diff options
Diffstat (limited to 'target/linux/generic/backport-4.14/500-ubifs-Handle-re-linking-of-inodes-correctly-while-re.patch')
| -rw-r--r-- | target/linux/generic/backport-4.14/500-ubifs-Handle-re-linking-of-inodes-correctly-while-re.patch | 89 |
1 files changed, 0 insertions, 89 deletions
diff --git a/target/linux/generic/backport-4.14/500-ubifs-Handle-re-linking-of-inodes-correctly-while-re.patch b/target/linux/generic/backport-4.14/500-ubifs-Handle-re-linking-of-inodes-correctly-while-re.patch deleted file mode 100644 index 71e036c920..0000000000 --- a/target/linux/generic/backport-4.14/500-ubifs-Handle-re-linking-of-inodes-correctly-while-re.patch +++ /dev/null @@ -1,89 +0,0 @@ -From: Richard Weinberger <richard@nod.at> -Date: Wed, 7 Nov 2018 23:04:43 +0100 -Subject: [PATCH] ubifs: Handle re-linking of inodes correctly while recovery -MIME-Version: 1.0 -Content-Type: text/plain; charset=UTF-8 -Content-Transfer-Encoding: 8bit - -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 -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> -Signed-off-by: Richard Weinberger <richard@nod.at> ---- - fs/ubifs/replay.c | 37 +++++++++++++++++++++++++++++++++++++ - 1 file changed, 37 insertions(+) - ---- a/fs/ubifs/replay.c -+++ b/fs/ubifs/replay.c -@@ -210,6 +210,38 @@ static int trun_remove_range(struct ubif - } - - /** -+ * 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 - * @r: replay entry to apply -@@ -239,6 +271,11 @@ static int apply_replay_entry(struct ubi - { - 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; - } |