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BKL: Remove BKL from ext2 filesystem 

The BKL is still used in ext2_put_super(), ext2_fill_super(), ext2_sync_fs()
ext2_remount() and ext2_write_inode(). From these calls ext2_put_super(),
ext2_fill_super() and ext2_remount() are protected against each other by
the struct super_block s_umount rw semaphore. The call in ext2_write_inode()
could only protect the modification of the ext2_sb_info through
ext2_update_dynamic_rev() against concurrent ext2_sync_fs() or ext2_remount().
ext2_fill_super() and ext2_put_super() can be left out because you need a
valid filesystem reference in all three cases, which you do not have when
you are one of these functions.

If the BKL is only protecting the modification of the ext2_sb_info it can
safely be removed since this is protected by the struct ext2_sb_info s_lock.

Signed-off-by: Jan Blunck <jblunck@suse.de>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jan Kara <jack@suse.cz>
This commit is contained in:
Jan Blunck 2010-04-14 14:38:39 +02:00 committed by Jan Kara
parent c15271f4e7
commit e0a5cbac02
2 changed files with 0 additions and 16 deletions
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3
fs/ext2/inode.c
View File

@ -22,7 +22,6 @@
* Assorted race fixes, rewrite of ext2_get_block() by Al Viro, 2000
*/
#include <linux/smp_lock.h>
#include <linux/time.h>
#include <linux/highuid.h>
#include <linux/pagemap.h>
@ -1406,13 +1405,11 @@ static int __ext2_write_inode(struct inode *inode, int do_sync)
/* If this is the first large file
* created, add a flag to the superblock.
*/
lock_kernel();
spin_lock(&EXT2_SB(sb)->s_lock);
ext2_update_dynamic_rev(sb);
EXT2_SET_RO_COMPAT_FEATURE(sb,
EXT2_FEATURE_RO_COMPAT_LARGE_FILE);
spin_unlock(&EXT2_SB(sb)->s_lock);
unlock_kernel();
ext2_write_super(sb);
}
}

13
fs/ext2/super.c
View File

@ -26,7 +26,6 @@
#include <linux/random.h>
#include <linux/buffer_head.h>
#include <linux/exportfs.h>
#include <linux/smp_lock.h>
#include <linux/vfs.h>
#include <linux/seq_file.h>
#include <linux/mount.h>
@ -120,8 +119,6 @@ static void ext2_put_super (struct super_block * sb)
int i;
struct ext2_sb_info *sbi = EXT2_SB(sb);
lock_kernel();
if (sb->s_dirt)
ext2_write_super(sb);
@ -147,8 +144,6 @@ static void ext2_put_super (struct super_block * sb)
sb->s_fs_info = NULL;
kfree(sbi->s_blockgroup_lock);
kfree(sbi);
unlock_kernel();
}
static struct kmem_cache * ext2_inode_cachep;
@ -1170,7 +1165,6 @@ static int ext2_sync_fs(struct super_block *sb, int wait)
struct ext2_sb_info *sbi = EXT2_SB(sb);
struct ext2_super_block *es = EXT2_SB(sb)->s_es;
lock_kernel();
spin_lock(&sbi->s_lock);
if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
ext2_debug("setting valid to 0\n");
@ -1178,8 +1172,6 @@ static int ext2_sync_fs(struct super_block *sb, int wait)
}
spin_unlock(&sbi->s_lock);
ext2_sync_super(sb, es, wait);
unlock_kernel();
return 0;
}
@ -1201,7 +1193,6 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data)
unsigned long old_sb_flags;
int err;
lock_kernel();
spin_lock(&sbi->s_lock);
/* Store the old options */
@ -1242,14 +1233,12 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data)
}
if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
spin_unlock(&sbi->s_lock);
unlock_kernel();
return 0;
}
if (*flags & MS_RDONLY) {
if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
!(sbi->s_mount_state & EXT2_VALID_FS)) {
spin_unlock(&sbi->s_lock);
unlock_kernel();
return 0;
}
/*
@ -1282,7 +1271,6 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data)
spin_unlock(&sbi->s_lock);
ext2_write_super(sb);
}
unlock_kernel();
return 0;
restore_opts:
sbi->s_mount_opt = old_opts.s_mount_opt;
@ -1290,7 +1278,6 @@ restore_opts:
sbi->s_resgid = old_opts.s_resgid;
sb->s_flags = old_sb_flags;
spin_unlock(&sbi->s_lock);
unlock_kernel();
return err;
}