lkml.org 
[lkml]   [2012]   [May]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v3 1/4] fat: introduce special inode for managing the FSINFO block
Date
From: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

This patch is just a preparation for further changes. It introduces a special
inode ('fsinfo_inode') in FAT file-system which we'll later use for managing
the FSINFO block. Note, this there is already one special inode ('fat_inode')
which is used for managing the FAT tables.

Introduce new 'MSDOS_FSINFO_INO' constant for this special inode. It is safe to
do because FAT file-system does not store inode numbers on the media but
generates them run-time.

I've also cleaned up the comment to existing 'MSDOS_ROOT_INO' constant, while
on it.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
---
fs/fat/fat.h | 1 +
fs/fat/inode.c | 12 ++++++++++++
include/linux/msdos_fs.h | 3 ++-
3 files changed, 15 insertions(+), 1 deletions(-)

diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index 66994f3..951d12b 100644
--- a/fs/fat/fat.h
+++ b/fs/fat/fat.h
@@ -82,6 +82,7 @@ struct msdos_sb_info {
int fatent_shift;
struct fatent_operations *fatent_ops;
struct inode *fat_inode;
+ struct inode *fsinfo_inode;

struct ratelimit_state ratelimit;

diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 21687e3..91e9a8a 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -490,6 +490,7 @@ static void fat_put_super(struct super_block *sb)
if (sb->s_dirt)
fat_write_super(sb);

+ iput(sbi->fsinfo_inode);
iput(sbi->fat_inode);

unload_nls(sbi->nls_disk);
@@ -1244,6 +1245,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
void (*setup)(struct super_block *))
{
struct inode *root_inode = NULL, *fat_inode = NULL;
+ struct inode *fsinfo_inode = NULL;
struct buffer_head *bh;
struct fat_boot_sector *b;
struct msdos_sb_info *sbi;
@@ -1490,6 +1492,14 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
goto out_fail;
MSDOS_I(fat_inode)->i_pos = 0;
sbi->fat_inode = fat_inode;
+
+ fsinfo_inode = new_inode(sb);
+ if (!fsinfo_inode)
+ goto out_fail;
+ fsinfo_inode->i_ino = MSDOS_FSINFO_INO;
+ sbi->fsinfo_inode = fsinfo_inode;
+ insert_inode_hash(fsinfo_inode);
+
root_inode = new_inode(sb);
if (!root_inode)
goto out_fail;
@@ -1516,6 +1526,8 @@ out_invalid:
fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem");

out_fail:
+ if (fsinfo_inode)
+ iput(fsinfo_inode);
if (fat_inode)
iput(fat_inode);
unload_nls(sbi->nls_io);
diff --git a/include/linux/msdos_fs.h b/include/linux/msdos_fs.h
index 34066e6..11cc2ac 100644
--- a/include/linux/msdos_fs.h
+++ b/include/linux/msdos_fs.h
@@ -21,8 +21,9 @@
#define CT_LE_W(v) cpu_to_le16(v)
#define CT_LE_L(v) cpu_to_le32(v)

+#define MSDOS_ROOT_INO 1 /* The root inode number */
+#define MSDOS_FSINFO_INO 2 /* Used for managing the FSINFO block */

-#define MSDOS_ROOT_INO 1 /* == MINIX_ROOT_INO */
#define MSDOS_DIR_BITS 5 /* log2(sizeof(struct msdos_dir_entry)) */

/* directory limit */
--
1.7.7.6


\
 
 \ /
  Last update: 2012-05-04 17:41    [W:0.026 / U:0.280 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site