6.6-stable review patch. If anyone has any objections, please let me know.
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From: Naohiro Aota naohiro.aota@wdc.com
commit 776a838f1fa95670c1c1cf7109a898090b473fa3 upstream.
Running the fio command below on a ZNS device results in "Resource temporarily unavailable" error.
$ sudo fio --name=w --directory=/mnt --filesize=1GB --bs=16MB --numjobs=16 \ --rw=write --ioengine=libaio --iodepth=128 --direct=1
fio: io_u error on file /mnt/w.2.0: Resource temporarily unavailable: write offset=117440512, buflen=16777216 fio: io_u error on file /mnt/w.2.0: Resource temporarily unavailable: write offset=134217728, buflen=16777216 ...
This happens because -EAGAIN error returned from btrfs_reserve_extent() called from btrfs_new_extent_direct() is spilling over to the userland.
btrfs_reserve_extent() returns -EAGAIN when there is no active zone available. Then, the caller should wait for some other on-going IO to finish a zone and retry the allocation.
This logic is already implemented for buffered write in cow_file_range(), but it is missing for the direct IO counterpart. Implement the same logic for it.
Reported-by: Shinichiro Kawasaki shinichiro.kawasaki@wdc.com Fixes: 2ce543f47843 ("btrfs: zoned: wait until zone is finished when allocation didn't progress") CC: stable@vger.kernel.org # 6.1+ Tested-by: Shinichiro Kawasaki shinichiro.kawasaki@wdc.com Reviewed-by: Johannes Thumshirn johannes.thumshirn@wdc.com Signed-off-by: Naohiro Aota naohiro.aota@wdc.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/inode.c | 7 +++++++ 1 file changed, 7 insertions(+)
--- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -6974,8 +6974,15 @@ static struct extent_map *btrfs_new_exte int ret;
alloc_hint = get_extent_allocation_hint(inode, start, len); +again: ret = btrfs_reserve_extent(root, len, len, fs_info->sectorsize, 0, alloc_hint, &ins, 1, 1); + if (ret == -EAGAIN) { + ASSERT(btrfs_is_zoned(fs_info)); + wait_on_bit_io(&inode->root->fs_info->flags, BTRFS_FS_NEED_ZONE_FINISH, + TASK_UNINTERRUPTIBLE); + goto again; + } if (ret) return ERR_PTR(ret);