From 2680d722bf2c5f75225dd9acb3ec9e5a9e2652f4 Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Fri, 17 Sep 2010 16:44:28 +0300 Subject: UBIFS: introduce new flag for RO due to errors The R/O state may have various reasons: 1. The UBI volume is R/O 2. The FS is mounted R/O 3. The FS switched to R/O mode because of an error However, in UBIFS we have only one variable which represents cases 1 and 3 - 'c->ro_media'. Indeed, we set this to 1 if we switch to R/O mode due to an error, and then we test it in many places to make sure that we stop writing as soon as the error happens. But this is very unclean. One consequence of this, for example, is that in 'ubifs_remount_fs()' we use 'c->ro_media' to check whether we are in R/O mode because on an error, and we print a message in this case. However, if we are in R/O mode because the media is R/O, our message is bogus. This patch introduces new flag - 'c->ro_error' which is set when we switch to R/O mode because of an error. It also changes all "if (c->ro_media)" checks to "if (c->ro_error)" checks, because this is what the checks actually mean. We do not need to check for 'c->ro_media' because if the UBI volume is in R/O mode, we do not allow R/W mounting, and now writes can happen. This is guaranteed by VFS. But it is good to double-check this, so this patch also adds many "ubifs_assert(!c->ro_media)" checks. In the 'ubifs_remount_fs()' function this patch makes a bit more changes - it fixes the error messages as well. Signed-off-by: Artem Bityutskiy --- fs/ubifs/journal.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'fs/ubifs/journal.c') diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c index d321baeca68d..a6da8aa68f37 100644 --- a/fs/ubifs/journal.c +++ b/fs/ubifs/journal.c @@ -122,11 +122,12 @@ static int reserve_space(struct ubifs_info *c, int jhead, int len) * better to try to allocate space at the ends of eraseblocks. This is * what the squeeze parameter does. */ + ubifs_assert(!c->ro_media); squeeze = (jhead == BASEHD); again: mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); - if (c->ro_media) { + if (c->ro_error) { err = -EROFS; goto out_unlock; } -- cgit v1.2.3 From 2ef13294d29bcfb306e0d360f1b97f37b647b0c0 Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Sun, 19 Sep 2010 18:34:26 +0300 Subject: UBIFS: introduce new flags for RO mounts Commit 2fde99cb55fb9d9b88180512a5e8a5d939d27fec "UBIFS: mark VFS SB RO too" introduced regression. This commit made UBIFS set the 'MS_RDONLY' flag in the VFS superblock when it switches to R/O mode due to an error. This was done to make VFS show the R/O UBIFS flag in /proc/mounts. However, several places in UBIFS relied on the 'MS_RDONLY' flag and assume this flag can only change when we re-mount. For example, 'ubifs_put_super()'. This patch introduces new UBIFS flag - 'c->ro_mount' which changes only when we re-mount, and preserves the way UBIFS was originally mounted (R/W or R/O). This allows us to de-initialize UBIFS cleanly in 'ubifs_put_super()'. This patch also changes all 'ubifs_assert(!c->ro_media)' assertions to 'ubifs_assert(!c->ro_media && !c->ro_mount)', because we never should write anything if the FS was mounter R/O. All the places where we test for 'MS_RDONLY' flag in the VFS SB were changed and now we test the 'c->ro_mount' flag instead, because it preserves the original UBIFS mount type, unlike the 'MS_RDONLY' flag. Signed-off-by: Artem Bityutskiy --- fs/ubifs/journal.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/ubifs/journal.c') diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c index a6da8aa68f37..914f1bd89e57 100644 --- a/fs/ubifs/journal.c +++ b/fs/ubifs/journal.c @@ -122,7 +122,7 @@ static int reserve_space(struct ubifs_info *c, int jhead, int len) * better to try to allocate space at the ends of eraseblocks. This is * what the squeeze parameter does. */ - ubifs_assert(!c->ro_media); + ubifs_assert(!c->ro_media && !c->ro_mount); squeeze = (jhead == BASEHD); again: mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); -- cgit v1.2.3