Commit Graph

4194 Commits

Author SHA1 Message Date
Linus Torvalds 630c12862c Merge tag 'unicode-for-next-5.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/krisman/unicode
Pull unicode cleanup from Gabriel Krisman Bertazi:
 "A fix from Christoph Hellwig merging the CONFIG_UNICODE_UTF8_DATA into
  the previous CONFIG_UNICODE. It is -rc material since we don't want to
  expose the former symbol on 5.17.

  This has been living on linux-next for the past week"

* tag 'unicode-for-next-5.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/krisman/unicode:
  unicode: clean up the Kconfig symbol confusion
2022-02-01 11:13:24 -08:00
Christoph Hellwig 0a4ee51818 mm: remove cleancache
Patch series "remove Xen tmem leftovers".

Since the removal of the Xen tmem driver in 2019, the cleancache hooks
are entirely unused, as are large parts of frontswap.  This series
against linux-next (with the folio changes included) removes
cleancaches, and cuts down frontswap to the bits actually used by zswap.

This patch (of 13):

The cleancache subsystem is unused since the removal of Xen tmem driver
in commit 814bbf49dc ("xen: remove tmem driver").

[akpm@linux-foundation.org: remove now-unreachable code]

Link: https://lkml.kernel.org/r/20211224062246.1258487-1-hch@lst.de
Link: https://lkml.kernel.org/r/20211224062246.1258487-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-22 08:33:38 +02:00
Muchun Song 359745d783 proc: remove PDE_DATA() completely
Remove PDE_DATA() completely and replace it with pde_data().

[akpm@linux-foundation.org: fix naming clash in drivers/nubus/proc.c]
[akpm@linux-foundation.org: now fix it properly]

Link: https://lkml.kernel.org/r/20211124081956.87711-2-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Alexey Gladkov <gladkov.alexey@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-22 08:33:37 +02:00
Christoph Hellwig 5298d4bfe8 unicode: clean up the Kconfig symbol confusion
Turn the CONFIG_UNICODE symbol into a tristate that generates some always
built in code and remove the confusing CONFIG_UNICODE_UTF8_DATA symbol.

Note that a lot of the IS_ENABLED() checks could be turned from cpp
statements into normal ifs, but this change is intended to be fairly
mechanic, so that should be cleaned up later.

Fixes: 2b3d047870 ("unicode: Add utf8-data module")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
2022-01-20 19:57:24 -05:00
Linus Torvalds 6661224e66 Merge tag 'unicode-for-next-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/krisman/unicode
Pull unicode updates from Gabriel Krisman Bertazi:
 "This includes patches from Christoph Hellwig to split the large data
  tables of the unicode subsystem into a loadable module, which allow
  users to not have them around if case-insensitive filesystems are not
  to be used. It also includes minor code fixes to unicode and its
  users, from the same author.

  All the patches here have been on linux-next releases for the past
  months"

* tag 'unicode-for-next-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/krisman/unicode:
  unicode: only export internal symbols for the selftests
  unicode: Add utf8-data module
  unicode: cache the normalization tables in struct unicode_map
  unicode: move utf8cursor to utf8-selftest.c
  unicode: simplify utf8len
  unicode: remove the unused utf8{,n}age{min,max} functions
  unicode: pass a UNICODE_AGE() tripple to utf8_load
  unicode: mark the version field in struct unicode_map unsigned
  unicode: remove the charset field from struct unicode_map
  f2fs: simplify f2fs_sb_read_encoding
  ext4: simplify ext4_sb_read_encoding
2022-01-17 05:40:02 +02:00
Linus Torvalds f56caedaf9 Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
 "146 patches.

  Subsystems affected by this patch series: kthread, ia64, scripts,
  ntfs, squashfs, ocfs2, vfs, and mm (slab-generic, slab, kmemleak,
  dax, kasan, debug, pagecache, gup, shmem, frontswap, memremap,
  memcg, selftests, pagemap, dma, vmalloc, memory-failure, hugetlb,
  userfaultfd, vmscan, mempolicy, oom-kill, hugetlbfs, migration, thp,
  ksm, page-poison, percpu, rmap, zswap, zram, cleanups, hmm, and
  damon)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (146 commits)
  mm/damon: hide kernel pointer from tracepoint event
  mm/damon/vaddr: hide kernel pointer from damon_va_three_regions() failure log
  mm/damon/vaddr: use pr_debug() for damon_va_three_regions() failure logging
  mm/damon/dbgfs: remove an unnecessary variable
  mm/damon: move the implementation of damon_insert_region to damon.h
  mm/damon: add access checking for hugetlb pages
  Docs/admin-guide/mm/damon/usage: update for schemes statistics
  mm/damon/dbgfs: support all DAMOS stats
  Docs/admin-guide/mm/damon/reclaim: document statistics parameters
  mm/damon/reclaim: provide reclamation statistics
  mm/damon/schemes: account how many times quota limit has exceeded
  mm/damon/schemes: account scheme actions that successfully applied
  mm/damon: remove a mistakenly added comment for a future feature
  Docs/admin-guide/mm/damon/usage: update for kdamond_pid and (mk|rm)_contexts
  Docs/admin-guide/mm/damon/usage: mention tracepoint at the beginning
  Docs/admin-guide/mm/damon/usage: remove redundant information
  Docs/admin-guide/mm/damon/usage: update for scheme quotas and watermarks
  mm/damon: convert macro functions to static inline functions
  mm/damon: modify damon_rand() macro to static inline function
  mm/damon: move damon_rand() definition into damon.h
  ...
2022-01-15 20:37:06 +02:00
NeilBrown 4034247a0d mm: introduce memalloc_retry_wait()
Various places in the kernel - largely in filesystems - respond to a
memory allocation failure by looping around and re-trying.  Some of
these cannot conveniently use __GFP_NOFAIL, for reasons such as:

 - a GFP_ATOMIC allocation, which __GFP_NOFAIL doesn't work on
 - a need to check for the process being signalled between failures
 - the possibility that other recovery actions could be performed
 - the allocation is quite deep in support code, and passing down an
   extra flag to say if __GFP_NOFAIL is wanted would be clumsy.

Many of these currently use congestion_wait() which (in almost all
cases) simply waits the given timeout - congestion isn't tracked for
most devices.

It isn't clear what the best delay is for loops, but it is clear that
the various filesystems shouldn't be responsible for choosing a timeout.

This patch introduces memalloc_retry_wait() with takes on that
responsibility.  Code that wants to retry a memory allocation can call
this function passing the GFP flags that were used.  It will wait
however is appropriate.

For now, it only considers __GFP_NORETRY and whatever
gfpflags_allow_blocking() tests.  If blocking is allowed without
__GFP_NORETRY, then alloc_page either made some reclaim progress, or
waited for a while, before failing.  So there is no need for much
further waiting.  memalloc_retry_wait() will wait until the current
jiffie ends.  If this condition is not met, then alloc_page() won't have
waited much if at all.  In that case memalloc_retry_wait() waits about
200ms.  This is the delay that most current loops uses.

linux/sched/mm.h needs to be included in some files now,
but linux/backing-dev.h does not.

Link: https://lkml.kernel.org/r/163754371968.13692.1277530886009912421@noble.neil.brown.name
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-15 16:30:29 +02:00
Linus Torvalds 3acbdbf42e Merge tag 'libnvdimm-for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull dax and libnvdimm updates from Dan Williams:
 "The bulk of this is a rework of the dax_operations API after
  discovering the obstacles it posed to the work-in-progress DAX+reflink
  support for XFS and other copy-on-write filesystem mechanics.

  Primarily the need to plumb a block_device through the API to handle
  partition offsets was a sticking point and Christoph untangled that
  dependency in addition to other cleanups to make landing the
  DAX+reflink support easier.

  The DAX_PMEM_COMPAT option has been around for 4 years and not only
  are distributions shipping userspace that understand the current
  configuration API, but some are not even bothering to turn this option
  on anymore, so it seems a good time to remove it per the deprecation
  schedule. Recall that this was added after the device-dax subsystem
  moved from /sys/class/dax to /sys/bus/dax for its sysfs organization.
  All recent functionality depends on /sys/bus/dax.

  Some other miscellaneous cleanups and reflink prep patches are
  included as well.

  Summary:

   - Simplify the dax_operations API:

      - Eliminate bdev_dax_pgoff() in favor of the filesystem
        maintaining and applying a partition offset to all its DAX iomap
        operations.

      - Remove wrappers and device-mapper stacked callbacks for
        ->copy_from_iter() and ->copy_to_iter() in favor of moving
        block_device relative offset responsibility to the
        dax_direct_access() caller.

      - Remove the need for an @bdev in filesystem-DAX infrastructure

      - Remove unused uio helpers copy_from_iter_flushcache() and
        copy_mc_to_iter() as only the non-check_copy_size() versions are
        used for DAX.

   - Prepare XFS for the pending (next merge window) DAX+reflink support

   - Remove deprecated DEV_DAX_PMEM_COMPAT support

   - Cleanup a straggling misuse of the GUID api"

* tag 'libnvdimm-for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (38 commits)
  iomap: Fix error handling in iomap_zero_iter()
  ACPI: NFIT: Import GUID before use
  dax: remove the copy_from_iter and copy_to_iter methods
  dax: remove the DAXDEV_F_SYNC flag
  dax: simplify dax_synchronous and set_dax_synchronous
  uio: remove copy_from_iter_flushcache() and copy_mc_to_iter()
  iomap: turn the byte variable in iomap_zero_iter into a ssize_t
  memremap: remove support for external pgmap refcounts
  fsdax: don't require CONFIG_BLOCK
  iomap: build the block based code conditionally
  dax: fix up some of the block device related ifdefs
  fsdax: shift partition offset handling into the file systems
  dax: return the partition offset from fs_dax_get_by_bdev
  iomap: add a IOMAP_DAX flag
  xfs: pass the mapping flags to xfs_bmbt_to_iomap
  xfs: use xfs_direct_write_iomap_ops for DAX zeroing
  xfs: move dax device handling into xfs_{alloc,free}_buftarg
  ext4: cleanup the dax handling in ext4_fill_super
  ext2: cleanup the dax handling in ext2_fill_super
  fsdax: decouple zeroing from the iomap buffered I/O code
  ...
2022-01-12 15:46:11 -08:00
Theodore Ts'o 6eeaf88fd5 ext4: don't use the orphan list when migrating an inode
We probably want to remove the indirect block to extents migration
feature after a deprecation window, but until then, let's fix a
potential data loss problem caused by the fact that we put the
tmp_inode on the orphan list.  In the unlikely case where we crash and
do a journal recovery, the data blocks belonging to the inode being
migrated are also represented in the tmp_inode on the orphan list ---
and so its data blocks will get marked unallocated, and available for
reuse.

Instead, stop putting the tmp_inode on the oprhan list.  So in the
case where we crash while migrating the inode, we'll leak an inode,
which is not a disaster.  It will be easily fixed the next time we run
fsck, and it's better than potentially having blocks getting claimed
by two different files, and losing data as a result.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Cc: stable@kernel.org
2022-01-10 13:25:56 -05:00
xu xin a2e3965df4 ext4: use BUG_ON instead of if condition followed by BUG
BUG_ON would be better.

This issue was detected with the help of Coccinelle.

Reported-by: Zeal robot <zealci@zte.com.cn>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Link: https://lore.kernel.org/r/20211228073252.580296-1-xu.xin16@zte.com.cn
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-01-10 13:25:56 -05:00
Dan Carpenter da9e480212 ext4: fix a copy and paste typo
This was obviously supposed to be an ext4 struct, not xfs.  GCC
doesn't care either way so it doesn't affect the build or runtime.

Fixes: cebe85d570 ("ext4: switch to the new mount api")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Link: https://lore.kernel.org/r/20211215114309.GB14552@kili
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-01-10 13:25:56 -05:00
Luís Henriques e81c9302a6 ext4: set csum seed in tmp inode while migrating to extents
When migrating to extents, the temporary inode will have it's own checksum
seed.  This means that, when swapping the inodes data, the inode checksums
will be incorrect.

This can be fixed by recalculating the extents checksums again.  Or simply
by copying the seed into the temporary inode.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=213357
Reported-by: Jeroen van Wolffelaar <jeroen@wolffelaar.nl>
Signed-off-by: Luís Henriques <lhenriques@suse.de>
Link: https://lore.kernel.org/r/20211214175058.19511-1-lhenriques@suse.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
2022-01-10 13:25:56 -05:00
luo penghao ae6ec194b5 ext4: remove unnecessary 'offset' assignment
Although it is in the loop, offset is reassigned at the beginning of the
while loop.  And after the loop, the value will not be used

The clang_analyzer complains as follows:

fs/ext4/dir.c:306:3 warning:

Value stored to 'offset' is never read

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: luo penghao <luo.penghao@zte.com.cn>
Link: https://lore.kernel.org/r/20211208075307.404703-1-luo.penghao@zte.com.cn
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-01-10 13:25:56 -05:00
luo penghao a6dbc76c4d ext4: remove redundant o_start statement
The if will goto out of the loop, and until the end of the
function execution, o_start will not be used again.

The clang_analyzer complains as follows:

fs/ext4/move_extent.c:635:5 warning:

Value stored to 'o_start' is never read

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: luo penghao <luo.penghao@zte.com.cn>
Link: https://lore.kernel.org/r/20211208075157.404535-1-luo.penghao@zte.com.cn
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-01-10 13:25:56 -05:00
Adam Borowski 037e7c525d ext4: drop an always true check
EXT_FIRST_INDEX(ptr) is ptr+12, which can't possibly be null; gcc-12
warns about this.

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/20211115172020.57853-1-kilobyte@angband.pl
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-01-10 13:25:56 -05:00
luo penghao fac888b2be ext4: remove unused assignments
The eh assignment in these two places is meaningless, because the
function will goto to merge, which will not use eh.

The clang_analyzer complains as follows:

fs/ext4/extents.c:1988:4 warning:
fs/ext4/extents.c:2016:4 warning:

Value stored to 'eh' is never read

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: luo penghao <luo.penghao@zte.com.cn>
Link: https://lore.kernel.org/r/20211104064007.2919-1-luo.penghao@zte.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-01-10 13:25:56 -05:00
luo penghao a660be97eb ext4: remove redundant statement
The local variable assignment at the end of the function is meaningless.

The clang_analyzer complains as follows:

fs/ext4/fast_commit.c:779:2 warning:

Value stored to 'dst' is never read

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: luo penghao <luo.penghao@zte.com.cn>
Link: https://lore.kernel.org/r/20211104063406.2747-1-luo.penghao@zte.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-01-10 13:25:56 -05:00
Nghia Le effc5b3b0d ext4: remove useless resetting io_end_size in mpage_process_page()
The command "make clang-analyzer" detects dead stores in
mpage_process_page() function.

Do not reset io_end_size to 0 in the current paths, as the function
exits on those paths without further using io_end_size.

Signed-off-by: Nghia Le <nghialm78@gmail.com>
Link: https://lore.kernel.org/r/20211025221803.3326-1-nghialm78@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-01-10 13:25:55 -05:00
Lukas Czerner 4a69aecbfb ext4: allow to change s_last_trim_minblks via sysfs
Ext4 has an optimization mechanism for batched disacrd (FITRIM) that
should help speed up subsequent calls of FITRIM ioctl by skipping the
groups that were previously trimmed. However because the FITRIM allows
to set the minimum size of an extent to trim, ext4 stores the last
minimum extent size and only avoids trimming the group if it was
previously trimmed with minimum extent size equal to, or smaller than
the current call.

There is currently no way to bypass the optimization without
umount/mount cycle. This becomes a problem when the file system is
live migrated to a different storage, because the optimization will
prevent possibly useful discard calls to the storage.

Fix it by exporting the s_last_trim_minblks via sysfs interface which
will allow us to set the minimum size to the number of blocks larger
than subsequent FITRIM call, effectively bypassing the optimization.

By setting the s_last_trim_minblks to ULONG_MAX the optimization will be
effectively cleared regardless of the previous state, or file system
configuration.

For example:
getconf ULONG_MAX > /sys/fs/ext4/dm-1/last_trim_minblks

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reported-by: Laurent GUERBY <laurent@guerby.net>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/20211103145122.17338-2-lczerner@redhat.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-01-10 13:25:55 -05:00
Lukas Czerner 2327fb2e23 ext4: change s_last_trim_minblks type to unsigned long
There is no good reason for the s_last_trim_minblks to be atomic. There is
no data integrity needed and there is no real danger in setting and
reading it in a racy manner. Change it to be unsigned long, the same type
as s_clusters_per_group which is the maximum that's allowed.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Suggested-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/20211103145122.17338-1-lczerner@redhat.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-01-10 13:25:55 -05:00
Lukas Czerner bbc605cdb1 ext4: implement support for get/set fs label
Implement support for FS_IOC_GETFSLABEL and FS_IOC_SETFSLABEL ioctls for
online reading and setting of file system label.

ext4_ioctl_getlabel() is simple, just get the label from the primary
superblock. This might not be the first sb on the file system if
'sb=' mount option is used.

In ext4_ioctl_setlabel() we update what ext4 currently views as a
primary superblock and then proceed to update backup superblocks. There
are two caveats:
 - the primary superblock might not be the first superblock and so it
   might not be the one used by userspace tools if read directly
   off the disk.
 - because the primary superblock might not be the first superblock we
   potentialy have to update it as part of backup superblock update.
   However the first sb location is a bit more complicated than the rest
   so we have to account for that.

The superblock modification is created generic enough so the
infrastructure can be used for other potential superblock modification
operations, such as chaning UUID.

Tested with generic/492 with various configurations. I also checked the
behavior with 'sb=' mount options, including very large file systems
with and without sparse_super/sparse_super2.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Link: https://lore.kernel.org/r/20211213135618.43303-1-lczerner@redhat.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-01-10 13:25:55 -05:00
Lukas Czerner 4c1bd5a90c ext4: only set EXT4_MOUNT_QUOTA when journalled quota file is specified
Only set EXT4_MOUNT_QUOTA when journalled quota file is specified,
otherwise simply disabling specific quota type (usrjquota=) will also
set the EXT4_MOUNT_QUOTA super block option.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Fixes: e6e268cb68 ("ext4: move quota configuration out of handle_mount_opt()")
Link: https://lore.kernel.org/r/20220104143518.134465-2-lczerner@redhat.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-01-10 13:25:55 -05:00
Lukas Czerner 13b215a9e6 ext4: don't use kfree() on rcu protected pointer sbi->s_qf_names
During ext4 mount api rework the commit e6e268cb68 ("ext4: move quota
configuration out of handle_mount_opt()") introduced a bug where we
would kfree(sbi->s_qf_names[i]) before assigning the new quota name in
ext4_apply_quota_options().

This is wrong because we're using kfree() on rcu prointer that could be
simultaneously accessed from ext4_show_quota_options() during remount.
Fix it by using rcu_replace_pointer() to replace the old qname with the
new one and then kfree_rcu() the old quota name.

Also use get_qf_name() instead of sbi->s_qf_names in strcmp() to silence
the sparse warning.

Fixes: e6e268cb68 ("ext4: move quota configuration out of handle_mount_opt()")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Link: https://lore.kernel.org/r/20220104143518.134465-1-lczerner@redhat.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-01-10 13:25:55 -05:00
Jan Kara 173b6e383d ext4: avoid trim error on fs with small groups
A user reported FITRIM ioctl failing for him on ext4 on some devices
without apparent reason.  After some debugging we've found out that
these devices (being LVM volumes) report rather large discard
granularity of 42MB and the filesystem had 1k blocksize and thus group
size of 8MB. Because ext4 FITRIM implementation puts discard
granularity into minlen, ext4_trim_fs() declared the trim request as
invalid. However just silently doing nothing seems to be a more
appropriate reaction to such combination of parameters since user did
not specify anything wrong.

CC: Lukas Czerner <lczerner@redhat.com>
Fixes: 5c2ed62fd4 ("ext4: Adjust minlen with discard_granularity in the FITRIM ioctl")
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20211112152202.26614-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-01-10 13:25:55 -05:00
Zhang Yi 5c48a7df91 ext4: fix an use-after-free issue about data=journal writeback mode
Our syzkaller report an use-after-free issue that accessing the freed
buffer_head on the writeback page in __ext4_journalled_writepage(). The
problem is that if there was a truncate racing with the data=journalled
writeback procedure, the writeback length could become zero and
bget_one() refuse to get buffer_head's refcount, then the truncate
procedure release buffer once we drop page lock, finally, the last
ext4_walk_page_buffers() trigger the use-after-free problem.

sync                               truncate
ext4_sync_file()
 file_write_and_wait_range()
                                   ext4_setattr(0)
                                    inode->i_size = 0
  ext4_writepage()
   len = 0
   __ext4_journalled_writepage()
    page_bufs = page_buffers(page)
    ext4_walk_page_buffers(bget_one) <- does not get refcount
                                    do_invalidatepage()
                                      free_buffer_head()
    ext4_walk_page_buffers(page_bufs) <- trigger use-after-free

After commit bdf96838ae ("ext4: fix race between truncate and
__ext4_journalled_writepage()"), we have already handled the racing
case, so the bget_one() and bput_one() are not needed. So this patch
simply remove these hunk, and recheck the i_size to make it safe.

Fixes: bdf96838ae ("ext4: fix race between truncate and __ext4_journalled_writepage()")
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20211225090937.712867-1-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-01-10 13:25:55 -05:00