kernel/git/stable/linux.git/fs/btrfs/file.c, branch linux-5.9.y

btrfs: fix missing delalloc new bit for new delalloc ranges

2020-12-02T07:51:44+00:00

commit c334730988ee07908ba4eb816ce78d3fe06fecaa upstream. When doing a buffered write, through one of the write family syscalls, we look for ranges which currently don't have allocated extents and set the 'delalloc new' bit on them, so that we can report a correct number of used blocks to the stat(2) syscall until delalloc is flushed and ordered extents complete. However there are a few other places where we can do a buffered write against a range that is mapped to a hole (no extent allocated) and where we do not set the 'new delalloc' bit. Those places are: - Doing a memory mapped write against a hole; - Cloning an inline extent into a hole starting at file offset 0; - Calling btrfs_cont_expand() when the i_size of the file is not aligned to the sector size and is located in a hole. For example when cloning to a destination offset beyond EOF. So after such cases, until the corresponding delalloc range is flushed and the respective ordered extents complete, we can report an incorrect number of blocks used through the stat(2) syscall. In some cases we can end up reporting 0 used blocks to stat(2), which is a particular bad value to report as it may mislead tools to think a file is completely sparse when its i_size is not zero, making them skip reading any data, an undesired consequence for tools such as archivers and other backup tools, as reported a long time ago in the following thread (and other past threads): https://lists.gnu.org/archive/html/bug-tar/2016-07/msg00001.html Example reproducer: $ cat reproducer.sh #!/bin/bash MNT=/mnt/sdi DEV=/dev/sdi mkfs.btrfs -f $DEV > /dev/null # mkfs.xfs -f $DEV > /dev/null # mkfs.ext4 -F $DEV > /dev/null # mkfs.f2fs -f $DEV > /dev/null mount $DEV $MNT xfs_io -f -c "truncate 64K" \ -c "mmap -w 0 64K" \ -c "mwrite -S 0xab 0 64K" \ -c "munmap" \ $MNT/foo blocks_used=$(stat -c %b $MNT/foo) echo "blocks used: $blocks_used" if [ $blocks_used -eq 0 ]; then echo "ERROR: blocks used is 0" fi umount $DEV $ ./reproducer.sh blocks used: 0 ERROR: blocks used is 0 So move the logic that decides to set the 'delalloc bit' bit into the function btrfs_set_extent_delalloc(), since that is what we use for all those missing cases as well as for the cases that currently work well. This change is also preparatory work for an upcoming patch that fixes other problems related to tracking and reporting the number of bytes used by an inode. CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Josef Bacik Signed-off-by: Filipe Manana Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman

Merge tag 'for-5.9-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

2020-08-24T19:01:20+00:00

Pull btrfs fixes from David Sterba: - fix swapfile activation on subvolumes with deleted snapshots - error value mixup when removing directory entries from tree log - fix lzo compression level reset after previous level setting - fix space cache memory leak after transaction abort - fix const function attribute - more error handling improvements * tag 'for-5.9-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: detect nocow for swap after snapshot delete btrfs: check the right error variable in btrfs_del_dir_entries_in_log btrfs: fix space cache memory leak after transaction abort btrfs: use the correct const function attribute for btrfs_get_num_csums btrfs: reset compression level for lzo on remount btrfs: handle errors from async submission

btrfs: detect nocow for swap after snapshot delete

2020-08-21T10:21:23+00:00

can_nocow_extent and btrfs_cross_ref_exist both rely on a heuristic for detecting a must cow condition which is not exactly accurate, but saves unnecessary tree traversal. The incorrect assumption is that if the extent was created in a generation smaller than the last snapshot generation, it must be referenced by that snapshot. That is true, except the snapshot could have since been deleted, without affecting the last snapshot generation. The original patch claimed a performance win from this check, but it also leads to a bug where you are unable to use a swapfile if you ever snapshotted the subvolume it's in. Make the check slower and more strict for the swapon case, without modifying the general cow checks as a compromise. Turning swap on does not seem to be a particularly performance sensitive operation, so incurring a possibly unnecessary btrfs_search_slot seems worthwhile for the added usability. Note: Until the snapshot is competely cleaned after deletion, check_committed_refs will still cause the logic to think that cow is necessary, so the user must until 'btrfs subvolu sync' finished before activating the swapfile swapon. CC: stable@vger.kernel.org # 5.4+ Suggested-by: Omar Sandoval Signed-off-by: Boris Burkov Signed-off-by: David Sterba

Merge tag 'for-5.9/io_uring-20200802' of git://git.kernel.dk/linux-block

2020-08-03T20:01:22+00:00

Pull io_uring updates from Jens Axboe: "Lots of cleanups in here, hardening the code and/or making it easier to read and fixing bugs, but a core feature/change too adding support for real async buffered reads. With the latter in place, we just need buffered write async support and we're done relying on kthreads for the fast path. In detail: - Cleanup how memory accounting is done on ring setup/free (Bijan) - sq array offset calculation fixup (Dmitry) - Consistently handle blocking off O_DIRECT submission path (me) - Support proper async buffered reads, instead of relying on kthread offload for that. This uses the page waitqueue to drive retries from task_work, like we handle poll based retry. (me) - IO completion optimizations (me) - Fix race with accounting and ring fd install (me) - Support EPOLLEXCLUSIVE (Jiufei) - Get rid of the io_kiocb unionizing, made possible by shrinking other bits (Pavel) - Completion side cleanups (Pavel) - Cleanup REQ_F_ flags handling, and kill off many of them (Pavel) - Request environment grabbing cleanups (Pavel) - File and socket read/write cleanups (Pavel) - Improve kiocb_set_rw_flags() (Pavel) - Tons of fixes and cleanups (Pavel) - IORING_SQ_NEED_WAKEUP clear fix (Xiaoguang)" * tag 'for-5.9/io_uring-20200802' of git://git.kernel.dk/linux-block: (127 commits) io_uring: flip if handling after io_setup_async_rw fs: optimise kiocb_set_rw_flags() io_uring: don't touch 'ctx' after installing file descriptor io_uring: get rid of atomic FAA for cq_timeouts io_uring: consolidate *_check_overflow accounting io_uring: fix stalled deferred requests io_uring: fix racy overflow count reporting io_uring: deduplicate __io_complete_rw() io_uring: de-unionise io_kiocb io-wq: update hash bits io_uring: fix missing io_queue_linked_timeout() io_uring: mark ->work uninitialised after cleanup io_uring: deduplicate io_grab_files() calls io_uring: don't do opcode prep twice io_uring: clear IORING_SQ_NEED_WAKEUP after executing task works io_uring: batch put_task_struct() tasks: add put_task_struct_many() io_uring: return locked and pinned page accounting io_uring: don't miscount pinned memory io_uring: don't open-code recv kbuf managment ...

btrfs: make btrfs_check_data_free_space take btrfs_inode

2020-07-27T10:55:36+00:00

Instead of calling BTRFS_I on the passed vfs_inode take btrfs_inode directly. Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: make btrfs_delalloc_release_space take btrfs_inode

2020-07-27T10:55:36+00:00

It needs btrfs_inode so take it as a parameter directly. Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: make btrfs_free_reserved_data_space take btrfs_inode

2020-07-27T10:55:36+00:00

It only uses btrfs_inode internally so take it as a parameter. Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: make btrfs_qgroup_reserve_data take btrfs_inode

2020-07-27T10:55:35+00:00

There's only a single use of vfs_inode in a tracepoint so let's take btrfs_inode directly. Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: make btrfs_dirty_pages take btrfs_inode

2020-07-27T10:55:35+00:00

There is a single use of the generic vfs_inode so let's take btrfs_inode as a parameter and remove couple of redundant BTRFS_I() calls. Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: make btrfs_set_extent_delalloc take btrfs_inode

2020-07-27T10:55:35+00:00

Preparation to make btrfs_dirty_pages take btrfs_inode as parameter. Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba Signed-off-by: David Sterba