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
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(-)