diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2016-03-06 14:20:52 -0500 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2016-03-14 00:15:46 -0400 |
| commit | 949a852e46dda07caaa0ff02e181f55d24e3ebf8 (patch) | |
| tree | 7f2d5177638fb4fd6257a2e2571a3c556de08ce9 | |
| parent | e3c13928086f1ed3620329b9fff678df2294d327 (diff) | |
| download | linux-stable-949a852e46dda07caaa0ff02e181f55d24e3ebf8.tar.gz linux-stable-949a852e46dda07caaa0ff02e181f55d24e3ebf8.tar.bz2 linux-stable-949a852e46dda07caaa0ff02e181f55d24e3ebf8.zip | |
namei: teach lookup_slow() to skip revalidate
... and make mountpoint_last() use it. That makes all
candidates for lookup with parent locked shared go
through lookup_slow().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | fs/namei.c | 58 | ||||
| -rw-r--r-- | include/linux/namei.h | 1 |
2 files changed, 36 insertions, 23 deletions
diff --git a/fs/namei.c b/fs/namei.c index cb70a817d439..dbb8ec1a2006 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1605,7 +1605,29 @@ static struct dentry *lookup_slow(const struct qstr *name, { struct dentry *dentry; inode_lock(dir->d_inode); - dentry = __lookup_hash(name, dir, flags); + dentry = d_lookup(dir, name); + if (unlikely(dentry)) { + if ((dentry->d_flags & DCACHE_OP_REVALIDATE) && + !(flags & LOOKUP_NO_REVAL)) { + int error = d_revalidate(dentry, flags); + if (unlikely(error <= 0)) { + if (!error) + d_invalidate(dentry); + dput(dentry); + dentry = ERR_PTR(error); + } + } + if (dentry) { + inode_unlock(dir->d_inode); + return dentry; + } + } + dentry = d_alloc(dir, name); + if (unlikely(!dentry)) { + inode_unlock(dir->d_inode); + return ERR_PTR(-ENOMEM); + } + dentry = lookup_real(dir->d_inode, dentry, flags); inode_unlock(dir->d_inode); return dentry; } @@ -2425,31 +2447,21 @@ mountpoint_last(struct nameidata *nd, struct path *path) if (error) return error; dentry = dget(nd->path.dentry); - goto done; - } - - inode_lock(dir->d_inode); - dentry = d_lookup(dir, &nd->last); - if (!dentry) { - /* - * No cached dentry. Mounted dentries are pinned in the cache, - * so that means that this dentry is probably a symlink or the - * path doesn't actually point to a mounted dentry. - */ - dentry = d_alloc(dir, &nd->last); + } else { + dentry = d_lookup(dir, &nd->last); if (!dentry) { - inode_unlock(dir->d_inode); - return -ENOMEM; - } - dentry = lookup_real(dir->d_inode, dentry, nd->flags); - if (IS_ERR(dentry)) { - inode_unlock(dir->d_inode); - return PTR_ERR(dentry); + /* + * No cached dentry. Mounted dentries are pinned in the + * cache, so that means that this dentry is probably + * a symlink or the path doesn't actually point + * to a mounted dentry. + */ + dentry = lookup_slow(&nd->last, dir, + nd->flags | LOOKUP_NO_REVAL); + if (IS_ERR(dentry)) + return PTR_ERR(dentry); } } - inode_unlock(dir->d_inode); - -done: if (d_is_negative(dentry)) { dput(dentry); return -ENOENT; diff --git a/include/linux/namei.h b/include/linux/namei.h index d0f25d81b46a..77d01700daf7 100644 --- a/include/linux/namei.h +++ b/include/linux/namei.h @@ -31,6 +31,7 @@ enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND}; #define LOOKUP_PARENT 0x0010 #define LOOKUP_REVAL 0x0020 #define LOOKUP_RCU 0x0040 +#define LOOKUP_NO_REVAL 0x0080 /* * Intent data |