diff options
| author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2006-06-04 02:51:37 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-06-05 12:29:16 -0700 |
| commit | 6d09bb627d2470299dfb1af0e6d27fb4aece9196 (patch) | |
| tree | ce62b91f11c5df5fbee41aa053b33add79c2c37a /fs | |
| parent | c7d2d28b9851d0ffc9924b0e36bac806d18ebf25 (diff) | |
[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>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/namei.c | 19 |
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(¤t->fs->lock); if (*name=='/') { + read_lock(¤t->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(¤t->fs->lock); } else if (dfd == AT_FDCWD) { + read_lock(¤t->fs->lock); nd->mnt = mntget(current->fs->pwdmnt); nd->dentry = dget(current->fs->pwd); + read_unlock(¤t->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(¤t->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(¤t->fs->lock); - return retval; + goto out_fail; } int fastcall path_lookup(const char *name, unsigned int flags, |