle);
+out:
+ return ret;
+}
+
+static ssize_t ext3_journal_orphan_del(struct inode *inode, ssize_t ret,
+ loff_t offset)
+{
+ struct ext3_inode_info *ei = EXT3_I(inode);
+ handle_t *handle;
+ int err;
+
+ /* Credits for sb + inode write */
+ handle = ext3_journal_start(inode, 2);
+ if (IS_ERR(handle)) {
+ /* This is really bad luck. We've written the data
+ * but cannot extend i_size. Truncate allocated blocks
+ * and pretend the write failed... */
+ ext3_truncate_failed_direct_write(inode);
+ ret = PTR_ERR(handle);
+ goto out;
+ }
+ if (inode->i_nlink)
+ ext3_orphan_del(handle, inode);
+ if (ret > 0) {
+ loff_t end = offset + ret;
+ if (end > inode->i_size) {
+ ei->i_disksize = end;
+ i_size_write(inode, end);
+ /*
+ * We're going to return a positive `ret'
+ * here due to non-zero-length I/O, so there's
+ * no way of reporting error returns from
+ * ext3_mark_inode_dirty() to userspace. So
+ * ignore it.
+ */
+ ext3_mark_inode_dirty(handle, inode);
+ }
+ }
+ err = ext3_journal_stop(handle);
+ if (ret == 0)
+ ret = err;
+out:
+ return ret;
+}
+
/*
* If the O_DIRECT write will extend the file then add this inode to the
* orphan list. So recovery will truncate it back to the original size
@@ -1868,8 +1932,6 @@ static ssize_t ext3_direct_IO(int rw, struct kiocb *iocb,
{
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_mapping->host;
- struct ext3_inode_info *ei = EXT3_I(inode);
- handle_t *handle;
ssize_t ret;
int orphan = 0;
size_t count = iov_length(iov, nr_segs);
@@ -1881,20 +1943,10 @@ static ssize_t ext3_direct_IO(int rw, struct kiocb *iocb,
loff_t final_size = offset + count;

if (final_size > inode->i_size) {
- /* Credits for sb + inode write */
- handle = ext3_journal_start(inode, 2);
- if (IS_ERR(handle)) {
- ret = PTR_ERR(handle);
+ ret = ext3_journal_orphan_add(inode);
+ if (ret)
goto out;
- }
- ret = ext3_orphan_add(handle, inode);
- if (ret) {
- ext3_journal_stop(handle);
- goto out;
- }
orphan = 1;
- ei->i_disksize = inode->i_size;
- ext3_journal_stop(handle);
}
}

@@ -1915,43 +1967,46 @@ retry:
if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
goto retry;

- if (orphan) {
- int err;
+ if (orphan)
+ ret = ext3_journal_orphan_del(inode, ret, offset);
+out:
+ return ret;
+}

- /* Credits for sb + inode write */
- handle = ext3_journal_start(inode, 2);
- if (IS_ERR(handle)) {
- /* This is really bad luck. We've written the data
- * but cannot extend i_size. Truncate allocated blocks
- * and pretend the write failed... */
- ext3_truncate_failed_direct_write(inode);
- ret = PTR_ERR(handle);
- goto out;
- }
- if (inode->i_nlink)
- ext3_orphan_del(handle, inode);
- if (ret > 0) {
- loff_t end = offset + ret;
- if (end > inode->i_size) {
- ei->i_disksize = end;
- i_size_write(inode, end);
- /*
- * We're going to return a positive `ret'
- * here due to non-zero-length I/O, so there's
- * no way of reporting error returns from
- * ext3_mark_inode_dirty() to userspace. So
- * ignore it.
- */
- ext3_mark_inode_dirty(handle, inode);
- }
+static ssize_t ext3_direct_IO_bvec(int rw, struct kiocb *iocb,
+ struct bio_vec *bvec, loff_t offset,
+ unsigned long bvec_len)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file->f_mapping->host;
+ ssize_t ret;
+ int orphan = 0;
+ size_t count = bvec_length(bvec, bvec_len);
+ int retries = 0;
+
+ if (rw == WRITE) {
+ loff_t final_size = offset + count;
+
+ if (final_size > inode->i_size) {
+ ret = ext3_journal_orphan_add(inode);
+ if (ret)
+ goto out;
+ orphan = 1;
}
- err = ext3_journal_stop(handle);
- if (ret == 0)
- ret = err;
}
+
+retry:
+ ret = blockdev_direct_IO_bvec(rw, iocb, inode, inode->i_sb->s_bdev,
+ bvec, offset, bvec_len, ext3_get_block,
+ NULL);
+ if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
+ goto retry;
+
+ if (orphan)
+ ret = ext3_journal_orphan_del(inode, ret, offset);
out:
trace_ext3_direct_IO_exit(inode, offset,
- iov_length(iov, nr_segs), rw, ret);
+ bvec_length(bvec, bvec_len), rw, ret);
return ret;
}

@@ -1984,6 +2039,7 @@ static const struct address_space_operations ext3_ordered_aops = {
.invalidatepage = ext3_invalidatepage,
.releasepage = ext3_releasepage,
.direct_IO = ext3_direct_IO,
+ .direct_IO_bvec = ext3_direct_IO_bvec,
.migratepage = buffer_migrate_page,
.is_partially_uptodate = block_is_partially_uptodate,
.error_remove_page = generic_error_remove_page,
@@ -1999,6 +2055,7 @@ static const struct address_space_operations ext3_writeback_aops = {
.invalidatepage = ext3_invalidatepage,
.releasepage = ext3_releasepage,
.direct_IO = ext3_direct_IO,
+ .direct_IO_bvec = ext3_direct_IO_bvec,
.migratepage = buffer_migrate_page,
.is_partially_uptodate = block_is_partially_uptodate,
.error_remove_page = generic_error_remove_page,
diff --git a/include/linux/loop.h b/include/linux/loop.h
index 11a41a8..5163fd3 100644
--- a/include/linux/loop.h
+++ b/include/linux/loop.h
@@ -75,6 +75,7 @@ enum {
LO_FLAGS_READ_ONLY = 1,
LO_FLAGS_AUTOCLEAR = 4,
LO_FLAGS_PARTSCAN = 8,
+ LO_FLAGS_USE_AIO = 16,
};

#include <asm/posix_types.h> /* for __kernel_old_dev_t */
--
1.7.9.2


\
 
 \ /
  Last update: 2012-02-27 22:23    [W:0.130 / U:5.280 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site