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1714 Commits (842c4cd688268859f077f552fd60f0521abf52dc)

Author SHA1 Message Date
Filipe Manana 842c4cd688 Btrfs: fix infinite loop during nocow writeback due to race
commit de7999afed upstream.

When starting writeback for a range that covers part of a preallocated
extent, due to a race with writeback for another range that also covers
another part of the same preallocated extent, we can end up in an infinite
loop.

Consider the following example where for inode 280 we have two dirty
ranges:

  range A, from 294912 to 303103, 8192 bytes
  range B, from 348160 to 438271, 90112 bytes

and we have the following file extent item layout for our inode:

  leaf 38895616 gen 24544 total ptrs 29 free space 13820 owner 5
      (...)
      item 27 key (280 108 200704) itemoff 14598 itemsize 53
          extent data disk bytenr 0 nr 0 type 1 (regular)
          extent data offset 0 nr 94208 ram 94208
      item 28 key (280 108 294912) itemoff 14545 itemsize 53
          extent data disk bytenr 10433052672 nr 81920 type 2 (prealloc)
          extent data offset 0 nr 81920 ram 81920

Then the following happens:

1) Writeback starts for range B (from 348160 to 438271), execution of
   run_delalloc_nocow() starts;

2) The first iteration of run_delalloc_nocow()'s whil loop leaves us at
   the extent item at slot 28, pointing to the prealloc extent item
   covering the range from 294912 to 376831. This extent covers part of
   our range;

3) An ordered extent is created against that extent, covering the file
   range from 348160 to 376831 (28672 bytes);

4) We adjust 'cur_offset' to 376832 and move on to the next iteration of
   the while loop;

5) The call to btrfs_lookup_file_extent() leaves us at the same leaf,
   pointing to slot 29, 1 slot after the last item (the extent item
   we processed in the previous iteration);

6) Because we are a slot beyond the last item, we call btrfs_next_leaf(),
   which releases the search path before doing a another search for the
   last key of the leaf (280 108 294912);

7) Right after btrfs_next_leaf() released the path, and before it did
   another search for the last key of the leaf, writeback for the range
   A (from 294912 to 303103) completes (it was previously started at
   some point);

8) Upon completion of the ordered extent for range A, the prealloc extent
   we previously found got split into two extent items, one covering the
   range from 294912 to 303103 (8192 bytes), with a type of regular extent
   (and no longer prealloc) and another covering the range from 303104 to
   376831 (73728 bytes), with a type of prealloc and an offset of 8192
   bytes. So our leaf now has the following layout:

     leaf 38895616 gen 24544 total ptrs 31 free space 13664 owner 5
         (...)
         item 27 key (280 108 200704) itemoff 14598 itemsize 53
             extent data disk bytenr 0 nr 0 type 1
             extent data offset 0 nr 8192 ram 94208
         item 28 key (280 108 208896) itemoff 14545 itemsize 53
             extent data disk bytenr 10433142784 nr 86016 type 1
             extent data offset 0 nr 86016 ram 86016
         item 29 key (280 108 294912) itemoff 14492 itemsize 53
             extent data disk bytenr 10433052672 nr 81920 type 1
             extent data offset 0 nr 8192 ram 81920
         item 30 key (280 108 303104) itemoff 14439 itemsize 53
             extent data disk bytenr 10433052672 nr 81920 type 2
             extent data offset 8192 nr 73728 ram 81920

9) After btrfs_next_leaf() returns, we have our path pointing to that same
   leaf and at slot 30, since it has a key we didn't have before and it's
   the first key greater then the key that was previously the last key of
   the leaf (key (280 108 294912));

10) The extent item at slot 30 covers the range from 303104 to 376831
    which is in our target range, so we process it, despite having already
    created an ordered extent against this extent for the file range from
    348160 to 376831. This is because we skip to the next extent item only
    if its end is less than or equals to the start of our delalloc range,
    and not less than or equals to the current offset ('cur_offset');

11) As a result we compute 'num_bytes' as:

    num_bytes = min(end + 1, extent_end) - cur_offset;
              = min(438271 + 1, 376832) - 376832 = 0

12) We then call create_io_em() for a 0 bytes range starting at offset
    376832;

13) Then create_io_em() enters an infinite loop because its calls to
    btrfs_drop_extent_cache() do nothing due to the 0 length range
    passed to it. So no existing extent maps that cover the offset
    376832 get removed, and therefore calls to add_extent_mapping()
    return -EEXIST, resulting in an infinite loop. This loop from
    create_io_em() is the following:

    do {
        btrfs_drop_extent_cache(BTRFS_I(inode), em->start,
                                em->start + em->len - 1, 0);
        write_lock(&em_tree->lock);
        ret = add_extent_mapping(em_tree, em, 1);
        write_unlock(&em_tree->lock);
        /*
         * The caller has taken lock_extent(), who could race with us
         * to add em?
         */
    } while (ret == -EEXIST);

Also, each call to btrfs_drop_extent_cache() triggers a warning because
the start offset passed to it (376832) is smaller then the end offset
(376832 - 1) passed to it by -1, due to the 0 length:

  [258532.052621] ------------[ cut here ]------------
  [258532.052643] WARNING: CPU: 0 PID: 9987 at fs/btrfs/file.c:602 btrfs_drop_extent_cache+0x3f4/0x590 [btrfs]
  (...)
  [258532.052672] CPU: 0 PID: 9987 Comm: fsx Tainted: G        W         5.4.0-rc7-btrfs-next-64 #1
  [258532.052673] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
  [258532.052691] RIP: 0010:btrfs_drop_extent_cache+0x3f4/0x590 [btrfs]
  (...)
  [258532.052695] RSP: 0018:ffffb4be0153f860 EFLAGS: 00010287
  [258532.052700] RAX: ffff975b445ee360 RBX: ffff975b44eb3e08 RCX: 0000000000000000
  [258532.052700] RDX: 0000000000038fff RSI: 0000000000039000 RDI: ffff975b445ee308
  [258532.052700] RBP: 0000000000038fff R08: 0000000000000000 R09: 0000000000000001
  [258532.052701] R10: ffff975b513c5c10 R11: 00000000e3c0cfa9 R12: 0000000000039000
  [258532.052703] R13: ffff975b445ee360 R14: 00000000ffffffef R15: ffff975b445ee308
  [258532.052705] FS:  00007f86a821de80(0000) GS:ffff975b76a00000(0000) knlGS:0000000000000000
  [258532.052707] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [258532.052708] CR2: 00007fdacf0f3ab4 CR3: 00000001f9d26002 CR4: 00000000003606f0
  [258532.052712] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [258532.052717] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [258532.052717] Call Trace:
  [258532.052718]  ? preempt_schedule_common+0x32/0x70
  [258532.052722]  ? ___preempt_schedule+0x16/0x20
  [258532.052741]  create_io_em+0xff/0x180 [btrfs]
  [258532.052767]  run_delalloc_nocow+0x942/0xb10 [btrfs]
  [258532.052791]  btrfs_run_delalloc_range+0x30b/0x520 [btrfs]
  [258532.052812]  ? find_lock_delalloc_range+0x221/0x250 [btrfs]
  [258532.052834]  writepage_delalloc+0xe4/0x140 [btrfs]
  [258532.052855]  __extent_writepage+0x110/0x4e0 [btrfs]
  [258532.052876]  extent_write_cache_pages+0x21c/0x480 [btrfs]
  [258532.052906]  extent_writepages+0x52/0xb0 [btrfs]
  [258532.052911]  do_writepages+0x23/0x80
  [258532.052915]  __filemap_fdatawrite_range+0xd2/0x110
  [258532.052938]  btrfs_fdatawrite_range+0x1b/0x50 [btrfs]
  [258532.052954]  start_ordered_ops+0x57/0xa0 [btrfs]
  [258532.052973]  ? btrfs_sync_file+0x225/0x490 [btrfs]
  [258532.052988]  btrfs_sync_file+0x225/0x490 [btrfs]
  [258532.052997]  __x64_sys_msync+0x199/0x200
  [258532.053004]  do_syscall_64+0x5c/0x250
  [258532.053007]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [258532.053010] RIP: 0033:0x7f86a7dfd760
  (...)
  [258532.053014] RSP: 002b:00007ffd99af0368 EFLAGS: 00000246 ORIG_RAX: 000000000000001a
  [258532.053016] RAX: ffffffffffffffda RBX: 0000000000000ec9 RCX: 00007f86a7dfd760
  [258532.053017] RDX: 0000000000000004 RSI: 000000000000836c RDI: 00007f86a8221000
  [258532.053019] RBP: 0000000000021ec9 R08: 0000000000000003 R09: 00007f86a812037c
  [258532.053020] R10: 0000000000000001 R11: 0000000000000246 R12: 00000000000074a3
  [258532.053021] R13: 00007f86a8221000 R14: 000000000000836c R15: 0000000000000001
  [258532.053032] irq event stamp: 1653450494
  [258532.053035] hardirqs last  enabled at (1653450493): [<ffffffff9dec69f9>] _raw_spin_unlock_irq+0x29/0x50
  [258532.053037] hardirqs last disabled at (1653450494): [<ffffffff9d4048ea>] trace_hardirqs_off_thunk+0x1a/0x20
  [258532.053039] softirqs last  enabled at (1653449852): [<ffffffff9e200466>] __do_softirq+0x466/0x6bd
  [258532.053042] softirqs last disabled at (1653449845): [<ffffffff9d4c8a0c>] irq_exit+0xec/0x120
  [258532.053043] ---[ end trace 8476fce13d9ce20a ]---

Which results in flooding dmesg/syslog since btrfs_drop_extent_cache()
uses WARN_ON() and not WARN_ON_ONCE().

So fix this issue by changing run_delalloc_nocow()'s loop to move to the
next extent item when the current extent item ends at at offset less than
or equals to the current offset instead of the start offset.

Fixes: 80ff385665 ("Btrfs: update nodatacow code v2")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-09 10:19:58 +01:00
Josef Bacik e3fb5bb7eb btrfs: do not call synchronize_srcu() in inode_tree_del
commit f72ff01df9 upstream.

Testing with the new fsstress uncovered a pretty nasty deadlock with
lookup and snapshot deletion.

Process A
unlink
 -> final iput
   -> inode_tree_del
     -> synchronize_srcu(subvol_srcu)

Process B
btrfs_lookup  <- srcu_read_lock() acquired here
  -> btrfs_iget
    -> find inode that has I_FREEING set
      -> __wait_on_freeing_inode()

We're holding the srcu_read_lock() while doing the iget in order to make
sure our fs root doesn't go away, and then we are waiting for the inode
to finish freeing.  However because the free'ing process is doing a
synchronize_srcu() we deadlock.

Fix this by dropping the synchronize_srcu() in inode_tree_del().  We
don't need people to stop accessing the fs root at this point, we're
only adding our empty root to the dead roots list.

A larger much more invasive fix is forthcoming to address how we deal
with fs roots, but this fixes the immediate problem.

Fixes: 76dda93c6a ("Btrfs: add snapshot/subvolume destroy ioctl")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-31 16:41:53 +01:00
Josef Bacik 831140602a btrfs: don't double lock the subvol_sem for rename exchange
commit 943eb3bf25 upstream.

If we're rename exchanging two subvols we'll try to lock this lock
twice, which is bad.  Just lock once if either of the ino's are subvols.

Fixes: cdd1fedf82 ("btrfs: add support for RENAME_EXCHANGE and RENAME_WHITEOUT")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-31 16:41:50 +01:00
Josef Bacik cab5f4c6fd btrfs: record all roots for rename exchange on a subvol
commit 3e1740993e upstream.

Testing with the new fsstress support for subvolumes uncovered a pretty
bad problem with rename exchange on subvolumes.  We're modifying two
different subvolumes, but we only start the transaction on one of them,
so the other one is not added to the dirty root list.  This is caught by
btrfs_cow_block() with a warning because the root has not been updated,
however if we do not modify this root again we'll end up pointing at an
invalid root because the root item is never updated.

Fix this by making sure we add the destination root to the trans list,
the same as we do with normal renames.  This fixes the corruption.

Fixes: cdd1fedf82 ("btrfs: add support for RENAME_EXCHANGE and RENAME_WHITEOUT")
CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-17 19:56:07 +01:00
Filipe Manana 17b22f8594 Btrfs: fix metadata space leak on fixup worker failure to set range as delalloc
commit 536870071d upstream.

In the fixup worker, if we fail to mark the range as delalloc in the io
tree, we must release the previously reserved metadata, as well as update
the outstanding extents counter for the inode, otherwise we leak metadata
space.

In pratice we can't return an error from btrfs_set_extent_delalloc(),
which is just a wrapper around __set_extent_bit(), as for most errors
__set_extent_bit() does a BUG_ON() (or panics which hits a BUG_ON() as
well) and returning an -EEXIST error doesn't happen in this case since
the exclusive bits parameter always has a value of 0 through this code
path. Nevertheless, just fix the error handling in the fixup worker,
in case one day __set_extent_bit() can return an error to this code
path.

Fixes: f3038ee3a3 ("btrfs: Handle btrfs_set_extent_delalloc failure in fixup worker")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-17 19:56:04 +01:00
Filipe Manana e6c617102c Btrfs: fix log context list corruption after rename exchange operation
During rename exchange we might have successfully log the new name in the
source root's log tree, in which case we leave our log context (allocated
on stack) in the root's list of log contextes. However we might fail to
log the new name in the destination root, in which case we fallback to
a transaction commit later and never sync the log of the source root,
which causes the source root log context to remain in the list of log
contextes. This later causes invalid memory accesses because the context
was allocated on stack and after rename exchange finishes the stack gets
reused and overwritten for other purposes.

The kernel's linked list corruption detector (CONFIG_DEBUG_LIST=y) can
detect this and report something like the following:

  [  691.489929] ------------[ cut here ]------------
  [  691.489947] list_add corruption. prev->next should be next (ffff88819c944530), but was ffff8881c23f7be4. (prev=ffff8881c23f7a38).
  [  691.489967] WARNING: CPU: 2 PID: 28933 at lib/list_debug.c:28 __list_add_valid+0x95/0xe0
  (...)
  [  691.489998] CPU: 2 PID: 28933 Comm: fsstress Not tainted 5.4.0-rc6-btrfs-next-62 #1
  [  691.490001] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
  [  691.490003] RIP: 0010:__list_add_valid+0x95/0xe0
  (...)
  [  691.490007] RSP: 0018:ffff8881f0b3faf8 EFLAGS: 00010282
  [  691.490010] RAX: 0000000000000000 RBX: ffff88819c944530 RCX: 0000000000000000
  [  691.490011] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffffa2c497e0
  [  691.490013] RBP: ffff8881f0b3fe68 R08: ffffed103eaa4115 R09: ffffed103eaa4114
  [  691.490015] R10: ffff88819c944000 R11: ffffed103eaa4115 R12: 7fffffffffffffff
  [  691.490016] R13: ffff8881b4035610 R14: ffff8881e7b84728 R15: 1ffff1103e167f7b
  [  691.490019] FS:  00007f4b25ea2e80(0000) GS:ffff8881f5500000(0000) knlGS:0000000000000000
  [  691.490021] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [  691.490022] CR2: 00007fffbb2d4eec CR3: 00000001f2a4a004 CR4: 00000000003606e0
  [  691.490025] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [  691.490027] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [  691.490029] Call Trace:
  [  691.490058]  btrfs_log_inode_parent+0x667/0x2730 [btrfs]
  [  691.490083]  ? join_transaction+0x24a/0xce0 [btrfs]
  [  691.490107]  ? btrfs_end_log_trans+0x80/0x80 [btrfs]
  [  691.490111]  ? dget_parent+0xb8/0x460
  [  691.490116]  ? lock_downgrade+0x6b0/0x6b0
  [  691.490121]  ? rwlock_bug.part.0+0x90/0x90
  [  691.490127]  ? do_raw_spin_unlock+0x142/0x220
  [  691.490151]  btrfs_log_dentry_safe+0x65/0x90 [btrfs]
  [  691.490172]  btrfs_sync_file+0x9f1/0xc00 [btrfs]
  [  691.490195]  ? btrfs_file_write_iter+0x1800/0x1800 [btrfs]
  [  691.490198]  ? rcu_read_lock_any_held.part.11+0x20/0x20
  [  691.490204]  ? __do_sys_newstat+0x88/0xd0
  [  691.490207]  ? cp_new_stat+0x5d0/0x5d0
  [  691.490218]  ? do_fsync+0x38/0x60
  [  691.490220]  do_fsync+0x38/0x60
  [  691.490224]  __x64_sys_fdatasync+0x32/0x40
  [  691.490228]  do_syscall_64+0x9f/0x540
  [  691.490233]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [  691.490235] RIP: 0033:0x7f4b253ad5f0
  (...)
  [  691.490239] RSP: 002b:00007fffbb2d6078 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
  [  691.490242] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f4b253ad5f0
  [  691.490244] RDX: 00007fffbb2d5fe0 RSI: 00007fffbb2d5fe0 RDI: 0000000000000003
  [  691.490245] RBP: 000000000000000d R08: 0000000000000001 R09: 00007fffbb2d608c
  [  691.490247] R10: 00000000000002e8 R11: 0000000000000246 R12: 00000000000001f4
  [  691.490248] R13: 0000000051eb851f R14: 00007fffbb2d6120 R15: 00005635a498bda0

This started happening recently when running some test cases from fstests
like btrfs/004 for example, because support for rename exchange was added
last week to fsstress from fstests.

So fix this by deleting the log context for the source root from the list
if we have logged the new name in the source root.

Reported-by: Su Yue <Damenly_Su@gmx.com>
Fixes: d4682ba03e ("Btrfs: sync log after logging new name")
CC: stable@vger.kernel.org # 4.19+
Tested-by: Su Yue <Damenly_Su@gmx.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-11 19:46:02 +01:00
Josef Bacik d98da49977 btrfs: save i_size to avoid double evaluation of i_size_read in compress_file_range
We hit a regression while rolling out 5.2 internally where we were
hitting the following panic

  kernel BUG at mm/page-writeback.c:2659!
  RIP: 0010:clear_page_dirty_for_io+0xe6/0x1f0
  Call Trace:
   __process_pages_contig+0x25a/0x350
   ? extent_clear_unlock_delalloc+0x43/0x70
   submit_compressed_extents+0x359/0x4d0
   normal_work_helper+0x15a/0x330
   process_one_work+0x1f5/0x3f0
   worker_thread+0x2d/0x3d0
   ? rescuer_thread+0x340/0x340
   kthread+0x111/0x130
   ? kthread_create_on_node+0x60/0x60
   ret_from_fork+0x1f/0x30

This is happening because the page is not locked when doing
clear_page_dirty_for_io.  Looking at the core dump it was because our
async_extent had a ram_size of 24576 but our async_chunk range only
spanned 20480, so we had a whole extra page in our ram_size for our
async_extent.

This happened because we try not to compress pages outside of our
i_size, however a cleanup patch changed us to do

actual_end = min_t(u64, i_size_read(inode), end + 1);

which is problematic because i_size_read() can evaluate to different
values in between checking and assigning.  So either an expanding
truncate or a fallocate could increase our i_size while we're doing
writeout and actual_end would end up being past the range we have
locked.

I confirmed this was what was happening by installing a debug kernel
that had

  actual_end = min_t(u64, i_size_read(inode), end + 1);
  if (actual_end > end + 1) {
	  printk(KERN_ERR "KABOOM\n");
	  actual_end = end + 1;
  }

and installing it onto 500 boxes of the tier that had been seeing the
problem regularly.  Last night I got my debug message and no panic,
confirming what I expected.

[ dsterba: the assembly confirms a tiny race window:

    mov    0x20(%rsp),%rax
    cmp    %rax,0x48(%r15)           # read
    movl   $0x0,0x18(%rsp)
    mov    %rax,%r12
    mov    %r14,%rax
    cmovbe 0x48(%r15),%r12           # eval

  Where r15 is inode and 0x48 is offset of i_size.

  The original fix was to revert 62b3762271 that would do an
  intermediate assignment and this would also avoid the doulble
  evaluation but is not future-proof, should the compiler merge the
  stores and call i_size_read anyway.

  There's a patch adding READ_ONCE to i_size_read but that's not being
  applied at the moment and we need to fix the bug. Instead, emulate
  READ_ONCE by two barrier()s that's what effectively happens. The
  assembly confirms single evaluation:

    mov    0x48(%rbp),%rax          # read once
    mov    0x20(%rsp),%rcx
    mov    $0x20,%edx
    cmp    %rax,%rcx
    cmovbe %rcx,%rax
    mov    %rax,(%rsp)
    mov    %rax,%rcx
    mov    %r14,%rax

  Where 0x48(%rbp) is inode->i_size stored to %eax.
]

Fixes: 62b3762271 ("btrfs: Remove isize local variable in compress_file_range")
CC: stable@vger.kernel.org # v5.1+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ changelog updated ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-04 21:41:49 +01:00
Qu Wenruo 8702ba9396 btrfs: qgroup: Always free PREALLOC META reserve in btrfs_delalloc_release_extents()
[Background]
Btrfs qgroup uses two types of reserved space for METADATA space,
PERTRANS and PREALLOC.

PERTRANS is metadata space reserved for each transaction started by
btrfs_start_transaction().
While PREALLOC is for delalloc, where we reserve space before joining a
transaction, and finally it will be converted to PERTRANS after the
writeback is done.

[Inconsistency]
However there is inconsistency in how we handle PREALLOC metadata space.

The most obvious one is:
In btrfs_buffered_write():
	btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes, true);

We always free qgroup PREALLOC meta space.

While in btrfs_truncate_block():
	btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize, (ret != 0));

We only free qgroup PREALLOC meta space when something went wrong.

[The Correct Behavior]
The correct behavior should be the one in btrfs_buffered_write(), we
should always free PREALLOC metadata space.

The reason is, the btrfs_delalloc_* mechanism works by:
- Reserve metadata first, even it's not necessary
  In btrfs_delalloc_reserve_metadata()

- Free the unused metadata space
  Normally in:
  btrfs_delalloc_release_extents()
  |- btrfs_inode_rsv_release()
     Here we do calculation on whether we should release or not.

E.g. for 64K buffered write, the metadata rsv works like:

/* The first page */
reserve_meta:	num_bytes=calc_inode_reservations()
free_meta:	num_bytes=0
total:		num_bytes=calc_inode_reservations()
/* The first page caused one outstanding extent, thus needs metadata
   rsv */

/* The 2nd page */
reserve_meta:	num_bytes=calc_inode_reservations()
free_meta:	num_bytes=calc_inode_reservations()
total:		not changed
/* The 2nd page doesn't cause new outstanding extent, needs no new meta
   rsv, so we free what we have reserved */

/* The 3rd~16th pages */
reserve_meta:	num_bytes=calc_inode_reservations()
free_meta:	num_bytes=calc_inode_reservations()
total:		not changed (still space for one outstanding extent)

This means, if btrfs_delalloc_release_extents() determines to free some
space, then those space should be freed NOW.
So for qgroup, we should call btrfs_qgroup_free_meta_prealloc() other
than btrfs_qgroup_convert_reserved_meta().

The good news is:
- The callers are not that hot
  The hottest caller is in btrfs_buffered_write(), which is already
  fixed by commit 336a8bb8e3 ("btrfs: Fix wrong
  btrfs_delalloc_release_extents parameter"). Thus it's not that
  easy to cause false EDQUOT.

- The trans commit in advance for qgroup would hide the bug
  Since commit f5fef45936 ("btrfs: qgroup: Make qgroup async transaction
  commit more aggressive"), when btrfs qgroup metadata free space is slow,
  it will try to commit transaction and free the wrongly converted
  PERTRANS space, so it's not that easy to hit such bug.

[FIX]
So to fix the problem, remove the @qgroup_free parameter for
btrfs_delalloc_release_extents(), and always pass true to
btrfs_inode_rsv_release().

Reported-by: Filipe Manana <fdmanana@suse.com>
Fixes: 43b18595d6 ("btrfs: qgroup: Use separate meta reservation type for delalloc")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-10-15 18:50:07 +02:00
Josef Bacik 11a19a9087 btrfs: allocate new inode in NOFS context
A user reported a lockdep splat

 ======================================================
 WARNING: possible circular locking dependency detected
 5.2.11-gentoo #2 Not tainted
 ------------------------------------------------------
 kswapd0/711 is trying to acquire lock:
 000000007777a663 (sb_internal){.+.+}, at: start_transaction+0x3a8/0x500

but task is already holding lock:
 000000000ba86300 (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x0/0x30

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (fs_reclaim){+.+.}:
 kmem_cache_alloc+0x1f/0x1c0
 btrfs_alloc_inode+0x1f/0x260
 alloc_inode+0x16/0xa0
 new_inode+0xe/0xb0
 btrfs_new_inode+0x70/0x610
 btrfs_symlink+0xd0/0x420
 vfs_symlink+0x9c/0x100
 do_symlinkat+0x66/0xe0
 do_syscall_64+0x55/0x1c0
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #0 (sb_internal){.+.+}:
 __sb_start_write+0xf6/0x150
 start_transaction+0x3a8/0x500
 btrfs_commit_inode_delayed_inode+0x59/0x110
 btrfs_evict_inode+0x19e/0x4c0
 evict+0xbc/0x1f0
 inode_lru_isolate+0x113/0x190
 __list_lru_walk_one.isra.4+0x5c/0x100
 list_lru_walk_one+0x32/0x50
 prune_icache_sb+0x36/0x80
 super_cache_scan+0x14a/0x1d0
 do_shrink_slab+0x131/0x320
 shrink_node+0xf7/0x380
 balance_pgdat+0x2d5/0x640
 kswapd+0x2ba/0x5e0
 kthread+0x147/0x160
 ret_from_fork+0x24/0x30

other info that might help us debug this:

 Possible unsafe locking scenario:

 CPU0 CPU1
 ---- ----
 lock(fs_reclaim);
 lock(sb_internal);
 lock(fs_reclaim);
 lock(sb_internal);
*** DEADLOCK ***

 3 locks held by kswapd0/711:
 #0: 000000000ba86300 (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x0/0x30
 #1: 000000004a5100f8 (shrinker_rwsem){++++}, at: shrink_node+0x9a/0x380
 #2: 00000000f956fa46 (&type->s_umount_key#30){++++}, at: super_cache_scan+0x35/0x1d0

stack backtrace:
 CPU: 7 PID: 711 Comm: kswapd0 Not tainted 5.2.11-gentoo #2
 Hardware name: Dell Inc. Precision Tower 3620/0MWYPT, BIOS 2.4.2 09/29/2017
 Call Trace:
 dump_stack+0x85/0xc7
 print_circular_bug.cold.40+0x1d9/0x235
 __lock_acquire+0x18b1/0x1f00
 lock_acquire+0xa6/0x170
 ? start_transaction+0x3a8/0x500
 __sb_start_write+0xf6/0x150
 ? start_transaction+0x3a8/0x500
 start_transaction+0x3a8/0x500
 btrfs_commit_inode_delayed_inode+0x59/0x110
 btrfs_evict_inode+0x19e/0x4c0
 ? var_wake_function+0x20/0x20
 evict+0xbc/0x1f0
 inode_lru_isolate+0x113/0x190
 ? discard_new_inode+0xc0/0xc0
 __list_lru_walk_one.isra.4+0x5c/0x100
 ? discard_new_inode+0xc0/0xc0
 list_lru_walk_one+0x32/0x50
 prune_icache_sb+0x36/0x80
 super_cache_scan+0x14a/0x1d0
 do_shrink_slab+0x131/0x320
 shrink_node+0xf7/0x380
 balance_pgdat+0x2d5/0x640
 kswapd+0x2ba/0x5e0
 ? __wake_up_common_lock+0x90/0x90
 kthread+0x147/0x160
 ? balance_pgdat+0x640/0x640
 ? __kthread_create_on_node+0x160/0x160
 ret_from_fork+0x24/0x30

This is because btrfs_new_inode() calls new_inode() under the
transaction.  We could probably move the new_inode() outside of this but
for now just wrap it in memalloc_nofs_save().

Reported-by: Zdenek Sojka <zsojka@seznam.cz>
Fixes: 712e36c5f2 ("btrfs: use GFP_KERNEL in btrfs_alloc_inode")
CC: stable@vger.kernel.org # 4.16+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-10-01 20:12:27 +02:00
Omar Sandoval e182163d9c btrfs: stop clearing EXTENT_DIRTY in inode I/O tree
Since commit fee187d9d9 ("Btrfs: do not set EXTENT_DIRTY along with
EXTENT_DELALLOC"), we never set EXTENT_DIRTY in inode->io_tree, so we
can simplify and stop trying to clear it.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:17 +02:00
David Sterba c82f823c9b btrfs: tie extent buffer and it's token together
Further simplifaction of the get/set helpers is possible when the token
is uniquely tied to an extent buffer. A condition and an assignment can
be avoided.

The initializations are moved closer to the first use when the extent
buffer is valid. There's one exception in __push_leaf_left where the
token is reused.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:16 +02:00
David Sterba 602cbe91fb btrfs: move cond_wake_up functions out of ctree
The file ctree.h serves as a header for everything and has become quite
bloated. Split some helpers that are generic and create a new file that
should be the catch-all for code that's not btrfs-specific.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:15 +02:00
Christophe Leroy 3acd48507d btrfs: fix allocation of free space cache v1 bitmap pages
Various notifications of type "BUG kmalloc-4096 () : Redzone
overwritten" have been observed recently in various parts of the kernel.
After some time, it has been made a relation with the use of BTRFS
filesystem and with SLUB_DEBUG turned on.

[   22.809700] BUG kmalloc-4096 (Tainted: G        W        ): Redzone overwritten

[   22.810286] INFO: 0xbe1a5921-0xfbfc06cd. First byte 0x0 instead of 0xcc
[   22.810866] INFO: Allocated in __load_free_space_cache+0x588/0x780 [btrfs] age=22 cpu=0 pid=224
[   22.811193] 	__slab_alloc.constprop.26+0x44/0x70
[   22.811345] 	kmem_cache_alloc_trace+0xf0/0x2ec
[   22.811588] 	__load_free_space_cache+0x588/0x780 [btrfs]
[   22.811848] 	load_free_space_cache+0xf4/0x1b0 [btrfs]
[   22.812090] 	cache_block_group+0x1d0/0x3d0 [btrfs]
[   22.812321] 	find_free_extent+0x680/0x12a4 [btrfs]
[   22.812549] 	btrfs_reserve_extent+0xec/0x220 [btrfs]
[   22.812785] 	btrfs_alloc_tree_block+0x178/0x5f4 [btrfs]
[   22.813032] 	__btrfs_cow_block+0x150/0x5d4 [btrfs]
[   22.813262] 	btrfs_cow_block+0x194/0x298 [btrfs]
[   22.813484] 	commit_cowonly_roots+0x44/0x294 [btrfs]
[   22.813718] 	btrfs_commit_transaction+0x63c/0xc0c [btrfs]
[   22.813973] 	close_ctree+0xf8/0x2a4 [btrfs]
[   22.814107] 	generic_shutdown_super+0x80/0x110
[   22.814250] 	kill_anon_super+0x18/0x30
[   22.814437] 	btrfs_kill_super+0x18/0x90 [btrfs]
[   22.814590] INFO: Freed in proc_cgroup_show+0xc0/0x248 age=41 cpu=0 pid=83
[   22.814841] 	proc_cgroup_show+0xc0/0x248
[   22.814967] 	proc_single_show+0x54/0x98
[   22.815086] 	seq_read+0x278/0x45c
[   22.815190] 	__vfs_read+0x28/0x17c
[   22.815289] 	vfs_read+0xa8/0x14c
[   22.815381] 	ksys_read+0x50/0x94
[   22.815475] 	ret_from_syscall+0x0/0x38

Commit 69d2480456 ("btrfs: use copy_page for copying pages instead of
memcpy") changed the way bitmap blocks are copied. But allthough bitmaps
have the size of a page, they were allocated with kzalloc().

Most of the time, kzalloc() allocates aligned blocks of memory, so
copy_page() can be used. But when some debug options like SLAB_DEBUG are
activated, kzalloc() may return unaligned pointer.

On powerpc, memcpy(), copy_page() and other copying functions use
'dcbz' instruction which provides an entire zeroed cacheline to avoid
memory read when the intention is to overwrite a full line. Functions
like memcpy() are writen to care about partial cachelines at the start
and end of the destination, but copy_page() assumes it gets pages. As
pages are naturally cache aligned, copy_page() doesn't care about
partial lines. This means that when copy_page() is called with a
misaligned pointer, a few leading bytes are zeroed.

To fix it, allocate bitmaps through kmem_cache instead of using kzalloc()
The cache pool is created with PAGE_SIZE alignment constraint.

Reported-by: Erhard F. <erhard_f@mailbox.org>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=204371
Fixes: 69d2480456 ("btrfs: use copy_page for copying pages instead of memcpy")
Cc: stable@vger.kernel.org # 4.19+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: David Sterba <dsterba@suse.com>
[ rename to btrfs_free_space_bitmap ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:14 +02:00
Nikolay Borisov 762bf09893 btrfs: improve error handling in run_delalloc_nocow
Correctly handle failure cases when adding an ordered extents in case
of REGULAR or PREALLOC extents. Remove the BUG_ON.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:14 +02:00
Nikolay Borisov e8e210075a btrfs: comment and minor simplifications in run_delalloc_nocow
Add a comment explaining why we keep the BUG also use the already read
and cached value of extent ram bytes stored in 'ram_bytes'.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:13 +02:00
Nikolay Borisov 922f051824 btrfs: streamline code in run_delalloc_nocow in case of inline extents
The extent range check right after the "out_check" label is redundant,
because the only way it can trigger is if we have an inline extent. In
this case it makes more sense to actually move it in the branch
explictly dealing with inlines extents.

What's more, the nested 'if (nocow)' can never be true because for
inline extents we always do COW and there is no chance 'nocow' can be
true, just remove that check.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:13 +02:00
Nikolay Borisov bb55f6260b btrfs: simplify extent type checks in run_delalloc_nocow
There is no point in checking the type of the extent again just to set
the 'type' variable, when this check has already been performed before.
Instead, extend the original if branch with an 'else' clause. This
allows to remove one local variable and make it obvious how the code
flow differs for prealloc/regular extents.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:13 +02:00
Nikolay Borisov a6bd9cd155 btrfs: improve comments around nocow path
run_delalloc_nocow contains numerous, somewhat subtle, checks when
figuring out whether a particular extent should be CoW'ed or not. This
patch explicitly states the assumptions those checks verify. As a
result also document 2 of the more subtle checks in check_committed_ref
as well.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:13 +02:00
Nikolay Borisov 3e024846d2 btrfs: refactor variable scope in run_delalloc_nocow
Of the 22 (!!!) local variables declared in this function only 9 have
function-wide context. Of the remaining 13, 12 are needed in the main
while loop of the function and 1 is needed in a tiny if branch, only in
case we have prealloc extent. This commit reduces the lifespan of every
variable to its bare minimum. It also renames the 'nolock' boolean to
freespace_inode to clearly indicate its purpose.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:13 +02:00
Josef Bacik 2bd36e7b4f btrfs: rename the btrfs_calc_*_metadata_size helpers
btrfs_calc_trunc_metadata_size differs from trans_metadata_size in that
it doesn't take into account any splitting at the levels, because
truncate will never split nodes.  However truncate _and_ changing will
never split nodes, so rename btrfs_calc_trunc_metadata_size to
btrfs_calc_metadata_size.  Also btrfs_calc_trans_metadata_size is purely
for inserting items, so rename this to btrfs_calc_insert_metadata_size.
Making these clearer will help when I start using them differently in
upcoming patches.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:13 +02:00
Josef Bacik d3984c9041 btrfs: introduce an evict flushing state
We have this weird space flushing loop inside inode.c for evict where
we'll do the normal LIMIT flush, and then commit the transaction and
hope we get our space.  This is super janky, and in fact there's really
nothing stopping us from using FLUSH_ALL except that we run delayed
iputs, which means we could deadlock.  So introduce a new flush state
for eviction that does the normal priority flushing with all of the
states that are safe for eviction.

The nice side-effect of this is that we'll try harder for evictions.
Previously if (for example generic/269) you had a bunch of other
operations happening on the fs you could race with those reservations
when committing the transaction, and eventually miss getting a
reservation for the evict.  With this code we'll have our ticket in
place through the transaction commit, so any pinned bytes will go to our
pending evictions first.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:11 +02:00
Josef Bacik aac0023c21 btrfs: move basic block_group definitions to their own header
This is prep work for moving all of the block group cache code into its
own file.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor comment updates ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:03 +02:00
Jia-Ju Bai 982f1f5d16 btrfs: Add an assertion to warn incorrect case in insert_inline_extent()
In insert_inline_extent(), the case that checks compressed_size > 0
and compressed_pages = NULL cannot occur, otherwise a null-pointer
dereference may occur on line 215:

     cpage = compressed_pages[i];

To catch this incorrect case, an assertion is added.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:00 +02:00
Nikolay Borisov 330a582790 btrfs: Remove leftover of in-band dedupe
It's unlikely in-band dedupe is going to land so just remove any
leftovers - dedupe.h header as well as the 'dedupe' parameter to
btrfs_set_extent_delalloc.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:58:59 +02:00
Nikolay Borisov 74e9194afb btrfs: Remove delalloc_end argument from extent_clear_unlock_delalloc
It was added in ba8b04c1d4 ("btrfs: extend btrfs_set_extent_delalloc
and its friends to support in-band dedupe and subpage size patchset") as
a preparatory patch for in-band and subapge block size patchsets.
However neither of those are likely to be merged anytime soon and the
code has diverged significantly from the last public post of either
of those patchsets.

It's unlikely either of the patchests are going to use those preparatory
steps so just remove the variables. Since cow_file_range also took
delalloc_end to pass it to extent_clear_unlock_delalloc remove the
parameter from that function as well.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:58:59 +02:00
Nikolay Borisov cecc8d9038 btrfs: Move free_pages_out label in inline extent handling branch in compress_file_range
This label is only executed if compress_file_range fails to create an
inline extent. So move its code in the semantically related inline
extent handling branch. No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:58:59 +02:00
Nikolay Borisov ac3e99334d btrfs: Return number of compressed extents directly in compress_file_range
compress_file_range returns a void, yet uses a function parameter as a
return value. Make that more idiomatic by simply returning the number
of compressed extents directly. Also track such extents in more aptly
named variables. No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:58:59 +02:00
Qu Wenruo 42c16da6d6 btrfs: inode: Don't compress if NODATASUM or NODATACOW set
As btrfs(5) specified:

	Note
	If nodatacow or nodatasum are enabled, compression is disabled.

If NODATASUM or NODATACOW set, we should not compress the extent.

Normally NODATACOW is detected properly in run_delalloc_range() so
compression won't happen for NODATACOW.

However for NODATASUM we don't have any check, and it can cause
compressed extent without csum pretty easily, just by:
  mkfs.btrfs -f $dev
  mount $dev $mnt -o nodatasum
  touch $mnt/foobar
  mount -o remount,datasum,compress $mnt
  xfs_io -f -c "pwrite 0 128K" $mnt/foobar

And in fact, we have a bug report about corrupted compressed extent
without proper data checksum so even RAID1 can't recover the corruption.
(https://bugzilla.kernel.org/show_bug.cgi?id=199707)

Running compression without proper checksum could cause more damage when
corruption happens, as compressed data could make the whole extent
unreadable, so there is no need to allow compression for
NODATACSUM.

The fix will refactor the inode compression check into two parts:

- inode_can_compress()
  As the hard requirement, checked at btrfs_run_delalloc_range(), so no
  compression will happen for NODATASUM inode at all.

- inode_need_compress()
  As the soft requirement, checked at btrfs_run_delalloc_range() and
  compress_file_range().

Reported-by: James Harvey <jamespharvey20@gmail.com>
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-17 17:03:28 +02:00
Josef Bacik 867363429d btrfs: migrate the delalloc space stuff to it's own home
We have code for data and metadata reservations for delalloc.  There's
quite a bit of code here, and it's used in a lot of places so I've
separated it out to it's own file.  inode.c and file.c are already
pretty large, and this code is complicated enough to live in its own
space.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-04 17:26:17 +02:00
Josef Bacik 63611e738a btrfs: run delayed iput at unlink time
We have been seeing issues in production where a cleaner script will end
up unlinking a bunch of files that have pending iputs.  This means they
will get their final iput's run at btrfs-cleaner time and thus are not
throttled, which impacts the workload.

Since we are unlinking these files we can just drop the delayed iput at
unlink time.  We are already holding a reference to the inode so this
will not be the final iput and thus is completely safe to do at this
point.  Doing this means we are more likely to be doing the final iput
at unlink time, and thus will get the IO charged to the caller and get
throttled appropriately without affecting the main workload.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:50 +02:00
Nikolay Borisov 89b798ad1b btrfs: Use btrfs_get_io_geometry appropriately
Presently btrfs_map_block is used not only to do everything necessary to
map a bio to the underlying allocation profile but it's also used to
identify how much data could be written based on btrfs' stripe logic
without actually submitting anything. This is achieved by passing NULL
for 'bbio_ret' parameter.

This patch refactors all callers that require just the mapping length
by switching them to using btrfs_io_geometry instead of calling
btrfs_map_block with a special NULL value for 'bbio_ret'. No functional
change.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:50 +02:00
Johannes Thumshirn ea41d6b278 btrfs: remove assumption about csum type form btrfs_print_data_csum_error()
btrfs_print_data_csum_error() still assumed checksums to be 32 bit in
size.  Make it size agnostic.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:02 +02:00
Johannes Thumshirn d5178578bc btrfs: directly call into crypto framework for checksumming
Currently btrfs_csum_data() relied on the crc32c() wrapper around the
crypto framework for calculating the CRCs.

As we have our own crypto_shash structure in the fs_info now, we can
directly call into the crypto framework without going trough the wrapper.

This way we can even remove the btrfs_csum_data() and btrfs_csum_final()
wrappers.

The module dependency on crc32c is preserved via MODULE_SOFTDEP("pre:
crc32c"), which was previously provided by LIBCRC32C config option doing
the same.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:02 +02:00
Nikolay Borisov 23d31bd476 btrfs: Use newly introduced btrfs_lock_and_flush_ordered_range
There several functions which open code
btrfs_lock_and_flush_ordered_range, just replace them with a call to the
function. No functional changes.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:59 +02:00
Liu Bo be9b8dfa9c Btrfs: remove unused variables in __btrfs_unlink_inode
This code was first introduced in 5f39d397df ("Btrfs: Create
extent_buffer interface for large blocksizes") and the function was
named btrfs_unlink_trans. It later got renamed to __btrfs_unlink_inode
and finally commit 16cdcec736 ("btrfs: implement delayed inode items
operation") changed the way inodes are deleted and obviated the need for
those two members.

Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ replace changelog by Nikolay's version ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:55 +02:00
Linus Torvalds 318adf8e4b for-5.2-rc2-tag
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Merge tag 'for-5.2-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "A few more fixes for bugs reported by users, fuzzing tools and
  regressions:

   - fix crashes in relocation:
       + resuming interrupted balance operation does not properly clean
         up orphan trees
       + with enabled qgroups, resuming needs to be more careful about
         block groups due to limited context when updating qgroups

   - fsync and logging fixes found by fuzzing

   - incremental send fixes for no-holes and clone

   - fix spin lock type used in timer function for zstd"

* tag 'for-5.2-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix race updating log root item during fsync
  Btrfs: fix wrong ctime and mtime of a directory after log replay
  Btrfs: fix fsync not persisting changed attributes of a directory
  btrfs: qgroup: Check bg while resuming relocation to avoid NULL pointer dereference
  btrfs: reloc: Also queue orphan reloc tree for cleanup to avoid BUG_ON()
  Btrfs: incremental send, fix emission of invalid clone operations
  Btrfs: incremental send, fix file corruption when no-holes feature is enabled
  btrfs: correct zstd workspace manager lock to use spin_lock_bh()
  btrfs: Ensure replaced device doesn't have pending chunk allocation
2019-05-30 20:52:40 -07:00
Filipe Manana 5338e43abb Btrfs: fix wrong ctime and mtime of a directory after log replay
When replaying a log that contains a new file or directory name that needs
to be added to its parent directory, we end up updating the mtime and the
ctime of the parent directory to the current time after we have set their
values to the correct ones (set at fsync time), efectivelly losing them.

Sample reproducer:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt

  $ mkdir /mnt/dir
  $ touch /mnt/dir/file

  # fsync of the directory is optional, not needed
  $ xfs_io -c fsync /mnt/dir
  $ xfs_io -c fsync /mnt/dir/file

  $ stat -c %Y /mnt/dir
  1557856079

  <power failure>

  $ sleep 3
  $ mount /dev/sdb /mnt
  $ stat -c %Y /mnt/dir
  1557856082

    --> should have been 1557856079, the mtime is updated to the current
        time when replaying the log

Fix this by not updating the mtime and ctime to the current time at
btrfs_add_link() when we are replaying a log tree.

This could be triggered by my recent fsync fuzz tester for fstests, for
which an fstests patch exists titled "fstests: generic, fsync fuzz tester
with fsstress".

Fixes: e02119d5a7 ("Btrfs: Add a write ahead tree log to optimize synchronous operations")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-28 19:16:16 +02:00
Linus Torvalds 67a2422239 for-5.2/block-20190507
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Merge tag 'for-5.2/block-20190507' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:
 "Nothing major in this series, just fixes and improvements all over the
  map. This contains:

   - Series of fixes for sed-opal (David, Jonas)

   - Fixes and performance tweaks for BFQ (via Paolo)

   - Set of fixes for bcache (via Coly)

   - Set of fixes for md (via Song)

   - Enabling multi-page for passthrough requests (Ming)

   - Queue release fix series (Ming)

   - Device notification improvements (Martin)

   - Propagate underlying device rotational status in loop (Holger)

   - Removal of mtip32xx trim support, which has been disabled for years
     (Christoph)

   - Improvement and cleanup of nvme command handling (Christoph)

   - Add block SPDX tags (Christoph)

   - Cleanup/hardening of bio/bvec iteration (Christoph)

   - A few NVMe pull requests (Christoph)

   - Removal of CONFIG_LBDAF (Christoph)

   - Various little fixes here and there"

* tag 'for-5.2/block-20190507' of git://git.kernel.dk/linux-block: (164 commits)
  block: fix mismerge in bvec_advance
  block: don't drain in-progress dispatch in blk_cleanup_queue()
  blk-mq: move cancel of hctx->run_work into blk_mq_hw_sysfs_release
  blk-mq: always free hctx after request queue is freed
  blk-mq: split blk_mq_alloc_and_init_hctx into two parts
  blk-mq: free hw queue's resource in hctx's release handler
  blk-mq: move cancel of requeue_work into blk_mq_release
  blk-mq: grab .q_usage_counter when queuing request from plug code path
  block: fix function name in comment
  nvmet: protect discovery change log event list iteration
  nvme: mark nvme_core_init and nvme_core_exit static
  nvme: move command size checks to the core
  nvme-fabrics: check more command sizes
  nvme-pci: check more command sizes
  nvme-pci: remove an unneeded variable initialization
  nvme-pci: unquiesce admin queue on shutdown
  nvme-pci: shutdown on timeout during deletion
  nvme-pci: fix psdt field for single segment sgls
  nvme-multipath: don't print ANA group state by default
  nvme-multipath: split bios with the ns_head bio_set before submitting
  ...
2019-05-07 18:14:36 -07:00
Linus Torvalds 9f2e3a53f7 for-5.2-tag
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Merge tag 'for-5.2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "This time the majority of changes are cleanups, though there's still a
  number of changes of user interest.

  User visible changes:

   - better read time and write checks to catch errors early and before
     writing data to disk (to catch potential memory corruption on data
     that get checksummed)

   - qgroups + metadata relocation: last speed up patch int the series
     to address the slowness, there should be no overhead comparing
     balance with and without qgroups

   - FIEMAP ioctl does not start a transaction unnecessarily, this can
     result in a speed up and less blocking due to IO

   - LOGICAL_INO (v1, v2) does not start transaction unnecessarily, this
     can speed up the mentioned ioctl and scrub as well

   - fsync on files with many (but not too many) hardlinks is faster,
     finer decision if the links should be fsynced individually or
     completely

   - send tries harder to find ranges to clone

   - trim/discard will skip unallocated chunks that haven't been touched
     since the last mount

  Fixes:

   - send flushes delayed allocation before start, otherwise it could
     miss some changes in case of a very recent rw->ro switch of a
     subvolume

   - fix fallocate with qgroups that could lead to space accounting
     underflow, reported as a warning

   - trim/discard ioctl honours the requested range

   - starting send and dedupe on a subvolume at the same time will let
     only one of them succeed, this is to prevent changes that send
     could miss due to dedupe; both operations are restartable

  Core changes:

   - more tree-checker validations, errors reported by fuzzing tools:
      - device item
      - inode item
      - block group profiles

   - tracepoints for extent buffer locking

   - async cow preallocates memory to avoid errors happening too deep in
     the call chain

   - metadata reservations for delalloc reworked to better adapt in
     many-writers/low-space scenarios

   - improved space flushing logic for intense DIO vs buffered workloads

   - lots of cleanups
      - removed unused struct members
      - redundant argument removal
      - properties and xattrs
      - extent buffer locking
      - selftests
      - use common file type conversions
      - many-argument functions reduction"

* tag 'for-5.2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (227 commits)
  btrfs: Use kvmalloc for allocating compressed path context
  btrfs: Factor out common extent locking code in submit_compressed_extents
  btrfs: Set io_tree only once in submit_compressed_extents
  btrfs: Replace clear_extent_bit with unlock_extent
  btrfs: Make compress_file_range take only struct async_chunk
  btrfs: Remove fs_info from struct async_chunk
  btrfs: Rename async_cow to async_chunk
  btrfs: Preallocate chunks in cow_file_range_async
  btrfs: reserve delalloc metadata differently
  btrfs: track DIO bytes in flight
  btrfs: merge calls of btrfs_setxattr and btrfs_setxattr_trans in btrfs_set_prop
  btrfs: delete unused function btrfs_set_prop_trans
  btrfs: start transaction in xattr_handler_set_prop
  btrfs: drop local copy of inode i_mode
  btrfs: drop old_fsflags in btrfs_ioctl_setflags
  btrfs: modify local copy of btrfs_inode flags
  btrfs: drop useless inode i_flags copy and restore
  btrfs: start transaction in btrfs_ioctl_setflags()
  btrfs: export btrfs_set_prop
  btrfs: refactor btrfs_set_props to validate externally
  ...
2019-05-07 11:34:19 -07:00
Linus Torvalds 168e153d5e Merge branch 'work.icache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs inode freeing updates from Al Viro:
 "Introduction of separate method for RCU-delayed part of
  ->destroy_inode() (if any).

  Pretty much as posted, except that destroy_inode() stashes
  ->free_inode into the victim (anon-unioned with ->i_fops) before
  scheduling i_callback() and the last two patches (sockfs conversion
  and folding struct socket_wq into struct socket) are excluded - that
  pair should go through netdev once davem reopens his tree"

* 'work.icache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (58 commits)
  orangefs: make use of ->free_inode()
  shmem: make use of ->free_inode()
  hugetlb: make use of ->free_inode()
  overlayfs: make use of ->free_inode()
  jfs: switch to ->free_inode()
  fuse: switch to ->free_inode()
  ext4: make use of ->free_inode()
  ecryptfs: make use of ->free_inode()
  ceph: use ->free_inode()
  btrfs: use ->free_inode()
  afs: switch to use of ->free_inode()
  dax: make use of ->free_inode()
  ntfs: switch to ->free_inode()
  securityfs: switch to ->free_inode()
  apparmor: switch to ->free_inode()
  rpcpipe: switch to ->free_inode()
  bpf: switch to ->free_inode()
  mqueue: switch to ->free_inode()
  ufs: switch to ->free_inode()
  coda: switch to ->free_inode()
  ...
2019-05-07 10:57:05 -07:00
Nikolay Borisov b1c16ac978 btrfs: Use kvmalloc for allocating compressed path context
Recent refactoring of cow_file_range_async means it's now possible to
request a rather large physically contiguous memory via kmalloc. The
size is dependent on the number of 512k chunks that the compressed range
consists of. David reported multiple OOM messages on such large
allocations. Fix it by switching to using kvmalloc.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-02 13:48:19 +02:00
Nikolay Borisov 7447555fe7 btrfs: Factor out common extent locking code in submit_compressed_extents
Irrespective of whether the compress code fell back to uncompressed or
a compressed extent has to be submitted, the extent range is always
locked. So factor out the common lock_extent call at the beginning of
the loop. No functional changes just removes one duplicate lock_extent
call.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-02 13:48:19 +02:00
Nikolay Borisov 4336650aff btrfs: Set io_tree only once in submit_compressed_extents
The inode never changes so it's sufficient to dereference it and get
the iotree only once, before the execution of the main loop. No
functional changes, only the size of the function is decreased:

add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-44 (-44)
Function                                     old     new   delta
submit_compressed_extents                   1240    1196     -44
Total: Before=88476, After=88432, chg -0.05%

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-02 13:48:19 +02:00
Nikolay Borisov 69684c5a88 btrfs: Replace clear_extent_bit with unlock_extent
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-02 13:48:19 +02:00
Nikolay Borisov 1368c6dac7 btrfs: Make compress_file_range take only struct async_chunk
All context this function needs is held within struct async_chunk.
Currently we not only pass the struct but also every individual member.
This is redundant, simplify it by only passing struct async_chunk and
leaving it to compress_file_range to extract the values it requires.
No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-02 13:48:19 +02:00
Nikolay Borisov c5a68aec4e btrfs: Remove fs_info from struct async_chunk
The associated btrfs_work already contains a reference to the fs_info so
use that instead of passing it via async_chunk. No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-02 13:48:19 +02:00
Nikolay Borisov b5326271e7 btrfs: Rename async_cow to async_chunk
Now that we have an explicit async_chunk struct rename references to
variables of this type to async_chunk. No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-02 13:48:18 +02:00
Nikolay Borisov 97db120451 btrfs: Preallocate chunks in cow_file_range_async
This commit changes the implementation of cow_file_range_async in order
to get rid of the BUG_ON in the middle of the loop. Additionally it
reworks the inner loop in the hopes of making it more understandable.

The idea is to make async_cow be a top-level structured, shared amongst
all chunks being sent for compression. This allows to perform one memory
allocation at the beginning and gracefully fail the IO if there isn't
enough memory. Now, each chunk is going to be described by an
async_chunk struct. It's the responsibility of the final chunk
to actually free the memory.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-02 13:48:18 +02:00
Al Viro 26602cab41 btrfs: use ->free_inode()
a lot of stuff remains in ->destroy_inode()

Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-01 22:43:26 -04:00
Linus Torvalds 7e74e235bb gcc-9: don't warn about uninitialized btrfs extent_type variable
The 'extent_type' variable does seem to be reliably initialized, but
it's _very_ non-obvious, since there's a "goto next" case that jumps
over the normal initialization.  That will then always trigger the
"start >= extent_end" test, which will end up never falling through to
the use of that variable.

But the code is certainly not obvious, and the compiler warning looks
reasonable.  Make 'extent_type' an int, and initialize it to an invalid
negative value, which seems to be the common pattern in other places.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-01 12:19:20 -07:00