kernel/git/stable/linux.git/fs/btrfs/tree-defrag.c, branch master

btrfs: rename tree-defrag.c to defrag.c

2022-12-05T17:00:45+00:00

This currently has only one helper in it, and it's for tree based defrag. We have the various defrag code in 3 different places, so rename this to defrag.c. Followup patches will move the code into this new file. Reviewed-by: Johannes Thumshirn Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: move accessor helpers into accessors.h

2022-12-05T17:00:42+00:00

This is a large patch, but because they're all macros it's impossible to split up. Simply copy all of the item accessors in ctree.h and paste them in accessors.h, and then update any files to include the header so everything compiles. Reviewed-by: Anand Jain Signed-off-by: Josef Bacik Reviewed-by: David Sterba [ reformat comments, style fixups ] Signed-off-by: David Sterba

btrfs: remove unnecessary extent root check in btrfs_defrag_leaves

2022-01-03T14:09:48+00:00

We only defrag leaves on roots that have SHAREABLE set, so we don't need to check if we're the extent root as it doesn't have SHAREABLE set. Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: locking: remove all the blocking helpers

2020-12-08T14:54:01+00:00

Now that we're using a rw_semaphore we no longer need to indicate if a lock is blocking or not, nor do we need to flip the entire path from blocking to spinning. Remove these helpers and all the places they are called. Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: remove unused btrfs_root::defrag_trans_start

2020-07-27T10:55:28+00:00

Last touched in 2013 by commit de78b51a2852 ("btrfs: remove cache only arguments from defrag path") that was the only code that used the value. Now it's only set but never used for anything, so we can remove it. Reviewed-by: Nikolay Borisov Reviewed-by: Anand Jain Signed-off-by: David Sterba

btrfs: rename BTRFS_ROOT_REF_COWS to BTRFS_ROOT_SHAREABLE

2020-05-25T09:25:35+00:00

The name BTRFS_ROOT_REF_COWS is not very clear about the meaning. In fact, that bit can only be set to those trees: - Subvolume roots - Data reloc root - Reloc roots for above roots All other trees won't get this bit set. So just by the result, it is obvious that, roots with this bit set can have tree blocks shared with other trees. Either shared by snapshots, or by reloc roots (an special snapshot created by relocation). This patch will rename BTRFS_ROOT_REF_COWS to BTRFS_ROOT_SHAREABLE to make it easier to understand, and update all comment mentioning "reference counted" to follow the rename. Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: open code now trivial btrfs_set_lock_blocking

2019-02-25T13:13:27+00:00

btrfs_set_lock_blocking is now only a simple wrapper around btrfs_set_lock_blocking_write. The name does not bring any semantic value that could not be inferred from the new function so there's no point keeping it. Reviewed-by: Johannes Thumshirn Signed-off-by: David Sterba

btrfs: replace GPL boilerplate by SPDX -- sources

2018-04-12T14:29:51+00:00

Remove GPL boilerplate text (long, short, one-line) and keep the rest, ie. personal, company or original source copyright statements. Add the SPDX header. Signed-off-by: David Sterba

btrfs: add define for oldest generation

2018-03-30T23:26:50+00:00

Some functions can filter metadata by the generation. Add a define that will annotate such arguments. Signed-off-by: Anand Jain Reviewed-by: David Sterba [ update changelog ] Signed-off-by: David Sterba

Btrfs: fix locking bugs when defragging leaves

2015-12-18T02:51:32+00:00

When running fstests btrfs/070, with a higher number of fsstress operations, I ran frequently into two different locking bugs when defragging directories. The first bug produced the following traces: [133860.229792] ------------[ cut here ]------------ [133860.251062] WARNING: CPU: 2 PID: 26057 at fs/btrfs/locking.c:46 btrfs_set_lock_blocking_rw+0x57/0xbd [btrfs]() [133860.253576] Modules linked in: btrfs crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop fuse parport_pc i2c_piix4 psmouse parport [133860.282566] CPU: 2 PID: 26057 Comm: btrfs Tainted: G W 4.3.0-rc5-btrfs-next-17+ #1 [133860.284393] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014 [133860.286827] 0000000000000000 ffff880207697b78 ffffffff812566f4 0000000000000000 [133860.288341] ffff880207697bb0 ffffffff8104d0a6 ffffffffa052d4c1 ffff880178f60e00 [133860.294219] ffff880178f60e00 0000000000000000 00000000000000f6 ffff880207697bc0 [133860.295831] Call Trace: [133860.306518] [] dump_stack+0x4e/0x79 [133860.307473] [] warn_slowpath_common+0x9f/0xb8 [133860.308619] [] ? btrfs_set_lock_blocking_rw+0x57/0xbd [btrfs] [133860.310068] [] warn_slowpath_null+0x1a/0x1c [133860.312552] [] btrfs_set_lock_blocking_rw+0x57/0xbd [btrfs] [133860.314630] [] btrfs_set_lock_blocking+0xe/0x10 [btrfs] [133860.323596] [] btrfs_realloc_node+0xb3/0x341 [btrfs] [133860.325233] [] btrfs_defrag_leaves+0x239/0x2fa [btrfs] [133860.332427] [] btrfs_defrag_root+0x63/0xca [btrfs] [133860.337259] [] btrfs_ioctl_defrag+0x78/0x14e [btrfs] [133860.340147] [] btrfs_ioctl+0x746/0x24c6 [btrfs] [133860.344833] [] ? arch_local_irq_save+0x9/0xc [133860.346343] [] ? __might_fault+0x4c/0xa7 [133860.353248] [] ? __might_fault+0x4c/0xa7 [133860.354242] [] ? __might_fault+0xa5/0xa7 [133860.355232] [] ? cp_new_stat+0x15d/0x174 [133860.356237] [] do_vfs_ioctl+0x427/0x4e6 [133860.358587] [] ? SYSC_newfstat+0x25/0x2e [133860.360195] [] ? __fget_light+0x4d/0x71 [133860.361380] [] SyS_ioctl+0x57/0x79 [133860.363578] [] entry_SYSCALL_64_fastpath+0x12/0x6f [133860.366217] ---[ end trace 2cadb2f653437e49 ]--- [133860.367399] ------------[ cut here ]------------ [133860.368162] kernel BUG at fs/btrfs/locking.c:307! [133860.369430] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [133860.370205] Modules linked in: btrfs crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop fuse parport_pc i2c_piix4 psmouse parport [133860.370205] CPU: 2 PID: 26057 Comm: btrfs Tainted: G W 4.3.0-rc5-btrfs-next-17+ #1 [133860.370205] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014 [133860.370205] task: ffff8800aec6db40 ti: ffff880207694000 task.ti: ffff880207694000 [133860.370205] RIP: 0010:[] [] btrfs_assert_tree_locked+0x10/0x14 [btrfs] [133860.370205] RSP: 0018:ffff880207697bc0 EFLAGS: 00010246 [133860.370205] RAX: 0000000000000000 RBX: ffff880178f60e00 RCX: 0000000000000000 [133860.370205] RDX: ffff88023ec4fb50 RSI: 00000000ffffffff RDI: ffff880178f60e00 [133860.370205] RBP: ffff880207697bc0 R08: 0000000000000001 R09: 0000000000000000 [133860.370205] R10: 0000160000000000 R11: ffffffff81651000 R12: ffff880178f60e00 [133860.370205] R13: 0000000000000000 R14: 00000000000000f6 R15: ffff8801ff409000 [133860.370205] FS: 00007f763efd48c0(0000) GS:ffff88023ec40000(0000) knlGS:0000000000000000 [133860.370205] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [133860.370205] CR2: 0000000002158048 CR3: 000000003fd6c000 CR4: 00000000000006e0 [133860.370205] Stack: [133860.370205] ffff880207697bd8 ffffffffa052d4d0 0000000000000000 ffff880207697be8 [133860.370205] ffffffffa04d5787 ffff880207697c80 ffffffffa04d99cb ffff8801ff409590 [133860.370205] ffff880207697ca8 000000f507697c80 ffff880183c11bb8 0000000000000000 [133860.370205] Call Trace: [133860.370205] [] btrfs_set_lock_blocking_rw+0x66/0xbd [btrfs] [133860.370205] [] btrfs_set_lock_blocking+0xe/0x10 [btrfs] [133860.370205] [] btrfs_realloc_node+0xb3/0x341 [btrfs] [133860.370205] [] btrfs_defrag_leaves+0x239/0x2fa [btrfs] [133860.370205] [] btrfs_defrag_root+0x63/0xca [btrfs] [133860.370205] [] btrfs_ioctl_defrag+0x78/0x14e [btrfs] [133860.370205] [] btrfs_ioctl+0x746/0x24c6 [btrfs] [133860.370205] [] ? arch_local_irq_save+0x9/0xc [133860.370205] [] ? __might_fault+0x4c/0xa7 [133860.370205] [] ? __might_fault+0x4c/0xa7 [133860.370205] [] ? __might_fault+0xa5/0xa7 [133860.370205] [] ? cp_new_stat+0x15d/0x174 [133860.370205] [] do_vfs_ioctl+0x427/0x4e6 [133860.370205] [] ? SYSC_newfstat+0x25/0x2e [133860.370205] [] ? __fget_light+0x4d/0x71 [133860.370205] [] SyS_ioctl+0x57/0x79 [133860.370205] [] entry_SYSCALL_64_fastpath+0x12/0x6f This bug happened because we assumed that by setting keep_locks to 1 in our search path, our path after a call to btrfs_search_slot() would have all nodes locked, which is not always true because unlock_up() (called by btrfs_search_slot()) will unlock a node in a path if the slot of the node below it doesn't point to the last item or beyond the last item. For example, when the tree has a heigth of 2 and path->slots[0] has a value smaller than btrfs_header_nritems(path->nodes[0]) - 1, the node at level 2 will be unlocked (also because lowest_unlock is set to 1 due to the fact that the value passed as ins_len to btrfs_search_slot is 0). This resulted in btrfs_find_next_key(), called before btrfs_realloc_node(), to release out path and call again btrfs_search_slot(), but this time with the cow parameter set to 0, meaning the resulting path got only read locks. Therefore when we called btrfs_realloc_node(), with path->nodes[1] having a read lock, it resulted in the warning and BUG_ON when calling btrfs_set_lock_blocking() against the node, as that function expects the node to have a write lock. The second bug happened often when the first bug didn't happen, and made us hang and hitting the following warning at fs/btrfs/locking.c: 251 void btrfs_tree_lock(struct extent_buffer *eb) 252 { 253 WARN_ON(eb->lock_owner == current->pid); This happened because the tree search we made at btrfs_defrag_leaves() before calling btrfs_find_next_key() locked a leaf and all the other nodes in the path, so btrfs_find_next_key() had no need to release the path and make a new search (with path->lowest_level set to 1). This made btrfs_realloc_node() attempt to write lock the same leaf again, resulting in a hang/deadlock. So fix these issues by calling btrfs_find_next_key() after calling btrfs_realloc_node() and setting the search path's lowest_level to 1 to avoid the hang/deadlock when attempting to write lock the leaves at btrfs_realloc_node(). Signed-off-by: Filipe Manana