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* Btrfs: handle quota reserve failure properlyJosef Bacik2016-09-211-6/+3
| | | | | | | | | | btrfs/022 was spitting a warning for the case that we exceed the quota. If we fail to make our quota reservation we need to clean up our data space reservation. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Tested-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* Merge branch 'for-chris' of ↵Chris Mason2016-09-072-8/+16
|\ | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.8
| * btrfs: introduce tickets_id to determine whether asynchronous metadata ↵Wang Xiaoguang2016-09-062-5/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | reclaim work makes progress In btrfs_async_reclaim_metadata_space(), we use ticket's address to determine whether asynchronous metadata reclaim work is making progress. ticket = list_first_entry(&space_info->tickets, struct reserve_ticket, list); if (last_ticket == ticket) { flush_state++; } else { last_ticket = ticket; flush_state = FLUSH_DELAYED_ITEMS_NR; if (commit_cycles) commit_cycles--; } But indeed it's wrong, we should not rely on local variable's address to do this check, because addresses may be same. In my test environment, I dd one 168MB file in a 256MB fs, found that for this file, every time wait_reserve_ticket() called, local variable ticket's address is same, For above codes, assume a previous ticket's address is addrA, last_ticket is addrA. Btrfs_async_reclaim_metadata_space() finished this ticket and wake up it, then another ticket is added, but with the same address addrA, now last_ticket will be same to current ticket, then current ticket's flush work will start from current flush_state, not initial FLUSH_DELAYED_ITEMS_NR, which may result in some enospc issues(I have seen this in my test machine). Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
| * btrfs: do not decrease bytes_may_use when replaying extentsWang Xiaoguang2016-09-051-3/+9
| | | | | | | | | | | | | | | | | | | | | | When replaying extents, there is no need to update bytes_may_use in btrfs_alloc_logged_file_extent(), otherwise it'll trigger a WARN_ON about bytes_may_use. Fixes: ("btrfs: update btrfs_space_info's bytes_may_use timely") Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
* | Btrfs: remove root_log_ctx from ctx list before btrfs_sync_log returnsChris Mason2016-09-061-0/+1
|/ | | | | | | | | | | | | | We use a btrfs_log_ctx structure to pass information into the tree log commit, and get error values out. It gets added to a per log-transaction list which we walk when things go bad. Commit d1433debe added an optimization to skip waiting for the log commit, but didn't take root_log_ctx out of the list. This patch makes sure we remove things before exiting. Signed-off-by: Chris Mason <clm@fb.com> Fixes: d1433debe7f4346cf9fc0dafc71c3137d2a97bc4 cc: stable@vger.kernel.org # 3.15+
* btrfs: fix one bug that process may endlessly wait for ticket in ↵Wang Xiaoguang2016-09-011-5/+5
| | | | | | | | | | | | | | | | | wait_reserve_ticket() If can_overcommit() in btrfs_calc_reclaim_metadata_size() returns true, btrfs_async_reclaim_metadata_space() will not reclaim metadata space, just return directly and also forget to wake up process which are waiting for their tickets, so these processes will wait endlessly. Fstests case generic/172 with mount option "-o compress=lzo" have revealed this bug in my test machine. Here if we have tickets to handle, we must handle them first. Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
* Btrfs: fix endless loop in balancing block groupsLiu Bo2016-09-011-3/+5
| | | | | | | | | | | | | Qgroup function may overwrite the saved error 'err' with 0 in case quota is not enabled, and this ends up with a endless loop in balance because we keep going back to balance the same block group. It really should use 'ret' instead. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
* Btrfs: kill invalid ASSERT() in process_all_refs()Josef Bacik2016-09-011-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Suppose you have the following tree in snap1 on a file system mounted with -o inode_cache so that inode numbers are recycled └── [ 258] a └── [ 257] b and then you remove b, rename a to c, and then re-create b in c so you have the following tree └── [ 258] c └── [ 257] b and then you try to do an incremental send you will hit ASSERT(pending_move == 0); in process_all_refs(). This is because we assume that any recycling of inodes will not have a pending change in our path, which isn't the case. This is the case for the DELETE side, since we want to remove the old file using the old path, but on the create side we could have a pending move and need to do the normal pending rename dance. So remove this ASSERT() and put a comment about why we ignore pending_move. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
* Btrfs: fix lockdep warning on deadlock against an inode's log mutexFilipe Manana2016-08-253-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 44f714dae50a ("Btrfs: improve performance on fsync against new inode after rename/unlink"), which landed in 4.8-rc2, introduced a possibility for a deadlock due to double locking of an inode's log mutex by the same task, which lockdep reports with: [23045.433975] ============================================= [23045.434748] [ INFO: possible recursive locking detected ] [23045.435426] 4.7.0-rc6-btrfs-next-34+ #1 Not tainted [23045.436044] --------------------------------------------- [23045.436044] xfs_io/3688 is trying to acquire lock: [23045.436044] (&ei->log_mutex){+.+...}, at: [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] but task is already holding lock: [23045.436044] (&ei->log_mutex){+.+...}, at: [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] other info that might help us debug this: [23045.436044] Possible unsafe locking scenario: [23045.436044] CPU0 [23045.436044] ---- [23045.436044] lock(&ei->log_mutex); [23045.436044] lock(&ei->log_mutex); [23045.436044] *** DEADLOCK *** [23045.436044] May be due to missing lock nesting notation [23045.436044] 3 locks held by xfs_io/3688: [23045.436044] #0: (&sb->s_type->i_mutex_key#15){+.+...}, at: [<ffffffffa035f2ae>] btrfs_sync_file+0x14e/0x425 [btrfs] [23045.436044] #1: (sb_internal#2){.+.+.+}, at: [<ffffffff8118446b>] __sb_start_write+0x5f/0xb0 [23045.436044] #2: (&ei->log_mutex){+.+...}, at: [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] stack backtrace: [23045.436044] CPU: 4 PID: 3688 Comm: xfs_io Not tainted 4.7.0-rc6-btrfs-next-34+ #1 [23045.436044] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 [23045.436044] 0000000000000000 ffff88022f5f7860 ffffffff8127074d ffffffff82a54b70 [23045.436044] ffffffff82a54b70 ffff88022f5f7920 ffffffff81092897 ffff880228015d68 [23045.436044] 0000000000000000 ffffffff82a54b70 ffffffff829c3f00 ffff880228015d68 [23045.436044] Call Trace: [23045.436044] [<ffffffff8127074d>] dump_stack+0x67/0x90 [23045.436044] [<ffffffff81092897>] __lock_acquire+0xcbb/0xe4e [23045.436044] [<ffffffff8109155f>] ? mark_lock+0x24/0x201 [23045.436044] [<ffffffff8109179a>] ? mark_held_locks+0x5e/0x74 [23045.436044] [<ffffffff81092de0>] lock_acquire+0x12f/0x1c3 [23045.436044] [<ffffffff81092de0>] ? lock_acquire+0x12f/0x1c3 [23045.436044] [<ffffffffa038552d>] ? btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] [<ffffffffa038552d>] ? btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] [<ffffffff814a51a4>] mutex_lock_nested+0x77/0x3a7 [23045.436044] [<ffffffffa038552d>] ? btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] [<ffffffffa039705e>] ? btrfs_release_delayed_node+0xb/0xd [btrfs] [23045.436044] [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] [<ffffffffa038552d>] ? btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] [<ffffffff810a0ed1>] ? vprintk_emit+0x453/0x465 [23045.436044] [<ffffffffa0385a61>] btrfs_log_inode+0x66e/0xc95 [btrfs] [23045.436044] [<ffffffffa03c084d>] log_new_dir_dentries+0x26c/0x359 [btrfs] [23045.436044] [<ffffffffa03865aa>] btrfs_log_inode_parent+0x4a6/0x628 [btrfs] [23045.436044] [<ffffffffa0387552>] btrfs_log_dentry_safe+0x5a/0x75 [btrfs] [23045.436044] [<ffffffffa035f464>] btrfs_sync_file+0x304/0x425 [btrfs] [23045.436044] [<ffffffff811acaf4>] vfs_fsync_range+0x8c/0x9e [23045.436044] [<ffffffff811acb22>] vfs_fsync+0x1c/0x1e [23045.436044] [<ffffffff811acc79>] do_fsync+0x31/0x4a [23045.436044] [<ffffffff811ace99>] SyS_fsync+0x10/0x14 [23045.436044] [<ffffffff814a88e5>] entry_SYSCALL_64_fastpath+0x18/0xa8 [23045.436044] [<ffffffff8108f039>] ? trace_hardirqs_off_caller+0x3f/0xaa An example reproducer for this is: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/dir $ touch /mnt/dir/foo $ sync $ mv /mnt/dir/foo /mnt/dir/bar $ touch /mnt/dir/foo $ xfs_io -c "fsync" /mnt/dir/bar This is because while logging the inode of file bar we end up logging its parent directory (since its inode has an unlink_trans field matching the current transaction id due to the rename operation), which in turn logs the inodes for all its new dentries, so that the new inode for the new file named foo gets logged which in turn triggered another logging attempt for the inode we are fsync'ing, since that inode had an old name that corresponds to the name of the new inode. So fix this by ensuring that when logging the inode for a new dentry that has a name matching an old name of some other inode, we don't log again the original inode that we are fsync'ing. Fixes: 44f714dae50a ("Btrfs: improve performance on fsync against new inode after rename/unlink") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: detect corruption when non-root leaf has zero itemLiu Bo2016-08-251-1/+22
| | | | | | | | | | | | | | | | | Right now we treat leaf which has zero item as a valid one because we could have an empty tree, that is, a root that is also a leaf without any item, however, in the same case but when the leaf is not a root, we can end up with hitting the BUG_ON(1) in btrfs_extend_item() called by setup_inline_extent_backref(). This makes us check the situation as a corruption if leaf is not its own root. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: check btree node's nritemsLiu Bo2016-08-251-0/+16
| | | | | | | | | | | | | | | | | | | When btree node (level = 1) has nritems which equals to zero, we can end up with panic due to insert_ptr()'s BUG_ON(slot > nritems); where slot is 1 and nritems is 0, as copy_for_split() calls insert_ptr(.., path->slots[1] + 1, ...); A invalid value results in the whole mess, this adds the check for btree's node nritems so that we stop reading block when when something is wrong. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: don't create or leak aliased root while cleaning up orphansJeff Mahoney2016-08-253-11/+22
| | | | | | | | | | | | | | | commit 909c3a22da3 (Btrfs: fix loading of orphan roots leading to BUG_ON) avoids the BUG_ON but can add an aliased root to the dead_roots list or leak the root. Since we've already been loading roots into the radix tree, we should use it before looking the root up on disk. Cc: <stable@vger.kernel.org> # 4.5 Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: fix em leak in find_first_block_groupJosef Bacik2016-08-251-0/+1
| | | | | | | | | We need to call free_extent_map() on the em we look up. Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: do not background blkdev_put()Anand Jain2016-08-251-8/+19
| | | | | | | | | | | | | | | At the end of unmount/dev-delete, if the device exclusive open is not actually closed, then there might be a race with another program in the userland who is trying to open the device in exclusive mode and it may fail for eg: unmount /btrfs; fsck /dev/x btrfs dev del /dev/x /btrfs; fsck /dev/x so here background blkdev_put() is not a choice Signed-off-by: Anand Jain <Anand.Jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: clarify do_chunk_alloc()'s return valueLiu Bo2016-08-251-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Function start_transaction() can return ERR_PTR(1) when flush is BTRFS_RESERVE_FLUSH_LIMIT, so the call graph is start_transaction (return ERR_PTR(1)) -> btrfs_block_rsv_add (return 1) -> reserve_metadata_bytes (return 1) -> flush_space (return 1) -> do_chunk_alloc (return 1) With BTRFS_RESERVE_FLUSH_LIMIT, if flush_space is already on the flush_state of ALLOC_CHUNK and it successfully allocates a new chunk, then instead of trying to reserve space again, reserve_metadata_bytes returns 1 immediately. Eventually the callers who call start_transaction() usually just do the IS_ERR() check which ERR_PTR(1) can pass, then it'll get a panic when dereferencing a pointer which is ERR_PTR(1). The following patch fixes the above problem. "btrfs: flush_space: treat return value of do_chunk_alloc properly" https://patchwork.kernel.org/patch/7778651/ This add comments to clarify do_chunk_alloc()'s return value. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: fix fsfreeze hang caused by delayed iputs dealWang Xiaoguang2016-08-254-1/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When running fstests generic/068, sometimes we got below deadlock: xfs_io D ffff8800331dbb20 0 6697 6693 0x00000080 ffff8800331dbb20 ffff88007acfc140 ffff880034d895c0 ffff8800331dc000 ffff880032d243e8 fffffffeffffffff ffff880032d24400 0000000000000001 ffff8800331dbb38 ffffffff816a9045 ffff880034d895c0 ffff8800331dbba8 Call Trace: [<ffffffff816a9045>] schedule+0x35/0x80 [<ffffffff816abab2>] rwsem_down_read_failed+0xf2/0x140 [<ffffffff8118f5e1>] ? __filemap_fdatawrite_range+0xd1/0x100 [<ffffffff8134f978>] call_rwsem_down_read_failed+0x18/0x30 [<ffffffffa06631fc>] ? btrfs_alloc_block_rsv+0x2c/0xb0 [btrfs] [<ffffffff810d32b5>] percpu_down_read+0x35/0x50 [<ffffffff81217dfc>] __sb_start_write+0x2c/0x40 [<ffffffffa067f5d5>] start_transaction+0x2a5/0x4d0 [btrfs] [<ffffffffa067f857>] btrfs_join_transaction+0x17/0x20 [btrfs] [<ffffffffa068ba34>] btrfs_evict_inode+0x3c4/0x5d0 [btrfs] [<ffffffff81230a1a>] evict+0xba/0x1a0 [<ffffffff812316b6>] iput+0x196/0x200 [<ffffffffa06851d0>] btrfs_run_delayed_iputs+0x70/0xc0 [btrfs] [<ffffffffa067f1d8>] btrfs_commit_transaction+0x928/0xa80 [btrfs] [<ffffffffa0646df0>] btrfs_freeze+0x30/0x40 [btrfs] [<ffffffff81218040>] freeze_super+0xf0/0x190 [<ffffffff81229275>] do_vfs_ioctl+0x4a5/0x5c0 [<ffffffff81003176>] ? do_audit_syscall_entry+0x66/0x70 [<ffffffff810038cf>] ? syscall_trace_enter_phase1+0x11f/0x140 [<ffffffff81229409>] SyS_ioctl+0x79/0x90 [<ffffffff81003c12>] do_syscall_64+0x62/0x110 [<ffffffff816acbe1>] entry_SYSCALL64_slow_path+0x25/0x25 >From this warning, freeze_super() already holds SB_FREEZE_FS, but btrfs_freeze() will call btrfs_commit_transaction() again, if btrfs_commit_transaction() finds that it has delayed iputs to handle, it'll start_transaction(), which will try to get SB_FREEZE_FS lock again, then deadlock occurs. The root cause is that in btrfs, sync_filesystem(sb) does not make sure all metadata is updated. There still maybe some codes adding delayed iputs, see below sample race window: CPU1 | CPU2 |-> freeze_super() | |-> sync_filesystem(sb); | | |-> cleaner_kthread() | | |-> btrfs_delete_unused_bgs() | | |-> btrfs_remove_chunk() | | |-> btrfs_remove_block_group() | | |-> btrfs_add_delayed_iput() | | |-> sb->s_writers.frozen = SB_FREEZE_FS; | |-> sb_wait_write(sb, SB_FREEZE_FS); | | acquire SB_FREEZE_FS lock. | | | |-> btrfs_freeze() | |-> btrfs_commit_transaction() | |-> btrfs_run_delayed_iputs() | | will handle delayed iputs, | | that means start_transaction() | | will be called, which will try | | to get SB_FREEZE_FS lock. | To fix this issue, introduce a "int fs_frozen" to record internally whether fs has been frozen. If fs has been frozen, we can not handle delayed iputs. Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> [ add comment to btrfs_freeze ] Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: update btrfs_space_info's bytes_may_use timelyWang Xiaoguang2016-08-257-63/+73
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch can fix some false ENOSPC errors, below test script can reproduce one false ENOSPC error: #!/bin/bash dd if=/dev/zero of=fs.img bs=$((1024*1024)) count=128 dev=$(losetup --show -f fs.img) mkfs.btrfs -f -M $dev mkdir /tmp/mntpoint mount $dev /tmp/mntpoint cd /tmp/mntpoint xfs_io -f -c "falloc 0 $((64*1024*1024))" testfile Above script will fail for ENOSPC reason, but indeed fs still has free space to satisfy this request. Please see call graph: btrfs_fallocate() |-> btrfs_alloc_data_chunk_ondemand() | bytes_may_use += 64M |-> btrfs_prealloc_file_range() |-> btrfs_reserve_extent() |-> btrfs_add_reserved_bytes() | alloc_type is RESERVE_ALLOC_NO_ACCOUNT, so it does not | change bytes_may_use, and bytes_reserved += 64M. Now | bytes_may_use + bytes_reserved == 128M, which is greater | than btrfs_space_info's total_bytes, false enospc occurs. | Note, the bytes_may_use decrease operation will be done in | end of btrfs_fallocate(), which is too late. Here is another simple case for buffered write: CPU 1 | CPU 2 | |-> cow_file_range() |-> __btrfs_buffered_write() |-> btrfs_reserve_extent() | | | | | | | | | ..... | |-> btrfs_check_data_free_space() | | | | |-> extent_clear_unlock_delalloc() | In CPU 1, btrfs_reserve_extent()->find_free_extent()-> btrfs_add_reserved_bytes() do not decrease bytes_may_use, the decrease operation will be delayed to be done in extent_clear_unlock_delalloc(). Assume in this case, btrfs_reserve_extent() reserved 128MB data, CPU2's btrfs_check_data_free_space() tries to reserve 100MB data space. If 100MB > data_sinfo->total_bytes - data_sinfo->bytes_used - data_sinfo->bytes_reserved - data_sinfo->bytes_pinned - data_sinfo->bytes_readonly - data_sinfo->bytes_may_use btrfs_check_data_free_space() will try to allcate new data chunk or call btrfs_start_delalloc_roots(), or commit current transaction in order to reserve some free space, obviously a lot of work. But indeed it's not necessary as long as decreasing bytes_may_use timely, we still have free space, decreasing 128M from bytes_may_use. To fix this issue, this patch chooses to update bytes_may_use for both data and metadata in btrfs_add_reserved_bytes(). For compress path, real extent length may not be equal to file content length, so introduce a ram_bytes argument for btrfs_reserve_extent(), find_free_extent() and btrfs_add_reserved_bytes(), it's becasue bytes_may_use is increased by file content length. Then compress path can update bytes_may_use correctly. Also now we can discard RESERVE_ALLOC_NO_ACCOUNT, RESERVE_ALLOC and RESERVE_FREE. As we know, usually EXTENT_DO_ACCOUNTING is used for error path. In run_delalloc_nocow(), for inode marked as NODATACOW or extent marked as PREALLOC, we also need to update bytes_may_use, but can not pass EXTENT_DO_ACCOUNTING, because it also clears metadata reservation, so here we introduce EXTENT_CLEAR_DATA_RESV flag to indicate btrfs_clear_bit_hook() to update btrfs_space_info's bytes_may_use. Meanwhile __btrfs_prealloc_file_range() will call btrfs_free_reserved_data_space() internally for both sucessful and failed path, btrfs_prealloc_file_range()'s callers does not need to call btrfs_free_reserved_data_space() any more. Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: divide btrfs_update_reserved_bytes() into two functionsWang Xiaoguang2016-08-251-40/+57
| | | | | | | | | | | | This patch divides btrfs_update_reserved_bytes() into btrfs_add_reserved_bytes() and btrfs_free_reserved_bytes(), and next patch will extend btrfs_add_reserved_bytes（）to fix some false ENOSPC error, please see later patch for detailed info. Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: use correct offset for reloc_inode in prealloc_file_extent_cluster()Wang Xiaoguang2016-08-251-4/+6
| | | | | | | | | | | | | | | | | In prealloc_file_extent_cluster(), btrfs_check_data_free_space() uses wrong file offset for reloc_inode, it uses cluster->start and cluster->end, which indeed are extent's bytenr. The correct value should be cluster->[start|end] minus block group's start bytenr. start bytenr cluster->start | | extent | extent | ...| extent | |----------------------------------------------------------------| | block group reloc_inode | Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: qgroup: Fix qgroup incorrectness caused by log replayQu Wenruo2016-08-251-0/+16
| | | | | | | | | | | | | | | | When doing log replay at mount time(after power loss), qgroup will leak numbers of replayed data extents. The cause is almost the same of balance. So fix it by manually informing qgroup for owner changed extents. The bug can be detected by btrfs/119 test case. Cc: Mark Fasheh <mfasheh@suse.de> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-and-Tested-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: relocation: Fix leaking qgroups numbers on data extentsQu Wenruo2016-08-251-6/+103
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes a REGRESSION introduced in 4.2, caused by the big quota rework. When balancing data extents, qgroup will leak all its numbers for relocated data extents. The relocation is done in the following steps for data extents: 1) Create data reloc tree and inode 2) Copy all data extents to data reloc tree And commit transaction 3) Create tree reloc tree(special snapshot) for any related subvolumes 4) Replace file extent in tree reloc tree with new extents in data reloc tree And commit transaction 5) Merge tree reloc tree with original fs, by swapping tree blocks For 1)~4), since tree reloc tree and data reloc tree doesn't count to qgroup, everything is OK. But for 5), the swapping of tree blocks will only info qgroup to track metadata extents. If metadata extents contain file extents, qgroup number for file extents will get lost, leading to corrupted qgroup accounting. The fix is, before commit transaction of step 5), manually info qgroup to track all file extents in data reloc tree. Since at commit transaction time, the tree swapping is done, and qgroup will account these data extents correctly. Cc: Mark Fasheh <mfasheh@suse.de> Reported-by: Mark Fasheh <mfasheh@suse.de> Reported-by: Filipe Manana <fdmanana@gmail.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Tested-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: qgroup: Refactor btrfs_qgroup_insert_dirty_extent()Qu Wenruo2016-08-254-47/+71
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Refactor btrfs_qgroup_insert_dirty_extent() function, to two functions: 1. btrfs_qgroup_insert_dirty_extent_nolock() Almost the same with original code. For delayed_ref usage, which has delayed refs locked. Change the return value type to int, since caller never needs the pointer, but only needs to know if they need to free the allocated memory. 2. btrfs_qgroup_insert_dirty_extent() The more encapsulated version. Will do the delayed_refs lock, memory allocation, quota enabled check and other things. The original design is to keep exported functions to minimal, but since more btrfs hacks exposed, like replacing path in balance, we need to record dirty extents manually, so we have to add such functions. Also, add comment for both functions, to info developers how to keep qgroup correct when doing hacks. Cc: Mark Fasheh <mfasheh@suse.de> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-and-Tested-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: waiting on qgroup rescan should not always be interruptibleJeff Mahoney2016-08-254-6/+13
| | | | | | | | | | | | | | | We wait on qgroup rescan completion in three places: file system shutdown, the quota disable ioctl, and the rescan wait ioctl. If the user sends a signal while we're waiting, we continue happily along. This is expected behavior for the rescan wait ioctl. It's racy in the shutdown path but mostly works due to other unrelated synchronization points. In the quota disable path, it Oopses the kernel pretty much immediately. Cc: <stable@vger.kernel.org> # v4.4+ Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: properly track when rescan worker is runningJeff Mahoney2016-08-253-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | The qgroup_flags field is overloaded such that it reflects the on-disk status of qgroups and the runtime state. The BTRFS_QGROUP_STATUS_FLAG_RESCAN flag is used to indicate that a rescan operation is in progress, but if the file system is unmounted while a rescan is running, the rescan operation is paused. If the file system is then mounted read-only, the flag will still be present but the rescan operation will not have been resumed. When we go to umount, btrfs_qgroup_wait_for_completion will see the flag and interpret it to mean that the rescan worker is still running and will wait for a completion that will never come. This patch uses a separate flag to indicate when the worker is running. The locking and state surrounding the qgroup rescan worker needs a lot of attention beyond this patch but this is enough to avoid a hung umount. Cc: <stable@vger.kernel.org> # v4.4+ Signed-off-by; Jeff Mahoney <jeffm@suse.com> Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: flush_space: treat return value of do_chunk_alloc properlyAlex Lyakas2016-08-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | do_chunk_alloc returns 1 when it succeeds to allocate a new chunk. But flush_space will not convert this to 0, and will also return 1. As a result, reserve_metadata_bytes will think that flush_space failed, and may potentially return this value "1" to the caller (depends how reserve_metadata_bytes was called). The caller will also treat this as an error. For example, btrfs_block_rsv_refill does: int ret = -ENOSPC; ... ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush); if (!ret) { block_rsv_add_bytes(block_rsv, num_bytes, 0); return 0; } return ret; So it will return -ENOSPC. Signed-off-by: Alex Lyakas <alex@zadarastorage.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: add ASSERT for block group's memory leakLiu Bo2016-08-251-0/+5
| | | | | | | | | This adds several ASSERT()' s to report memory leak of block group cache. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: backref: Fix soft lockup in __merge_refs functionQu Wenruo2016-08-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When over 1000 file extents refers to one extent, find_parent_nodes() will be obviously slow, due to the O(n^2)~O(n^3) loops inside __merge_refs(). The following ftrace shows the cubic growth of execution time: 256 refs 5) + 91.768 us | __add_keyed_refs.isra.12 [btrfs](); 5) 1.447 us | __add_missing_keys.isra.13 [btrfs](); 5) ! 114.544 us | __merge_refs [btrfs](); 5) ! 136.399 us | __merge_refs [btrfs](); 512 refs 6) ! 279.859 us | __add_keyed_refs.isra.12 [btrfs](); 6) 3.164 us | __add_missing_keys.isra.13 [btrfs](); 6) ! 442.498 us | __merge_refs [btrfs](); 6) # 2091.073 us | __merge_refs [btrfs](); and 1024 refs 7) ! 368.683 us | __add_keyed_refs.isra.12 [btrfs](); 7) 4.810 us | __add_missing_keys.isra.13 [btrfs](); 7) # 2043.428 us | __merge_refs [btrfs](); 7) * 18964.23 us | __merge_refs [btrfs](); And sort them into the following char: (Unit: us) ------------------------------------------------------------------------ Trace function | 256 ref | 512 refs | 1024 refs | ------------------------------------------------------------------------ __add_keyed_refs | 91 | 249 | 368 | __add_missing_keys | 1 | 3 | 4 | __merge_refs 1st call | 114 | 442 | 2043 | __merge_refs 2nd call | 136 | 2091 | 18964 | ------------------------------------------------------------------------ We can see the that __add_keyed_refs() grows almost in linear behavior. And __add_missing_keys() in this case doesn't change much or takes much time. While for the 1st __merge_refs() it's square growth for the 2nd __merge_refs() call it's cubic growth. It's no doubt that merge_refs() will take a long long time to execute if the number of refs continues its grows. So add a cond_resced() into the loop of __merge_refs(). Although this will solve the problem of soft lockup, we need to use the new rb_tree based structure introduced by Lu Fengqi to really solve the long execution time. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: fix memory leak of reloc_rootLiu Bo2016-08-251-1/+8
| | | | | | | | | | | | | | | | | | When some critical errors occur and FS would be flipped into RO, if we have an on-going balance, we can end up with a memory leak of root->reloc_root since btrfs_drop_snapshots() bails out without freeing reloc_root at the very early start. However, we're not able to free reloc_root in btrfs_drop_snapshots() because its caller, merge_reloc_roots(), still needs to access it to cleanup reloc_root's rbtree. This makes us free reloc_root when we're going to free fs/file roots. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* Merge branch 'integration-4.8' of ↵Chris Mason2016-08-056-59/+283
|\ | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/fdmanana/linux into for-linus-4.8
| * Btrfs: remove unused function btrfs_add_delayed_qgroup_reserve()Filipe Manana2016-08-032-30/+0
| | | | | | | | | | | | | | No longer used as of commit 5846a3c26873 ("btrfs: qgroup: Fix a race in delayed_ref which leads to abort trans"). Signed-off-by: Filipe Manana <fdmanana@suse.com>
| * Btrfs: improve performance on fsync against new inode after rename/unlinkFilipe Manana2016-08-012-9/+95
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") we got simple fix for a functional issue when the following sequence of actions is done: at transaction N create file A at directory D at transaction N + M (where M >= 1) move/rename existing file A from directory D to directory E create a new file named A at directory D fsync the new file power fail The solution was to simply detect such scenario and fallback to a full transaction commit when we detect it. However this turned out to had a significant impact on throughput (and a bit on latency too) for benchmarks using the dbench tool, which simulates real workloads from smbd (Samba) servers. For example on a test vm (with a debug kernel): Unpatched: Throughput 19.1572 MB/sec 32 clients 32 procs max_latency=1005.229 ms Patched: Throughput 23.7015 MB/sec 32 clients 32 procs max_latency=809.206 ms The patched results (this patch is applied) are similar to the results of a kernel with the commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") reverted. This change avoids the fallback to a transaction commit and instead makes sure all the names of the conflicting inode (the one that had a name in a past transaction that matches the name of the new file in the same parent directory) are logged so that at log replay time we don't lose neither the new file nor the old file, and the old file gets the name it was renamed to. This also ends up avoiding a full transaction commit for a similar case that involves an unlink instead of a rename of the old file: at transaction N create file A at directory D at transaction N + M (where M >= 1) remove file A create a new file named A at directory D fsync the new file power fail Signed-off-by: Filipe Manana <fdmanana@suse.com>
| * Btrfs: be more precise on errors when getting an inode from diskFilipe Manana2016-08-011-9/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | When we attempt to read an inode from disk, we end up always returning an -ESTALE error to the caller regardless of the actual failure reason, which can be an out of memory problem (when allocating a path), some error found when reading from the fs/subvolume btree (like a genuine IO error) or the inode does not exists. So lets start returning the real error code to the callers so that they don't treat all -ESTALE errors as meaning that the inode does not exists (such as during orphan cleanup). This will also be needed for a subsequent patch in the same series dealing with a special fsync case. Signed-off-by: Filipe Manana <fdmanana@suse.com>
| * Btrfs: send, don't bug on inconsistent snapshotsFilipe Manana2016-08-011-3/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When doing an incremental send, if we find a new/modified/deleted extent, reference or xattr without having previously processed the corresponding inode item we end up exexuting a BUG_ON(). This is because whenever an extent, xattr or reference is added, modified or deleted, we always expect to have the corresponding inode item updated. However there are situations where this will not happen due to transient -ENOMEM or -ENOSPC errors when doing delayed inode updates. For example, when punching holes we can succeed in deleting and modifying (shrinking) extents but later fail to do the delayed inode update. So after such failure we close our transaction handle and right after a snapshot of the fs/subvol tree can be made and used later for a send operation. The same thing can happen during truncate, link, unlink, and xattr related operations. So instead of executing a BUG_ON, make send return an -EIO error and print an informative error message do dmesg/syslog. Signed-off-by: Filipe Manana <fdmanana@suse.com>
| * Btrfs: send, avoid incorrect leaf accesses when sending utimes operationsFilipe Manana2016-08-011-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The caller of send_utimes() is supposed to be sure that the inode number it passes to this function does actually exists in the send snapshot. However due to logic/algorithm bugs (such as the one fixed by the patch titled "Btrfs: send, fix invalid leaf accesses due to incorrect utimes operations"), this might not be the case and when that happens it makes send_utimes() access use an unrelated leaf item as the target inode item or access beyond a leaf's boundaries (when the leaf is full and path->slots[0] matches the number of items in the leaf). So if the call to btrfs_search_slot() done by send_utimes() does not find the inode item, just make sure send_utimes() returns -ENOENT and does not silently accesses unrelated leaf items or does invalid leaf accesses, also allowing us to easialy and deterministically catch such algorithmic/logic bugs. Signed-off-by: Filipe Manana <fdmanana@suse.com>
| * Btrfs: send, fix invalid leaf accesses due to incorrect utimes operationsRobbie Ko2016-08-011-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During an incremental send, if we have delayed rename operations for inodes that were children of directories which were removed in the send snapshot, we can end up accessing incorrect items in a leaf or accessing beyond the last item of the leaf due to issuing utimes operations for the removed inodes. Consider the following example: Parent snapshot: . (ino 256) |--- a/ (ino 257) | |--- c/ (ino 262) | |--- b/ (ino 258) | |--- d/ (ino 263) | |--- del/ (ino 261) |--- x/ (ino 259) |--- y/ (ino 260) Send snapshot: . (ino 256) |--- a/ (ino 257) | |--- b/ (ino 258) | |--- c/ (ino 262) | |--- y/ (ino 260) | |--- d/ (ino 263) |--- x/ (ino 259) 1) When processing inodes 259 and 260, we end up delaying their rename operations because their parents, inodes 263 and 262 respectively, were not yet processed and therefore not yet renamed; 2) When processing inode 262, its rename operation is issued and right after the rename operation for inode 260 is issued. However right after issuing the rename operation for inode 260, at send.c:apply_dir_move(), we issue utimes operations for all current and past parents of inode 260. This means we try to send a utimes operation for its old parent, inode 261 (deleted in the send snapshot), which does not cause any immediate and deterministic failure, because when the target inode is not found in the send snapshot, the send.c:send_utimes() function ignores it and uses the leaf region pointed to by path->slots[0], which can be any unrelated item (belonging to other inode) or it can be a region outside the leaf boundaries, if the leaf is full and path->slots[0] matches the number of items in the leaf. So we end up either successfully sending a utimes operation, which is fine and irrelevant because the old parent (inode 261) will end up being deleted later, or we end up doing an invalid memory access tha crashes the kernel. So fix this by making apply_dir_move() issue utimes operations only for parents that still exist in the send snapshot. In a separate patch we will make send_utimes() return an error (-ENOENT) if the given inode does not exists in the send snapshot. Signed-off-by: Robbie Ko <robbieko@synology.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> [Rewrote change log to be more detailed and better organized] Signed-off-by: Filipe Manana <fdmanana@suse.com>
| * Btrfs: send, fix warning due to late freeing of orphan_dir_info structuresRobbie Ko2016-08-011-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Under certain situations, when doing an incremental send, we can end up not freeing orphan_dir_info structures as soon as they are no longer needed. Instead we end up freeing them only after finishing the send stream, which causes a warning to be emitted: [282735.229200] ------------[ cut here ]------------ [282735.229968] WARNING: CPU: 9 PID: 10588 at fs/btrfs/send.c:6298 btrfs_ioctl_send+0xe2f/0xe51 [btrfs] [282735.231282] Modules linked in: btrfs crc32c_generic xor raid6_pq acpi_cpufreq tpm_tis ppdev tpm parport_pc psmouse parport sg pcspkr i2c_piix4 i2c_core evdev processor serio_raw button loop autofs4 ext4 crc16 jbd2 mbcache sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy [last unloaded: btrfs] [282735.237130] CPU: 9 PID: 10588 Comm: btrfs Tainted: G W 4.6.0-rc7-btrfs-next-31+ #1 [282735.239309] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [282735.240160] 0000000000000000 ffff880224273ca8 ffffffff8126b42c 0000000000000000 [282735.240160] 0000000000000000 ffff880224273ce8 ffffffff81052b14 0000189a24273ac8 [282735.240160] ffff8802210c9800 0000000000000000 0000000000000001 0000000000000000 [282735.240160] Call Trace: [282735.240160] [<ffffffff8126b42c>] dump_stack+0x67/0x90 [282735.240160] [<ffffffff81052b14>] __warn+0xc2/0xdd [282735.240160] [<ffffffff81052beb>] warn_slowpath_null+0x1d/0x1f [282735.240160] [<ffffffffa03c99d5>] btrfs_ioctl_send+0xe2f/0xe51 [btrfs] [282735.240160] [<ffffffffa0398358>] btrfs_ioctl+0x14f/0x1f81 [btrfs] [282735.240160] [<ffffffff8108e456>] ? arch_local_irq_save+0x9/0xc [282735.240160] [<ffffffff8118da05>] vfs_ioctl+0x18/0x34 [282735.240160] [<ffffffff8118e00c>] do_vfs_ioctl+0x550/0x5be [282735.240160] [<ffffffff81196f0c>] ? __fget+0x6b/0x77 [282735.240160] [<ffffffff81196fa1>] ? __fget_light+0x62/0x71 [282735.240160] [<ffffffff8118e0d1>] SyS_ioctl+0x57/0x79 [282735.240160] [<ffffffff8149e025>] entry_SYSCALL_64_fastpath+0x18/0xa8 [282735.240160] [<ffffffff81100c6b>] ? time_hardirqs_off+0x9/0x14 [282735.240160] [<ffffffff8108e87d>] ? trace_hardirqs_off_caller+0x1f/0xaa [282735.256343] ---[ end trace a4539270c8056f93 ]--- Consider the following example: Parent snapshot: . (ino 256) |--- a/ (ino 257) | |--- c/ (ino 260) | |--- del/ (ino 259) |--- tmp/ (ino 258) |--- x/ (ino 261) |--- y/ (ino 262) Send snapshot: . (ino 256) |--- a/ (ino 257) | |--- x/ (ino 261) | |--- y/ (ino 262) | |--- c/ (ino 260) |--- tmp/ (ino 258) 1) When processing inode 258, we end up delaying its rename operation because it has an ancestor (in the send snapshot) that has a higher inode number (inode 260) which was also renamed in the send snapshot, therefore we delay the rename of inode 258 so that it happens after inode 260 is renamed; 2) When processing inode 259, we end up delaying its deletion (rmdir operation) because it has a child inode (258) that has its rename operation delayed. At this point we allocate an orphan_dir_info structure and tag inode 258 so that we later attempt to see if we can delete (rmdir) inode 259 once inode 258 is renamed; 3) When we process inode 260, after renaming it we finally do the rename operation for inode 258. Once we issue the rename operation for inode 258 we notice that this inode was tagged so that we attempt to see if at this point we can delete (rmdir) inode 259. But at this point we can not still delete inode 259 because it has 2 children, inodes 261 and 262, that were not yet processed and therefore not yet moved (renamed) away from inode 259. We end up not freeing the orphan_dir_info structure allocated in step 2; 4) We process inodes 261 and 262, and once we move/rename inode 262 we issue the rmdir operation for inode 260; 5) We finish the send stream and notice that red black tree that contains orphan_dir_info structures is not empty, so we emit a warning and then free any orphan_dir_structures left. So fix this by freeing an orphan_dir_info structure once we try to apply a pending rename operation if we can not delete yet the tagged directory. A test case for fstests follows soon. Signed-off-by: Robbie Ko <robbieko@synology.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> [Modified changelog to be more detailed and easier to understand]
| * Btrfs: incremental send, fix premature rmdir operationsRobbie Ko2016-08-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Under certain situations, an incremental send operation can contain a rmdir operation that will make the receiving end fail when attempting to execute it, because the target directory is not yet empty. Consider the following example: Parent snapshot: . (ino 256) |--- a/ (ino 257) | |--- c/ (ino 260) | |--- del/ (ino 259) |--- tmp/ (ino 258) |--- x/ (ino 261) Send snapshot: . (ino 256) |--- a/ (ino 257) | |--- x/ (ino 261) | |--- c/ (ino 260) |--- tmp/ (ino 258) 1) When processing inode 258, we delay its rename operation because inode 260 is its new parent in the send snapshot and it was not yet renamed (since 260 > 258, that is, beyond the current progress); 2) When processing inode 259, we realize we can not yet send an rmdir operation (against inode 259) because inode 258 was still not yet renamed/moved away from inode 259. Therefore we update data structures so that after inode 258 is renamed, we try again to see if we can finally send an rmdir operation for inode 259; 3) When we process inode 260, we send a rename operation for it followed by a rename operation for inode 258. Once we send the rename operation for inode 258 we then check if we can finally issue an rmdir for its previous parent, inode 259, by calling the can_rmdir() function with a value of sctx->cur_ino + 1 (260 + 1 = 261) for its "progress" argument. This makes can_rmdir() return true (value 1) because even though there's still a child inode of inode 259 that was not yet renamed/moved, which is inode 261, the given value of progress (261) is not lower then 261 (that is, not lower than the inode number of some child of inode 259). So we end up sending a rmdir operation for inode 259 before its child inode 261 is processed and renamed. So fix this by passing the correct progress value to the call to can_rmdir() from within apply_dir_move() (where we issue delayed rename operations), which should match stcx->cur_ino (the number of the inode currently being processed) and not sctx->cur_ino + 1. A test case for fstests follows soon. Signed-off-by: Robbie Ko <robbieko@synology.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> [Rewrote change log to be more detailed, clear and well formatted] Signed-off-by: Filipe Manana <fdmanana@suse.com>
| * Btrfs: incremental send, fix invalid paths for rename operationsFilipe Manana2016-08-011-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Example scenario: Parent snapshot: . (ino 277) |---- tmp/ (ino 278) |---- pre/ (ino 280) | |---- wait_dir/ (ino 281) | |---- desc/ (ino 282) |---- ance/ (ino 283) | |---- below_ance/ (ino 279) | |---- other_dir/ (ino 284) Send snapshot: . (ino 277) |---- tmp/ (ino 278) |---- other_dir/ (ino 284) |---- below_ance/ (ino 279) | |---- pre/ (ino 280) | |---- wait_dir/ (ino 281) |---- desc/ (ino 282) |---- ance/ (ino 283) While computing the send stream the following steps happen: 1) While processing inode 279 we end up delaying its rename operation because its new parent in the send snapshot, inode 284, was not yet processed and therefore not yet renamed; 2) Later when processing inode 280 we end up renaming it immediately to "ance/below_once/pre" and not delay its rename operation because its new parent (inode 279 in the send snapshot) has its rename operation delayed and inode 280 is not an encestor of inode 279 (its parent in the send snapshot) in the parent snapshot; 3) When processing inode 281 we end up delaying its rename operation because its new parent in the send snapshot, inode 284, was not yet processed and therefore not yet renamed; 4) When processing inode 282 we do not delay its rename operation because its parent in the send snapshot, inode 281, already has its own rename operation delayed and our current inode (282) is not an ancestor of inode 281 in the parent snapshot. Therefore inode 282 is renamed to "ance/below_ance/pre/wait_dir"; 5) When processing inode 283 we realize that we can rename it because one of its ancestors in the send snapshot, inode 281, has its rename operation delayed and inode 283 is not an ancestor of inode 281 in the parent snapshot. So a rename operation to rename inode 283 to "ance/below_ance/pre/wait_dir/desc/ance" is issued. This path is invalid due to a missing path building loop that was undetected by the incremental send implementation, as inode 283 ends up getting included twice in the path (once with its path in the parent snapshot). Therefore its rename operation must wait before the ancestor inode 284 is renamed. Fix this by not terminating the rename dependency checks when we find an ancestor, in the send snapshot, that has its rename operation delayed. So that we continue doing the same checks if the current inode is not an ancestor, in the parent snapshot, of an ancestor in the send snapshot we are processing in the loop. The problem and reproducer were reported by Robbie Ko, as part of a patch titled "Btrfs: incremental send, avoid ancestor rename to descendant". However the fix was unnecessarily complicated and can be addressed with much less code and effort. Reported-by: Robbie Ko <robbieko@synology.com> Signed-off-by: Filipe Manana <fdmanana@suse.com>
| * Btrfs: send, add missing error check for calls to path_loop()Filipe Manana2016-08-011-0/+2
| | | | | | | | | | | | | | | | | | | | The function path_loop() can return a negative integer, signaling an error, 0 if there's no path loop and 1 if there's a path loop. We were treating any non zero values as meaning that a path loop exists. Fix this by explicitly checking for errors and gracefully return them to user space. Signed-off-by: Filipe Manana <fdmanana@suse.com>
| * Btrfs: send, fix failure to move directories with the same name aroundRobbie Ko2016-08-011-5/+95
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When doing an incremental send we can end up not moving directories that have the same name. This happens when the same parent directory has different child directories with the same name in the parent and send snapshots. For example, consider the following scenario: Parent snapshot: . (ino 256) |---- d/ (ino 257) | |--- p1/ (ino 258) | |---- p1/ (ino 259) Send snapshot: . (ino 256) |--- d/ (ino 257) |--- p1/ (ino 259) |--- p1/ (ino 258) The directory named "d" (inode 257) has in both snapshots an entry with the name "p1" but it refers to different inodes in both snapshots (inode 258 in the parent snapshot and inode 259 in the send snapshot). When attempting to move inode 258, the operation is delayed because its new parent, inode 259, was not yet moved/renamed (as the stream is currently processing inode 258). Then when processing inode 259, we also end up delaying its move/rename operation so that it happens after inode 258 is moved/renamed. This decision to delay the move/rename rename operation of inode 259 is due to the fact that the new parent inode (257) still has inode 258 as its child, which has the same name has inode 259. So we end up with inode 258 move/rename operation waiting for inode's 259 move/rename operation, which in turn it waiting for inode's 258 move/rename. This results in ending the send stream without issuing move/rename operations for inodes 258 and 259 and generating the following warnings in syslog/dmesg: [148402.979747] ------------[ cut here ]------------ [148402.980588] WARNING: CPU: 14 PID: 4117 at fs/btrfs/send.c:6177 btrfs_ioctl_send+0xe03/0xe51 [btrfs] [148402.981928] Modules linked in: btrfs crc32c_generic xor raid6_pq acpi_cpufreq tpm_tis ppdev tpm parport_pc psmouse parport sg pcspkr i2c_piix4 i2c_core evdev processor serio_raw button loop autofs4 ext4 crc16 jbd2 mbcache sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy [last unloaded: btrfs] [148402.986999] CPU: 14 PID: 4117 Comm: btrfs Tainted: G W 4.6.0-rc7-btrfs-next-31+ #1 [148402.988136] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [148402.988136] 0000000000000000 ffff88022139fca8 ffffffff8126b42c 0000000000000000 [148402.988136] 0000000000000000 ffff88022139fce8 ffffffff81052b14 000018212139fac8 [148402.988136] ffff88022b0db400 0000000000000000 0000000000000001 0000000000000000 [148402.988136] Call Trace: [148402.988136] [<ffffffff8126b42c>] dump_stack+0x67/0x90 [148402.988136] [<ffffffff81052b14>] __warn+0xc2/0xdd [148402.988136] [<ffffffff81052beb>] warn_slowpath_null+0x1d/0x1f [148402.988136] [<ffffffffa04bc831>] btrfs_ioctl_send+0xe03/0xe51 [btrfs] [148402.988136] [<ffffffffa048b358>] btrfs_ioctl+0x14f/0x1f81 [btrfs] [148402.988136] [<ffffffff8108e456>] ? arch_local_irq_save+0x9/0xc [148402.988136] [<ffffffff8108eb51>] ? __lock_is_held+0x3c/0x57 [148402.988136] [<ffffffff8118da05>] vfs_ioctl+0x18/0x34 [148402.988136] [<ffffffff8118e00c>] do_vfs_ioctl+0x550/0x5be [148402.988136] [<ffffffff81196f0c>] ? __fget+0x6b/0x77 [148402.988136] [<ffffffff81196fa1>] ? __fget_light+0x62/0x71 [148402.988136] [<ffffffff8118e0d1>] SyS_ioctl+0x57/0x79 [148402.988136] [<ffffffff8149e025>] entry_SYSCALL_64_fastpath+0x18/0xa8 [148402.988136] [<ffffffff8108e89d>] ? trace_hardirqs_off_caller+0x3f/0xaa [148403.011373] ---[ end trace a4539270c8056f8b ]--- [148403.012296] ------------[ cut here ]------------ [148403.013071] WARNING: CPU: 14 PID: 4117 at fs/btrfs/send.c:6194 btrfs_ioctl_send+0xe19/0xe51 [btrfs] [148403.014447] Modules linked in: btrfs crc32c_generic xor raid6_pq acpi_cpufreq tpm_tis ppdev tpm parport_pc psmouse parport sg pcspkr i2c_piix4 i2c_core evdev processor serio_raw button loop autofs4 ext4 crc16 jbd2 mbcache sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy [last unloaded: btrfs] [148403.019708] CPU: 14 PID: 4117 Comm: btrfs Tainted: G W 4.6.0-rc7-btrfs-next-31+ #1 [148403.020104] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [148403.020104] 0000000000000000 ffff88022139fca8 ffffffff8126b42c 0000000000000000 [148403.020104] 0000000000000000 ffff88022139fce8 ffffffff81052b14 000018322139fac8 [148403.020104] ffff88022b0db400 0000000000000000 0000000000000001 0000000000000000 [148403.020104] Call Trace: [148403.020104] [<ffffffff8126b42c>] dump_stack+0x67/0x90 [148403.020104] [<ffffffff81052b14>] __warn+0xc2/0xdd [148403.020104] [<ffffffff81052beb>] warn_slowpath_null+0x1d/0x1f [148403.020104] [<ffffffffa04bc847>] btrfs_ioctl_send+0xe19/0xe51 [btrfs] [148403.020104] [<ffffffffa048b358>] btrfs_ioctl+0x14f/0x1f81 [btrfs] [148403.020104] [<ffffffff8108e456>] ? arch_local_irq_save+0x9/0xc [148403.020104] [<ffffffff8108eb51>] ? __lock_is_held+0x3c/0x57 [148403.020104] [<ffffffff8118da05>] vfs_ioctl+0x18/0x34 [148403.020104] [<ffffffff8118e00c>] do_vfs_ioctl+0x550/0x5be [148403.020104] [<ffffffff81196f0c>] ? __fget+0x6b/0x77 [148403.020104] [<ffffffff81196fa1>] ? __fget_light+0x62/0x71 [148403.020104] [<ffffffff8118e0d1>] SyS_ioctl+0x57/0x79 [148403.020104] [<ffffffff8149e025>] entry_SYSCALL_64_fastpath+0x18/0xa8 [148403.020104] [<ffffffff8108e89d>] ? trace_hardirqs_off_caller+0x3f/0xaa [148403.038981] ---[ end trace a4539270c8056f8c ]--- There's another issue caused by similar (but more complex) changes in the directory hierarchy that makes move/rename operations fail, described with the following example: Parent snapshot: . |---- a/ (ino 262) | |---- c/ (ino 268) | |---- d/ (ino 263) |---- ance/ (ino 267) |---- e/ (ino 264) |---- f/ (ino 265) |---- ance/ (ino 266) Send snapshot: . |---- a/ (ino 262) |---- c/ (ino 268) | |---- ance/ (ino 267) | |---- d/ (ino 263) | |---- ance/ (ino 266) | |---- f/ (ino 265) |---- e/ (ino 264) When the inode 265 is processed, the path for inode 267 is computed, which at that time corresponds to "d/ance", and it's stored in the names cache. Later on when processing inode 266, we end up orphanizing (renaming to a name matching the pattern o<ino>-<gen>-<seq>) inode 267 because it has the same name as inode 266 and it's currently a child of the new parent directory (inode 263) for inode 266. After the orphanization and while we are still processing inode 266, a rename operation for inode 266 is generated. However the source path for that rename operation is incorrect because it ends up using the old, pre-orphanization, name of inode 267. The no longer valid name for inode 267 was previously cached when processing inode 265 and it remains usable and considered valid until the inode currently being processed has a number greater than 267. This resulted in the receiving side failing with the following error: ERROR: rename d/ance/ance -> d/ance failed: No such file or directory So fix these issues by detecting such circular dependencies for rename operations and by clearing the cached name of an inode once the inode is orphanized. A test case for fstests will follow soon. Signed-off-by: Robbie Ko <robbieko@synology.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> [Rewrote change log to be more detailed and organized, and improved comments] Signed-off-by: Filipe Manana <fdmanana@suse.com>
| * Btrfs: add missing check for writeback errors on fsyncFilipe Manana2016-08-011-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we start an fsync we start ordered extents for all delalloc ranges. However before attempting to log the inode, we only wait for those ordered extents if we are not doing a full sync (bit BTRFS_INODE_NEEDS_FULL_SYNC is set in the inode's flags). This means that if an ordered extent completes with an IO error before we check if we can skip logging the inode, we will not catch and report the IO error to user space. This is because on an IO error, when the ordered extent completes we do not update the inode, so if the inode was not previously updated by the current transaction we end up not logging it through calls to fsync and therefore not check its mapping flags for the presence of IO errors. Fix this by checking for errors in the flags of the inode's mapping when we notice we can skip logging the inode. This caused sporadic failures in the test generic/331 (which explicitly tests for IO errors during an fsync call). Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
* | Btrfs: fix __MAX_CSUM_ITEMSChris Mason2016-08-031-2/+3
| | | | | | | | | | | | | | | | | | Jeff Mahoney's cleanup commit (14a1e067b4) wasn't correct for csums on machines where the pagesize >= metadata blocksize. This just reverts the relevant hunks to bring the old math back. Signed-off-by: Chris Mason <clm@fb.com>
* | btrfs: btrfs_abort_transaction, drop root parameterJeff Mahoney2016-07-2617-152/+147
| | | | | | | | | | | | | | | | | | __btrfs_abort_transaction doesn't use its root parameter except to obtain an fs_info pointer. We can obtain that from trans->root->fs_info for now and from trans->fs_info in a later patch. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* | btrfs: add btrfs_trans_handle->fs_info pointerJeff Mahoney2016-07-264-4/+6
| | | | | | | | | | | | | | | | | | | | | | btrfs_trans_handle->root is documented as for use for confirming that the root passed in to start the transaction is the same as the one ending it. It's used in several places when an fs_info pointer is needed, so let's just add an fs_info pointer directly. Eventually, the root pointer can be removed. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* | btrfs: btrfs_relocate_chunk pass extent_root to btrfs_end_transactionJeff Mahoney2016-07-261-1/+1
| | | | | | | | | | | | | | | | | | | | In btrfs_relocate_chunk, we get a transaction handle via btrfs_start_trans_remove_block_group, which starts the transaction using the extent root. When we call btrfs_end_transaction, we're calling it using the chunk root. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* | btrfs: convert nodesize macros to static inlinesJeff Mahoney2016-07-261-15/+33
| | | | | | | | | | | | | | | | This patch converts the macros used to calculate various node size limits to static inlines. That way we get type checking for free. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* | btrfs: introduce BTRFS_MAX_ITEM_SIZEJeff Mahoney2016-07-264-10/+8
| | | | | | | | | | | | | | | | | | We use BTRFS_LEAF_DATA_SIZE - sizeof(struct btrfs_item) in several places. This introduces a BTRFS_MAX_ITEM_SIZE macro to do the same. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* | btrfs: cleanup, remove prototype for btrfs_find_root_refJeff Mahoney2016-07-261-3/+0
| | | | | | | | | | | | | | The function isn't implemented anywhere. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* | btrfs: copy_to_sk drop unused root parameterJeff Mahoney2016-07-261-3/+2
| | | | | | | | | | | | | | The root parameter for copy_to_sk is not used at all. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* | btrfs: simpilify btrfs_subvol_inherit_propsJeff Mahoney2016-07-261-3/+3
| | | | | | | | | | | | | | | | | | | | | | We just need a superblock, but we look it up using two different roots depending on the call site. Let's just use a superblock pointer initialized at the outset. This is mostly for Coccinelle not to choke on my root push up set. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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