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2016-05-21Merge branch 'for-linus-4.7' of ↵Linus Torvalds28-1788/+1530
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs updates from Chris Mason: "This has our merge window series of cleanups and fixes. These target a wide range of issues, but do include some important fixes for qgroups, O_DIRECT, and fsync handling. Jeff Mahoney moved around a few definitions to make them easier for userland to consume. Also whiteout support is included now that issues with overlayfs have been cleared up. I have one more fix pending for page faults during btrfs_copy_from_user, but I wanted to get this bulk out the door first" * 'for-linus-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (90 commits) btrfs: fix memory leak during RAID 5/6 device replacement Btrfs: add semaphore to synchronize direct IO writes with fsync Btrfs: fix race between block group relocation and nocow writes Btrfs: fix race between fsync and direct IO writes for prealloc extents Btrfs: fix number of transaction units for renames with whiteout Btrfs: pin logs earlier when doing a rename exchange operation Btrfs: unpin logs if rename exchange operation fails Btrfs: fix inode leak on failure to setup whiteout inode in rename btrfs: add support for RENAME_EXCHANGE and RENAME_WHITEOUT Btrfs: pin log earlier when renaming Btrfs: unpin log if rename operation fails Btrfs: don't do unnecessary delalloc flushes when relocating Btrfs: don't wait for unrelated IO to finish before relocation Btrfs: fix empty symlink after creating symlink and fsync parent dir Btrfs: fix for incorrect directory entries after fsync log replay btrfs: build fixup for qgroup_account_snapshot btrfs: qgroup: Fix qgroup accounting when creating snapshot Btrfs: fix fspath error deallocation btrfs: make find_workspace warn if there are no workspaces btrfs: make find_workspace always succeed ...
2016-05-21lib/uuid.c: move generate_random_uuid() to uuid.cAndy Shevchenko1-1/+1
Let's gather the UUID related functions under one hood. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com> Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-18Merge branch 'work.lookups' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull parallel lookup fixups from Al Viro: "Fix for xfs parallel readdir (turns out the cxfs exposure was not enough to catch all problems), and a reversion of btrfs back to ->iterate() until the fs/btrfs/delayed-inode.c gets fixed" * 'work.lookups' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: xfs: concurrent readdir hangs on data buffer locks Revert "btrfs: switch to ->iterate_shared()"
2016-05-18Revert "btrfs: switch to ->iterate_shared()"Al Viro1-1/+1
This reverts commit 972b241f8441dc37a3f89dcd7e71d7f013873d13. Quoth Chris: didn't take the delayed inode stuff into account it got an rbtree of items and it pulls things out so in shared mode, its hugely racey sorry, lets revert and fix it for real inside of btrfs Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-18Merge branch 'for-linus' of ↵Linus Torvalds3-30/+11
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull remaining vfs xattr work from Al Viro: "The rest of work.xattr (non-cifs conversions)" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: btrfs: Switch to generic xattr handlers ubifs: Switch to generic xattr handlers jfs: Switch to generic xattr handlers jfs: Clean up xattr name mapping gfs2: Switch to generic xattr handlers ceph: kill __ceph_removexattr() ceph: Switch to generic xattr handlers ceph: Get rid of d_find_alias in ceph_set_acl
2016-05-18btrfs: Switch to generic xattr handlersAndreas Gruenbacher3-30/+11
The btrfs_{set,remove}xattr inode operations check for a read-only root (btrfs_root_readonly) before calling into generic_{set,remove}xattr. If this check is moved into __btrfs_setxattr, we can get rid of btrfs_{set,remove}xattr. This patch applies to mainline, I would like to keep it together with the other xattr cleanups if possible, though. Could you please review? Thanks, Andreas Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-18Merge branch 'work.preadv2' of ↵Linus Torvalds2-13/+9
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs cleanups from Al Viro: "More cleanups from Christoph" * 'work.preadv2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: nfsd: use RWF_SYNC fs: add RWF_DSYNC aand RWF_SYNC ceph: use generic_write_sync fs: simplify the generic_write_sync prototype fs: add IOCB_SYNC and IOCB_DSYNC direct-io: remove the offset argument to dio_complete direct-io: eliminate the offset argument to ->direct_IO xfs: eliminate the pos variable in xfs_file_dio_aio_write filemap: remove the pos argument to generic_file_direct_write filemap: remove pos variables in generic_file_read_iter
2016-05-18Merge branch 'for-chris-4.7' of ↵Chris Mason12-134/+608
git://git.kernel.org/pub/scm/linux/kernel/git/fdmanana/linux into for-linus-4.7 Signed-off-by: Chris Mason <clm@fb.com>
2016-05-16Merge branch 'foreign/jeffm/uapi' into for-chris-4.7-20160516David Sterba2-1059/+1
# Conflicts: # include/uapi/linux/btrfs.h
2016-05-16Merge branch 'foreign/anand/dev-del-by-id-ext' into for-chris-4.7-20160516David Sterba5-241/+310
2016-05-16Merge branch 'cleanups-4.7' into for-chris-4.7-20160516David Sterba15-190/+176
2016-05-16btrfs: fix memory leak during RAID 5/6 device replacementScott Talbert1-0/+2
A 'struct bio' is allocated in scrub_missing_raid56_pages(), but it was never freed anywhere. Signed-off-by: Scott Talbert <scott.talbert@hgst.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-13Btrfs: add semaphore to synchronize direct IO writes with fsyncFilipe Manana3-118/+77
Due to the optimization of lockless direct IO writes (the inode's i_mutex is not held) introduced in commit 38851cc19adb ("Btrfs: implement unlocked dio write"), we started having races between such writes with concurrent fsync operations that use the fast fsync path. These races were addressed in the patches titled "Btrfs: fix race between fsync and lockless direct IO writes" and "Btrfs: fix race between fsync and direct IO writes for prealloc extents". The races happened because the direct IO path, like every other write path, does create extent maps followed by the corresponding ordered extents while the fast fsync path collected first ordered extents and then it collected extent maps. This made it possible to log file extent items (based on the collected extent maps) without waiting for the corresponding ordered extents to complete (get their IO done). The two fixes mentioned before added a solution that consists of making the direct IO path create first the ordered extents and then the extent maps, while the fsync path attempts to collect any new ordered extents once it collects the extent maps. This was simple and did not require adding any synchonization primitive to any data structure (struct btrfs_inode for example) but it makes things more fragile for future development endeavours and adds an exceptional approach compared to the other write paths. This change adds a read-write semaphore to the btrfs inode structure and makes the direct IO path create the extent maps and the ordered extents while holding read access on that semaphore, while the fast fsync path collects extent maps and ordered extents while holding write access on that semaphore. The logic for direct IO write path is encapsulated in a new helper function that is used both for cow and nocow direct IO writes. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com>
2016-05-13Btrfs: fix race between block group relocation and nocow writesFilipe Manana4-1/+81
Relocation of a block group waits for all existing tasks flushing dellaloc, starting direct IO writes and any ordered extents before starting the relocation process. However for direct IO writes that end up doing nocow (inode either has the flag nodatacow set or the write is against a prealloc extent) we have a short time window that allows for a race that makes relocation proceed without waiting for the direct IO write to complete first, resulting in data loss after the relocation finishes. This is illustrated by the following diagram: CPU 1 CPU 2 btrfs_relocate_block_group(bg X) direct IO write starts against an extent in block group X using nocow mode (inode has the nodatacow flag or the write is for a prealloc extent) btrfs_direct_IO() btrfs_get_blocks_direct() --> can_nocow_extent() returns 1 btrfs_inc_block_group_ro(bg X) --> turns block group into RO mode btrfs_wait_ordered_roots() --> returns and does not know about the DIO write happening at CPU 2 (the task there has not created yet an ordered extent) relocate_block_group(bg X) --> rc->stage == MOVE_DATA_EXTENTS find_next_extent() --> returns extent that the DIO write is going to write to relocate_data_extent() relocate_file_extent_cluster() --> reads the extent from disk into pages belonging to the relocation inode and dirties them --> creates DIO ordered extent btrfs_submit_direct() --> submits bio against a location on disk obtained from an extent map before the relocation started btrfs_wait_ordered_range() --> writes all the pages read before to disk (belonging to the relocation inode) relocation finishes bio completes and wrote new data to the old location of the block group So fix this by tracking the number of nocow writers for a block group and make sure relocation waits for that number to go down to 0 before starting to move the extents. The same race can also happen with buffered writes in nocow mode since the patch I recently made titled "Btrfs: don't do unnecessary delalloc flushes when relocating", because we are no longer flushing all delalloc which served as a synchonization mechanism (due to page locking) and ensured the ordered extents for nocow buffered writes were created before we called btrfs_wait_ordered_roots(). The race with direct IO writes in nocow mode existed before that patch (no pages are locked or used during direct IO) and that fixed only races with direct IO writes that do cow. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com>
2016-05-13Btrfs: fix race between fsync and direct IO writes for prealloc extentsFilipe Manana1-6/+37
When we do a direct IO write against a preallocated extent (fallocate) that does not go beyond the i_size of the inode, we do the write operation without holding the inode's i_mutex (an optimization that landed in commit 38851cc19adb ("Btrfs: implement unlocked dio write")). This allows for a very tiny time window where a race can happen with a concurrent fsync using the fast code path, as the direct IO write path creates first a new extent map (no longer flagged as a prealloc extent) and then it creates the ordered extent, while the fast fsync path first collects ordered extents and then it collects extent maps. This allows for the possibility of the fast fsync path to collect the new extent map without collecting the new ordered extent, and therefore logging an extent item based on the extent map without waiting for the ordered extent to be created and complete. This can result in a situation where after a log replay we end up with an extent not marked anymore as prealloc but it was only partially written (or not written at all), exposing random, stale or garbage data corresponding to the unwritten pages and without any checksums in the csum tree covering the extent's range. This is an extension of what was done in commit de0ee0edb21f ("Btrfs: fix race between fsync and lockless direct IO writes"). So fix this by creating first the ordered extent and then the extent map, so that this way if the fast fsync patch collects the new extent map it also collects the corresponding ordered extent. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com>
2016-05-13Btrfs: fix number of transaction units for renames with whiteoutFilipe Manana1-1/+8
When we do a rename with the whiteout flag, we need to create the whiteout inode, which in the worst case requires 5 transaction units (1 inode item, 1 inode ref, 2 dir items and 1 xattr if selinux is enabled). So bump the number of transaction units from 11 to 16 if the whiteout flag is set. Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-05-13Btrfs: pin logs earlier when doing a rename exchange operationFilipe Manana1-4/+4
The btrfs_rename_exchange() started as a copy-paste from btrfs_rename(), which had a race fixed by my previous patch titled "Btrfs: pin log earlier when renaming", and so it suffers from the same problem. We pin the logs of the affected roots after we insert the new inode references, leaving a time window where concurrent tasks logging the inodes can end up logging both the new and old references, resulting in log trees that when replayed can turn the metadata into inconsistent states. This behaviour was added to btrfs_rename() in 2009 without any explanation about why not pinning the logs earlier, just leaving a comment about the posibility for the race. As of today it's perfectly safe and sane to pin the logs before we start doing any of the steps involved in the rename operation. Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-05-13Btrfs: unpin logs if rename exchange operation failsFilipe Manana1-2/+36
If rename exchange operations fail at some point after we pinned any of the logs, we end up aborting the current transaction but never unpin the logs, which leaves concurrent tasks that are trying to sync the logs (as part of an fsync request from user space) blocked forever and preventing the filesystem from being unmountable. Fix this by safely unpinning the log. Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-05-13Btrfs: fix inode leak on failure to setup whiteout inode in renameFilipe Manana1-6/+6
If we failed to fully setup the whiteout inode during a rename operation with the whiteout flag, we ended up leaking the inode, not decrementing its link count nor removing all its items from the fs/subvol tree. Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-05-13btrfs: add support for RENAME_EXCHANGE and RENAME_WHITEOUTDan Fuhry1-7/+257
Two new flags, RENAME_EXCHANGE and RENAME_WHITEOUT, provide for new behavior in the renameat2() syscall. This behavior is primarily used by overlayfs. This patch adds support for these flags to btrfs, enabling it to be used as a fully functional upper layer for overlayfs. RENAME_EXCHANGE support was written by Davide Italiano originally submitted on 2 April 2015. Signed-off-by: Davide Italiano <dccitaliano@gmail.com> Signed-off-by: Dan Fuhry <dfuhry@datto.com> [ remove unlikely ] Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-05-13Btrfs: pin log earlier when renamingFilipe Manana1-9/+2
We were pinning the log right after the first step in the rename operation (inserting inode ref for the new name in the destination directory) instead of doing it before. This behaviour was introduced in 2009 for some reason that was not mentioned neither on the changelog nor any comment, with the drawback of a small time window where concurrent log writers can end up logging the new inode reference for the inode we are renaming while the rename operation is in progress (so that we can end up with a log containing both the new and old references). As of today there's no reason to not pin the log before that first step anymore, so just fix this. Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-05-13Btrfs: unpin log if rename operation failsFilipe Manana1-1/+27
If rename operations fail at some point after we pinned the log, we end up aborting the current transaction but never unpin the log, which leaves concurrent tasks that are trying to sync the log (as part of an fsync request from user space) blocked forever and preventing the filesystem from being unmountable. Fix this by safely unpinning the log. Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-05-13Btrfs: don't do unnecessary delalloc flushes when relocatingFilipe Manana4-7/+79
Before we start the actual relocation process of a block group, we do calls to flush delalloc of all inodes and then wait for ordered extents to complete. However we do these flush calls just to make sure we don't race with concurrent tasks that have actually already started to run delalloc and have allocated an extent from the block group we want to relocate, right before we set it to readonly mode, but have not yet created the respective ordered extents. The flush calls make us wait for such concurrent tasks because they end up calling filemap_fdatawrite_range() (through btrfs_start_delalloc_roots() -> __start_delalloc_inodes() -> btrfs_alloc_delalloc_work() -> btrfs_run_delalloc_work()) which ends up serializing us with those tasks due to attempts to lock the same pages (and the delalloc flush procedure calls the allocator and creates the ordered extents before unlocking the pages). These flushing calls not only make us waste time (cpu, IO) but also reduce the chances of writing larger extents (applications might be writing to contiguous ranges and we flush before they finish dirtying the whole ranges). So make sure we don't flush delalloc and just wait for concurrent tasks that have already started flushing delalloc and have allocated an extent from the block group we are about to relocate. This change also ends up fixing a race with direct IO writes that makes relocation not wait for direct IO ordered extents. This race is illustrated by the following diagram: CPU 1 CPU 2 btrfs_relocate_block_group(bg X) starts direct IO write, target inode currently has no ordered extents ongoing nor dirty pages (delalloc regions), therefore the root for our inode is not in the list fs_info->ordered_roots btrfs_direct_IO() __blockdev_direct_IO() btrfs_get_blocks_direct() btrfs_lock_extent_direct() locks range in the io tree btrfs_new_extent_direct() btrfs_reserve_extent() --> extent allocated from bg X btrfs_inc_block_group_ro(bg X) btrfs_start_delalloc_roots() __start_delalloc_inodes() --> does nothing, no dealloc ranges in the inode's io tree so the inode's root is not in the list fs_info->delalloc_roots btrfs_wait_ordered_roots() --> does not find the inode's root in the list fs_info->ordered_roots --> ends up not waiting for the direct IO write started by the task at CPU 2 relocate_block_group(rc->stage == MOVE_DATA_EXTENTS) prepare_to_relocate() btrfs_commit_transaction() iterates the extent tree, using its commit root and moves extents into new locations btrfs_add_ordered_extent_dio() --> now a ordered extent is created and added to the list root->ordered_extents and the root added to the list fs_info->ordered_roots --> this is too late and the task at CPU 1 already started the relocation btrfs_commit_transaction() btrfs_finish_ordered_io() btrfs_alloc_reserved_file_extent() --> adds delayed data reference for the extent allocated from bg X relocate_block_group(rc->stage == UPDATE_DATA_PTRS) prepare_to_relocate() btrfs_commit_transaction() --> delayed refs are run, so an extent item for the allocated extent from bg X is added to extent tree --> commit roots are switched, so the next scan in the extent tree will see the extent item sees the extent in the extent tree When this happens the relocation produces the following warning when it finishes: [ 7260.832836] ------------[ cut here ]------------ [ 7260.834653] WARNING: CPU: 5 PID: 6765 at fs/btrfs/relocation.c:4318 btrfs_relocate_block_group+0x245/0x2a1 [btrfs]() [ 7260.838268] Modules linked in: btrfs crc32c_generic xor ppdev raid6_pq psmouse sg acpi_cpufreq evdev i2c_piix4 tpm_tis serio_raw tpm i2c_core pcspkr parport_pc [ 7260.850935] CPU: 5 PID: 6765 Comm: btrfs Not tainted 4.5.0-rc6-btrfs-next-28+ #1 [ 7260.852998] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [ 7260.852998] 0000000000000000 ffff88020bf57bc0 ffffffff812648b3 0000000000000000 [ 7260.852998] 0000000000000009 ffff88020bf57bf8 ffffffff81051608 ffffffffa03c1b2d [ 7260.852998] ffff8800b2bbb800 0000000000000000 ffff8800b17bcc58 ffff8800399dd000 [ 7260.852998] Call Trace: [ 7260.852998] [<ffffffff812648b3>] dump_stack+0x67/0x90 [ 7260.852998] [<ffffffff81051608>] warn_slowpath_common+0x99/0xb2 [ 7260.852998] [<ffffffffa03c1b2d>] ? btrfs_relocate_block_group+0x245/0x2a1 [btrfs] [ 7260.852998] [<ffffffff810516d4>] warn_slowpath_null+0x1a/0x1c [ 7260.852998] [<ffffffffa03c1b2d>] btrfs_relocate_block_group+0x245/0x2a1 [btrfs] [ 7260.852998] [<ffffffffa039d9de>] btrfs_relocate_chunk.isra.29+0x66/0xdb [btrfs] [ 7260.852998] [<ffffffffa039f314>] btrfs_balance+0xde1/0xe4e [btrfs] [ 7260.852998] [<ffffffff8127d671>] ? debug_smp_processor_id+0x17/0x19 [ 7260.852998] [<ffffffffa03a9583>] btrfs_ioctl_balance+0x255/0x2d3 [btrfs] [ 7260.852998] [<ffffffffa03ac96a>] btrfs_ioctl+0x11e0/0x1dff [btrfs] [ 7260.852998] [<ffffffff811451df>] ? handle_mm_fault+0x443/0xd63 [ 7260.852998] [<ffffffff81491817>] ? _raw_spin_unlock+0x31/0x44 [ 7260.852998] [<ffffffff8108b36a>] ? arch_local_irq_save+0x9/0xc [ 7260.852998] [<ffffffff811876ab>] vfs_ioctl+0x18/0x34 [ 7260.852998] [<ffffffff81187cb2>] do_vfs_ioctl+0x550/0x5be [ 7260.852998] [<ffffffff81190c30>] ? __fget_light+0x4d/0x71 [ 7260.852998] [<ffffffff81187d77>] SyS_ioctl+0x57/0x79 [ 7260.852998] [<ffffffff81492017>] entry_SYSCALL_64_fastpath+0x12/0x6b [ 7260.893268] ---[ end trace eb7803b24ebab8ad ]--- This is because at the end of the first stage, in relocate_block_group(), we commit the current transaction, which makes delayed refs run, the commit roots are switched and so the second stage will find the extent item that the ordered extent added to the delayed refs. But this extent was not moved (ordered extent completed after first stage finished), so at the end of the relocation our block group item still has a positive used bytes counter, triggering a warning at the end of btrfs_relocate_block_group(). Later on when trying to read the extent contents from disk we hit a BUG_ON() due to the inability to map a block with a logical address that belongs to the block group we relocated and is no longer valid, resulting in the following trace: [ 7344.885290] BTRFS critical (device sdi): unable to find logical 12845056 len 4096 [ 7344.887518] ------------[ cut here ]------------ [ 7344.888431] kernel BUG at fs/btrfs/inode.c:1833! [ 7344.888431] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [ 7344.888431] Modules linked in: btrfs crc32c_generic xor ppdev raid6_pq psmouse sg acpi_cpufreq evdev i2c_piix4 tpm_tis serio_raw tpm i2c_core pcspkr parport_pc [ 7344.888431] CPU: 0 PID: 6831 Comm: od Tainted: G W 4.5.0-rc6-btrfs-next-28+ #1 [ 7344.888431] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [ 7344.888431] task: ffff880215818600 ti: ffff880204684000 task.ti: ffff880204684000 [ 7344.888431] RIP: 0010:[<ffffffffa037c88c>] [<ffffffffa037c88c>] btrfs_merge_bio_hook+0x54/0x6b [btrfs] [ 7344.888431] RSP: 0018:ffff8802046878f0 EFLAGS: 00010282 [ 7344.888431] RAX: 00000000ffffffea RBX: 0000000000001000 RCX: 0000000000000001 [ 7344.888431] RDX: ffff88023ec0f950 RSI: ffffffff8183b638 RDI: 00000000ffffffff [ 7344.888431] RBP: ffff880204687908 R08: 0000000000000001 R09: 0000000000000000 [ 7344.888431] R10: ffff880204687770 R11: ffffffff82f2d52d R12: 0000000000001000 [ 7344.888431] R13: ffff88021afbfee8 R14: 0000000000006208 R15: ffff88006cd199b0 [ 7344.888431] FS: 00007f1f9e1d6700(0000) GS:ffff88023ec00000(0000) knlGS:0000000000000000 [ 7344.888431] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 7344.888431] CR2: 00007f1f9dc8cb60 CR3: 000000023e3b6000 CR4: 00000000000006f0 [ 7344.888431] Stack: [ 7344.888431] 0000000000001000 0000000000001000 ffff880204687b98 ffff880204687950 [ 7344.888431] ffffffffa0395c8f ffffea0004d64d48 0000000000000000 0000000000001000 [ 7344.888431] ffffea0004d64d48 0000000000001000 0000000000000000 0000000000000000 [ 7344.888431] Call Trace: [ 7344.888431] [<ffffffffa0395c8f>] submit_extent_page+0xf5/0x16f [btrfs] [ 7344.888431] [<ffffffffa03970ac>] __do_readpage+0x4a0/0x4f1 [btrfs] [ 7344.888431] [<ffffffffa039680d>] ? btrfs_create_repair_bio+0xcb/0xcb [btrfs] [ 7344.888431] [<ffffffffa037eeb4>] ? btrfs_writepage_start_hook+0xbc/0xbc [btrfs] [ 7344.888431] [<ffffffff8108df55>] ? trace_hardirqs_on+0xd/0xf [ 7344.888431] [<ffffffffa039728c>] __do_contiguous_readpages.constprop.26+0xc2/0xe4 [btrfs] [ 7344.888431] [<ffffffffa037eeb4>] ? btrfs_writepage_start_hook+0xbc/0xbc [btrfs] [ 7344.888431] [<ffffffffa039739b>] __extent_readpages.constprop.25+0xed/0x100 [btrfs] [ 7344.888431] [<ffffffff81129d24>] ? lru_cache_add+0xe/0x10 [ 7344.888431] [<ffffffffa0397ea8>] extent_readpages+0x160/0x1aa [btrfs] [ 7344.888431] [<ffffffffa037eeb4>] ? btrfs_writepage_start_hook+0xbc/0xbc [btrfs] [ 7344.888431] [<ffffffff8115daad>] ? alloc_pages_current+0xa9/0xcd [ 7344.888431] [<ffffffffa037cdc9>] btrfs_readpages+0x1f/0x21 [btrfs] [ 7344.888431] [<ffffffff81128316>] __do_page_cache_readahead+0x168/0x1fc [ 7344.888431] [<ffffffff811285a0>] ondemand_readahead+0x1f6/0x207 [ 7344.888431] [<ffffffff811285a0>] ? ondemand_readahead+0x1f6/0x207 [ 7344.888431] [<ffffffff8111cf34>] ? pagecache_get_page+0x2b/0x154 [ 7344.888431] [<ffffffff8112870e>] page_cache_sync_readahead+0x3d/0x3f [ 7344.888431] [<ffffffff8111dbf7>] generic_file_read_iter+0x197/0x4e1 [ 7344.888431] [<ffffffff8117773a>] __vfs_read+0x79/0x9d [ 7344.888431] [<ffffffff81178050>] vfs_read+0x8f/0xd2 [ 7344.888431] [<ffffffff81178a38>] SyS_read+0x50/0x7e [ 7344.888431] [<ffffffff81492017>] entry_SYSCALL_64_fastpath+0x12/0x6b [ 7344.888431] Code: 8d 4d e8 45 31 c9 45 31 c0 48 8b 00 48 c1 e2 09 48 8b 80 80 fc ff ff 4c 89 65 e8 48 8b b8 f0 01 00 00 e8 1d 42 02 00 85 c0 79 02 <0f> 0b 4c 0 [ 7344.888431] RIP [<ffffffffa037c88c>] btrfs_merge_bio_hook+0x54/0x6b [btrfs] [ 7344.888431] RSP <ffff8802046878f0> [ 7344.970544] ---[ end trace eb7803b24ebab8ae ]--- Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
2016-05-13Btrfs: don't wait for unrelated IO to finish before relocationFilipe Manana8-19/+38
Before the relocation process of a block group starts, it sets the block group to readonly mode, then flushes all delalloc writes and then finally it waits for all ordered extents to complete. This last step includes waiting for ordered extents destinated at extents allocated in other block groups, making us waste unecessary time. So improve this by waiting only for ordered extents that fall into the block group's range. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
2016-05-13Btrfs: fix empty symlink after creating symlink and fsync parent dirFilipe Manana1-1/+1
If we create a symlink, fsync its parent directory, crash/power fail and mount the filesystem, we end up with an empty symlink, which not only is useless it's also not allowed in linux (the man page symlink(2) is well explicit about that). So we just need to make sure to fully log an inode if it's a symlink, to ensure its inline extent gets logged, ensuring the same behaviour as ext3, ext4, xfs, reiserfs, f2fs, nilfs2, etc. Example reproducer: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ sync $ ln -s /mnt/foo /mnt/testdir/bar $ xfs_io -c fsync /mnt/testdir <power fail> $ mount /dev/sdb /mnt $ readlink /mnt/testdir/bar <empty string> A test case for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-05-13Btrfs: fix for incorrect directory entries after fsync log replayFilipe Manana1-5/+8
If we move a directory to a new parent and later log that parent and don't explicitly log the old parent, when we replay the log we can end up with entries for the moved directory in both the old and new parent directories. Besides being ilegal to have directories with multiple hard links in linux, it also resulted in the leaving the inode item with a link count of 1. A similar issue also happens if we move a regular file - after the log tree is replayed the file has a link in both the old and new parent directories, when it should be only at the new directory. Sample reproducer: $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt $ mkdir /mnt/x $ mkdir /mnt/y $ touch /mnt/x/foo $ mkdir /mnt/y/z $ sync $ ln /mnt/x/foo /mnt/x/bar $ mv /mnt/y/z /mnt/x/z < power fail > $ mount /dev/sdc /mnt $ ls -1Ri /mnt /mnt: 257 x 258 y /mnt/x: 259 bar 259 foo 260 z /mnt/x/z: /mnt/y: 260 z /mnt/y/z: $ umount /dev/sdc $ btrfs check /dev/sdc Checking filesystem on /dev/sdc UUID: a67e2c4a-a4b4-4fdc-b015-9d9af1e344be checking extents checking free space cache checking fs roots root 5 inode 260 errors 2000, link count wrong unresolved ref dir 257 index 4 namelen 1 name z filetype 2 errors 0 unresolved ref dir 258 index 2 namelen 1 name z filetype 2 errors 0 (...) Attempting to remove the directory becomes impossible: $ mount /dev/sdc /mnt $ rmdir /mnt/y/z $ ls -lh /mnt/y ls: cannot access /mnt/y/z: No such file or directory total 0 d????????? ? ? ? ? ? z $ rmdir /mnt/x/z rmdir: failed to remove ‘/mnt/x/z’: Stale file handle $ ls -lh /mnt/x ls: cannot access /mnt/x/z: Stale file handle total 0 -rw-r--r-- 2 root root 0 Apr 6 18:06 bar -rw-r--r-- 2 root root 0 Apr 6 18:06 foo d????????? ? ? ? ? ? z So make sure that on rename we set the last_unlink_trans value for our inode, even if it's a directory, to the value of the current transaction's ID and that if the new parent directory is logged that we fallback to a transaction commit. A test case for fstests is being submitted as well. Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-05-12btrfs: build fixup for qgroup_account_snapshotDavid Sterba1-0/+5
The macro btrfs_std_error got renamed to btrfs_handle_fs_error in an independent branch for the same merge target (4.7). To make the code compilable for bisectability reasons, add a temporary stub. Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-12btrfs: qgroup: Fix qgroup accounting when creating snapshotQu Wenruo1-24/+105
Current btrfs qgroup design implies a requirement that after calling btrfs_qgroup_account_extents() there must be a commit root switch. Normally this is OK, as btrfs_qgroup_accounting_extents() is only called inside btrfs_commit_transaction() just be commit_cowonly_roots(). However there is a exception at create_pending_snapshot(), which will call btrfs_qgroup_account_extents() but no any commit root switch. In case of creating a snapshot whose parent root is itself (create a snapshot of fs tree), it will corrupt qgroup by the following trace: (skipped unrelated data) ====== btrfs_qgroup_account_extent: bytenr = 29786112, num_bytes = 16384, nr_old_roots = 0, nr_new_roots = 1 qgroup_update_counters: qgid = 5, cur_old_count = 0, cur_new_count = 1, rfer = 0, excl = 0 qgroup_update_counters: qgid = 5, cur_old_count = 0, cur_new_count = 1, rfer = 16384, excl = 16384 btrfs_qgroup_account_extent: bytenr = 29786112, num_bytes = 16384, nr_old_roots = 0, nr_new_roots = 0 ====== The problem here is in first qgroup_account_extent(), the nr_new_roots of the extent is 1, which means its reference got increased, and qgroup increased its rfer and excl. But at second qgroup_account_extent(), its reference got decreased, but between these two qgroup_account_extent(), there is no switch roots. This leads to the same nr_old_roots, and this extent just got ignored by qgroup, which means this extent is wrongly accounted. Fix it by call commit_cowonly_roots() after qgroup_account_extent() in create_pending_snapshot(), with needed preparation. Mark: I added a check at the top of qgroup_account_snapshot() to skip this code if qgroups are turned off. xfstest btrfs/122 exposes this problem. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Mark Fasheh <mfasheh@suse.de> Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-10Btrfs: fix fspath error deallocationVincent Stehlé1-1/+1
Make sure to deallocate fspath with vfree() in case of error in init_ipath(). fspath is allocated with vmalloc() in init_data_container() since commit 425d17a290c0 ("Btrfs: use larger limit for translation of logical to inode"). Signed-off-by: Vincent Stehlé <vincent.stehle@intel.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-10btrfs: make find_workspace warn if there are no workspacesDavid Sterba1-0/+14
Be verbose if there are no workspaces at all, ie. the module init time preallocation failed. Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-10btrfs: make find_workspace always succeedDavid Sterba1-8/+12
With just one preallocated workspace we can guarantee forward progress even if there's no memory available for new workspaces. The cost is more waiting but we also get rid of several error paths. On average, there will be several idle workspaces, so the waiting penalty won't be so bad. In the worst case, all cpus will compete for one workspace until there's some memory. Attempts to allocate a new one are done each time the waiters are woken up. Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-10btrfs: preallocate compression workspacesDavid Sterba1-0/+16
Preallocate one workspace for each compression type so we can guarantee forward progress in the worst case. A failure cannot be a hard error as we might not use compression at all on the filesystem. If we can't allocate the workspaces later when need them, it might actually deadlock, but in such situation the system has effectively not enough memory to operate properly. Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-10btrfs: rename and document compression workspace membersDavid Sterba1-16/+19
The names are confusing, pick more fitting names and add comments. Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-10btrfs: GFP_NOFS does not GFP_HIGHMEMDavid Sterba3-4/+4
Masking HIGHMEM out of NOFS does not make sense. Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-10btrfs: switch to common message helpers in open_ctree, adjust messagesDavid Sterba1-52/+50
Currently we lack the identification of the filesystem in most if not all mount messages, done via printk/pr_* functions. We can use the btrfs_* helpers in open_ctree, as the fs_info <-> sb link is established at the beginning of the function. The messages have been updated at the same time to be more consistent: * dropped sb->s_id, as it's not available via btrfs_* * added %d for return code where appropriate * wording changed * %Lx replaced by %llx Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-09btrfs: switch to ->iterate_shared()Al Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-09btrfs: fix int32 overflow in shrink_delalloc().Adam Borowski1-1/+1
UBSAN: Undefined behaviour in fs/btrfs/extent-tree.c:4623:21 signed integer overflow: 10808 * 262144 cannot be represented in type 'int [8]' If 8192<=items<16384, we request a writeback of an insane number of pages which is benign (everything will be written). But if items>=16384, the space reservation won't be enough. Signed-off-by: Adam Borowski <kilobyte@angband.pl> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06btrfs: don't force mounts to wait for cleaner_kthread to delete one or more ↵Zygo Blaxell1-3/+15
subvolumes During a mount, we start the cleaner kthread first because the transaction kthread wants to wake up the cleaner kthread. We start the transaction kthread next because everything in btrfs wants transactions. We do reloc recovery in the thread that was doing the original mount call once the transaction kthread is running. This means that the cleaner kthread could already be running when reloc recovery happens (e.g. if a snapshot delete was started before a crash). Relocation does not play well with the cleaner kthread, so a mutex was added in commit 5f3164813b90f7dbcb5c3ab9006906222ce471b7 "Btrfs: fix race between balance recovery and root deletion" to prevent both from being active at the same time. If the cleaner kthread is already holding the mutex by the time we get to btrfs_recover_relocation, the mount will be blocked until at least one deleted subvolume is cleaned (possibly more if the mount process doesn't get the lock right away). During this time (which could be an arbitrarily long time on a large/slow filesystem), the mount process is stuck and the filesystem is unnecessarily inaccessible. Fix this by locking cleaner_mutex before we start cleaner_kthread, and unlocking the mutex after mount no longer requires it. This ensures that the mounting process will not be blocked by the cleaner kthread. The cleaner kthread is already prepared for mutex contention and will just go to sleep until the mutex is available. Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06btrfs: ioctl: reorder exclusive op check in RM_DEVDavid Sterba1-12/+11
Move the op exclusivity check before the other code (same as in ADD_DEV). Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06btrfs: add write protection to SET_FEATURES ioctlDavid Sterba1-3/+13
Perform the want_write check if we get far enough to do any writes. Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06btrfs: fix lock dep warning move scratch super outside of chunk_mutexAnand Jain1-4/+5
Move scratch super outside of the chunk lock to avoid below lockdep warning. The better place to scratch super is in the function btrfs_rm_dev_replace_free_srcdev() just before free_device, which is outside of the chunk lock as well. To reproduce: (fresh boot) mkfs.btrfs -f -draid5 -mraid5 /dev/sdc /dev/sdd /dev/sde mount /dev/sdc /btrfs dd if=/dev/zero of=/btrfs/tf1 bs=4096 count=100 (get devmgt from https://github.com/asj/devmgt.git) devmgt detach /dev/sde dd if=/dev/zero of=/btrfs/tf1 bs=4096 count=100 sync btrfs replace start -Brf 3 /dev/sdf /btrfs <-- devmgt attach host7 ====================================================== [ INFO: possible circular locking dependency detected ] 4.6.0-rc2asj+ #1 Not tainted --------------------------------------------------- btrfs/2174 is trying to acquire lock: (sb_writers){.+.+.+}, at: [<ffffffff812449b4>] __sb_start_write+0xb4/0xf0 but task is already holding lock: (&fs_info->chunk_mutex){+.+.+.}, at: [<ffffffffa05c5f55>] btrfs_dev_replace_finishing+0x145/0x980 [btrfs] which lock already depends on the new lock. Chain exists of: sb_writers --> &fs_devs->device_list_mutex --> &fs_info->chunk_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&fs_info->chunk_mutex); lock(&fs_devs->device_list_mutex); lock(&fs_info->chunk_mutex); lock(sb_writers); *** DEADLOCK *** -> #0 (sb_writers){.+.+.+}: [<ffffffff810e6415>] __lock_acquire+0x1bc5/0x1ee0 [<ffffffff810e707e>] lock_acquire+0xbe/0x210 [<ffffffff810df49a>] percpu_down_read+0x4a/0xa0 [<ffffffff812449b4>] __sb_start_write+0xb4/0xf0 [<ffffffff81265534>] mnt_want_write+0x24/0x50 [<ffffffff812508a2>] path_openat+0x952/0x1190 [<ffffffff81252451>] do_filp_open+0x91/0x100 [<ffffffff8123f5cc>] file_open_name+0xfc/0x140 [<ffffffff8123f643>] filp_open+0x33/0x60 [<ffffffffa0572bb6>] update_dev_time+0x16/0x40 [btrfs] [<ffffffffa057f60d>] btrfs_scratch_superblocks+0x5d/0xb0 [btrfs] [<ffffffffa057f70e>] btrfs_rm_dev_replace_remove_srcdev+0xae/0xd0 [btrfs] [<ffffffffa05c62c5>] btrfs_dev_replace_finishing+0x4b5/0x980 [btrfs] [<ffffffffa05c6ae8>] btrfs_dev_replace_start+0x358/0x530 [btrfs] Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06btrfs: Fix BUG_ON condition in scrub_setup_recheck_block()Ashish Samant1-1/+1
pagev array in scrub_block{} is of size SCRUB_MAX_PAGES_PER_BLOCK. page_index should be checked with the same to trigger BUG_ON(). Signed-off-by: Ashish Samant <ashish.samant@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06Btrfs: remove BUG_ON()'s in btrfs_map_blockJosef Bacik1-2/+16
btrfs_map_block can go horribly wrong in the face of fs corruption, lets agree to not be assholes and panic at any possible chance things are all fucked up. Signed-off-by: Josef Bacik <jbacik@fb.com> [ removed type casts ] Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06Btrfs: fix divide error upon chunk's stripe_lenLiu Bo3-3/+3
The struct 'map_lookup' uses type int for @stripe_len, while btrfs_chunk_stripe_len() can return a u64 value, and it may end up with @stripe_len being undefined value and it can lead to 'divide error' in __btrfs_map_block(). This changes 'map_lookup' to use type u64 for stripe_len, also right now we only use BTRFS_STRIPE_LEN for stripe_len, so this adds a valid checker for BTRFS_STRIPE_LEN. Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Reported-by: Quentin Casasnovas <quentin.casasnovas@oracle.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> [ folded division fix to scrub_raid56_parity ] Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06btrfs: sysfs: protect reading label by lockDavid Sterba1-1/+7
If the label setting ioctl races with sysfs label handler, we could get mixed result in the output, part old part new. We should either get the old or new label. The chances to hit this race are low. Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06btrfs: add check to sysfs handler of labelDavid Sterba1-0/+3
Add a sanity check for the fs_info as we will dereference it, similar to what the 'store features' handler does. Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06btrfs: add read-only check to sysfs handler of featuresDavid Sterba1-0/+3
We don't want to trigger the change on a read-only filesystem, similar to what the label handler does. Signed-off-by: David Sterba <dsterba@suse.cz>
2016-05-06btrfs: reuse existing variable in scrub_stripe, reduce stack usageDavid Sterba1-10/+9
The key variable occupies 17 bytes, the key_start is used once, we can simply reuse existing 'key' for that purpose. As the key is not a simple type, compiler doest not do it on itself. Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06btrfs: use dynamic allocation for root item in create_subvolDavid Sterba1-28/+37
The size of root item is more than 400 bytes, which is quite a lot of stack space. As we do IO from inside the subvolume ioctls, we should keep the stack usage low in case the filesystem is on top of other layers (NFS, device mapper, iscsi, etc). Reviewed-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06btrfs: clone: use vmalloc only as fallback for nodesize buferDavid Sterba1-5/+8
Signed-off-by: David Sterba <dsterba@suse.com>