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Darrick J. Wong 288e1f693f xfs: restrict when we try to align cow fork delalloc to cowextsz hints
xfs/205 produces the following failure when always_cow is enabled:

  --- a/tests/xfs/205.out	2024-02-28 16:20:24.437887970 -0800
  +++ b/tests/xfs/205.out.bad	2024-06-03 21:13:40.584000000 -0700
  @@ -1,4 +1,5 @@
   QA output created by 205
   *** one file
  +   !!! disk full (expected)
   *** one file, a few bytes at a time
   *** done

This is the result of overly aggressive attempts to align cow fork
delalloc reservations to the CoW extent size hint.  Looking at the trace
data, we're trying to append a single fsblock to the "fred" file.
Trying to create a speculative post-eof reservation fails because
there's not enough space.

We then set @prealloc_blocks to zero and try again, but the cowextsz
alignment code triggers, which expands our request for a 1-fsblock
reservation into a 39-block reservation.  There's not enough space for
that, so the whole write fails with ENOSPC even though there's
sufficient space in the filesystem to allocate the single block that we
need to land the write.

There are two things wrong here -- first, we shouldn't be attempting
speculative preallocations beyond what was requested when we're low on
space.  Second, if we've already computed a posteof preallocation, we
shouldn't bother trying to align that to the cowextsize hint.

Fix both of these problems by adding a flag that only enables the
expansion of the delalloc reservation to the cowextsize if we're doing a
non-extending write, and only if we're not doing an ENOSPC retry.  This
requires us to move the ENOSPC retry logic to xfs_bmapi_reserve_delalloc.

I probably should have caught this six years ago when 6ca30729c2 was
being reviewed, but oh well.  Update the comments to reflect what the
code does now.

Fixes: 6ca30729c2 ("xfs: bmap code cleanup")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-06-26 14:29:24 +05:30
arch - fix lseek in o32 compat mode 2024-06-23 07:20:02 -07:00
block block: unmap and free user mapped integrity via submitter 2024-06-12 11:00:50 -06:00
certs kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
crypto This push fixes a bug in the new ecc P521 code as well as a buggy 2024-05-20 08:47:54 -07:00
Documentation The core gains placeholders for recently added functions when CONFIG_I2C 2024-06-23 11:06:01 -04:00
drivers The core gains placeholders for recently added functions when CONFIG_I2C 2024-06-23 11:06:01 -04:00
fs xfs: restrict when we try to align cow fork delalloc to cowextsz hints 2024-06-26 14:29:24 +05:30
include The core gains placeholders for recently added functions when CONFIG_I2C 2024-06-23 11:06:01 -04:00
init gcc: disable '-Warray-bounds' for gcc-9 2024-06-15 10:43:04 -07:00
io_uring io_uring/rsrc: fix incorrect assignment of iter->nr_segs in io_import_fixed 2024-06-20 06:51:56 -06:00
ipc Mainly singleton patches, documented in their respective changelogs. 2024-05-19 14:02:03 -07:00
kernel Including fixes from wireless, bpf and netfilter. 2024-06-20 10:49:50 -07:00
lib bcachefs fixes for 6.10-rc5 2024-06-22 09:02:39 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm memblock: fix fragility in checks for unset node ID 2024-06-23 10:32:24 -04:00
net nfsd-6.10 fixes: 2024-06-22 13:55:56 -07:00
rust rust: avoid unused import warning in rusttest 2024-06-11 23:33:28 +02:00
samples tracing/treewide: Remove second parameter of __assign_str() 2024-05-22 20:14:47 -04:00
scripts Kbuild fixes for v6.10 (second) 2024-06-08 10:12:33 -07:00
security lsm/stable-6.10 PR 20240617 2024-06-17 18:35:12 -07:00
sound ALSA: hda: Use imply for suggesting CONFIG_SERIAL_MULTI_INSTANTIATE 2024-06-21 12:04:19 +02:00
tools ARM: 2024-06-22 07:41:57 -07:00
usr kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
virt KVM fixes for 6.10 2024-06-21 08:03:55 -04:00
.clang-format clang-format: Update with v6.7-rc4's for_each macro list 2023-12-08 23:54:38 +01:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: create a list of all built DTB files 2024-02-19 18:20:39 +09:00
.mailmap bpf-for-netdev 2024-06-14 17:57:10 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Drop Gustavo Pimentel as PCI DWC Maintainer 2024-03-27 13:41:02 -05:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS ARM: 2024-06-22 07:41:57 -07:00
Makefile Linux 6.10-rc5 2024-06-23 17:08:54 -04:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.