linux-fsdevel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	Miklos Szeredi <mszeredi@redhat.com>
Subject: [RFC][PATCH 40/42] make path_init() unconditionally paired with terminate_walk()
Date: Wed, 11 Jul 2018 03:22:04 +0100	[thread overview]
Message-ID: <20180711022206.12571-40-viro@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20180711022206.12571-1-viro@ZenIV.linux.org.uk>

From: Al Viro <viro@zeniv.linux.org.uk>

including the failure exits

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/namei.c | 32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index ca3f4dec8cda..a9a2a8ac8b9d 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2125,12 +2125,15 @@ static int link_path_walk(const char *name, struct nameidata *nd)
 	}
 }
 
+/* must be paired with terminate_walk() */
 static const char *path_init(struct nameidata *nd, unsigned flags)
 {
 	const char *s = nd->name->name;
 
 	if (!*s)
 		flags &= ~LOOKUP_RCU;
+	if (flags & LOOKUP_RCU)
+		rcu_read_lock();
 
 	nd->last_type = LAST_ROOT; /* if there are only slashes... */
 	nd->flags = flags | LOOKUP_JUMPED | LOOKUP_PARENT;
@@ -2143,7 +2146,6 @@ static const char *path_init(struct nameidata *nd, unsigned flags)
 		nd->path = nd->root;
 		nd->inode = inode;
 		if (flags & LOOKUP_RCU) {
-			rcu_read_lock();
 			nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);
 			nd->root_seq = nd->seq;
 			nd->m_seq = read_seqbegin(&mount_lock);
@@ -2159,21 +2161,15 @@ static const char *path_init(struct nameidata *nd, unsigned flags)
 
 	nd->m_seq = read_seqbegin(&mount_lock);
 	if (*s == '/') {
-		if (flags & LOOKUP_RCU)
-			rcu_read_lock();
 		set_root(nd);
 		if (likely(!nd_jump_root(nd)))
 			return s;
-		nd->root.mnt = NULL;
-		rcu_read_unlock();
 		return ERR_PTR(-ECHILD);
 	} else if (nd->dfd == AT_FDCWD) {
 		if (flags & LOOKUP_RCU) {
 			struct fs_struct *fs = current->fs;
 			unsigned seq;
 
-			rcu_read_lock();
-
 			do {
 				seq = read_seqcount_begin(&fs->seq);
 				nd->path = fs->pwd;
@@ -2195,16 +2191,13 @@ static const char *path_init(struct nameidata *nd, unsigned flags)
 
 		dentry = f.file->f_path.dentry;
 
-		if (*s) {
-			if (!d_can_lookup(dentry)) {
-				fdput(f);
-				return ERR_PTR(-ENOTDIR);
-			}
+		if (*s && unlikely(!d_can_lookup(dentry))) {
+			fdput(f);
+			return ERR_PTR(-ENOTDIR);
 		}
 
 		nd->path = f.file->f_path;
 		if (flags & LOOKUP_RCU) {
-			rcu_read_lock();
 			nd->inode = nd->path.dentry->d_inode;
 			nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
 		} else {
@@ -2272,8 +2265,10 @@ static int path_lookupat(struct nameidata *nd, unsigned flags, struct path *path
 	const char *s = path_init(nd, flags);
 	int err;
 
-	if (IS_ERR(s))
+	if (IS_ERR(s)) {
+		terminate_walk(nd);
 		return PTR_ERR(s);
+	}
 
 	if (unlikely(flags & LOOKUP_DOWN)) {
 		err = handle_lookup_down(nd);
@@ -2337,8 +2332,10 @@ static int path_parentat(struct nameidata *nd, unsigned flags,
 {
 	const char *s = path_init(nd, flags);
 	int err;
-	if (IS_ERR(s))
+	if (IS_ERR(s)) {
+		terminate_walk(nd);
 		return PTR_ERR(s);
+	}
 	err = link_path_walk(s, nd);
 	if (!err)
 		err = complete_walk(nd);
@@ -2666,8 +2663,10 @@ path_mountpoint(struct nameidata *nd, unsigned flags, struct path *path)
 {
 	const char *s = path_init(nd, flags);
 	int err;
-	if (IS_ERR(s))
+	if (IS_ERR(s)) {
+		terminate_walk(nd);
 		return PTR_ERR(s);
+	}
 	while (!(err = link_path_walk(s, nd)) &&
 		(err = mountpoint_last(nd)) > 0) {
 		s = trailing_symlink(nd);
@@ -3514,6 +3513,7 @@ static struct file *path_openat(struct nameidata *nd,
 
 	s = path_init(nd, flags);
 	if (IS_ERR(s)) {
+		terminate_walk(nd);
 		fput(file);
 		return ERR_CAST(s);
 	}
-- 
2.11.0

  parent reply	other threads:[~2018-07-11  2:22 UTC|newest]

Thread overview: 77+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20180710101736.32d6cc6c@canb.auug.org.au>
     [not found] ` <20180710150455.GK30522@ZenIV.linux.org.uk>
2018-07-11  2:11   ` linux-next: manual merge of the vfs tree with the overlayfs tree Al Viro
2018-07-11  2:21     ` [RFC][PATCH 01/42] drm_mode_create_lease_ioctl(): fix open-coded filp_clone_open() Al Viro
2018-07-11  2:21       ` [RFC][PATCH 02/42] cxl_getfile(): fix double-iput() on alloc_file() failures Al Viro
2018-07-11  2:21       ` [RFC][PATCH 03/42] ocxlflash_getfile(): " Al Viro
2018-07-11  2:21       ` [RFC][PATCH 04/42] make get_empty_filp() to call file_free_rcu() directly Al Viro
2018-07-11  2:35         ` Linus Torvalds
2018-07-11  2:43           ` Al Viro
2018-07-11  2:21       ` [RFC][PATCH 05/42] fold security_file_free() into file_free() Al Viro
2018-07-11  2:21       ` [RFC][PATCH 06/42] turn filp_clone_open() into inline wrapper for dentry_open() Al Viro
2018-07-11  2:21       ` [RFC][PATCH 07/42] create_pipe_files(): use fput() if allocation of the second file fails Al Viro
2018-07-11  2:21       ` [RFC][PATCH 08/42] make sure do_dentry_open() won't return positive as an error Al Viro
2018-07-11  2:39         ` Linus Torvalds
2018-07-11  2:41           ` Al Viro
2018-07-11  2:21       ` [RFC][PATCH 09/42] pass creds to get_empty_filp(), make sure dentry_open() passes the right creds Al Viro
2018-07-11  2:21       ` [RFC][PATCH 10/42] get rid of cred argument of vfs_open() and do_dentry_open() Al Viro
2018-07-11  2:21       ` [RFC][PATCH 11/42] security_file_open(): lose cred argument Al Viro
2018-07-11  2:21       ` [RFC][PATCH 12/42] ->file_open(): " Al Viro
2018-07-11  2:21       ` [RFC][PATCH 13/42] introduce FMODE_OPENED Al Viro
2018-07-11  2:21       ` [RFC][PATCH 14/42] fold put_filp() into fput() Al Viro
2018-07-11  2:21       ` [RFC][PATCH 15/42] lift fput() on late failures into path_openat() Al Viro
2018-07-11  5:43         ` Amir Goldstein
2018-07-11  2:21       ` [RFC][PATCH 16/42] now we can fold open_check_o_direct() into do_dentry_open() Al Viro
2018-07-11  2:44         ` Linus Torvalds
2018-07-11  2:59           ` Al Viro
2018-07-11  3:13             ` Linus Torvalds
2018-07-11  2:21       ` [RFC][PATCH 17/42] switch all remaining checks for FILE_OPENED to FMODE_OPENED Al Viro
2018-07-11  2:21       ` [RFC][PATCH 18/42] introduce FMODE_CREATED and switch to it Al Viro
2018-07-11  2:21       ` [RFC][PATCH 19/42] IMA: don't propagate opened through the entire thing Al Viro
2018-07-11  2:21       ` [RFC][PATCH 20/42] getting rid of 'opened' argument of ->atomic_open() - step 1 Al Viro
2018-07-11  2:21       ` [RFC][PATCH 21/42] getting rid of 'opened' argument of ->atomic_open() - part 2 Al Viro
2018-07-11  2:21       ` [RFC][PATCH 22/42] get rid of 'opened' argument of ->atomic_open() - part 3 Al Viro
2018-07-11  2:21       ` [RFC][PATCH 23/42] get rid of 'opened' in path_openat() and the helpers downstream Al Viro
2018-07-11  2:21       ` [RFC][PATCH 24/42] ->atomic_open(): return 0 in all success cases Al Viro
2018-07-11  2:21       ` [RFC][PATCH 25/42] document ->atomic_open() changes Al Viro
2018-07-11  2:21       ` [RFC][PATCH 26/42] switch atomic_open() and lookup_open() to returning 0 in all success cases Al Viro
2018-07-11  2:21       ` [RFC][PATCH 27/42] kill FILE_{CREATED,OPENED} Al Viro
2018-07-11  2:21       ` [RFC][PATCH 28/42] new wrapper: alloc_file_pseudo() Al Viro
2018-07-11  2:21       ` [RFC][PATCH 29/42] __shmem_file_setup(): reorder allocations Al Viro
2018-07-11  2:21       ` [RFC][PATCH 30/42] ... and switch shmem_file_setup() to alloc_file_pseudo() Al Viro
2018-07-11  2:21       ` [RFC][PATCH 31/42] cxl_getfile(): switch " Al Viro
2018-07-11  2:21       ` [RFC][PATCH 32/42] ocxlflash_getfile(): " Al Viro
2018-07-11  2:21       ` [RFC][PATCH 33/42] hugetlb_file_setup(): " Al Viro
2018-07-11  2:21       ` [RFC][PATCH 34/42] anon_inode_getfile(): " Al Viro
2018-07-11  2:21       ` [RFC][PATCH 35/42] create_pipe_files(): switch the first allocation " Al Viro
2018-07-11  2:22       ` [RFC][PATCH 36/42] new helper: alloc_file_clone() Al Viro
2018-07-11  2:22       ` [RFC][PATCH 37/42] do_shmat(): grab shp->shm_file earlier, switch to alloc_file_clone() Al Viro
2018-07-11  2:22       ` [RFC][PATCH 38/42] make alloc_file() static Al Viro
2018-07-11  2:22       ` [RFC][PATCH 39/42] document alloc_file() changes Al Viro
2018-07-11  2:22       ` Al Viro [this message]
2018-07-11  2:22       ` [RFC][PATCH 41/42] allow link_path_walk() to take ERR_PTR() Al Viro
2018-07-11  2:22       ` [RFC][PATCH 42/42] few more cleanups of link_path_walk() callers Al Viro
2018-07-11  2:56       ` [RFC][PATCH 01/42] drm_mode_create_lease_ioctl(): fix open-coded filp_clone_open() Linus Torvalds
2018-07-11 15:25         ` Al Viro
2018-07-11 16:15           ` Al Viro
2018-07-12 12:43             ` Al Viro
2018-07-12 15:05               ` Linus Torvalds
2018-07-12 15:53                 ` vfs / overlayfs conflict resolution for linux-next Al Viro
2018-07-18  2:56                   ` Al Viro
2018-07-18  3:29                     ` Stephen Rothwell
2018-07-18  7:25                       ` Miklos Szeredi
2018-07-18 12:10                         ` Miklos Szeredi
2018-07-18 12:43                           ` Al Viro
2018-07-18 13:46                             ` Al Viro
2018-07-18 15:46                             ` Miklos Szeredi
2018-07-18 18:12                               ` [RFC] call_with_creds() Al Viro
2018-07-18 18:19                                 ` Linus Torvalds
2018-07-18 19:46                                   ` Al Viro
2018-07-18 19:53                                     ` Linus Torvalds
2018-07-18 20:04                                       ` Al Viro
2018-07-18 20:15                                         ` Al Viro
2018-07-18 20:43                                         ` Linus Torvalds
2018-07-18 21:22                                           ` Al Viro
2018-07-18 23:06                                             ` Linus Torvalds
2018-07-18 21:27                                         ` David Howells
2018-07-18 23:16                                           ` Linus Torvalds
2018-07-18 21:28                                 ` David Howells
2018-07-18 23:13                                   ` Linus Torvalds

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180711022206.12571-40-viro@ZenIV.linux.org.uk \
    --to=viro@zeniv.linux.org.uk \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mszeredi@redhat.com \
    --cc=torvalds@linux-foundation.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).