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BKL: Explicitly add BKL around get_sb/fill_super

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This patch is a preparation necessary to remove the BKL from do_new_mount().
It explicitly adds calls to lock_kernel()/unlock_kernel() around
get_sb/fill_super operations for filesystems that still uses the BKL.

I've read through all the code formerly covered by the BKL inside
do_kern_mount() and have satisfied myself that it doesn't need the BKL
any more.

do_kern_mount() is already called without the BKL when mounting the rootfs
and in nfsctl. do_kern_mount() calls vfs_kern_mount(), which is called
from various places without BKL: simple_pin_fs(), nfs_do_clone_mount()
through nfs_follow_mountpoint(), afs_mntpt_do_automount() through
afs_mntpt_follow_link(). Both later functions are actually the filesystems
follow_link inode operation. vfs_kern_mount() is calling the specified
get_sb function and lets the filesystem do its job by calling the given
fill_super function.

Therefore I think it is safe to push down the BKL from the VFS to the
low-level filesystems get_sb/fill_super operation.

[arnd: do not add the BKL to those file systems that already
       don't use it elsewhere]

Signed-off-by: Jan Blunck <jblunck@infradead.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Christoph Hellwig <hch@infradead.org>
This commit is contained in:
Jan Blunck
2010-08-15 22:51:10 +02:00
committed by Arnd Bergmann
parent 899611ee7d
commit db71922217
28 changed files with 187 additions and 25 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
fs/jfs/super.c
View File

@@ -438,14 +438,20 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent)
s64 newLVSize = 0;
int flag, ret = -EINVAL;
lock_kernel();
jfs_info("In jfs_read_super: s_flags=0x%lx", sb->s_flags);
if (!new_valid_dev(sb->s_bdev->bd_dev))
if (!new_valid_dev(sb->s_bdev->bd_dev)) {
unlock_kernel();
return -EOVERFLOW;
}
sbi = kzalloc(sizeof (struct jfs_sb_info), GFP_KERNEL);
if (!sbi)
if (!sbi) {
unlock_kernel();
return -ENOMEM;
}
sb->s_fs_info = sbi;
sbi->sb = sb;
sbi->uid = sbi->gid = sbi->umask = -1;
@@ -542,6 +548,7 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent)
sb->s_maxbytes = min(((u64) PAGE_CACHE_SIZE << 32) - 1, (u64)sb->s_maxbytes);
#endif
sb->s_time_gran = 1;
unlock_kernel();
return 0;
out_no_root:
@@ -564,6 +571,7 @@ out_unload:
unload_nls(sbi->nls_tab);
out_kfree:
kfree(sbi);
unlock_kernel();
return ret;
}