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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/fat
parent899611ee7d373e5eeda08e9a8632684e1ebbbf00 (diff)
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/fat')
-rw-r--r--fs/fat/namei_msdos.c7
-rw-r--r--fs/fat/namei_vfat.c7
2 files changed, 12 insertions, 2 deletions
diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c
index bbc94ae4fd7..e2b0b978340 100644
--- a/fs/fat/namei_msdos.c
+++ b/fs/fat/namei_msdos.c
@@ -9,6 +9,7 @@
#include <linux/module.h>
#include <linux/time.h>
#include <linux/buffer_head.h>
+#include <linux/smp_lock.h> /* For lock_kernel() */
#include "fat.h"
/* Characters that are undesirable in an MS-DOS file name */
@@ -662,12 +663,16 @@ static int msdos_fill_super(struct super_block *sb, void *data, int silent)
{
int res;
+ lock_kernel();
res = fat_fill_super(sb, data, silent, &msdos_dir_inode_operations, 0);
- if (res)
+ if (res) {
+ unlock_kernel();
return res;
+ }
sb->s_flags |= MS_NOATIME;
sb->s_root->d_op = &msdos_dentry_operations;
+ unlock_kernel();
return 0;
}
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
index 6fcc7e71fba..9006ad9c7b1 100644
--- a/fs/fat/namei_vfat.c
+++ b/fs/fat/namei_vfat.c
@@ -21,6 +21,7 @@
#include <linux/slab.h>
#include <linux/buffer_head.h>
#include <linux/namei.h>
+#include <linux/smp_lock.h> /* For lock_kernel() */
#include "fat.h"
/*
@@ -1055,15 +1056,19 @@ static int vfat_fill_super(struct super_block *sb, void *data, int silent)
{
int res;
+ lock_kernel();
res = fat_fill_super(sb, data, silent, &vfat_dir_inode_operations, 1);
- if (res)
+ if (res) {
+ unlock_kernel();
return res;
+ }
if (MSDOS_SB(sb)->options.name_check != 's')
sb->s_root->d_op = &vfat_ci_dentry_ops;
else
sb->s_root->d_op = &vfat_dentry_ops;
+ unlock_kernel();
return 0;
}