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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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4
fs/ecryptfs/main.c
View File

@ -36,6 +36,7 @@
#include <linux/parser.h>
#include <linux/fs_stack.h>
#include <linux/slab.h>
#include <linux/smp_lock.h> /* For lock_kernel() */
#include "ecryptfs_kernel.h"
/**
@ -550,6 +551,7 @@ static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags,
const char *err = "Getting sb failed";
int rc;
lock_kernel();
sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL);
if (!sbi) {
rc = -ENOMEM;
@ -608,6 +610,7 @@ static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags,
goto out;
}
simple_set_mnt(mnt, s);
unlock_kernel();
return 0;
out:
@ -616,6 +619,7 @@ out:
kmem_cache_free(ecryptfs_sb_info_cache, sbi);
}
printk(KERN_ERR "%s; rc = [%d]\n", err, rc);
unlock_kernel();
return rc;
}