kernel.git/fs/ext4/mmp.c, branch linux-6.7.y

ext4: replace read-only check for shutdown check in mmp code

2023-07-29T22:37:53Z

The multi-mount protection kthread checks for read-only filesystem and aborts in that case. The remount code actually handles stopping of the kthread on remount so the only purpose of the check is in case of emergency remount read-only. Replace the check for read-only filesystem with a check for shutdown filesystem as running MMP on such is risky anyway and it makes ordering of things during remount simpler. Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20230616165109.21695-11-jack@suse.cz Signed-off-by: Theodore Ts'o

ext4: fix lockdep warning when enabling MMP

2023-05-08T01:11:18Z

When we enable MMP in ext4_multi_mount_protect() during mount or remount, we end up calling sb_start_write() from write_mmp_block(). This triggers lockdep warning because freeze protection ranks above s_umount semaphore we are holding during mount / remount. The problem is harmless because we are guaranteed the filesystem is not frozen during mount / remount but still let's fix the warning by not grabbing freeze protection from ext4_multi_mount_protect(). Cc: stable@kernel.org Reported-by: syzbot+6b7df7d5506b32467149@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=ab7e5b6f400b7778d46f01841422e5718fb81843 Signed-off-by: Jan Kara Reviewed-by: Christian Brauner Link: https://lore.kernel.org/r/20230411121019.21940-1-jack@suse.cz Signed-off-by: Theodore Ts'o

ext4: reflect error codes from ext4_multi_mount_protect() to its callers

2023-04-28T16:56:40Z

This will allow more fine-grained errno codes to be returned by the mount system call. Cc: Andreas Dilger Signed-off-by: Theodore Ts'o

treewide: use get_random_u32_{above,below}() instead of manual loop

2022-11-18T01:15:22Z

These cases were done with this Coccinelle: @@ expression E; identifier I; @@ - do { ... when != I - I = get_random_u32(); ... when != I - } while (I > E); + I = get_random_u32_below(E + 1); @@ expression E; identifier I; @@ - do { ... when != I - I = get_random_u32(); ... when != I - } while (I >= E); + I = get_random_u32_below(E); @@ expression E; identifier I; @@ - do { ... when != I - I = get_random_u32(); ... when != I - } while (I < E); + I = get_random_u32_above(E - 1); @@ expression E; identifier I; @@ - do { ... when != I - I = get_random_u32(); ... when != I - } while (I <= E); + I = get_random_u32_above(E); @@ identifier I; @@ - do { ... when != I - I = get_random_u32(); ... when != I - } while (!I); + I = get_random_u32_above(0); @@ identifier I; @@ - do { ... when != I - I = get_random_u32(); ... when != I - } while (I == 0); + I = get_random_u32_above(0); @@ expression E; @@ - E + 1 + get_random_u32_below(U32_MAX - E) + get_random_u32_above(E) Reviewed-by: Kees Cook Reviewed-by: Greg Kroah-Hartman Signed-off-by: Jason A. Donenfeld

treewide: use get_random_u32() when possible

2022-10-11T23:42:58Z

The prandom_u32() function has been a deprecated inline wrapper around get_random_u32() for several releases now, and compiles down to the exact same code. Replace the deprecated wrapper with a direct call to the real function. The same also applies to get_random_int(), which is just a wrapper around get_random_u32(). This was done as a basic find and replace. Reviewed-by: Greg Kroah-Hartman Reviewed-by: Kees Cook Reviewed-by: Yury Norov Reviewed-by: Jan Kara # for ext4 Acked-by: Toke Høiland-Jørgensen # for sch_cake Acked-by: Chuck Lever # for nfsd Acked-by: Jakub Kicinski Acked-by: Mika Westerberg # for thunderbolt Acked-by: Darrick J. Wong # for xfs Acked-by: Helge Deller # for parisc Acked-by: Heiko Carstens # for s390 Signed-off-by: Jason A. Donenfeld

fs/buffer: Combine two submit_bh() and ll_rw_block() arguments

2022-07-14T18:14:32Z

Both submit_bh() and ll_rw_block() accept a request operation type and request flags as their first two arguments. Micro-optimize these two functions by combining these first two arguments into a single argument. This patch does not change the behavior of any of the modified code. Cc: Alexander Viro Cc: Jan Kara Acked-by: Song Liu (for the md changes) Signed-off-by: Bart Van Assche Link: https://lore.kernel.org/r/20220714180729.1065367-48-bvanassche@acm.org Signed-off-by: Jens Axboe

block: remove bdevname

2022-07-14T16:27:56Z

Replace the remaining calls of bdevname with snprintf using the %pg format specifier. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Chaitanya Kulkarni Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20220713055317.1888500-10-hch@lst.de Signed-off-by: Jens Axboe

ext4: only initialize mmp_bdevname once

2022-07-14T16:27:56Z

mmp_bdevname is currently both initialized nested inside the kthread_run call in ext4_multi_mount_protect and in the kmmpd thread started by it. Lift the initiaization out of the kthread_run call in ext4_multi_mount_protect, move the BUILD_BUG_ON next to it and remove the duplicate assignment inside of kmmpd. Signed-off-by: Christoph Hellwig Acked-by: Theodore Ts'o Reviewed-by: Jan Kara Reviewed-by: Chaitanya Kulkarni Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20220713055317.1888500-9-hch@lst.de Signed-off-by: Jens Axboe

ext4: remove unnecessary type castings

2022-05-11T19:19:06Z

remove unnecessary void* type castings. Signed-off-by: Yu Zhe Link: https://lore.kernel.org/r/20220401081321.73735-1-yuzhe@nfschina.com Signed-off-by: Theodore Ts'o

ext4: fix potential uninitialized access to retval in kmmpd

2021-07-23T11:31:29Z

if (!ext4_has_feature_mmp(sb)) then retval can be unitialized before we jump to the wait_to_exit label. Fixes: 61bb4a1c417e ("ext4: fix possible UAF when remounting r/o a mmp-protected file system") Signed-off-by: Ye Bin Link: https://lore.kernel.org/r/20210713022728.2533770-1-yebin10@huawei.com Signed-off-by: Theodore Ts'o