diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index d5457015801d8be935353826fcb1b4dbf99c56c8..df8d92c7ac1e65b12221ee93a84bfa8c17e5e944 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -663,11 +663,6 @@ cifs_get_root(struct smb_vol *vol, struct super_block *sb) struct inode *dir = d_inode(dentry); struct dentry *child; - if (!dir) { - dput(dentry); - dentry = ERR_PTR(-ENOENT); - break; - } if (!S_ISDIR(dir->i_mode)) { dput(dentry); dentry = ERR_PTR(-ENOTDIR); @@ -684,7 +679,7 @@ cifs_get_root(struct smb_vol *vol, struct super_block *sb) while (*s && *s != sep) s++; - child = lookup_one_len_unlocked(p, dentry, s - p); + child = lookup_positive_unlocked(p, dentry, s - p); dput(dentry); dentry = child; } while (!IS_ERR(dentry)); diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index e5126fad57c5ae2ca18fe1c539f01bc1c1dcc3a6..1dbe6d08111aa00f52dae022764a18ae6c9356f5 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -275,13 +275,9 @@ struct dentry *debugfs_lookup(const char *name, struct dentry *parent) if (!parent) parent = debugfs_mount->mnt_root; - dentry = lookup_one_len_unlocked(name, parent, strlen(name)); + dentry = lookup_positive_unlocked(name, parent, strlen(name)); if (IS_ERR(dentry)) return NULL; - if (!d_really_is_positive(dentry)) { - dput(dentry); - return NULL; - } return dentry; } EXPORT_SYMBOL_GPL(debugfs_lookup); diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c index 0b22c39dad4779dd0c35272b15050d9c839eb417..b2a126a947e31e827d50da2ad53241f78bd6ea85 100644 --- a/fs/kernfs/mount.c +++ b/fs/kernfs/mount.c @@ -212,7 +212,7 @@ struct dentry *kernfs_node_dentry(struct kernfs_node *kn, dput(dentry); return ERR_PTR(-EINVAL); } - dtmp = lookup_one_len_unlocked(kntmp->name, dentry, + dtmp = lookup_positive_unlocked(kntmp->name, dentry, strlen(kntmp->name)); dput(dentry); if (IS_ERR(dtmp)) diff --git a/fs/namei.c b/fs/namei.c index 8ca6faa62f7fdc138e6a90d0d42c6ded9945e008..ced524c56b8ffa8823f076d2c6c7399437c5e110 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2568,6 +2568,26 @@ struct dentry *lookup_one_len_unlocked(const char *name, } EXPORT_SYMBOL(lookup_one_len_unlocked); +/* + * Like lookup_one_len_unlocked(), except that it yields ERR_PTR(-ENOENT) + * on negatives. Returns known positive or ERR_PTR(); that's what + * most of the users want. Note that pinned negative with unlocked parent + * _can_ become positive at any time, so callers of lookup_one_len_unlocked() + * need to be very careful; pinned positives have ->d_inode stable, so + * this one avoids such problems. + */ +struct dentry *lookup_positive_unlocked(const char *name, + struct dentry *base, int len) +{ + struct dentry *ret = lookup_one_len_unlocked(name, base, len); + if (!IS_ERR(ret) && d_is_negative(ret)) { + dput(ret); + ret = ERR_PTR(-ENOENT); + } + return ret; +} +EXPORT_SYMBOL(lookup_positive_unlocked); + #ifdef CONFIG_UNIX98_PTYS int path_pts(struct path *path) { diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c index 83919116d5cbe4455c04c8f9b377b581666a8da6..b551d1b59d83f60dc4d3bfcd482a31ac9e480ec3 100644 --- a/fs/nfsd/nfs3xdr.c +++ b/fs/nfsd/nfs3xdr.c @@ -850,13 +850,11 @@ compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp, } else dchild = dget(dparent); } else - dchild = lookup_one_len_unlocked(name, dparent, namlen); + dchild = lookup_positive_unlocked(name, dparent, namlen); if (IS_ERR(dchild)) return rv; if (d_mountpoint(dchild)) goto out; - if (d_really_is_negative(dchild)) - goto out; if (dchild->d_inode->i_ino != ino) goto out; rv = fh_compose(fhp, exp, dchild, &cd->fh); diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index db0beefe65ec2c0613c4348dd09aabcaa039314c..5bf7c01d1c3e987d43b4782957a3adbb3b298a1c 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -2984,18 +2984,9 @@ nfsd4_encode_dirent_fattr(struct xdr_stream *xdr, struct nfsd4_readdir *cd, __be32 nfserr; int ignore_crossmnt = 0; - dentry = lookup_one_len_unlocked(name, cd->rd_fhp->fh_dentry, namlen); + dentry = lookup_positive_unlocked(name, cd->rd_fhp->fh_dentry, namlen); if (IS_ERR(dentry)) return nfserrno(PTR_ERR(dentry)); - if (d_really_is_negative(dentry)) { - /* - * we're not holding the i_mutex here, so there's - * a window where this directory entry could have gone - * away. - */ - dput(dentry); - return nfserr_noent; - } exp_get(exp); /* diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c index badf039267a2fdb415fdcbb1493dc2db1d4ecd35..e51dc7f16596c5201d74e69598e876b3afc6af3b 100644 --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -203,7 +203,7 @@ static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d, int err; bool last_element = !post[0]; - this = lookup_one_len_unlocked(name, base, namelen); + this = lookup_positive_unlocked(name, base, namelen); if (IS_ERR(this)) { err = PTR_ERR(this); this = NULL; @@ -211,8 +211,6 @@ static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d, goto out; goto out_err; } - if (!this->d_inode) - goto put_and_out; if (ovl_dentry_weird(this)) { /* Don't support traversing automounts and other weirdness */ @@ -654,7 +652,7 @@ struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh) if (err) return ERR_PTR(err); - index = lookup_one_len_unlocked(name.name, ofs->indexdir, name.len); + index = lookup_positive_unlocked(name.name, ofs->indexdir, name.len); kfree(name.name); if (IS_ERR(index)) { if (PTR_ERR(index) == -ENOENT) @@ -662,9 +660,7 @@ struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh) return index; } - if (d_is_negative(index)) - err = 0; - else if (ovl_is_whiteout(index)) + if (ovl_is_whiteout(index)) err = -ESTALE; else if (ovl_dentry_weird(index)) err = -EIO; @@ -688,7 +684,7 @@ struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper, if (err) return ERR_PTR(err); - index = lookup_one_len_unlocked(name.name, ofs->indexdir, name.len); + index = lookup_positive_unlocked(name.name, ofs->indexdir, name.len); if (IS_ERR(index)) { err = PTR_ERR(index); if (err == -ENOENT) { @@ -703,9 +699,7 @@ struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper, } inode = d_inode(index); - if (d_is_negative(index)) { - goto out_dput; - } else if (ovl_is_whiteout(index) && !verify) { + if (ovl_is_whiteout(index) && !verify) { /* * When index lookup is called with !verify for decoding an * overlay file handle, a whiteout index implies that decode @@ -1134,7 +1128,7 @@ bool ovl_lower_positive(struct dentry *dentry) struct dentry *this; struct dentry *lowerdir = poe->lowerstack[i].dentry; - this = lookup_one_len_unlocked(name->name, lowerdir, + this = lookup_positive_unlocked(name->name, lowerdir, name->len); if (IS_ERR(this)) { switch (PTR_ERR(this)) { @@ -1151,10 +1145,8 @@ bool ovl_lower_positive(struct dentry *dentry) break; } } else { - if (this->d_inode) { - positive = !ovl_is_whiteout(this); - done = true; - } + positive = !ovl_is_whiteout(this); + done = true; dput(this); } } diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index 59b00d8db22ca2f6fdd82477bb671a9dc2f47a77..c65ff62c0155adc5ba54766460b24380f727ceed 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -2500,15 +2500,10 @@ int dquot_quota_on_mount(struct super_block *sb, char *qf_name, struct dentry *dentry; int error; - dentry = lookup_one_len_unlocked(qf_name, sb->s_root, strlen(qf_name)); + dentry = lookup_positive_unlocked(qf_name, sb->s_root, strlen(qf_name)); if (IS_ERR(dentry)) return PTR_ERR(dentry); - if (d_really_is_negative(dentry)) { - error = -ENOENT; - goto out; - } - error = security_quota_on(dentry); if (!error) error = vfs_load_quota_inode(d_inode(dentry), type, format_id, diff --git a/include/linux/namei.h b/include/linux/namei.h index a78606e8e3df7c155410da7a366490354fb9dcb6..4632f4ca334263dbff7ac7ba132e770f271a2871 100644 --- a/include/linux/namei.h +++ b/include/linux/namei.h @@ -84,6 +84,7 @@ extern int kern_path_mountpoint(int, const char *, struct path *, unsigned int); extern struct dentry *try_lookup_one_len(const char *, struct dentry *, int); extern struct dentry *lookup_one_len(const char *, struct dentry *, int); extern struct dentry *lookup_one_len_unlocked(const char *, struct dentry *, int); +extern struct dentry *lookup_positive_unlocked(const char *, struct dentry *, int); extern int follow_down_one(struct path *); extern int follow_down(struct path *);