Commit Graph

405 Commits

Author SHA1 Message Date
Thorsten Blum
c0247d289e btrfs: send: annotate struct name_cache_entry with __counted_by()
Add the __counted_by compiler attribute to the flexible array member
name to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
CONFIG_FORTIFY_SOURCE.

Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-15 20:35:32 +02:00
Filipe Manana
46a6e10a1a btrfs: send: allow cloning non-aligned extent if it ends at i_size
If we a find that an extent is shared but its end offset is not sector
size aligned, then we don't clone it and issue write operations instead.
This is because the reflink (remap_file_range) operation does not allow
to clone unaligned ranges, except if the end offset of the range matches
the i_size of the source and destination files (and the start offset is
sector size aligned).

While this is not incorrect because send can only guarantee that a file
has the same data in the source and destination snapshots, it's not
optimal and generates confusion and surprising behaviour for users.

For example, running this test:

  $ cat test.sh
  #!/bin/bash

  DEV=/dev/sdi
  MNT=/mnt/sdi

  mkfs.btrfs -f $DEV
  mount $DEV $MNT

  # Use a file size not aligned to any possible sector size.
  file_size=$((1 * 1024 * 1024 + 5)) # 1MB + 5 bytes
  dd if=/dev/random of=$MNT/foo bs=$file_size count=1
  cp --reflink=always $MNT/foo $MNT/bar

  btrfs subvolume snapshot -r $MNT/ $MNT/snap
  rm -f /tmp/send-test
  btrfs send -f /tmp/send-test $MNT/snap

  umount $MNT
  mkfs.btrfs -f $DEV
  mount $DEV $MNT

  btrfs receive -vv -f /tmp/send-test $MNT

  xfs_io -r -c "fiemap -v" $MNT/snap/bar

  umount $MNT

Gives the following result:

  (...)
  mkfile o258-7-0
  rename o258-7-0 -> bar
  write bar - offset=0 length=49152
  write bar - offset=49152 length=49152
  write bar - offset=98304 length=49152
  write bar - offset=147456 length=49152
  write bar - offset=196608 length=49152
  write bar - offset=245760 length=49152
  write bar - offset=294912 length=49152
  write bar - offset=344064 length=49152
  write bar - offset=393216 length=49152
  write bar - offset=442368 length=49152
  write bar - offset=491520 length=49152
  write bar - offset=540672 length=49152
  write bar - offset=589824 length=49152
  write bar - offset=638976 length=49152
  write bar - offset=688128 length=49152
  write bar - offset=737280 length=49152
  write bar - offset=786432 length=49152
  write bar - offset=835584 length=49152
  write bar - offset=884736 length=49152
  write bar - offset=933888 length=49152
  write bar - offset=983040 length=49152
  write bar - offset=1032192 length=16389
  chown bar - uid=0, gid=0
  chmod bar - mode=0644
  utimes bar
  utimes
  BTRFS_IOC_SET_RECEIVED_SUBVOL uuid=06d640da-9ca1-604c-b87c-3375175a8eb3, stransid=7
  /mnt/sdi/snap/bar:
   EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
     0: [0..2055]:       26624..28679      2056   0x1

There's no clone operation to clone extents from the file foo into file
bar and fiemap confirms there's no shared flag (0x2000).

So update send_write_or_clone() so that it proceeds with cloning if the
source and destination ranges end at the i_size of the respective files.

After this changes the result of the test is:

  (...)
  mkfile o258-7-0
  rename o258-7-0 -> bar
  clone bar - source=foo source offset=0 offset=0 length=1048581
  chown bar - uid=0, gid=0
  chmod bar - mode=0644
  utimes bar
  utimes
  BTRFS_IOC_SET_RECEIVED_SUBVOL uuid=582420f3-ea7d-564e-bbe5-ce440d622190, stransid=7
  /mnt/sdi/snap/bar:
   EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
     0: [0..2055]:       26624..28679      2056 0x2001

A test case for fstests will also follow up soon.

Link: https://github.com/kdave/btrfs-progs/issues/572#issuecomment-2282841416
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Qu Wenruo <wqu@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>
2024-08-13 13:45:42 +02:00
Linus Torvalds
fbc90c042c - 875fa64577da ("mm/hugetlb_vmemmap: fix race with speculative PFN
walkers") is known to cause a performance regression
   (https://lore.kernel.org/all/3acefad9-96e5-4681-8014-827d6be71c7a@linux.ibm.com/T/#mfa809800a7862fb5bdf834c6f71a3a5113eb83ff).
   Yu has a fix which I'll send along later via the hotfixes branch.
 
 - In the series "mm: Avoid possible overflows in dirty throttling" Jan
   Kara addresses a couple of issues in the writeback throttling code.
   These fixes are also targetted at -stable kernels.
 
 - Ryusuke Konishi's series "nilfs2: fix potential issues related to
   reserved inodes" does that.  This should actually be in the
   mm-nonmm-stable tree, along with the many other nilfs2 patches.  My bad.
 
 - More folio conversions from Kefeng Wang in the series "mm: convert to
   folio_alloc_mpol()"
 
 - Kemeng Shi has sent some cleanups to the writeback code in the series
   "Add helper functions to remove repeated code and improve readability of
   cgroup writeback"
 
 - Kairui Song has made the swap code a little smaller and a little
   faster in the series "mm/swap: clean up and optimize swap cache index".
 
 - In the series "mm/memory: cleanly support zeropage in
   vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David
   Hildenbrand has reworked the rather sketchy handling of the use of the
   zeropage in MAP_SHARED mappings.  I don't see any runtime effects here -
   more a cleanup/understandability/maintainablity thing.
 
 - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling of
   higher addresses, for aarch64.  The (poorly named) series is
   "Restructure va_high_addr_switch".
 
 - The core TLB handling code gets some cleanups and possible slight
   optimizations in Bang Li's series "Add update_mmu_tlb_range() to
   simplify code".
 
 - Jane Chu has improved the handling of our
   fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in the
   series "Enhance soft hwpoison handling and injection".
 
 - Jeff Johnson has sent a billion patches everywhere to add
   MODULE_DESCRIPTION() to everything.  Some landed in this pull.
 
 - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang has
   simplified migration's use of hardware-offload memory copying.
 
 - Yosry Ahmed performs more folio API conversions in his series "mm:
   zswap: trivial folio conversions".
 
 - In the series "large folios swap-in: handle refault cases first",
   Chuanhua Han inches us forward in the handling of large pages in the
   swap code.  This is a cleanup and optimization, working toward the end
   objective of full support of large folio swapin/out.
 
 - In the series "mm,swap: cleanup VMA based swap readahead window
   calculation", Huang Ying has contributed some cleanups and a possible
   fixlet to his VMA based swap readahead code.
 
 - In the series "add mTHP support for anonymous shmem" Baolin Wang has
   taught anonymous shmem mappings to use multisize THP.  By default this
   is a no-op - users must opt in vis sysfs controls.  Dramatic
   improvements in pagefault latency are realized.
 
 - David Hildenbrand has some cleanups to our remaining use of
   page_mapcount() in the series "fs/proc: move page_mapcount() to
   fs/proc/internal.h".
 
 - David also has some highmem accounting cleanups in the series
   "mm/highmem: don't track highmem pages manually".
 
 - Build-time fixes and cleanups from John Hubbard in the series
   "cleanups, fixes, and progress towards avoiding "make headers"".
 
 - Cleanups and consolidation of the core pagemap handling from Barry
   Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers
   and utilize them".
 
 - Lance Yang's series "Reclaim lazyfree THP without splitting" has
   reduced the latency of the reclaim of pmd-mapped THPs under fairly
   common circumstances.  A 10x speedup is seen in a microbenchmark.
 
   It does this by punting to aother CPU but I guess that's a win unless
   all CPUs are pegged.
 
 - hugetlb_cgroup cleanups from Xiu Jianfeng in the series
   "mm/hugetlb_cgroup: rework on cftypes".
 
 - Miaohe Lin's series "Some cleanups for memory-failure" does just that
   thing.
 
 - Is anyone reading this stuff?  If so, email me!
 
 - Someone other than SeongJae has developed a DAMON feature in Honggyu
   Kim's series "DAMON based tiered memory management for CXL memory".
   This adds DAMON features which may be used to help determine the
   efficiency of our placement of CXL/PCIe attached DRAM.
 
 - DAMON user API centralization and simplificatio work in SeongJae
   Park's series "mm/damon: introduce DAMON parameters online commit
   function".
 
 - In the series "mm: page_type, zsmalloc and page_mapcount_reset()"
   David Hildenbrand does some maintenance work on zsmalloc - partially
   modernizing its use of pageframe fields.
 
 - Kefeng Wang provides more folio conversions in the series "mm: remove
   page_maybe_dma_pinned() and page_mkclean()".
 
 - More cleanup from David Hildenbrand, this time in the series
   "mm/memory_hotplug: use PageOffline() instead of PageReserved() for
   !ZONE_DEVICE".  It "enlightens memory hotplug more about PageOffline()
   pages" and permits the removal of some virtio-mem hacks.
 
 - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and
   __folio_add_anon_rmap()" is a cleanup to the anon folio handling in
   preparation for mTHP (multisize THP) swapin.
 
 - Kefeng Wang's series "mm: improve clear and copy user folio"
   implements more folio conversions, this time in the area of large folio
   userspace copying.
 
 - The series "Docs/mm/damon/maintaier-profile: document a mailing tool
   and community meetup series" tells people how to get better involved
   with other DAMON developers.  From SeongJae Park.
 
 - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does
   that.
 
 - David Hildenbrand sends along more cleanups, this time against the
   migration code.  The series is "mm/migrate: move NUMA hinting fault
   folio isolation + checks under PTL".
 
 - Jan Kara has found quite a lot of strangenesses and minor errors in
   the readahead code.  He addresses this in the series "mm: Fix various
   readahead quirks".
 
 - SeongJae Park's series "selftests/damon: test DAMOS tried regions and
   {min,max}_nr_regions" adds features and addresses errors in DAMON's self
   testing code.
 
 - Gavin Shan has found a userspace-triggerable WARN in the pagecache
   code.  The series "mm/filemap: Limit page cache size to that supported
   by xarray" addresses this.  The series is marked cc:stable.
 
 - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations
   and cleanup" cleans up and slightly optimizes KSM.
 
 - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of
   code motion.  The series (which also makes the memcg-v1 code
   Kconfigurable) are
 
   "mm: memcg: separate legacy cgroup v1 code and put under config
   option" and
   "mm: memcg: put cgroup v1-specific memcg data under CONFIG_MEMCG_V1"
 
 - Dan Schatzberg's series "Add swappiness argument to memory.reclaim"
   adds an additional feature to this cgroup-v2 control file.
 
 - The series "Userspace controls soft-offline pages" from Jiaqi Yan
   permits userspace to stop the kernel's automatic treatment of excessive
   correctable memory errors.  In order to permit userspace to monitor and
   handle this situation.
 
 - Kefeng Wang's series "mm: migrate: support poison recover from migrate
   folio" teaches the kernel to appropriately handle migration from
   poisoned source folios rather than simply panicing.
 
 - SeongJae Park's series "Docs/damon: minor fixups and improvements"
   does those things.
 
 - In the series "mm/zsmalloc: change back to per-size_class lock"
   Chengming Zhou improves zsmalloc's scalability and memory utilization.
 
 - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for
   pinning memfd folios" makes the GUP code use FOLL_PIN rather than bare
   refcount increments.  So these paes can first be moved aside if they
   reside in the movable zone or a CMA block.
 
 - Andrii Nakryiko has added a binary ioctl()-based API to /proc/pid/maps
   for much faster reading of vma information.  The series is "query VMAs
   from /proc/<pid>/maps".
 
 - In the series "mm: introduce per-order mTHP split counters" Lance Yang
   improves the kernel's presentation of developer information related to
   multisize THP splitting.
 
 - Michael Ellerman has developed the series "Reimplement huge pages
   without hugepd on powerpc (8xx, e500, book3s/64)".  This permits
   userspace to use all available huge page sizes.
 
 - In the series "revert unconditional slab and page allocator fault
   injection calls" Vlastimil Babka removes a performance-affecting and not
   very useful feature from slab fault injection.
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Merge tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - In the series "mm: Avoid possible overflows in dirty throttling" Jan
   Kara addresses a couple of issues in the writeback throttling code.
   These fixes are also targetted at -stable kernels.

 - Ryusuke Konishi's series "nilfs2: fix potential issues related to
   reserved inodes" does that. This should actually be in the
   mm-nonmm-stable tree, along with the many other nilfs2 patches. My
   bad.

 - More folio conversions from Kefeng Wang in the series "mm: convert to
   folio_alloc_mpol()"

 - Kemeng Shi has sent some cleanups to the writeback code in the series
   "Add helper functions to remove repeated code and improve readability
   of cgroup writeback"

 - Kairui Song has made the swap code a little smaller and a little
   faster in the series "mm/swap: clean up and optimize swap cache
   index".

 - In the series "mm/memory: cleanly support zeropage in
   vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David
   Hildenbrand has reworked the rather sketchy handling of the use of
   the zeropage in MAP_SHARED mappings. I don't see any runtime effects
   here - more a cleanup/understandability/maintainablity thing.

 - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling
   of higher addresses, for aarch64. The (poorly named) series is
   "Restructure va_high_addr_switch".

 - The core TLB handling code gets some cleanups and possible slight
   optimizations in Bang Li's series "Add update_mmu_tlb_range() to
   simplify code".

 - Jane Chu has improved the handling of our
   fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in
   the series "Enhance soft hwpoison handling and injection".

 - Jeff Johnson has sent a billion patches everywhere to add
   MODULE_DESCRIPTION() to everything. Some landed in this pull.

 - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang
   has simplified migration's use of hardware-offload memory copying.

 - Yosry Ahmed performs more folio API conversions in his series "mm:
   zswap: trivial folio conversions".

 - In the series "large folios swap-in: handle refault cases first",
   Chuanhua Han inches us forward in the handling of large pages in the
   swap code. This is a cleanup and optimization, working toward the end
   objective of full support of large folio swapin/out.

 - In the series "mm,swap: cleanup VMA based swap readahead window
   calculation", Huang Ying has contributed some cleanups and a possible
   fixlet to his VMA based swap readahead code.

 - In the series "add mTHP support for anonymous shmem" Baolin Wang has
   taught anonymous shmem mappings to use multisize THP. By default this
   is a no-op - users must opt in vis sysfs controls. Dramatic
   improvements in pagefault latency are realized.

 - David Hildenbrand has some cleanups to our remaining use of
   page_mapcount() in the series "fs/proc: move page_mapcount() to
   fs/proc/internal.h".

 - David also has some highmem accounting cleanups in the series
   "mm/highmem: don't track highmem pages manually".

 - Build-time fixes and cleanups from John Hubbard in the series
   "cleanups, fixes, and progress towards avoiding "make headers"".

 - Cleanups and consolidation of the core pagemap handling from Barry
   Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers
   and utilize them".

 - Lance Yang's series "Reclaim lazyfree THP without splitting" has
   reduced the latency of the reclaim of pmd-mapped THPs under fairly
   common circumstances. A 10x speedup is seen in a microbenchmark.

   It does this by punting to aother CPU but I guess that's a win unless
   all CPUs are pegged.

 - hugetlb_cgroup cleanups from Xiu Jianfeng in the series
   "mm/hugetlb_cgroup: rework on cftypes".

 - Miaohe Lin's series "Some cleanups for memory-failure" does just that
   thing.

 - Someone other than SeongJae has developed a DAMON feature in Honggyu
   Kim's series "DAMON based tiered memory management for CXL memory".
   This adds DAMON features which may be used to help determine the
   efficiency of our placement of CXL/PCIe attached DRAM.

 - DAMON user API centralization and simplificatio work in SeongJae
   Park's series "mm/damon: introduce DAMON parameters online commit
   function".

 - In the series "mm: page_type, zsmalloc and page_mapcount_reset()"
   David Hildenbrand does some maintenance work on zsmalloc - partially
   modernizing its use of pageframe fields.

 - Kefeng Wang provides more folio conversions in the series "mm: remove
   page_maybe_dma_pinned() and page_mkclean()".

 - More cleanup from David Hildenbrand, this time in the series
   "mm/memory_hotplug: use PageOffline() instead of PageReserved() for
   !ZONE_DEVICE". It "enlightens memory hotplug more about PageOffline()
   pages" and permits the removal of some virtio-mem hacks.

 - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and
   __folio_add_anon_rmap()" is a cleanup to the anon folio handling in
   preparation for mTHP (multisize THP) swapin.

 - Kefeng Wang's series "mm: improve clear and copy user folio"
   implements more folio conversions, this time in the area of large
   folio userspace copying.

 - The series "Docs/mm/damon/maintaier-profile: document a mailing tool
   and community meetup series" tells people how to get better involved
   with other DAMON developers. From SeongJae Park.

 - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does
   that.

 - David Hildenbrand sends along more cleanups, this time against the
   migration code. The series is "mm/migrate: move NUMA hinting fault
   folio isolation + checks under PTL".

 - Jan Kara has found quite a lot of strangenesses and minor errors in
   the readahead code. He addresses this in the series "mm: Fix various
   readahead quirks".

 - SeongJae Park's series "selftests/damon: test DAMOS tried regions and
   {min,max}_nr_regions" adds features and addresses errors in DAMON's
   self testing code.

 - Gavin Shan has found a userspace-triggerable WARN in the pagecache
   code. The series "mm/filemap: Limit page cache size to that supported
   by xarray" addresses this. The series is marked cc:stable.

 - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations
   and cleanup" cleans up and slightly optimizes KSM.

 - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of
   code motion. The series (which also makes the memcg-v1 code
   Kconfigurable) are "mm: memcg: separate legacy cgroup v1 code and put
   under config option" and "mm: memcg: put cgroup v1-specific memcg
   data under CONFIG_MEMCG_V1"

 - Dan Schatzberg's series "Add swappiness argument to memory.reclaim"
   adds an additional feature to this cgroup-v2 control file.

 - The series "Userspace controls soft-offline pages" from Jiaqi Yan
   permits userspace to stop the kernel's automatic treatment of
   excessive correctable memory errors. In order to permit userspace to
   monitor and handle this situation.

 - Kefeng Wang's series "mm: migrate: support poison recover from
   migrate folio" teaches the kernel to appropriately handle migration
   from poisoned source folios rather than simply panicing.

 - SeongJae Park's series "Docs/damon: minor fixups and improvements"
   does those things.

 - In the series "mm/zsmalloc: change back to per-size_class lock"
   Chengming Zhou improves zsmalloc's scalability and memory
   utilization.

 - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for
   pinning memfd folios" makes the GUP code use FOLL_PIN rather than
   bare refcount increments. So these paes can first be moved aside if
   they reside in the movable zone or a CMA block.

 - Andrii Nakryiko has added a binary ioctl()-based API to
   /proc/pid/maps for much faster reading of vma information. The series
   is "query VMAs from /proc/<pid>/maps".

 - In the series "mm: introduce per-order mTHP split counters" Lance
   Yang improves the kernel's presentation of developer information
   related to multisize THP splitting.

 - Michael Ellerman has developed the series "Reimplement huge pages
   without hugepd on powerpc (8xx, e500, book3s/64)". This permits
   userspace to use all available huge page sizes.

 - In the series "revert unconditional slab and page allocator fault
   injection calls" Vlastimil Babka removes a performance-affecting and
   not very useful feature from slab fault injection.

* tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (411 commits)
  mm/mglru: fix ineffective protection calculation
  mm/zswap: fix a white space issue
  mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folio
  mm/hugetlb: fix possible recursive locking detected warning
  mm/gup: clear the LRU flag of a page before adding to LRU batch
  mm/numa_balancing: teach mpol_to_str about the balancing mode
  mm: memcg1: convert charge move flags to unsigned long long
  alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting
  lib: reuse page_ext_data() to obtain codetag_ref
  lib: add missing newline character in the warning message
  mm/mglru: fix overshooting shrinker memory
  mm/mglru: fix div-by-zero in vmpressure_calc_level()
  mm/kmemleak: replace strncpy() with strscpy()
  mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC
  mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB
  mm: ignore data-race in __swap_writepage
  hugetlbfs: ensure generic_hugetlb_get_unmapped_area() returns higher address than mmap_min_addr
  mm: shmem: rename mTHP shmem counters
  mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async()
  mm/migrate: putback split folios when numa hint migration fails
  ...
2024-07-21 17:15:46 -07:00
David Sterba
24e7459849 btrfs: pass a btrfs_inode to btrfs_ioctl_send()
Pass a struct btrfs_inode to btrfs_ioctl_send() and _btrfs_ioctl_send()
as it's an internal interface, allowing to remove some use of BTRFS_I.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-07-11 15:33:28 +02:00
Filipe Manana
d13240dd0a btrfs: remove super block argument from btrfs_iget()
It's pointless to pass a super block argument to btrfs_iget() because we
always pass a root and from it we can get the super block through:

   root->fs_info->sb

So remove the super block argument.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@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>
2024-07-11 15:33:25 +02:00
David Sterba
2917f74102 btrfs: constify pointer parameters where applicable
We can add const to many parameters, this is for clarity and minor
addition to safety. There are some minor effects, in the assembly
code and .ko measured on release config. This patch does not cover all
possible conversions.

Signed-off-by: David Sterba <dsterba@suse.com>
2024-07-11 15:33:22 +02:00
Filipe Manana
f9763e4d15 btrfs: send: get rid of the label and gotos at ensure_commit_roots_uptodate()
Now that there is a helper to commit the current transaction and we are
using it, there's no need for the label and goto statements at
ensure_commit_roots_uptodate(). So replace them with direct return
statements that call btrfs_commit_current_transaction().

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@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>
2024-07-11 15:33:20 +02:00
Filipe Manana
ded980eb3f btrfs: add and use helper to commit the current transaction
We have several places that attach to the current transaction with
btrfs_attach_transaction_barrier() and then commit the transaction if
there is one. Add a helper and use it to deduplicate this pattern.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@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>
2024-07-11 15:33:20 +02:00
Filipe Manana
0557feab70 btrfs: send: avoid create/commit empty transaction at ensure_commit_roots_uptodate()
At ensure_commit_roots_uptodate() we use btrfs_join_transaction() to
catch any running transaction and then commit it. This will however create
a new and empty transaction in case there's no running transaction anymore
(got committed by the transaction kthread or other task for example) or
there's a running transaction finishing its commit and with a state >=
TRANS_STATE_UNBLOCKED. In the former case we don't need to do anything
while in the second case we just need to wait for the transaction to
complete its commit.

So improve this by using btrfs_attach_transaction_barrier() instead, which
does not create a new transaction if there's none running, and if there's
a current transaction that is committing, it will wait for it to fully
commit and not create a new transaction. This helps avoiding creating and
committing empty transactions, saving IO, time and unnecessary rotation of
the backup roots in the super block.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@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>
2024-07-11 15:33:19 +02:00
Filipe Manana
9e79c497f8 btrfs: send: make ensure_commit_roots_uptodate() simpler and more efficient
Before starting a send operation we have to make sure that every root has
its commit root matching the regular root, to that send doesn't find stale
inodes in the commit root (inodes that were deleted in the regular root)
and fails the inode lookups with -ESTALE.

Currently we keep looking for roots used by the send operation and as soon
as we find one we commit the current transaction (or a new one since
btrfs_join_transaction() creates one if there isn't any running or the
running one is in a state >= TRANS_STATE_UNBLOCKED). It's pointless to
keep looking until we don't find any, because after the first transaction
commit all the other roots are updated too, as they were already tagged in
the fs_info->fs_roots_radix radix tree when they were modified in order to
have a commit root different from the regular root.

Currently we are also always passing the main send root into
btrfs_join_transaction(), which despite not having any functional issue,
it is not optimal because in case the root wasn't modified we end up
adding it to fs_info->fs_roots_radix and then update its root item in the
root tree when committing the transaction, causing unnecessary work.

So simplify and make this more efficient by removing the looping and by
passing the first root we found that is modified as the argument to
btrfs_join_transaction().

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@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>
2024-07-11 15:33:19 +02:00
David Sterba
42317ab440 btrfs: simplify range parameters of btrfs_wait_ordered_roots()
The range is specified only in two ways, we can simplify the case for
the whole filesystem range as a NULL block group parameter.

Signed-off-by: David Sterba <dsterba@suse.com>
2024-07-11 15:33:19 +02:00
Jan Kara
bb82ac31dd readahead: drop index argument of page_cache_async_readahead()
The index argument of page_cache_async_readahead() is just folio->index so
there's no point in passing is separately.  Drop it.

Link: https://lkml.kernel.org/r/20240625101909.12234-5-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Tested-by: Zhang Peng <zhangpengpeng0808@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:27 -07:00
Josef Bacik
e094f48040 btrfs: change root->root_key.objectid to btrfs_root_id()
A comment from Filipe on one of my previous cleanups brought my
attention to a new helper we have for getting the root id of a root,
which makes it easier to read in the code.

The changes where made with the following Coccinelle semantic patch:

// <smpl>
@@
expression E,E1;
@@
(
 E->root_key.objectid = E1
|
- E->root_key.objectid
+ btrfs_root_id(E)
)
// </smpl>

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor style fixups ]
Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07 21:31:06 +02:00
Goldwyn Rodrigues
01b69bf990 btrfs: convert put_file_data() to folios
Use folio instead of page in put_file_data(). Add a warning in case
higher order folio is found, this will be implemented in the future.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07 21:31:01 +02:00
David Sterba
e925671666 btrfs: open code trivial btrfs_lru_cache_size()
The helper is really trivial, reading a cache size can be done directly.

Signed-off-by: David Sterba <dsterba@suse.com>
2024-03-04 16:24:53 +01:00
Filipe Manana
0e9e135e7c btrfs: send: avoid duplicated search for last extent when sending hole
During an incremental send, before determining if we need to send a hole
(write operations full of zeroes) we will search for the last extent's
end offset if we are at the first slot of a leaf and the last processed
extent's end offset is smaller then the current extent's start offset.
However we are repeating this search in case we had the last extent's end
offset undefined (set to the (u64)-1 value) when we entered
maybe_send_hole(), wasting time.

So avoid this duplicated search by combining the two conditions that
trigger a search for the last extent's end offset into a single if
statement.

Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-03-04 16:24:52 +01:00
David Sterba
56f335e043 btrfs: change BUG_ON to assertion in tree_move_down()
There's only one caller of tree_move_down() that does not pass level 0
so the assertion is better suited here.

Signed-off-by: David Sterba <dsterba@suse.com>
2024-03-04 16:24:51 +01:00
David Sterba
3c6ee34c6f btrfs: send: handle path ref underflow in header iterate_inode_ref()
Change BUG_ON to proper error handling if building the path buffer
fails. The pointers are not printed so we don't accidentally leak kernel
addresses.

Signed-off-by: David Sterba <dsterba@suse.com>
2024-03-04 16:24:51 +01:00
David Sterba
5d2288711c btrfs: send: handle unexpected inode in header process_recorded_refs()
Change BUG_ON to proper error handling when an unexpected inode number
is encountered. As the comment says this should never happen.

Signed-off-by: David Sterba <dsterba@suse.com>
2024-03-04 16:24:51 +01:00
David Sterba
e80e3f732c btrfs: send: handle unexpected data in header buffer in begin_cmd()
Change BUG_ON to a proper error handling in the unlikely case of seeing
data when the command is started. This is supposed to be reset when the
command is finished (send_cmd, send_encoded_extent).

Signed-off-by: David Sterba <dsterba@suse.com>
2024-03-04 16:24:51 +01:00
David Sterba
2b712e3bb2 btrfs: remove unused included headers
With help of neovim, LSP and clangd we can identify header files that
are not actually needed to be included in the .c files. This is focused
only on removal (with minor fixups), further cleanups are possible but
will require doing the header files properly with forward declarations,
minimized includes and include-what-you-use care.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-03-04 16:24:46 +01:00
David Sterba
4e00422ee6 btrfs: replace sb::s_blocksize by fs_info::sectorsize
The block size stored in the super block is used by subsystems outside
of btrfs and it's a copy of fs_info::sectorsize. Unify that to always
use our sectorsize, with the exception of mount where we first need to
use fixed values (4K) until we read the super block and can set the
sectorsize.

Replace all uses, in most cases it's fewer pointer indirections.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-03-04 16:24:46 +01:00
Filipe Manana
5897710b28 btrfs: send: don't issue unnecessary zero writes for trailing hole
If we have a sparse file with a trailing hole (from the last extent's end
to i_size) and then create an extent in the file that ends before the
file's i_size, then when doing an incremental send we will issue a write
full of zeroes for the range that starts immediately after the new extent
ends up to i_size. While this isn't incorrect because the file ends up
with exactly the same data, it unnecessarily results in using extra space
at the destination with one or more extents full of zeroes instead of
having a hole. In same cases this results in using megabytes or even
gigabytes of unnecessary space.

Example, reproducer:

   $ cat test.sh
   #!/bin/bash

   DEV=/dev/sdh
   MNT=/mnt/sdh

   mkfs.btrfs -f $DEV
   mount $DEV $MNT

   # Create 1G sparse file.
   xfs_io -f -c "truncate 1G" $MNT/foobar

   # Create base snapshot.
   btrfs subvolume snapshot -r $MNT $MNT/mysnap1

   # Create send stream (full send) for the base snapshot.
   btrfs send -f /tmp/1.snap $MNT/mysnap1

   # Now write one extent at the beginning of the file and one somewhere
   # in the middle, leaving a gap between the end of this second extent
   # and the file's size.
   xfs_io -c "pwrite -S 0xab 0 128K" \
          -c "pwrite -S 0xcd 512M 128K" \
          $MNT/foobar

   # Now create a second snapshot which is going to be used for an
   # incremental send operation.
   btrfs subvolume snapshot -r $MNT $MNT/mysnap2

   # Create send stream (incremental send) for the second snapshot.
   btrfs send -p $MNT/mysnap1 -f /tmp/2.snap $MNT/mysnap2

   # Now recreate the filesystem by receiving both send streams and
   # verify we get the same content that the original filesystem had
   # and file foobar has only two extents with a size of 128K each.
   umount $MNT
   mkfs.btrfs -f $DEV
   mount $DEV $MNT

   btrfs receive -f /tmp/1.snap $MNT
   btrfs receive -f /tmp/2.snap $MNT

   echo -e "\nFile fiemap in the second snapshot:"
   # Should have:
   #
   # 128K extent at file range [0, 128K[
   # hole at file range [128K, 512M[
   # 128K extent file range [512M, 512M + 128K[
   # hole at file range [512M + 128K, 1G[
   xfs_io -r -c "fiemap -v" $MNT/mysnap2/foobar

   # File should be using 256K of data (two 128K extents).
   echo -e "\nSpace used by the file: $(du -h $MNT/mysnap2/foobar | cut -f 1)"

   umount $MNT

Running the test, we can see with fiemap that we get an extent for the
range [512M, 1G[, while in the source filesystem we have an extent for
the range [512M, 512M + 128K[ and a hole for the rest of the file (the
range [512M + 128K, 1G[):

   $ ./test.sh
   (...)
   File fiemap in the second snapshot:
   /mnt/sdh/mysnap2/foobar:
    EXT: FILE-OFFSET        BLOCK-RANGE        TOTAL FLAGS
      0: [0..255]:          26624..26879         256   0x0
      1: [256..1048575]:    hole             1048320
      2: [1048576..2097151]: 2156544..3205119 1048576   0x1

   Space used by the file: 513M

This happens because once we finish processing an inode, at
finish_inode_if_needed(), we always issue a hole (write operations full
of zeros) if there's a gap between the end of the last processed extent
and the file's size, even if that range is already a hole in the parent
snapshot. Fix this by issuing the hole only if the range is not already
a hole.

After this change, running the test above, we get the expected layout:

   $ ./test.sh
   (...)
   File fiemap in the second snapshot:
   /mnt/sdh/mysnap2/foobar:
    EXT: FILE-OFFSET        BLOCK-RANGE      TOTAL FLAGS
      0: [0..255]:          26624..26879       256   0x0
      1: [256..1048575]:    hole             1048320
      2: [1048576..1048831]: 26880..27135       256   0x1
      3: [1048832..2097151]: hole             1048320

   Space used by the file: 256K

A test case for fstests will follow soon.

CC: stable@vger.kernel.org # 6.1+
Reported-by: Dorai Ashok S A <dash.btrfs@inix.me>
Link: https://lore.kernel.org/linux-btrfs/c0bf7818-9c45-46a8-b3d3-513230d0c86e@inix.me/
Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-02-22 12:14:31 +01:00
David Sterba
f884a9f9e5 btrfs: send: return EOPNOTSUPP on unknown flags
When some ioctl flags are checked we return EOPNOTSUPP, like for
BTRFS_SCRUB_SUPPORTED_FLAGS, BTRFS_SUBVOL_CREATE_ARGS_MASK or fallocate
modes. The EINVAL is supposed to be for a supported but invalid
values or combination of options. Fix that when checking send flags so
it's consistent with the rest.

CC: stable@vger.kernel.org # 4.14+
Link: https://lore.kernel.org/linux-btrfs/CAL3q7H5rryOLzp3EKq8RTbjMHMHeaJubfpsVLF6H4qJnKCUR1w@mail.gmail.com/
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-01-31 08:42:30 +01:00
Dmitry Antipov
6ff09b6b8c btrfs: fix kvcalloc() arguments order in btrfs_ioctl_send()
When compiling with gcc version 14.0.0 20231220 (experimental)
and W=1, I've noticed the following warning:

fs/btrfs/send.c: In function 'btrfs_ioctl_send':
fs/btrfs/send.c:8208:44: warning: 'kvcalloc' sizes specified with 'sizeof'
in the earlier argument and not in the later argument [-Wcalloc-transposed-args]
 8208 |         sctx->clone_roots = kvcalloc(sizeof(*sctx->clone_roots),
      |                                            ^

Since 'n' and 'size' arguments of 'kvcalloc()' are multiplied to
calculate the final size, their actual order doesn't affect the result
and so this is not a bug. But it's still worth to fix it.

Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-01-12 01:59:45 +01:00
Jann Horn
0ac1d13a55 btrfs: send: ensure send_fd is writable
kernel_write() requires the caller to ensure that the file is writable.
Let's do that directly after looking up the ->send_fd.

We don't need a separate bailout path because the "out" path already
does fput() if ->send_filp is non-NULL.

This has no security impact for two reasons:

 - the ioctl requires CAP_SYS_ADMIN
 - __kernel_write() bails out on read-only files - but only since 5.8,
   see commit a01ac27be4 ("fs: check FMODE_WRITE in __kernel_write")

Reported-and-tested-by: syzbot+12e098239d20385264d3@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=12e098239d20385264d3
Fixes: 31db9f7c23 ("Btrfs: introduce BTRFS_IOC_SEND for btrfs send/receive")
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-11-24 18:50:53 +01:00
Josef Bacik
03e8634896 btrfs: remove btrfs_crc32c wrapper
This simply sends the same arguments into crc32c(), and is just used in
a few places.  Remove this wrapper and directly call crc32c() in these
instances.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12 16:44:02 +02:00
Ruan Jinjie
84af994b85 btrfs: use LIST_HEAD() to initialize the list_head
Use LIST_HEAD() to initialize the list_head instead of open-coding it.

Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-08-21 14:54:46 +02:00
Filipe Manana
6f3eb72a1f btrfs: send: do not BUG_ON() on unexpected symlink data extent
There's really no need to BUG_ON() if we find a symlink with an extent
that is not inline or is compressed. We can just make send fail with
an error (-EUCLEAN) and log an informative error message, so just do
that instead of BUG_ON().

Reviewed-by: Qu Wenruo <wqu@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>
2023-06-19 13:59:39 +02:00
Genjian Zhang
8ba7d5f5ba btrfs: fix uninitialized variable warnings
There are some warnings on older compilers (gcc 10, 7) or non-x86_64
architectures (aarch64).  As btrfs wants to enable -Wmaybe-uninitialized
by default, fix the warnings even though it's not necessary on recent
compilers (gcc 12+).

../fs/btrfs/volumes.c: In function ‘btrfs_init_new_device’:
../fs/btrfs/volumes.c:2703:3: error: ‘seed_devices’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
 2703 |   btrfs_setup_sprout(fs_info, seed_devices);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

../fs/btrfs/send.c: In function ‘get_cur_inode_state’:
../include/linux/compiler.h:70:32: error: ‘right_gen’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
   70 |   (__if_trace.miss_hit[1]++,1) :  \
      |                                ^
../fs/btrfs/send.c:1878:6: note: ‘right_gen’ was declared here
 1878 |  u64 right_gen;
      |      ^~~~~~~~~

Reported-by: k2ci <kernel-bot@kylinos.cn>
Signed-off-by: Genjian Zhang <zhanggenjian@kylinos.cn>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2023-04-17 19:52:19 +02:00
Filipe Manana
3e49363be6 btrfs: send: cache utimes operations for directories if possible
Whenever we add or remove an entry to a directory, we issue an utimes
command for the directory. If we add 1000 entries to a directory (create
1000 files under it or move 1000 files to it), then we issue the same
utimes command 1000 times, which increases the send stream size, results
in more pipe IO, one search in the send b+tree, allocating one path for
the search, etc, as well as making the receiver do a system call for each
duplicated utimes command.

We also issue an utimes command when we create a new directory, but later
we might add entries to it corresponding to inodes with an higher inode
number, so it's pointless to issue the utimes command before we create
the last inode under the directory.

So use a lru cache to track directories for which we must send a utimes
command. When we need to remove an entry from the cache, we issue the
utimes command for the respective directory. When finishing the send
operation, we go over each cache element and issue the respective utimes
command. Finally the caching is entirely optional, just a performance
optimization, meaning that if we fail to cache (due to memory allocation
failure), we issue the utimes command right away, that is, we fallback
to the previous, unoptimized, behaviour.

This patch belongs to a patchset comprised of the following patches:

  btrfs: send: directly return from did_overwrite_ref() and simplify it
  btrfs: send: avoid unnecessary generation search at did_overwrite_ref()
  btrfs: send: directly return from will_overwrite_ref() and simplify it
  btrfs: send: avoid extra b+tree searches when checking reference overrides
  btrfs: send: remove send_progress argument from can_rmdir()
  btrfs: send: avoid duplicated orphan dir allocation and initialization
  btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir()
  btrfs: send: reduce searches on parent root when checking if dir can be removed
  btrfs: send: iterate waiting dir move rbtree only once when processing refs
  btrfs: send: initialize all the red black trees earlier
  btrfs: send: genericize the backref cache to allow it to be reused
  btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems
  btrfs: send: cache information about created directories
  btrfs: allow a generation number to be associated with lru cache entries
  btrfs: add an api to delete a specific entry from the lru cache
  btrfs: send: use the lru cache to implement the name cache
  btrfs: send: update size of roots array for backref cache entries
  btrfs: send: cache utimes operations for directories if possible

The following test was run before and after applying the whole patchset,
and on a non-debug kernel (Debian's default kernel config):

   #!/bin/bash

   MNT=/mnt/sdi
   DEV=/dev/sdi

   mkfs.btrfs -f $DEV > /dev/null
   mount $DEV $MNT

   mkdir $MNT/A
   for ((i = 1; i <= 20000; i++)); do
       echo -n > $MNT/A/file_$i
   done

   btrfs subvolume snapshot -r $MNT $MNT/snap1

   mkdir $MNT/B
   for ((i = 20000; i <= 40000; i++)); do
       echo -n > $MNT/B/file_$i
   done

   mv $MNT/A/file_* $MNT/B/

   btrfs subvolume snapshot -r $MNT $MNT/snap2

   start=$(date +%s%N)
   btrfs send -p $MNT/snap1 $MNT/snap2 > /dev/null
   end=$(date +%s%N)

   dur=$(( (end - start) / 1000000 ))
   echo "Incremental send took $dur milliseconds"

   umount $MNT

Before the whole patchset: 18408 milliseconds
After the whole patchset:   1942 milliseconds  (9.5x speedup)

Using 60000 files instead of 40000:

Before the whole patchset: 39764 milliseconds
After the whole patchset:   3076 milliseconds  (12.9x speedup)

Using 20000 files instead of 40000:

Before the whole patchset:  5072 milliseconds
After the whole patchset:    916 milliseconds  (5.5x speedup)

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15 19:38:50 +01:00
Filipe Manana
ace79df8a4 btrfs: send: update size of roots array for backref cache entries
Currently we limit the size of the roots array, for backref cache entries,
to 12 elements. This is because that number is enough for most cases and
to make the backref cache entry size to be exactly 128 bytes, so that
memory is allocated from the kmalloc-128 slab and no space is wasted.

However recent changes in the series refactored the backref cache to be
more generic and allow it to be reused for other purposes, which resulted
in increasing the size of the embedded structure btrfs_lru_cache_entry in
order to allow for supporting inode numbers as keys on 32 bits system and
allow multiple generations per key. This resulted in increasing the size
of struct backref_cache_entry from 128 bytes to 152 bytes. Since the cache
entries are allocated with kmalloc(), it means we end up using the slab
kmalloc-192, so we end up wasting 40 bytes of memory. So bump the size of
the roots array from 12 elements to 17 elements, so we end up using 192
bytes for each backref cache entry.

This patch is part of a larger patchset and the changelog of the last
patch in the series contains a sample performance test and results.
The patches that comprise the patchset are the following:

  btrfs: send: directly return from did_overwrite_ref() and simplify it
  btrfs: send: avoid unnecessary generation search at did_overwrite_ref()
  btrfs: send: directly return from will_overwrite_ref() and simplify it
  btrfs: send: avoid extra b+tree searches when checking reference overrides
  btrfs: send: remove send_progress argument from can_rmdir()
  btrfs: send: avoid duplicated orphan dir allocation and initialization
  btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir()
  btrfs: send: reduce searches on parent root when checking if dir can be removed
  btrfs: send: iterate waiting dir move rbtree only once when processing refs
  btrfs: send: initialize all the red black trees earlier
  btrfs: send: genericize the backref cache to allow it to be reused
  btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems
  btrfs: send: cache information about created directories
  btrfs: allow a generation number to be associated with lru cache entries
  btrfs: add an api to delete a specific entry from the lru cache
  btrfs: send: use the lru cache to implement the name cache
  btrfs: send: update size of roots array for backref cache entries
  btrfs: send: cache utimes operations for directories if possible

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15 19:36:39 +01:00
Filipe Manana
c48545debf btrfs: send: use the lru cache to implement the name cache
The name cache in send is basically a lru cache implemented with a radix
tree and linked lists, very similar to the lru cache module which is used
for the send backref cache and the cache of previously created directories
during a send operation. So remove all the custom caching code for the
name cache and make it use the lru cache instead.

One particular detail to note is that the current cache behaves a bit
differently when it comes to eviction of entries. Namely when after
inserting a new name in the cache, if the cache now has 256 entries, we
evict the last 128 LRU entries. The lru_cache.{c,h} module behaves a bit
differently in that once we reach the cache limit, we evict a single LRU
entry. In practice this doesn't make much difference, but it's actually
better to evict just one entry instead of half of the entries, as there's
always a chance we will need a name stored in one of that last 128 removed
entries.

This patch is part of a larger patchset and the changelog of the last
patch in the series contains a sample performance test and results.
The patches that comprise the patchset are the following:

  btrfs: send: directly return from did_overwrite_ref() and simplify it
  btrfs: send: avoid unnecessary generation search at did_overwrite_ref()
  btrfs: send: directly return from will_overwrite_ref() and simplify it
  btrfs: send: avoid extra b+tree searches when checking reference overrides
  btrfs: send: remove send_progress argument from can_rmdir()
  btrfs: send: avoid duplicated orphan dir allocation and initialization
  btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir()
  btrfs: send: reduce searches on parent root when checking if dir can be removed
  btrfs: send: iterate waiting dir move rbtree only once when processing refs
  btrfs: send: initialize all the red black trees earlier
  btrfs: send: genericize the backref cache to allow it to be reused
  btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems
  btrfs: send: cache information about created directories
  btrfs: allow a generation number to be associated with lru cache entries
  btrfs: add an api to delete a specific entry from the lru cache
  btrfs: send: use the lru cache to implement the name cache
  btrfs: send: update size of roots array for backref cache entries
  btrfs: send: cache utimes operations for directories if possible

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15 19:36:32 +01:00
Filipe Manana
0da0c5605e btrfs: allow a generation number to be associated with lru cache entries
This allows an optional generation number to be associated to each entry
of the lru cache. Entries with the same key but different generations, are
stored in the linked list to which the maple tree points to. This is meant
to be used when there's a small number of different generations, so the
impact of searching a linked list is negligible. The goal is to get rid of
the open coded name cache in the send code (which uses a radix tree and
a similar linked list of values/entries) and use instead the lru cache
module. For that particular use case we have at most 2 generations that
are associated to each key (inode number): one generation for the send
root and another generation for the parent root. The actual migration of
the send name cache is done in the next patch in the series.

This patch is part of a larger patchset and the changelog of the last
patch in the series contains a sample performance test and results.
The patches that comprise the patchset are the following:

  btrfs: send: directly return from did_overwrite_ref() and simplify it
  btrfs: send: avoid unnecessary generation search at did_overwrite_ref()
  btrfs: send: directly return from will_overwrite_ref() and simplify it
  btrfs: send: avoid extra b+tree searches when checking reference overrides
  btrfs: send: remove send_progress argument from can_rmdir()
  btrfs: send: avoid duplicated orphan dir allocation and initialization
  btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir()
  btrfs: send: reduce searches on parent root when checking if dir can be removed
  btrfs: send: iterate waiting dir move rbtree only once when processing refs
  btrfs: send: initialize all the red black trees earlier
  btrfs: send: genericize the backref cache to allow it to be reused
  btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems
  btrfs: send: cache information about created directories
  btrfs: allow a generation number to be associated with lru cache entries
  btrfs: add an api to delete a specific entry from the lru cache
  btrfs: send: use the lru cache to implement the name cache
  btrfs: send: update size of roots array for backref cache entries
  btrfs: send: cache utimes operations for directories if possible

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13 17:50:36 +01:00
Filipe Manana
e8a7f49d9b btrfs: send: cache information about created directories
During an incremental send, when processing the reference for an inode
we need to check if the directory where the new reference is located was
already created before creating the new reference. This check, which is
done by the helper did_create_dir(), can be expensive if the directory
has many entries, since it consists in searching the send root's b+tree
and visiting every single dir index key until we either find one which
points to an inode with a number smaller than the current inode's number
or until we visited all index keys. So it doesn't scale well for very
large directories.

So improve on this by caching created directories using a lru cache, and
limiting its size to 64 entries, which results in using at most 4096
bytes of memory. The caching is optional, if we fail to allocate memory,
we just proceed as before and use the existing slower path.

This patch is part of a larger patchset and the changelog of the last
patch in the series contains a sample performance test and results.
The patches that comprise the patchset are the following:

  btrfs: send: directly return from did_overwrite_ref() and simplify it
  btrfs: send: avoid unnecessary generation search at did_overwrite_ref()
  btrfs: send: directly return from will_overwrite_ref() and simplify it
  btrfs: send: avoid extra b+tree searches when checking reference overrides
  btrfs: send: remove send_progress argument from can_rmdir()
  btrfs: send: avoid duplicated orphan dir allocation and initialization
  btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir()
  btrfs: send: reduce searches on parent root when checking if dir can be removed
  btrfs: send: iterate waiting dir move rbtree only once when processing refs
  btrfs: send: initialize all the red black trees earlier
  btrfs: send: genericize the backref cache to allow it to be reused
  btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems
  btrfs: send: cache information about created directories
  btrfs: allow a generation number to be associated with lru cache entries
  btrfs: add an api to delete a specific entry from the lru cache
  btrfs: send: use the lru cache to implement the name cache
  btrfs: send: update size of roots array for backref cache entries
  btrfs: send: cache utimes operations for directories if possible

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13 17:50:36 +01:00
Filipe Manana
90b90d4ac0 btrfs: send: genericize the backref cache to allow it to be reused
The backref cache is a cache backed by a maple tree and a linked list to
keep track of temporal access to cached entries (the LRU entry always at
the head of the list). This type of caching method is going to be useful
in other scenarios, so make the cache implementation more generic and
move it into its own header and source files.

This patch is part of a larger patchset and the changelog of the last
patch in the series contains a sample performance test and results.
The patches that comprise the patchset are the following:

  btrfs: send: directly return from did_overwrite_ref() and simplify it
  btrfs: send: avoid unnecessary generation search at did_overwrite_ref()
  btrfs: send: directly return from will_overwrite_ref() and simplify it
  btrfs: send: avoid extra b+tree searches when checking reference overrides
  btrfs: send: remove send_progress argument from can_rmdir()
  btrfs: send: avoid duplicated orphan dir allocation and initialization
  btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir()
  btrfs: send: reduce searches on parent root when checking if dir can be removed
  btrfs: send: iterate waiting dir move rbtree only once when processing refs
  btrfs: send: initialize all the red black trees earlier
  btrfs: send: genericize the backref cache to allow it to be reused
  btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems
  btrfs: send: cache information about created directories
  btrfs: allow a generation number to be associated with lru cache entries
  btrfs: add an api to delete a specific entry from the lru cache
  btrfs: send: use the lru cache to implement the name cache
  btrfs: send: update size of roots array for backref cache entries
  btrfs: send: cache utimes operations for directories if possible

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13 17:50:35 +01:00
Filipe Manana
d307d2f35c btrfs: send: initialize all the red black trees earlier
After we allocate the send context object and before we initialize all
the red black trees, we can jump to the 'out' label if some errors happen,
and then under the 'out' label we use RB_EMPTY_ROOT() against some of the
those trees, which we have not yet initialized. This happens to work out
ok because the send context object was initialized to zeroes with kzalloc
and the RB_ROOT initializer just happens to have the following definition:

    #define RB_ROOT (struct rb_root) { NULL, }

But it's really neither clean nor a good practice as RB_ROOT is supposed
to be opaque and in case it changes or we change those red black trees to
some other data structure, it leaves us in a precarious situation.

So initialize all the red black trees immediately after allocating the
send context and before any jump into the 'out' label.

This patch is part of a larger patchset and the changelog of the last
patch in the series contains a sample performance test and results.
The patches that comprise the patchset are the following:

  btrfs: send: directly return from did_overwrite_ref() and simplify it
  btrfs: send: avoid unnecessary generation search at did_overwrite_ref()
  btrfs: send: directly return from will_overwrite_ref() and simplify it
  btrfs: send: avoid extra b+tree searches when checking reference overrides
  btrfs: send: remove send_progress argument from can_rmdir()
  btrfs: send: avoid duplicated orphan dir allocation and initialization
  btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir()
  btrfs: send: reduce searches on parent root when checking if dir can be removed
  btrfs: send: iterate waiting dir move rbtree only once when processing refs
  btrfs: send: initialize all the red black trees earlier
  btrfs: send: genericize the backref cache to allow it to be reused
  btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems
  btrfs: send: cache information about created directories
  btrfs: allow a generation number to be associated with lru cache entries
  btrfs: add an api to delete a specific entry from the lru cache
  btrfs: send: use the lru cache to implement the name cache
  btrfs: send: update size of roots array for backref cache entries
  btrfs: send: cache utimes operations for directories if possible

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13 17:50:35 +01:00
Filipe Manana
8c139e1d78 btrfs: send: iterate waiting dir move rbtree only once when processing refs
When processing the new references for an inode, we unnecessarily iterate
twice the waiting dir moves rbtree, once with is_waiting_for_move() and
if we found an entry in the rbtree, we iterate it again with a call to
get_waiting_dir_move(). This is pointless, we can make this simpler and
more efficient by calling only get_waiting_dir_move(), so just do that.

This patch is part of a larger patchset and the changelog of the last
patch in the series contains a sample performance test and results.
The patches that comprise the patchset are the following:

  btrfs: send: directly return from did_overwrite_ref() and simplify it
  btrfs: send: avoid unnecessary generation search at did_overwrite_ref()
  btrfs: send: directly return from will_overwrite_ref() and simplify it
  btrfs: send: avoid extra b+tree searches when checking reference overrides
  btrfs: send: remove send_progress argument from can_rmdir()
  btrfs: send: avoid duplicated orphan dir allocation and initialization
  btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir()
  btrfs: send: reduce searches on parent root when checking if dir can be removed
  btrfs: send: iterate waiting dir move rbtree only once when processing refs
  btrfs: send: initialize all the red black trees earlier
  btrfs: send: genericize the backref cache to allow it to be reused
  btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems
  btrfs: send: cache information about created directories
  btrfs: allow a generation number to be associated with lru cache entries
  btrfs: add an api to delete a specific entry from the lru cache
  btrfs: send: use the lru cache to implement the name cache
  btrfs: send: update size of roots array for backref cache entries
  btrfs: send: cache utimes operations for directories if possible

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13 17:50:35 +01:00
Filipe Manana
474e4761f6 btrfs: send: reduce searches on parent root when checking if dir can be removed
During an incremental send, every time we remove a reference (dentry) for
an inode and the parent directory does not exists anymore in the send
root, we go check if we can remove the directory by making a call to
can_rmdir(). This helper can only return true (value 1) if all dentries
were already removed, and for that it always does a search on the parent
root for dir index keys - if it finds any dentry referring to an inode
with a number higher then the inode currently being processed, then the
directory can not be removed and it must return false (value 0).

However that means if a directory that was deleted had 1000 dentries, and
each one pointed to an inode with a number higher then the number of the
directory's inode, we end up doing 1000 searches on the parent root.
Typically files are created in a directory after the directory was created
and therefore they get an higher inode number than the directory. It's
also common to have the each dentry pointing to an inode with a higher
number then the inodes the previous dentries point to, for example when
creating a series of files inside a directory, a very common pattern.

So improve on that by having the first call to can_rmdir() for a directory
to check the number of the inode that the last dentry points to and cache
that inode number in the orphan dir structure. Then every subsequent call
to can_rmdir() can avoid doing a search on the parent root if the number
of the inode currently being processed is smaller than cached inode number
at the directory's orphan dir structure.

This patch is part of a larger patchset and the changelog of the last
patch in the series contains a sample performance test and results.
The patches that comprise the patchset are the following:

  btrfs: send: directly return from did_overwrite_ref() and simplify it
  btrfs: send: avoid unnecessary generation search at did_overwrite_ref()
  btrfs: send: directly return from will_overwrite_ref() and simplify it
  btrfs: send: avoid extra b+tree searches when checking reference overrides
  btrfs: send: remove send_progress argument from can_rmdir()
  btrfs: send: avoid duplicated orphan dir allocation and initialization
  btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir()
  btrfs: send: reduce searches on parent root when checking if dir can be removed
  btrfs: send: iterate waiting dir move rbtree only once when processing refs
  btrfs: send: initialize all the red black trees earlier
  btrfs: send: genericize the backref cache to allow it to be reused
  btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems
  btrfs: send: cache information about created directories
  btrfs: allow a generation number to be associated with lru cache entries
  btrfs: add an api to delete a specific entry from the lru cache
  btrfs: send: use the lru cache to implement the name cache
  btrfs: send: update size of roots array for backref cache entries
  btrfs: send: cache utimes operations for directories if possible

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13 17:50:35 +01:00
Filipe Manana
78cf1a954d btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir()
At can_rmdir() we start by searching the orphan dirs rbtree for an orphan
dir object for the target directory. Later when iterating over the dir
index keys, if we find that any dir entry points to inode for which there
is a pending dir move or the inode was not yet processed, we exit because
we can't remove the directory yet. However we end up always calling
add_orphan_dir_info(), which will iterate again the rbtree and if there is
already an orphan dir object (created by the first call to can_rmdir()),
it returns the existing object. This is unnecessary work because in case
there is already an existing orphan dir object, we got a reference to it
at the start of can_rmdir(). So skip the call to add_orphan_dir_info()
if we already have a reference for an orphan dir object.

This patch is part of a larger patchset and the changelog of the last
patch in the series contains a sample performance test and results.
The patches that comprise the patchset are the following:

  btrfs: send: directly return from did_overwrite_ref() and simplify it
  btrfs: send: avoid unnecessary generation search at did_overwrite_ref()
  btrfs: send: directly return from will_overwrite_ref() and simplify it
  btrfs: send: avoid extra b+tree searches when checking reference overrides
  btrfs: send: remove send_progress argument from can_rmdir()
  btrfs: send: avoid duplicated orphan dir allocation and initialization
  btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir()
  btrfs: send: reduce searches on parent root when checking if dir can be removed
  btrfs: send: iterate waiting dir move rbtree only once when processing refs
  btrfs: send: initialize all the red black trees earlier
  btrfs: send: genericize the backref cache to allow it to be reused
  btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems
  btrfs: send: cache information about created directories
  btrfs: allow a generation number to be associated with lru cache entries
  btrfs: add an api to delete a specific entry from the lru cache
  btrfs: send: use the lru cache to implement the name cache
  btrfs: send: update size of roots array for backref cache entries
  btrfs: send: cache utimes operations for directories if possible

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13 17:50:35 +01:00
Filipe Manana
d921b9cf91 btrfs: send: avoid duplicated orphan dir allocation and initialization
At can_rmdir() we are allocating and initializing an orphan dir object
twice. This can be deduplicated outside of the loop that iterates over
the dir index keys. So deduplicate that code, even because other patch
in the series will need to add more initialization code and another one
will add one more condition.

This patch is part of a larger patchset and the changelog of the last
patch in the series contains a sample performance test and results.
The patches that comprise the patchset are the following:

  btrfs: send: directly return from did_overwrite_ref() and simplify it
  btrfs: send: avoid unnecessary generation search at did_overwrite_ref()
  btrfs: send: directly return from will_overwrite_ref() and simplify it
  btrfs: send: avoid extra b+tree searches when checking reference overrides
  btrfs: send: remove send_progress argument from can_rmdir()
  btrfs: send: avoid duplicated orphan dir allocation and initialization
  btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir()
  btrfs: send: reduce searches on parent root when checking if dir can be removed
  btrfs: send: iterate waiting dir move rbtree only once when processing refs
  btrfs: send: initialize all the red black trees earlier
  btrfs: send: genericize the backref cache to allow it to be reused
  btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems
  btrfs: send: cache information about created directories
  btrfs: allow a generation number to be associated with lru cache entries
  btrfs: add an api to delete a specific entry from the lru cache
  btrfs: send: use the lru cache to implement the name cache
  btrfs: send: update size of roots array for backref cache entries
  btrfs: send: cache utimes operations for directories if possible

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13 17:50:35 +01:00
Filipe Manana
24970ccb24 btrfs: send: remove send_progress argument from can_rmdir()
All callers of can_rmdir() pass sctx->cur_ino as the value for the
send_progress argument, so remove the argument and directly use
sctx->cur_ino.

This patch is part of a larger patchset and the changelog of the last
patch in the series contains a sample performance test and results.
The patches that comprise the patchset are the following:

  btrfs: send: directly return from did_overwrite_ref() and simplify it
  btrfs: send: avoid unnecessary generation search at did_overwrite_ref()
  btrfs: send: directly return from will_overwrite_ref() and simplify it
  btrfs: send: avoid extra b+tree searches when checking reference overrides
  btrfs: send: remove send_progress argument from can_rmdir()
  btrfs: send: avoid duplicated orphan dir allocation and initialization
  btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir()
  btrfs: send: reduce searches on parent root when checking if dir can be removed
  btrfs: send: iterate waiting dir move rbtree only once when processing refs
  btrfs: send: initialize all the red black trees earlier
  btrfs: send: genericize the backref cache to allow it to be reused
  btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems
  btrfs: send: cache information about created directories
  btrfs: allow a generation number to be associated with lru cache entries
  btrfs: add an api to delete a specific entry from the lru cache
  btrfs: send: use the lru cache to implement the name cache
  btrfs: send: update size of roots array for backref cache entries
  btrfs: send: cache utimes operations for directories if possible

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13 17:50:35 +01:00
Filipe Manana
498581f33c btrfs: send: avoid extra b+tree searches when checking reference overrides
During an incremental send, when processing the new references of an inode
(either it's a new inode or an existing one renamed/moved), he will search
the b+tree of the send or parent roots in order to find out the inode item
of the parent directory and extract its generation. However we are doing
that search twice, once with is_inode_existent() -> get_cur_inode_state()
and then again at did_overwrite_ref() or will_overwrite_ref().

So avoid that and get the generation at get_cur_inode_state() and then
propagate it up to did_overwrite_ref() and will_overwrite_ref().

This patch is part of a larger patchset and the changelog of the last
patch in the series contains a sample performance test and results.
The patches that comprise the patchset are the following:

  btrfs: send: directly return from did_overwrite_ref() and simplify it
  btrfs: send: avoid unnecessary generation search at did_overwrite_ref()
  btrfs: send: directly return from will_overwrite_ref() and simplify it
  btrfs: send: avoid extra b+tree searches when checking reference overrides
  btrfs: send: remove send_progress argument from can_rmdir()
  btrfs: send: avoid duplicated orphan dir allocation and initialization
  btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir()
  btrfs: send: reduce searches on parent root when checking if dir can be removed
  btrfs: send: iterate waiting dir move rbtree only once when processing refs
  btrfs: send: initialize all the red black trees earlier
  btrfs: send: genericize the backref cache to allow it to be reused
  btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems
  btrfs: send: cache information about created directories
  btrfs: allow a generation number to be associated with lru cache entries
  btrfs: add an api to delete a specific entry from the lru cache
  btrfs: send: use the lru cache to implement the name cache
  btrfs: send: update size of roots array for backref cache entries
  btrfs: send: cache utimes operations for directories if possible

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13 17:50:35 +01:00
Filipe Manana
b3047a42f5 btrfs: send: directly return from will_overwrite_ref() and simplify it
There are no resources to release before will_overwrite_ref() returns, so
we don't really need the 'out' label and jumping to it when conditions are
met - we can directly return and get rid of the label and jumps. Also we
can deal with -ENOENT and other errors in a single if-else logic, as it's
more straightforward.

This helps the next patch in the series to be more simple as well.

This patch is part of a larger patchset and the changelog of the last
patch in the series contains a sample performance test and results.
The patches that comprise the patchset are the following:

  btrfs: send: directly return from did_overwrite_ref() and simplify it
  btrfs: send: avoid unnecessary generation search at did_overwrite_ref()
  btrfs: send: directly return from will_overwrite_ref() and simplify it
  btrfs: send: avoid extra b+tree searches when checking reference overrides
  btrfs: send: remove send_progress argument from can_rmdir()
  btrfs: send: avoid duplicated orphan dir allocation and initialization
  btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir()
  btrfs: send: reduce searches on parent root when checking if dir can be removed
  btrfs: send: iterate waiting dir move rbtree only once when processing refs
  btrfs: send: initialize all the red black trees earlier
  btrfs: send: genericize the backref cache to allow it to be reused
  btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems
  btrfs: send: cache information about created directories
  btrfs: allow a generation number to be associated with lru cache entries
  btrfs: add an api to delete a specific entry from the lru cache
  btrfs: send: use the lru cache to implement the name cache
  btrfs: send: update size of roots array for backref cache entries
  btrfs: send: cache utimes operations for directories if possible

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13 17:50:35 +01:00
Filipe Manana
cb68948194 btrfs: send: avoid unnecessary generation search at did_overwrite_ref()
At did_overwrite_ref() we always call get_inode_gen() to find out the
generation of the inode 'ow_inode'. However we don't always need to use
that generation, and in fact it's very common to not use it, so we end
up doing a b+tree search on the send root, allocating a path, etc, for
nothing. So improve on this by getting the generation only if we need
to use it.

This patch is part of a larger patchset and the changelog of the last
patch in the series contains a sample performance test and results.
The patches that comprise the patchset are the following:

  btrfs: send: directly return from did_overwrite_ref() and simplify it
  btrfs: send: avoid unnecessary generation search at did_overwrite_ref()
  btrfs: send: directly return from will_overwrite_ref() and simplify it
  btrfs: send: avoid extra b+tree searches when checking reference overrides
  btrfs: send: remove send_progress argument from can_rmdir()
  btrfs: send: avoid duplicated orphan dir allocation and initialization
  btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir()
  btrfs: send: reduce searches on parent root when checking if dir can be removed
  btrfs: send: iterate waiting dir move rbtree only once when processing refs
  btrfs: send: initialize all the red black trees earlier
  btrfs: send: genericize the backref cache to allow it to be reused
  btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems
  btrfs: send: cache information about created directories
  btrfs: allow a generation number to be associated with lru cache entries
  btrfs: add an api to delete a specific entry from the lru cache
  btrfs: send: use the lru cache to implement the name cache
  btrfs: send: update size of roots array for backref cache entries
  btrfs: send: cache utimes operations for directories if possible

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13 17:50:35 +01:00
Filipe Manana
e739ba307f btrfs: send: directly return from did_overwrite_ref() and simplify it
There are no resources to release before did_overwrite_ref() returns, so
we don't really need the 'out' label and jumping to it when conditions are
met - we can directly return and get rid of the label and jumps. Also we
can deal with -ENOENT and other errors in a single if-else logic, as it's
more straightforward.

This helps the next patch in the series to be more simple as well.

This patch is part of a larger patchset and the changelog of the last
patch in the series contains a sample performance test and results.
The patches that comprise the patchset are the following:

  btrfs: send: directly return from did_overwrite_ref() and simplify it
  btrfs: send: avoid unnecessary generation search at did_overwrite_ref()
  btrfs: send: directly return from will_overwrite_ref() and simplify it
  btrfs: send: avoid extra b+tree searches when checking reference overrides
  btrfs: send: remove send_progress argument from can_rmdir()
  btrfs: send: avoid duplicated orphan dir allocation and initialization
  btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir()
  btrfs: send: reduce searches on parent root when checking if dir can be removed
  btrfs: send: iterate waiting dir move rbtree only once when processing refs
  btrfs: send: initialize all the red black trees earlier
  btrfs: send: genericize the backref cache to allow it to be reused
  btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems
  btrfs: send: cache information about created directories
  btrfs: allow a generation number to be associated with lru cache entries
  btrfs: add an api to delete a specific entry from the lru cache
  btrfs: send: use the lru cache to implement the name cache
  btrfs: send: update size of roots array for backref cache entries
  btrfs: send: cache utimes operations for directories if possible

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13 17:50:35 +01:00
Yushan Zhou
ce394a7f39 btrfs: use PAGE_{ALIGN, ALIGNED, ALIGN_DOWN} macro
The header file linux/mm.h provides PAGE_ALIGN, PAGE_ALIGNED,
PAGE_ALIGN_DOWN macros. Use these macros to make code more
concise.

Signed-off-by: Yushan Zhou <katrinzhou@tencent.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13 17:50:34 +01:00
Josef Bacik
ab19901359 btrfs: fix uninitialized variable warning in get_inode_gen
Anybody that calls get_inode_gen() can have an uninitialized gen if
there's an error.  This isn't a big deal because all the users just exit
if they get an error, however it makes -Wmaybe-uninitialized complain,
so fix this up to always initialize the passed in gen, this quiets all
of the uninitialized warnings in send.c.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Qu Wenruo <wqu@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>
2023-02-13 17:50:33 +01:00
Linus Torvalds
66fcf74e5c for-6.2-rc7-tag
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Merge tag 'for-6.2-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - explicitly initialize zlib work memory to fix a KCSAN warning

 - limit number of send clones by maximum memory allocated

 - limit device size extent in case it device shrink races with chunk
   allocation

 - raid56 fixes:
     - fix copy&paste error in RAID6 stripe recovery
     - make error bitmap update atomic

* tag 'for-6.2-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: raid56: make error_bitmap update atomic
  btrfs: send: limit number of clones and allocated memory size
  btrfs: zlib: zero-initialize zlib workspace
  btrfs: limit device extents to the device size
  btrfs: raid56: fix stripes if vertical errors are found
2023-02-06 14:05:16 -08:00
David Sterba
33e17b3f5a btrfs: send: limit number of clones and allocated memory size
The arg->clone_sources_count is u64 and can trigger a warning when a
huge value is passed from user space and a huge array is allocated.
Limit the allocated memory to 8MiB (can be increased if needed), which
in turn limits the number of clone sources to 8M / sizeof(struct
clone_root) = 8M / 40 = 209715.  Real world number of clones is from
tens to hundreds, so this is future proof.

Reported-by: syzbot+4376a9a073770c173269@syzkaller.appspotmail.com
Signed-off-by: David Sterba <dsterba@suse.com>
2023-01-27 14:57:05 +01:00