On 04/04/2022 17:41, Filipe Manana wrote:
On Sat, Apr 02, 2022 at 06:25:37PM +0800, Anand Jain wrote:
This set fixes a process hang issue in btrfs and gf2 filesystems. When we do a direct IO read or write when the buffer given by the user is memory-mapped to the file range we are going to do IO, we end up ending in a deadlock. This is triggered by the test case generic/647 from fstests.
This fix depends on the iov_iter and iomap changes introduced in the commit c03098d4b9ad ("Merge tag 'gfs2-v5.15-rc5-mmap-fault' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2") and they are part of this set for stable-5.15.y.
Please note that patch 3/17 in this patchset changes the prototype and renames an exported symbol as below. All its references are updated as well.
-EXPORT_SYMBOL(iov_iter_fault_in_readable); +EXPORT_SYMBOL(fault_in_iov_iter_readable);
Andreas Gruenbacher (15): powerpc/kvm: Fix kvm_use_magic_page gup: Turn fault_in_pages_{readable,writeable} into fault_in_{readable,writeable} iov_iter: Turn iov_iter_fault_in_readable into fault_in_iov_iter_readable iov_iter: Introduce fault_in_iov_iter_writeable gfs2: Add wrapper for iomap_file_buffered_write gfs2: Clean up function may_grant gfs2: Move the inode glock locking to gfs2_file_buffered_write gfs2: Eliminate ip->i_gh gfs2: Fix mmap + page fault deadlocks for buffered I/O iomap: Fix iomap_dio_rw return value for user copies iomap: Support partial direct I/O on user copy failures iomap: Add done_before argument to iomap_dio_rw gup: Introduce FOLL_NOFAULT flag to disable page faults iov_iter: Introduce nofault flag to disable page faults gfs2: Fix mmap + page fault deadlocks for direct I/O
Bob Peterson (1): gfs2: Introduce flag for glock holder auto-demotion
Filipe Manana (1): btrfs: fix deadlock due to page faults during direct IO reads and writes
If this patchset is backported, then at least the following two commits must also be backported:
commit fe673d3f5bf1fc50cdc4b754831db91a2ec10126 Author: Linus Torvalds torvalds@linux-foundation.org Date: Tue Mar 8 11:55:48 2022 -0800
mm: gup: make fault_in_safe_writeable() use fixup_user_fault()commit ca93e44bfb5fd7996b76f0f544999171f647f93b Author: Filipe Manana fdmanana@suse.com Date: Wed Mar 2 11:48:39 2022 +0000
btrfs: fallback to blocking mode when doing async dio over multiple extents
Thanks for pointing it out.
Maybe there's more that need to be backported. So cc'ing Andreas in case he's aware of any such other commits.
I have scanned through the commits. I didn't find any further Fixes for this series.
I am sending these two patches in a new patch set as part2. Instead, if it is better, I am ok to include these and send v2.
Thanks, Anand
arch/powerpc/kernel/kvm.c | 3 +- arch/powerpc/kernel/signal_32.c | 4 +- arch/powerpc/kernel/signal_64.c | 2 +- arch/x86/kernel/fpu/signal.c | 7 +- drivers/gpu/drm/armada/armada_gem.c | 7 +- fs/btrfs/file.c | 142 ++++++++++-- fs/btrfs/ioctl.c | 5 +- fs/erofs/data.c | 2 +- fs/ext4/file.c | 5 +- fs/f2fs/file.c | 2 +- fs/fuse/file.c | 2 +- fs/gfs2/bmap.c | 60 +---- fs/gfs2/file.c | 252 +++++++++++++++++++-- fs/gfs2/glock.c | 330 +++++++++++++++++++++------- fs/gfs2/glock.h | 20 ++ fs/gfs2/incore.h | 4 +- fs/iomap/buffered-io.c | 2 +- fs/iomap/direct-io.c | 29 ++- fs/ntfs/file.c | 2 +- fs/ntfs3/file.c | 2 +- fs/xfs/xfs_file.c | 6 +- fs/zonefs/super.c | 4 +- include/linux/iomap.h | 11 +- include/linux/mm.h | 3 +- include/linux/pagemap.h | 58 +---- include/linux/uio.h | 4 +- lib/iov_iter.c | 98 +++++++-- mm/filemap.c | 4 +- mm/gup.c | 139 +++++++++++- 29 files changed, 911 insertions(+), 298 deletions(-)
-- 2.33.1