diff options
Diffstat (limited to 'fs/namei.c')
| -rw-r--r-- | fs/namei.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/fs/namei.c b/fs/namei.c index 14ab8d3f2f0..5ba42c453e3 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1134,6 +1134,30 @@ static struct dentry *d_alloc_and_lookup(struct dentry *parent, } /* + * We already have a dentry, but require a lookup to be performed on the parent + * directory to fill in d_inode. Returns the new dentry, or ERR_PTR on error. + * parent->d_inode->i_mutex must be held. d_lookup must have verified that no + * child exists while under i_mutex. + */ +static struct dentry *d_inode_lookup(struct dentry *parent, struct dentry *dentry, + struct nameidata *nd) +{ + struct inode *inode = parent->d_inode; + struct dentry *old; + + /* Don't create child dentry for a dead directory. */ + if (unlikely(IS_DEADDIR(inode))) + return ERR_PTR(-ENOENT); + + old = inode->i_op->lookup(inode, dentry, nd); + if (unlikely(old)) { + dput(dentry); + dentry = old; + } + return dentry; +} + +/* * It's more convoluted than I'd like it to be, but... it's still fairly * small and for now I'd prefer to have fast path as straight as possible. * It _is_ time-critical. @@ -1172,6 +1196,8 @@ static int do_lookup(struct nameidata *nd, struct qstr *name, goto unlazy; } } + if (unlikely(d_need_lookup(dentry))) + goto unlazy; path->mnt = mnt; path->dentry = dentry; if (unlikely(!__follow_mount_rcu(nd, path, inode))) @@ -1186,6 +1212,10 @@ unlazy: dentry = __d_lookup(parent, name); } + if (dentry && unlikely(d_need_lookup(dentry))) { + dput(dentry); + dentry = NULL; + } retry: if (unlikely(!dentry)) { struct inode *dir = parent->d_inode; @@ -1202,6 +1232,15 @@ retry: /* known good */ need_reval = 0; status = 1; + } else if (unlikely(d_need_lookup(dentry))) { + dentry = d_inode_lookup(parent, dentry, nd); + if (IS_ERR(dentry)) { + mutex_unlock(&dir->i_mutex); + return PTR_ERR(dentry); + } + /* known good */ + need_reval = 0; + status = 1; } mutex_unlock(&dir->i_mutex); } @@ -1683,6 +1722,16 @@ static struct dentry *__lookup_hash(struct qstr *name, */ dentry = d_lookup(base, name); + if (dentry && d_need_lookup(dentry)) { + /* + * __lookup_hash is called with the parent dir's i_mutex already + * held, so we are good to go here. + */ + dentry = d_inode_lookup(base, dentry, nd); + if (IS_ERR(dentry)) + return dentry; + } + if (dentry && (dentry->d_flags & DCACHE_OP_REVALIDATE)) dentry = do_revalidate(dentry, nd); |