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authorJan Blunck <jblunck@infradead.org>2010-08-15 22:51:10 +0200
committerArnd Bergmann <arnd@arndb.de>2010-10-04 21:10:10 +0200
commitdb71922217a214e5c9268448e537b54fc1f301ea (patch)
tree9c9afbf29411547891f6968e5ade29ce59d66c07 /fs/nilfs2/super.c
parent899611ee7d373e5eeda08e9a8632684e1ebbbf00 (diff)
downloadlinux-db71922217a214e5c9268448e537b54fc1f301ea.tar.bz2
BKL: Explicitly add BKL around get_sb/fill_super
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>
Diffstat (limited to 'fs/nilfs2/super.c')
-rw-r--r--fs/nilfs2/super.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 922263393c76..0d573c2a6860 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -1113,9 +1113,12 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags,
if (!(flags & MS_RDONLY))
mode |= FMODE_WRITE;
+ lock_kernel();
sd.bdev = open_bdev_exclusive(dev_name, mode, fs_type);
- if (IS_ERR(sd.bdev))
+ if (IS_ERR(sd.bdev)) {
+ unlock_kernel();
return PTR_ERR(sd.bdev);
+ }
/*
* To get mount instance using sget() vfs-routine, NILFS needs
@@ -1198,6 +1201,7 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags,
if (need_to_close)
close_bdev_exclusive(sd.bdev, mode);
simple_set_mnt(mnt, s);
+ unlock_kernel();
return 0;
failed_unlock:
@@ -1206,6 +1210,7 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags,
failed:
close_bdev_exclusive(sd.bdev, mode);
+ unlock_kernel();
return err;
cancel_new:
@@ -1218,6 +1223,7 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags,
* We must finish all post-cleaning before this call;
* put_nilfs() needs the block device.
*/
+ unlock_kernel();
return err;
}