1. 26 Jan, 2024 5 commits
    • Yang Shi's avatar
      mm: mmap: map MAP_STACK to VM_NOHUGEPAGE · c4608d1b
      Yang Shi authored
      commit efa7df3e ("mm: align larger anonymous mappings on THP
      boundaries") incured regression for stress-ng pthread benchmark [1].  It
      is because THP get allocated to pthread's stack area much more possible
      than before.  Pthread's stack area is allocated by mmap without
      VM_GROWSDOWN or VM_GROWSUP flag, so kernel can't tell whether it is a
      stack area or not.
      
      The MAP_STACK flag is used to mark the stack area, but it is a no-op on
      Linux.  Mapping MAP_STACK to VM_NOHUGEPAGE to prevent from allocating THP
      for such stack area.
      
      With this change the stack area looks like:
      
      fffd18e10000-fffd19610000 rw-p 00000000 00:00 0
      Size:               8192 kB
      KernelPageSize:        4 kB
      MMUPageSize:           4 kB
      Rss:                  12 kB
      Pss:                  12 kB
      Pss_Dirty:            12 kB
      Shared_Clean:          0 kB
      Shared_Dirty:          0 kB
      Private_Clean:         0 kB
      Private_Dirty:        12 kB
      Referenced:           12 kB
      Anonymous:            12 kB
      KSM:                   0 kB
      LazyFree:              0 kB
      AnonHugePages:         0 kB
      ShmemPmdMapped:        0 kB
      FilePmdMapped:         0 kB
      Shared_Hugetlb:        0 kB
      Private_Hugetlb:       0 kB
      Swap:                  0 kB
      SwapPss:               0 kB
      Locked:                0 kB
      THPeligible:           0
      VmFlags: rd wr mr mw me ac nh
      
      The "nh" flag is set.
      
      [1] https://lore.kernel.org/linux-mm/202312192310.56367035-oliver.sang@intel.com/
      
      Link: https://lkml.kernel.org/r/20231221065943.2803551-2-shy828301@gmail.com
      Fixes: efa7df3e ("mm: align larger anonymous mappings on THP boundaries")
      Signed-off-by: default avatarYang Shi <yang@os.amperecomputing.com>
      Reported-by: default avatarkernel test robot <oliver.sang@intel.com>
      Tested-by: default avatarOliver Sang <oliver.sang@intel.com>
      Reviewed-by: default avatarYin Fengwei <fengwei.yin@intel.com>
      Cc: Rik van Riel <riel@surriel.com>
      Cc: Matthew Wilcox <willy@infradead.org>
      Cc: Christopher Lameter <cl@linux.com>
      Cc: Huang, Ying <ying.huang@intel.com>
      Cc: <stable@vger.kerenl.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      c4608d1b
    • David Hildenbrand's avatar
      uprobes: use pagesize-aligned virtual address when replacing pages · 4dca82d1
      David Hildenbrand authored
      uprobes passes an unaligned page mapping address to
      folio_add_new_anon_rmap(), which ends up triggering a VM_BUG_ON() we
      recently extended in commit 372cbd4d ("mm: non-pmd-mappable, large
      folios for folio_add_new_anon_rmap()").
      
      Arguably, this is uprobes code doing something wrong; however, for the
      time being it would have likely worked in rmap code because
      __folio_set_anon() would set folio->index to the same value.
      
      Looking at __replace_page(), we'd also pass slightly wrong values to
      mmu_notifier_range_init(), page_vma_mapped_walk(), flush_cache_page(),
      ptep_clear_flush() and set_pte_at_notify().  I suspect most of them are
      fine, but let's just mark the introducing commit as the one needed fixing.
      I don't think CC stable is warranted.
      
      We'll add more sanity checks in rmap code separately, to make sure that we
      always get properly aligned addresses.
      
      Link: https://lkml.kernel.org/r/20240115100731.91007-1-david@redhat.com
      Fixes: c517ee74 ("uprobes: __replace_page() should not use page_address_in_vma()")
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Reported-by: default avatarJiri Olsa <jolsa@kernel.org>
      Closes: https://lkml.kernel.org/r/ZaMR2EWN-HvlCfUl@kravaTested-by: default avatarJiri Olsa <jolsa@kernel.org>
      Reviewed-by: default avatarRyan Roberts <ryan.roberts@arm.com>
      Acked-by: default avatarOleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Alexander Shishkin
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Ian Rogers <irogers@google.com>
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      4dca82d1
    • Muhammad Usama Anjum's avatar
      selftests/mm: mremap_test: fix build warning · f8ee4361
      Muhammad Usama Anjum authored
      Use 2 separate variables of types int and unsigned long long instead of
      confusing them.  This corrects the correct print format for each of them
      and removes the build warning:
      
      warning: format `%d' expects argument of type `int', but argument 2 has type `long long unsigned int'
      
      Link: https://lkml.kernel.org/r/20240112071851.612930-1-usama.anjum@collabora.com
      Fixes: a4cb3b24 ("selftests: mm: add a test for remapping to area immediately after existing mapping")
      Signed-off-by: default avatarMuhammad Usama Anjum <usama.anjum@collabora.com>
      Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
      Cc: Lorenzo Stoakes <lstoakes@gmail.com>
      Cc: Shuah Khan <shuah@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      f8ee4361
    • Sidhartha Kumar's avatar
      fs/hugetlbfs/inode.c: mm/memory-failure.c: fix hugetlbfs hwpoison handling · 19d3e221
      Sidhartha Kumar authored
      has_extra_refcount() makes the assumption that the page cache adds a ref
      count of 1 and subtracts this in the extra_pins case.  Commit a08c7193
      (mm/filemap: remove hugetlb special casing in filemap.c) modifies
      __filemap_add_folio() by calling folio_ref_add(folio, nr); for all cases
      (including hugtetlb) where nr is the number of pages in the folio.  We
      should adjust the number of references coming from the page cache by
      subtracing the number of pages rather than 1.
      
      In hugetlbfs_read_iter(), folio_test_has_hwpoisoned() is testing the wrong
      flag as, in the hugetlb case, memory-failure code calls
      folio_test_set_hwpoison() to indicate poison.  folio_test_hwpoison() is
      the correct function to test for that flag.
      
      After these fixes, the hugetlb hwpoison read selftest passes all cases.
      
      Link: https://lkml.kernel.org/r/20240112180840.367006-1-sidhartha.kumar@oracle.com
      Fixes: a08c7193 ("mm/filemap: remove hugetlb special casing in filemap.c")
      Signed-off-by: default avatarSidhartha Kumar <sidhartha.kumar@oracle.com>
      Closes: https://lore.kernel.org/linux-mm/20230713001833.3778937-1-jiaqiyan@google.com/T/#m8e1469119e5b831bbd05d495f96b842e4a1c5519Reported-by: default avatarMuhammad Usama Anjum <usama.anjum@collabora.com>
      Tested-by: default avatarMuhammad Usama Anjum <usama.anjum@collabora.com>
      Acked-by: default avatarMiaohe Lin <linmiaohe@huawei.com>
      Acked-by: default avatarMuchun Song <muchun.song@linux.dev>
      Cc: James Houghton <jthoughton@google.com>
      Cc: Jiaqi Yan <jiaqiyan@google.com>
      Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
      Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
      Cc: <stable@vger.kernel.org>	[6.7+]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      19d3e221
    • Jan Kara's avatar
      readahead: avoid multiple marked readahead pages · ab4443fe
      Jan Kara authored
      ra_alloc_folio() marks a page that should trigger next round of async
      readahead.  However it rounds up computed index to the order of page being
      allocated.  This can however lead to multiple consecutive pages being
      marked with readahead flag.  Consider situation with index == 1, mark ==
      1, order == 0.  We insert order 0 page at index 1 and mark it.  Then we
      bump order to 1, index to 2, mark (still == 1) is rounded up to 2 so page
      at index 2 is marked as well.  Then we bump order to 2, index is
      incremented to 4, mark gets rounded to 4 so page at index 4 is marked as
      well.  The fact that multiple pages get marked within a single readahead
      window confuses the readahead logic and results in readahead window being
      trimmed back to 1.  This situation is triggered in particular when maximum
      readahead window size is not a power of two (in the observed case it was
      768 KB) and as a result sequential read throughput suffers.
      
      Fix the problem by rounding 'mark' down instead of up.  Because the index
      is naturally aligned to 'order', we are guaranteed 'rounded mark' == index
      iff 'mark' is within the page we are allocating at 'index' and thus
      exactly one page is marked with readahead flag as required by the
      readahead code and sequential read performance is restored.
      
      This effectively reverts part of commit b9ff43dd ("mm/readahead: Fix
      readahead with large folios").  The commit changed the rounding with the
      rationale:
      
      "...  we were setting the readahead flag on the folio which contains the
      last byte read from the block.  This is wrong because we will trigger
      readahead at the end of the read without waiting to see if a subsequent
      read is going to use the pages we just read."
      
      Although this is true, the fact is this was always the case with read
      sizes not aligned to folio boundaries and large folios in the page cache
      just make the situation more obvious (and frequent).  Also for sequential
      read workloads it is better to trigger the readahead earlier rather than
      later.  It is true that the difference in the rounding and thus earlier
      triggering of the readahead can result in reading more for semi-random
      workloads.  However workloads really suffering from this seem to be rare. 
      In particular I have verified that the workload described in commit
      b9ff43dd ("mm/readahead: Fix readahead with large folios") of reading
      random 100k blocks from a file like:
      
      [reader]
      bs=100k
      rw=randread
      numjobs=1
      size=64g
      runtime=60s
      
      is not impacted by the rounding change and achieves ~70MB/s in both cases.
      
      [jack@suse.cz: fix one more place where mark rounding was done as well]
        Link: https://lkml.kernel.org/r/20240123153254.5206-1-jack@suse.cz
      Link: https://lkml.kernel.org/r/20240104085839.21029-1-jack@suse.cz
      Fixes: b9ff43dd ("mm/readahead: Fix readahead with large folios")
      Signed-off-by: default avatarJan Kara <jack@suse.cz>
      Cc: Matthew Wilcox <willy@infradead.org>
      Cc: Guo Xuenan <guoxuenan@huawei.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      ab4443fe
  2. 23 Jan, 2024 1 commit
  3. 21 Jan, 2024 34 commits
    • Linus Torvalds's avatar
      Linux 6.8-rc1 · 6613476e
      Linus Torvalds authored
      6613476e
    • Linus Torvalds's avatar
      Merge tag 'bcachefs-2024-01-21' of https://evilpiepirate.org/git/bcachefs · 35a4474b
      Linus Torvalds authored
      Pull more bcachefs updates from Kent Overstreet:
       "Some fixes, Some refactoring, some minor features:
      
         - Assorted prep work for disk space accounting rewrite
      
         - BTREE_TRIGGER_ATOMIC: after combining our trigger callbacks, this
           makes our trigger context more explicit
      
         - A few fixes to avoid excessive transaction restarts on
           multithreaded workloads: fstests (in addition to ktest tests) are
           now checking slowpath counters, and that's shaking out a few bugs
      
         - Assorted tracepoint improvements
      
         - Starting to break up bcachefs_format.h and move on disk types so
           they're with the code they belong to; this will make room to start
           documenting the on disk format better.
      
         - A few minor fixes"
      
      * tag 'bcachefs-2024-01-21' of https://evilpiepirate.org/git/bcachefs: (46 commits)
        bcachefs: Improve inode_to_text()
        bcachefs: logged_ops_format.h
        bcachefs: reflink_format.h
        bcachefs; extents_format.h
        bcachefs: ec_format.h
        bcachefs: subvolume_format.h
        bcachefs: snapshot_format.h
        bcachefs: alloc_background_format.h
        bcachefs: xattr_format.h
        bcachefs: dirent_format.h
        bcachefs: inode_format.h
        bcachefs; quota_format.h
        bcachefs: sb-counters_format.h
        bcachefs: counters.c -> sb-counters.c
        bcachefs: comment bch_subvolume
        bcachefs: bch_snapshot::btime
        bcachefs: add missing __GFP_NOWARN
        bcachefs: opts->compression can now also be applied in the background
        bcachefs: Prep work for variable size btree node buffers
        bcachefs: grab s_umount only if snapshotting
        ...
      35a4474b
    • Linus Torvalds's avatar
      Merge tag 'timers-core-2024-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 4fbbed78
      Linus Torvalds authored
      Pull timer updates from Thomas Gleixner:
       "Updates for time and clocksources:
      
         - A fix for the idle and iowait time accounting vs CPU hotplug.
      
           The time is reset on CPU hotplug which makes the accumulated
           systemwide time jump backwards.
      
         - Assorted fixes and improvements for clocksource/event drivers"
      
      * tag 'timers-core-2024-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        tick-sched: Fix idle and iowait sleeptime accounting vs CPU hotplug
        clocksource/drivers/ep93xx: Fix error handling during probe
        clocksource/drivers/cadence-ttc: Fix some kernel-doc warnings
        clocksource/drivers/timer-ti-dm: Fix make W=n kerneldoc warnings
        clocksource/timer-riscv: Add riscv_clock_shutdown callback
        dt-bindings: timer: Add StarFive JH8100 clint
        dt-bindings: timer: thead,c900-aclint-mtimer: separate mtime and mtimecmp regs
      4fbbed78
    • Linus Torvalds's avatar
      Merge tag 'powerpc-6.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux · 7b297a5c
      Linus Torvalds authored
      Pull powerpc fixes from Aneesh Kumar:
      
       - Increase default stack size to 32KB for Book3S
      
      Thanks to Michael Ellerman.
      
      * tag 'powerpc-6.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
        powerpc/64s: Increase default stack size to 32KB
      7b297a5c
    • Kent Overstreet's avatar
      bcachefs: Improve inode_to_text() · 249f441f
      Kent Overstreet authored
      Add line breaks - inode_to_text() is now much easier to read.
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      249f441f
    • Kent Overstreet's avatar
      bcachefs: logged_ops_format.h · d826cc57
      Kent Overstreet authored
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      d826cc57
    • Kent Overstreet's avatar
      bcachefs: reflink_format.h · 8d52ba60
      Kent Overstreet authored
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      8d52ba60
    • Kent Overstreet's avatar
      bcachefs; extents_format.h · b2fa1b63
      Kent Overstreet authored
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      b2fa1b63
    • Kent Overstreet's avatar
      bcachefs: ec_format.h · 0560eb9a
      Kent Overstreet authored
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      0560eb9a
    • Kent Overstreet's avatar
      bcachefs: subvolume_format.h · c6c4ff65
      Kent Overstreet authored
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      c6c4ff65
    • Kent Overstreet's avatar
      bcachefs: snapshot_format.h · 8fed323b
      Kent Overstreet authored
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      8fed323b
    • Kent Overstreet's avatar
      d455179f
    • Kent Overstreet's avatar
      bcachefs: xattr_format.h · 72e08010
      Kent Overstreet authored
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      72e08010
    • Kent Overstreet's avatar
      bcachefs: dirent_format.h · 7ffc4daa
      Kent Overstreet authored
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      7ffc4daa
    • Kent Overstreet's avatar
      bcachefs: inode_format.h · b36425da
      Kent Overstreet authored
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      b36425da
    • Kent Overstreet's avatar
      bcachefs; quota_format.h · 82de6207
      Kent Overstreet authored
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      82de6207
    • Kent Overstreet's avatar
      bcachefs: sb-counters_format.h · 43314801
      Kent Overstreet authored
      bcachefs_format.h has gotten too big; let's do some organizing.
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      43314801
    • Kent Overstreet's avatar
      3a58dfbc
    • Kent Overstreet's avatar
      12207f49
    • Kent Overstreet's avatar
      bcachefs: bch_snapshot::btime · d32088f2
      Kent Overstreet authored
      Add a field to bch_snapshot for creation time; this will be important
      when we start exposing the snapshot tree to userspace.
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      d32088f2
    • Kent Overstreet's avatar
      7be0208f
    • Kent Overstreet's avatar
      bcachefs: opts->compression can now also be applied in the background · d7e77f53
      Kent Overstreet authored
      The "apply this compression method in the background" paths now use the
      compression option if background_compression is not set; this means that
      setting or changing the compression option will cause existing data to
      be compressed accordingly in the background.
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      d7e77f53
    • Kent Overstreet's avatar
      bcachefs: Prep work for variable size btree node buffers · ec4edd7b
      Kent Overstreet authored
      bcachefs btree nodes are big - typically 256k - and btree roots are
      pinned in memory. As we're now up to 18 btrees, we now have significant
      memory overhead in mostly empty btree roots.
      
      And in the future we're going to start enforcing that certain btree node
      boundaries exist, to solve lock contention issues - analagous to XFS's
      AGIs.
      
      Thus, we need to start allocating smaller btree node buffers when we
      can. This patch changes code that refers to the filesystem constant
      c->opts.btree_node_size to refer to the btree node buffer size -
      btree_buf_bytes() - where appropriate.
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      ec4edd7b
    • Su Yue's avatar
      bcachefs: grab s_umount only if snapshotting · 2acc59dd
      Su Yue authored
      When I was testing mongodb over bcachefs with compression,
      there is a lockdep warning when snapshotting mongodb data volume.
      
      $ cat test.sh
      prog=bcachefs
      
      $prog subvolume create /mnt/data
      $prog subvolume create /mnt/data/snapshots
      
      while true;do
          $prog subvolume snapshot /mnt/data /mnt/data/snapshots/$(date +%s)
          sleep 1s
      done
      
      $ cat /etc/mongodb.conf
      systemLog:
        destination: file
        logAppend: true
        path: /mnt/data/mongod.log
      
      storage:
        dbPath: /mnt/data/
      
      lockdep reports:
      [ 3437.452330] ======================================================
      [ 3437.452750] WARNING: possible circular locking dependency detected
      [ 3437.453168] 6.7.0-rc7-custom+ #85 Tainted: G            E
      [ 3437.453562] ------------------------------------------------------
      [ 3437.453981] bcachefs/35533 is trying to acquire lock:
      [ 3437.454325] ffffa0a02b2b1418 (sb_writers#10){.+.+}-{0:0}, at: filename_create+0x62/0x190
      [ 3437.454875]
                     but task is already holding lock:
      [ 3437.455268] ffffa0a02b2b10e0 (&type->s_umount_key#48){.+.+}-{3:3}, at: bch2_fs_file_ioctl+0x232/0xc90 [bcachefs]
      [ 3437.456009]
                     which lock already depends on the new lock.
      
      [ 3437.456553]
                     the existing dependency chain (in reverse order) is:
      [ 3437.457054]
                     -> #3 (&type->s_umount_key#48){.+.+}-{3:3}:
      [ 3437.457507]        down_read+0x3e/0x170
      [ 3437.457772]        bch2_fs_file_ioctl+0x232/0xc90 [bcachefs]
      [ 3437.458206]        __x64_sys_ioctl+0x93/0xd0
      [ 3437.458498]        do_syscall_64+0x42/0xf0
      [ 3437.458779]        entry_SYSCALL_64_after_hwframe+0x6e/0x76
      [ 3437.459155]
                     -> #2 (&c->snapshot_create_lock){++++}-{3:3}:
      [ 3437.459615]        down_read+0x3e/0x170
      [ 3437.459878]        bch2_truncate+0x82/0x110 [bcachefs]
      [ 3437.460276]        bchfs_truncate+0x254/0x3c0 [bcachefs]
      [ 3437.460686]        notify_change+0x1f1/0x4a0
      [ 3437.461283]        do_truncate+0x7f/0xd0
      [ 3437.461555]        path_openat+0xa57/0xce0
      [ 3437.461836]        do_filp_open+0xb4/0x160
      [ 3437.462116]        do_sys_openat2+0x91/0xc0
      [ 3437.462402]        __x64_sys_openat+0x53/0xa0
      [ 3437.462701]        do_syscall_64+0x42/0xf0
      [ 3437.462982]        entry_SYSCALL_64_after_hwframe+0x6e/0x76
      [ 3437.463359]
                     -> #1 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}:
      [ 3437.463843]        down_write+0x3b/0xc0
      [ 3437.464223]        bch2_write_iter+0x5b/0xcc0 [bcachefs]
      [ 3437.464493]        vfs_write+0x21b/0x4c0
      [ 3437.464653]        ksys_write+0x69/0xf0
      [ 3437.464839]        do_syscall_64+0x42/0xf0
      [ 3437.465009]        entry_SYSCALL_64_after_hwframe+0x6e/0x76
      [ 3437.465231]
                     -> #0 (sb_writers#10){.+.+}-{0:0}:
      [ 3437.465471]        __lock_acquire+0x1455/0x21b0
      [ 3437.465656]        lock_acquire+0xc6/0x2b0
      [ 3437.465822]        mnt_want_write+0x46/0x1a0
      [ 3437.465996]        filename_create+0x62/0x190
      [ 3437.466175]        user_path_create+0x2d/0x50
      [ 3437.466352]        bch2_fs_file_ioctl+0x2ec/0xc90 [bcachefs]
      [ 3437.466617]        __x64_sys_ioctl+0x93/0xd0
      [ 3437.466791]        do_syscall_64+0x42/0xf0
      [ 3437.466957]        entry_SYSCALL_64_after_hwframe+0x6e/0x76
      [ 3437.467180]
                     other info that might help us debug this:
      
      [ 3437.469670] 2 locks held by bcachefs/35533:
                     other info that might help us debug this:
      
      [ 3437.467507] Chain exists of:
                       sb_writers#10 --> &c->snapshot_create_lock --> &type->s_umount_key#48
      
      [ 3437.467979]  Possible unsafe locking scenario:
      
      [ 3437.468223]        CPU0                    CPU1
      [ 3437.468405]        ----                    ----
      [ 3437.468585]   rlock(&type->s_umount_key#48);
      [ 3437.468758]                                lock(&c->snapshot_create_lock);
      [ 3437.469030]                                lock(&type->s_umount_key#48);
      [ 3437.469291]   rlock(sb_writers#10);
      [ 3437.469434]
                      *** DEADLOCK ***
      
      [ 3437.469670] 2 locks held by bcachefs/35533:
      [ 3437.469838]  #0: ffffa0a02ce00a88 (&c->snapshot_create_lock){++++}-{3:3}, at: bch2_fs_file_ioctl+0x1e3/0xc90 [bcachefs]
      [ 3437.470294]  #1: ffffa0a02b2b10e0 (&type->s_umount_key#48){.+.+}-{3:3}, at: bch2_fs_file_ioctl+0x232/0xc90 [bcachefs]
      [ 3437.470744]
                     stack backtrace:
      [ 3437.470922] CPU: 7 PID: 35533 Comm: bcachefs Kdump: loaded Tainted: G            E      6.7.0-rc7-custom+ #85
      [ 3437.471313] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
      [ 3437.471694] Call Trace:
      [ 3437.471795]  <TASK>
      [ 3437.471884]  dump_stack_lvl+0x57/0x90
      [ 3437.472035]  check_noncircular+0x132/0x150
      [ 3437.472202]  __lock_acquire+0x1455/0x21b0
      [ 3437.472369]  lock_acquire+0xc6/0x2b0
      [ 3437.472518]  ? filename_create+0x62/0x190
      [ 3437.472683]  ? lock_is_held_type+0x97/0x110
      [ 3437.472856]  mnt_want_write+0x46/0x1a0
      [ 3437.473025]  ? filename_create+0x62/0x190
      [ 3437.473204]  filename_create+0x62/0x190
      [ 3437.473380]  user_path_create+0x2d/0x50
      [ 3437.473555]  bch2_fs_file_ioctl+0x2ec/0xc90 [bcachefs]
      [ 3437.473819]  ? lock_acquire+0xc6/0x2b0
      [ 3437.474002]  ? __fget_files+0x2a/0x190
      [ 3437.474195]  ? __fget_files+0xbc/0x190
      [ 3437.474380]  ? lock_release+0xc5/0x270
      [ 3437.474567]  ? __x64_sys_ioctl+0x93/0xd0
      [ 3437.474764]  ? __pfx_bch2_fs_file_ioctl+0x10/0x10 [bcachefs]
      [ 3437.475090]  __x64_sys_ioctl+0x93/0xd0
      [ 3437.475277]  do_syscall_64+0x42/0xf0
      [ 3437.475454]  entry_SYSCALL_64_after_hwframe+0x6e/0x76
      [ 3437.475691] RIP: 0033:0x7f2743c313af
      ======================================================
      
      In __bch2_ioctl_subvolume_create(), we grab s_umount unconditionally
      and unlock it at the end of the function. There is a comment
      "why do we need this lock?" about the lock coming from
      commit 42d23732 ("bcachefs: Snapshot creation, deletion")
      The reason is that __bch2_ioctl_subvolume_create() calls
      sync_inodes_sb() which enforce locked s_umount to writeback all dirty
      nodes before doing snapshot works.
      
      Fix it by read locking s_umount for snapshotting only and unlocking
      s_umount after sync_inodes_sb().
      Signed-off-by: default avatarSu Yue <glass.su@suse.com>
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      2acc59dd
    • Su Yue's avatar
      bcachefs: kvfree bch_fs::snapshots in bch2_fs_snapshots_exit · 369acf97
      Su Yue authored
      bch_fs::snapshots is allocated by kvzalloc in __snapshot_t_mut.
      It should be freed by kvfree not kfree.
      Or umount will triger:
      
      [  406.829178 ] BUG: unable to handle page fault for address: ffffe7b487148008
      [  406.830676 ] #PF: supervisor read access in kernel mode
      [  406.831643 ] #PF: error_code(0x0000) - not-present page
      [  406.832487 ] PGD 0 P4D 0
      [  406.832898 ] Oops: 0000 [#1] PREEMPT SMP PTI
      [  406.833512 ] CPU: 2 PID: 1754 Comm: umount Kdump: loaded Tainted: G           OE      6.7.0-rc7-custom+ #90
      [  406.834746 ] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
      [  406.835796 ] RIP: 0010:kfree+0x62/0x140
      [  406.836197 ] Code: 80 48 01 d8 0f 82 e9 00 00 00 48 c7 c2 00 00 00 80 48 2b 15 78 9f 1f 01 48 01 d0 48 c1 e8 0c 48 c1 e0 06 48 03 05 56 9f 1f 01 <48> 8b 50 08 48 89 c7 f6 c2 01 0f 85 b0 00 00 00 66 90 48 8b 07 f6
      [  406.837810 ] RSP: 0018:ffffb9d641607e48 EFLAGS: 00010286
      [  406.838213 ] RAX: ffffe7b487148000 RBX: ffffb9d645200000 RCX: ffffb9d641607dc4
      [  406.838738 ] RDX: 000065bb00000000 RSI: ffffffffc0d88b84 RDI: ffffb9d645200000
      [  406.839217 ] RBP: ffff9a4625d00068 R08: 0000000000000001 R09: 0000000000000001
      [  406.839650 ] R10: 0000000000000001 R11: 000000000000001f R12: ffff9a4625d4da80
      [  406.840055 ] R13: ffff9a4625d00000 R14: ffffffffc0e2eb20 R15: 0000000000000000
      [  406.840451 ] FS:  00007f0a264ffb80(0000) GS:ffff9a4e2d500000(0000) knlGS:0000000000000000
      [  406.840851 ] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      [  406.841125 ] CR2: ffffe7b487148008 CR3: 000000018c4d2000 CR4: 00000000000006f0
      [  406.841464 ] Call Trace:
      [  406.841583 ]  <TASK>
      [  406.841682 ]  ? __die+0x1f/0x70
      [  406.841828 ]  ? page_fault_oops+0x159/0x470
      [  406.842014 ]  ? fixup_exception+0x22/0x310
      [  406.842198 ]  ? exc_page_fault+0x1ed/0x200
      [  406.842382 ]  ? asm_exc_page_fault+0x22/0x30
      [  406.842574 ]  ? bch2_fs_release+0x54/0x280 [bcachefs]
      [  406.842842 ]  ? kfree+0x62/0x140
      [  406.842988 ]  ? kfree+0x104/0x140
      [  406.843138 ]  bch2_fs_release+0x54/0x280 [bcachefs]
      [  406.843390 ]  kobject_put+0xb7/0x170
      [  406.843552 ]  deactivate_locked_super+0x2f/0xa0
      [  406.843756 ]  cleanup_mnt+0xba/0x150
      [  406.843917 ]  task_work_run+0x59/0xa0
      [  406.844083 ]  exit_to_user_mode_prepare+0x197/0x1a0
      [  406.844302 ]  syscall_exit_to_user_mode+0x16/0x40
      [  406.844510 ]  do_syscall_64+0x4e/0xf0
      [  406.844675 ]  entry_SYSCALL_64_after_hwframe+0x6e/0x76
      [  406.844907 ] RIP: 0033:0x7f0a2664e4fb
      Signed-off-by: default avatarSu Yue <glass.su@suse.com>
      Reviewed-by: default avatarBrian Foster <bfoster@redhat.com>
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      369acf97
    • Kent Overstreet's avatar
      bcachefs: bios must be 512 byte algined · 00fff4dd
      Kent Overstreet authored
      Fixes: 023f9ac9 bcachefs: Delete dio read alignment check
      Reported-by: default avatarBrian Foster <bfoster@redhat.com>
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      00fff4dd
    • Colin Ian King's avatar
      bcachefs: remove redundant variable tmp · aead3428
      Colin Ian King authored
      The variable tmp is being assigned a value but it isn't being
      read afterwards. The assignment is redundant and so tmp can be
      removed.
      
      Cleans up clang scan build warning:
      warning: Although the value stored to 'ret' is used in the enclosing
      expression, the value is never actually read from 'ret'
      [deadcode.DeadStores]
      Signed-off-by: default avatarColin Ian King <colin.i.king@gmail.com>
      Reviewed-by: default avatarBrian Foster <bfoster@redhat.com>
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      aead3428
    • Kent Overstreet's avatar
    • Kent Overstreet's avatar
      bcachefs: Fix excess transaction restarts in __bchfs_fallocate() · 46bf2e9c
      Kent Overstreet authored
      drop_locks_do() should not be used in a fastpath without first trying
      the do in nonblocking mode - the unlock and relock will cause excessive
      transaction restarts and potentially livelocking with other threads that
      are contending for the same locks.
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      46bf2e9c
    • Kent Overstreet's avatar
      bcachefs: extents_to_bp_state · 1a503904
      Kent Overstreet authored
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      1a503904
    • Kent Overstreet's avatar
      bcachefs: bkey_and_val_eq() · ba96d36c
      Kent Overstreet authored
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      ba96d36c
    • Kent Overstreet's avatar
      bcachefs: Better journal tracepoints · e6a2566f
      Kent Overstreet authored
      Factor out bch2_journal_bufs_to_text(), and use it in the
      journal_entry_full() tracepoint; when we can't get a journal reservation
      we need to know the outstanding journal entry sizes to know if the
      problem is due to excessive flushing.
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      e6a2566f
    • Kent Overstreet's avatar
    • Kent Overstreet's avatar
      bcachefs: Avoid flushing the journal in the discard path · a6548c8b
      Kent Overstreet authored
      When issuing discards, we may need to flush the journal if there's too
      many buckets that can't be discarded until a journal flush.
      
      But the heuristic was bad; we should be comparing the number of buckets
      that need to flushes against the number of free buckets, not the number
      of buckets we saw.
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      a6548c8b