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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/affs
parent899611ee7d373e5eeda08e9a8632684e1ebbbf00 (diff)
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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/affs')
-rw-r--r--fs/affs/super.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/fs/affs/super.c b/fs/affs/super.c
index 33c4e7eef470..3a6d1dee4a51 100644
--- a/fs/affs/super.c
+++ b/fs/affs/super.c
@@ -291,6 +291,8 @@ static int affs_fill_super(struct super_block *sb, void *data, int silent)
u8 sig[4];
int ret = -EINVAL;
+ lock_kernel();
+
save_mount_options(sb, data);
pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
@@ -300,8 +302,10 @@ static int affs_fill_super(struct super_block *sb, void *data, int silent)
sb->s_flags |= MS_NODIRATIME;
sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
- if (!sbi)
+ if (!sbi) {
+ unlock_kernel();
return -ENOMEM;
+ }
sb->s_fs_info = sbi;
mutex_init(&sbi->s_bmlock);
spin_lock_init(&sbi->symlink_lock);
@@ -312,6 +316,7 @@ static int affs_fill_super(struct super_block *sb, void *data, int silent)
printk(KERN_ERR "AFFS: Error parsing options\n");
kfree(sbi->s_prefix);
kfree(sbi);
+ unlock_kernel();
return -EINVAL;
}
/* N.B. after this point s_prefix must be released */
@@ -482,6 +487,7 @@ got_root:
sb->s_root->d_op = &affs_dentry_operations;
pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
+ unlock_kernel();
return 0;
/*
@@ -496,6 +502,7 @@ out_error_noinode:
kfree(sbi->s_prefix);
kfree(sbi);
sb->s_fs_info = NULL;
+ unlock_kernel();
return ret;
}