From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
stable@vger.kernel.org,
"Russell Senior" <russell@personaltelco.net>,
"Rafał Miłecki" <zajec5@gmail.com>,
"Rafał Miłecki" <rafal@milecki.pl>,
"Richard Weinberger" <richard@nod.at>,
"Sasha Levin" <sashal@kernel.org>
Subject: [PATCH 4.9 19/22] ubifs: Handle re-linking of inodes correctly while recovery
Date: Fri, 28 Dec 2018 12:52:56 +0100 [thread overview]
Message-ID: <20181228113127.486628766@linuxfoundation.org> (raw)
In-Reply-To: <20181228113126.144310132@linuxfoundation.org>
4.9-stable review patch. If anyone has any objections, please let me know.
------------------
commit e58725d51fa8da9133f3f1c54170aa2e43056b91 upstream.
UBIFS's recovery code strictly assumes that a deleted inode will never
come back, therefore it removes all data which belongs to that inode
as soon it faces an inode with link count 0 in the replay list.
Before O_TMPFILE this assumption was perfectly fine. With O_TMPFILE
it can lead to data loss upon a power-cut.
Consider a journal with entries like:
0: inode X (nlink = 0) /* O_TMPFILE was created */
1: data for inode X /* Someone writes to the temp file */
2: inode X (nlink = 0) /* inode was changed, xattr, chmod, … */
3: inode X (nlink = 1) /* inode was re-linked via linkat() */
Upon replay of entry #2 UBIFS will drop all data that belongs to inode X,
this will lead to an empty file after mounting.
As solution for this problem, scan the replay list for a re-link entry
before dropping data.
Fixes: 474b93704f32 ("ubifs: Implement O_TMPFILE")
Cc: stable@vger.kernel.org # 4.9-4.18
Cc: Russell Senior <russell@personaltelco.net>
Cc: Rafał Miłecki <zajec5@gmail.com>
Reported-by: Russell Senior <russell@personaltelco.net>
Reported-by: Rafał Miłecki <zajec5@gmail.com>
Tested-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Richard Weinberger <richard@nod.at>
[rmilecki: update ubifs_assert() calls to compile with 4.18 and older]
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
(cherry picked from commit e58725d51fa8da9133f3f1c54170aa2e43056b91)
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/ubifs/replay.c | 37 +++++++++++++++++++++++++++++++++++++
1 file changed, 37 insertions(+)
diff --git a/fs/ubifs/replay.c b/fs/ubifs/replay.c
index fb0f44cd1e28..de7799a0a9d1 100644
--- a/fs/ubifs/replay.c
+++ b/fs/ubifs/replay.c
@@ -209,6 +209,38 @@ static int trun_remove_range(struct ubifs_info *c, struct replay_entry *r)
return ubifs_tnc_remove_range(c, &min_key, &max_key);
}
+/**
+ * inode_still_linked - check whether inode in question will be re-linked.
+ * @c: UBIFS file-system description object
+ * @rino: replay entry to test
+ *
+ * O_TMPFILE files can be re-linked, this means link count goes from 0 to 1.
+ * This case needs special care, otherwise all references to the inode will
+ * be removed upon the first replay entry of an inode with link count 0
+ * is found.
+ */
+static bool inode_still_linked(struct ubifs_info *c, struct replay_entry *rino)
+{
+ struct replay_entry *r;
+
+ ubifs_assert(rino->deletion);
+ ubifs_assert(key_type(c, &rino->key) == UBIFS_INO_KEY);
+
+ /*
+ * Find the most recent entry for the inode behind @rino and check
+ * whether it is a deletion.
+ */
+ list_for_each_entry_reverse(r, &c->replay_list, list) {
+ ubifs_assert(r->sqnum >= rino->sqnum);
+ if (key_inum(c, &r->key) == key_inum(c, &rino->key))
+ return r->deletion == 0;
+
+ }
+
+ ubifs_assert(0);
+ return false;
+}
+
/**
* apply_replay_entry - apply a replay entry to the TNC.
* @c: UBIFS file-system description object
@@ -239,6 +271,11 @@ static int apply_replay_entry(struct ubifs_info *c, struct replay_entry *r)
{
ino_t inum = key_inum(c, &r->key);
+ if (inode_still_linked(c, r)) {
+ err = 0;
+ break;
+ }
+
err = ubifs_tnc_remove_ino(c, inum);
break;
}
--
2.19.1
next prev parent reply other threads:[~2018-12-28 12:17 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-28 11:52 [PATCH 4.9 00/22] 4.9.148-stable review Greg Kroah-Hartman
2018-12-28 11:52 ` [PATCH 4.9 01/22] block: break discard submissions into the user defined size Greg Kroah-Hartman
2018-12-28 11:52 ` [PATCH 4.9 02/22] block: fix infinite loop if the device loses discard capability Greg Kroah-Hartman
2018-12-28 11:52 ` [PATCH 4.9 03/22] ib_srpt: Fix a use-after-free in __srpt_close_all_ch() Greg Kroah-Hartman
2018-12-28 11:52 ` [PATCH 4.9 04/22] USB: hso: Fix OOB memory access in hso_probe/hso_get_config_data Greg Kroah-Hartman
2018-12-28 11:52 ` [PATCH 4.9 05/22] xhci: Dont prevent USB2 bus suspend in state check intended for USB3 only Greg Kroah-Hartman
2018-12-28 11:52 ` [PATCH 4.9 06/22] USB: serial: option: add GosunCn ZTE WeLink ME3630 Greg Kroah-Hartman
2018-12-28 11:52 ` [PATCH 4.9 07/22] USB: serial: option: add HP lt4132 Greg Kroah-Hartman
2018-12-28 11:52 ` [PATCH 4.9 08/22] USB: serial: option: add Simcom SIM7500/SIM7600 (MBIM mode) Greg Kroah-Hartman
2018-12-28 11:52 ` [PATCH 4.9 09/22] USB: serial: option: add Fibocom NL668 series Greg Kroah-Hartman
2018-12-28 11:52 ` [PATCH 4.9 10/22] USB: serial: option: add Telit LN940 series Greg Kroah-Hartman
2018-12-28 11:52 ` [PATCH 4.9 11/22] mmc: core: Reset HPI enabled state during re-init and in case of errors Greg Kroah-Hartman
2018-12-28 11:52 ` [PATCH 4.9 12/22] mmc: core: Allow BKOPS and CACHE ctrl even if no HPI support Greg Kroah-Hartman
2018-12-28 11:52 ` [PATCH 4.9 13/22] mmc: core: Use a minimum 1600ms timeout when enabling CACHE ctrl Greg Kroah-Hartman
2018-12-28 11:52 ` [PATCH 4.9 14/22] mmc: omap_hsmmc: fix DMA API warning Greg Kroah-Hartman
2018-12-28 11:52 ` [PATCH 4.9 15/22] gpio: max7301: fix driver for use with CONFIG_VMAP_STACK Greg Kroah-Hartman
2018-12-28 11:52 ` [PATCH 4.9 16/22] Drivers: hv: vmbus: Return -EINVAL for the sys files for unopened channels Greg Kroah-Hartman
2018-12-28 11:52 ` [PATCH 4.9 17/22] x86/mtrr: Dont copy uninitialized gentry fields back to userspace Greg Kroah-Hartman
2018-12-28 11:52 ` [PATCH 4.9 18/22] x86/fpu: Disable bottom halves while loading FPU registers Greg Kroah-Hartman
2020-07-24 17:07 ` Jan Kiszka
2020-07-24 17:44 ` Greg Kroah-Hartman
2020-07-24 18:12 ` Sasha Levin
2018-12-28 11:52 ` Greg Kroah-Hartman [this message]
2018-12-28 11:52 ` [PATCH 4.9 20/22] panic: avoid deadlocks in re-entrant console drivers Greg Kroah-Hartman
2018-12-28 11:52 ` [PATCH 4.9 21/22] proc/sysctl: dont return ENOMEM on lookup when a table is unregistering Greg Kroah-Hartman
2018-12-28 11:52 ` [PATCH 4.9 22/22] drm/ioctl: Fix Spectre v1 vulnerabilities Greg Kroah-Hartman
2018-12-28 18:12 ` [PATCH 4.9 00/22] 4.9.148-stable review Dan Rue
2018-12-28 20:10 ` shuah
2018-12-28 21:27 ` Guenter Roeck
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=20181228113127.486628766@linuxfoundation.org \
--to=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=rafal@milecki.pl \
--cc=richard@nod.at \
--cc=russell@personaltelco.net \
--cc=sashal@kernel.org \
--cc=stable@vger.kernel.org \
--cc=zajec5@gmail.com \
/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).