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authorTrond Myklebust <Trond.Myklebust@netapp.com>2006-06-04 02:51:37 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-05 12:29:16 -0700
commit6d09bb627d2470299dfb1af0e6d27fb4aece9196 (patch)
treece62b91f11c5df5fbee41aa053b33add79c2c37a
parentc7d2d28b9851d0ffc9924b0e36bac806d18ebf25 (diff)
downloadlinux-stericsson-6d09bb627d2470299dfb1af0e6d27fb4aece9196.tar.gz
[PATCH] fs/namei.c: Call to file_permission() under a spinlock in do_lookup_path()
From: Trond Myklebust <Trond.Myklebust@netapp.com> We're presently running lock_kernel() under fs_lock via nfs's ->permission handler. That's a ranking bug and sometimes a sleep-in-spinlock bug. This problem was introduced in the openat() patchset. We should not need to hold the current->fs->lock for a codepath that doesn't use current->fs. [vsu@altlinux.ru: fix error path] Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Al Viro <viro@ftp.linux.org.uk> Signed-off-by: Sergey Vlasov <vsu@altlinux.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--fs/namei.c19
1 files changed, 10 insertions, 9 deletions
diff --git a/fs/namei.c b/fs/namei.c
index 96723ae83c89..d6e2ee251736 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1080,8 +1080,8 @@ static int fastcall do_path_lookup(int dfd, const char *name,
nd->flags = flags;
nd->depth = 0;
- read_lock(&current->fs->lock);
if (*name=='/') {
+ read_lock(&current->fs->lock);
if (current->fs->altroot && !(nd->flags & LOOKUP_NOALT)) {
nd->mnt = mntget(current->fs->altrootmnt);
nd->dentry = dget(current->fs->altroot);
@@ -1092,33 +1092,35 @@ static int fastcall do_path_lookup(int dfd, const char *name,
}
nd->mnt = mntget(current->fs->rootmnt);
nd->dentry = dget(current->fs->root);
+ read_unlock(&current->fs->lock);
} else if (dfd == AT_FDCWD) {
+ read_lock(&current->fs->lock);
nd->mnt = mntget(current->fs->pwdmnt);
nd->dentry = dget(current->fs->pwd);
+ read_unlock(&current->fs->lock);
} else {
struct dentry *dentry;
file = fget_light(dfd, &fput_needed);
retval = -EBADF;
if (!file)
- goto unlock_fail;
+ goto out_fail;
dentry = file->f_dentry;
retval = -ENOTDIR;
if (!S_ISDIR(dentry->d_inode->i_mode))
- goto fput_unlock_fail;
+ goto fput_fail;
retval = file_permission(file, MAY_EXEC);
if (retval)
- goto fput_unlock_fail;
+ goto fput_fail;
nd->mnt = mntget(file->f_vfsmnt);
nd->dentry = dget(dentry);
fput_light(file, fput_needed);
}
- read_unlock(&current->fs->lock);
current->total_link_count = 0;
retval = link_path_walk(name, nd);
out:
@@ -1127,13 +1129,12 @@ out:
nd->dentry->d_inode))
audit_inode(name, nd->dentry->d_inode, flags);
}
+out_fail:
return retval;
-fput_unlock_fail:
+fput_fail:
fput_light(file, fput_needed);
-unlock_fail:
- read_unlock(&current->fs->lock);
- return retval;
+ goto out_fail;
}
int fastcall path_lookup(const char *name, unsigned int flags,