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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-13 20:14:13 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-13 20:14:13 -0800 |
| commit | db9effe99adc67c53e6aedadadd2aa9a02342e48 (patch) | |
| tree | efe7ebfe951972568189ef2548130f0abd515210 /fs/namei.c | |
| parent | 9c4bc1c2befbbdce4b9fd526e67a7a2ea143ffa2 (diff) | |
| parent | f20877d94a74557b7c28b4ed8920d834c31e0ea5 (diff) | |
| download | lwn-db9effe99adc67c53e6aedadadd2aa9a02342e48.tar.gz lwn-db9effe99adc67c53e6aedadadd2aa9a02342e48.zip | |
Merge branch 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin
* 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin:
fs: fix do_last error case when need_reval_dot
nfs: add missing rcu-walk check
fs: hlist UP debug fixup
fs: fix dropping of rcu-walk from force_reval_path
fs: force_reval_path drop rcu-walk before d_invalidate
fs: small rcu-walk documentation fixes
Fixed up trivial conflicts in Documentation/filesystems/porting
Diffstat (limited to 'fs/namei.c')
| -rw-r--r-- | fs/namei.c | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/fs/namei.c b/fs/namei.c index 0b14f6910fc6..86643302079e 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -479,6 +479,14 @@ static int nameidata_dentry_drop_rcu(struct nameidata *nd, struct dentry *dentry struct fs_struct *fs = current->fs; struct dentry *parent = nd->path.dentry; + /* + * It can be possible to revalidate the dentry that we started + * the path walk with. force_reval_path may also revalidate the + * dentry already committed to the nameidata. + */ + if (unlikely(parent == dentry)) + return nameidata_drop_rcu(nd); + BUG_ON(!(nd->flags & LOOKUP_RCU)); if (nd->root.mnt) { spin_lock(&fs->lock); @@ -583,6 +591,13 @@ void release_open_intent(struct nameidata *nd) fput(nd->intent.open.file); } +/* + * Call d_revalidate and handle filesystems that request rcu-walk + * to be dropped. This may be called and return in rcu-walk mode, + * regardless of success or error. If -ECHILD is returned, the caller + * must return -ECHILD back up the path walk stack so path walk may + * be restarted in ref-walk mode. + */ static int d_revalidate(struct dentry *dentry, struct nameidata *nd) { int status; @@ -673,6 +688,9 @@ force_reval_path(struct path *path, struct nameidata *nd) return 0; if (!status) { + /* Don't d_invalidate in rcu-walk mode */ + if (nameidata_drop_rcu(nd)) + return -ECHILD; d_invalidate(dentry); status = -ESTALE; } @@ -2105,11 +2123,13 @@ static struct file *do_last(struct nameidata *nd, struct path *path, dir = nd->path.dentry; case LAST_DOT: if (need_reval_dot(dir)) { - error = d_revalidate(nd->path.dentry, nd); - if (!error) - error = -ESTALE; - if (error < 0) + int status = d_revalidate(nd->path.dentry, nd); + if (!status) + status = -ESTALE; + if (status < 0) { + error = status; goto exit; + } } /* fallthrough */ case LAST_ROOT: |