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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
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8
fs/coda/inode.c
View File

@@ -148,6 +148,8 @@ static int coda_fill_super(struct super_block *sb, void *data, int silent)
int error;
int idx;
lock_kernel();
idx = get_device_index((struct coda_mount_data *) data);
/* Ignore errors in data, for backward compatibility */
@@ -159,11 +161,13 @@ static int coda_fill_super(struct super_block *sb, void *data, int silent)
vc = &coda_comms[idx];
if (!vc->vc_inuse) {
printk("coda_read_super: No pseudo device\n");
unlock_kernel();
return -EINVAL;
}
if ( vc->vc_sb ) {
printk("coda_read_super: Device already mounted\n");
unlock_kernel();
return -EBUSY;
}
@@ -202,7 +206,8 @@ static int coda_fill_super(struct super_block *sb, void *data, int silent)
sb->s_root = d_alloc_root(root);
if (!sb->s_root)
goto error;
return 0;
unlock_kernel();
return 0;
error:
bdi_destroy(&vc->bdi);
@@ -212,6 +217,7 @@ static int coda_fill_super(struct super_block *sb, void *data, int silent)
if (vc)
vc->vc_sb = NULL;
unlock_kernel();
return -EINVAL;
}