<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/fs/hfs, branch v6.18.21</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v6.18.21</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v6.18.21'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2026-02-16T09:19:44+00:00</updated>
<entry>
<title>hfs: ensure sb-&gt;s_fs_info is always cleaned up</title>
<updated>2026-02-16T09:19:44+00:00</updated>
<author>
<name>Mehdi Ben Hadj Khelifa</name>
<email>mehdi.benhadjkhelifa@gmail.com</email>
</author>
<published>2025-12-01T22:23:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=46c1d56ad321fb024761abd9af61a0cb616cf2f6'/>
<id>urn:sha1:46c1d56ad321fb024761abd9af61a0cb616cf2f6</id>
<content type='text'>
commit 05ce49a902be15dc93854cbfc20161205a9ee446 upstream.

When hfs was converted to the new mount api a bug was introduced by
changing the allocation pattern of sb-&gt;s_fs_info. If setup_bdev_super()
fails after a new superblock has been allocated by sget_fc(), but before
hfs_fill_super() takes ownership of the filesystem-specific s_fs_info
data it was leaked.

Fix this by freeing sb-&gt;s_fs_info in hfs_kill_super().

Cc: stable@vger.kernel.org
Fixes: ffcd06b6d13b ("hfs: convert hfs to use the new mount api")
Reported-by: syzbot+ad45f827c88778ff7df6@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=ad45f827c88778ff7df6
Tested-by: Viacheslav Dubeyko &lt;Slava.Dubeyko@ibm.com&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Mehdi Ben Hadj Khelifa &lt;mehdi.benhadjkhelifa@gmail.com&gt;
Reviewed-by: Viacheslav Dubeyko &lt;slava@dubeyko.com&gt;
Signed-off-by: Viacheslav Dubeyko &lt;slava@dubeyko.com&gt;
Link: https://lore.kernel.org/r/20251201222843.82310-2-mehdi.benhadjkhelifa@gmail.com
Signed-off-by: Viacheslav Dubeyko &lt;slava@dubeyko.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>hfs: fix potential use after free in hfs_correct_next_unused_CNID()</title>
<updated>2025-12-18T13:02:52+00:00</updated>
<author>
<name>Dan Carpenter</name>
<email>dan.carpenter@linaro.org</email>
</author>
<published>2025-10-03T09:30:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=40a1e0142096dd7dd6cb5373841222b528698588'/>
<id>urn:sha1:40a1e0142096dd7dd6cb5373841222b528698588</id>
<content type='text'>
[ Upstream commit c105e76bb17cf4b55fe89c6ad4f6a0e3972b5b08 ]

This code calls hfs_bnode_put(node) which drops the refcount and then
dreferences "node" on the next line.  It's only safe to use "node"
when we're holding a reference so flip these two lines around.

Fixes: a06ec283e125 ("hfs: add logic of correcting a next unused CNID")
Signed-off-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Reviewed-by: Viacheslav Dubeyko &lt;slava@dubeyko.com&gt;
Signed-off-by: Viacheslav Dubeyko &lt;slava@dubeyko.com&gt;
Link: https://lore.kernel.org/r/aN-Xw8KnbSnuIcLk@stanley.mountain
Signed-off-by: Viacheslav Dubeyko &lt;slava@dubeyko.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>hfs/hfsplus: rework debug output subsystem</title>
<updated>2025-09-24T23:30:34+00:00</updated>
<author>
<name>Viacheslav Dubeyko</name>
<email>slava@dubeyko.com</email>
</author>
<published>2025-09-24T23:24:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=f32a26fab3672e60f622bd7461bf978fc72f29ec'/>
<id>urn:sha1:f32a26fab3672e60f622bd7461bf978fc72f29ec</id>
<content type='text'>
Currently, HFS/HFS+ has very obsolete and inconvenient
debug output subsystem. Also, the code is duplicated
in HFS and HFS+ driver. This patch introduces
linux/hfs_common.h for gathering common declarations,
inline functions, and common short methods. Currently,
this file contains only hfs_dbg() function that
employs pr_debug() with the goal to print a debug-level
messages conditionally.

So, now, it is possible to enable the debug output
by means of:

echo 'file extent.c +p' &gt; /proc/dynamic_debug/control
echo 'func hfsplus_evict_inode +p' &gt; /proc/dynamic_debug/control

And debug output looks like this:

hfs: pid 5831:fs/hfs/catalog.c:228 hfs_cat_delete(): delete_cat: 00,48
hfs: pid 5831:fs/hfs/extent.c:484 hfs_file_truncate(): truncate: 48, 409600 -&gt; 0
hfs: pid 5831:fs/hfs/extent.c:212 hfs_dump_extent():
hfs: pid 5831:fs/hfs/extent.c:214 hfs_dump_extent():  78:4
hfs: pid 5831:fs/hfs/extent.c:214 hfs_dump_extent():  0:0
hfs: pid 5831:fs/hfs/extent.c:214 hfs_dump_extent():  0:0

v4
Debug messages have been reworked and information about
new HFS/HFS+ shared declarations file has been added
to MAINTAINERS file.

v5
Yangtao Li suggested to clean up debug output and
fix several typos.

Signed-off-by: Viacheslav Dubeyko &lt;slava@dubeyko.com&gt;
cc: John Paul Adrian Glaubitz &lt;glaubitz@physik.fu-berlin.de&gt;
cc: Yangtao Li &lt;frank.li@vivo.com&gt;
cc: linux-fsdevel@vger.kernel.org
cc: Johannes Thumshirn &lt;Johannes.Thumshirn@wdc.com&gt;
Signed-off-by: Viacheslav Dubeyko &lt;slava@dubeyko.com&gt;
</content>
</entry>
<entry>
<title>hfs: clear offset and space out of valid records in b-tree node</title>
<updated>2025-09-01T01:16:00+00:00</updated>
<author>
<name>Viacheslav Dubeyko</name>
<email>slava@dubeyko.com</email>
</author>
<published>2025-08-15T19:49:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=18b07c44f245beb03588b00b212b38fce9af7cc9'/>
<id>urn:sha1:18b07c44f245beb03588b00b212b38fce9af7cc9</id>
<content type='text'>
Currently, hfs_brec_remove() executes moving records
towards the location of deleted record and it updates
offsets of moved records. However, the hfs_brec_remove()
logic ignores the "mess" of b-tree node's free space and
it doesn't touch the offsets out of records number.
Potentially, it could confuse fsck or driver logic or
to be a reason of potential corruption cases.

This patch reworks the logic of hfs_brec_remove()
by means of clearing freed space of b-tree node
after the records moving. And it clear the last
offset that keeping old location of free space
because now the offset before this one is keeping
the actual offset to the free space after the record
deletion.

Signed-off-by: Viacheslav Dubeyko &lt;slava@dubeyko.com&gt;
cc: John Paul Adrian Glaubitz &lt;glaubitz@physik.fu-berlin.de&gt;
cc: Yangtao Li &lt;frank.li@vivo.com&gt;
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20250815194918.38165-1-slava@dubeyko.com
Signed-off-by: Viacheslav Dubeyko &lt;slava@dubeyko.com&gt;
</content>
</entry>
<entry>
<title>hfs: add logic of correcting a next unused CNID</title>
<updated>2025-09-01T01:15:21+00:00</updated>
<author>
<name>Viacheslav Dubeyko</name>
<email>slava@dubeyko.com</email>
</author>
<published>2025-06-10T23:16:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=a06ec283e125e334155fe13005c76c9f484ce759'/>
<id>urn:sha1:a06ec283e125e334155fe13005c76c9f484ce759</id>
<content type='text'>
The generic/736 xfstest fails for HFS case:

BEGIN TEST default (1 test): hfs Mon May 5 03:18:32 UTC 2025
DEVICE: /dev/vdb
HFS_MKFS_OPTIONS:
MOUNT_OPTIONS: MOUNT_OPTIONS
FSTYP -- hfs
PLATFORM -- Linux/x86_64 kvm-xfstests 6.15.0-rc4-xfstests-g00b827f0cffa #1 SMP PREEMPT_DYNAMIC Fri May 25
MKFS_OPTIONS -- /dev/vdc
MOUNT_OPTIONS -- /dev/vdc /vdc

generic/736 [03:18:33][ 3.510255] run fstests generic/736 at 2025-05-05 03:18:33
_check_generic_filesystem: filesystem on /dev/vdb is inconsistent
(see /results/hfs/results-default/generic/736.full for details)
Ran: generic/736
Failures: generic/736
Failed 1 of 1 tests

The HFS volume becomes corrupted after the test run:

sudo fsck.hfs -d /dev/loop50
** /dev/loop50
Using cacheBlockSize=32K cacheTotalBlock=1024 cacheSize=32768K.
Executing fsck_hfs (version 540.1-Linux).
** Checking HFS volume.
The volume name is untitled
** Checking extents overflow file.
** Checking catalog file.
** Checking catalog hierarchy.
** Checking volume bitmap.
** Checking volume information.
invalid MDB drNxtCNID
Master Directory Block needs minor repair
(1, 0)
Verify Status: VIStat = 0x8000, ABTStat = 0x0000 EBTStat = 0x0000
CBTStat = 0x0000 CatStat = 0x00000000
** Repairing volume.
** Rechecking volume.
** Checking HFS volume.
The volume name is untitled
** Checking extents overflow file.
** Checking catalog file.
** Checking catalog hierarchy.
** Checking volume bitmap.
** Checking volume information.
** The volume untitled was repaired successfully.

The main reason of the issue is the absence of logic that
corrects mdb-&gt;drNxtCNID/HFS_SB(sb)-&gt;next_id (next unused
CNID) after deleting a record in Catalog File. This patch
introduces a hfs_correct_next_unused_CNID() method that
implements the necessary logic. In the case of Catalog File's
record delete operation, the function logic checks that
(deleted_CNID + 1) == next_unused_CNID and it finds/sets the new
value of next_unused_CNID.

sudo ./check generic/736
FSTYP -- hfs
PLATFORM -- Linux/x86_64 hfsplus-testing-0001 6.15.0+ #6 SMP PREEMPT_DYNAMIC Tue Jun 10 15:02:48 PDT 2025
MKFS_OPTIONS -- /dev/loop51
MOUNT_OPTIONS -- /dev/loop51 /mnt/scratch

generic/736 33s
Ran: generic/736
Passed all 1 tests

sudo fsck.hfs -d /dev/loop50
** /dev/loop50
Using cacheBlockSize=32K cacheTotalBlock=1024 cacheSize=32768K.
Executing fsck_hfs (version 540.1-Linux).
** Checking HFS volume.
The volume name is untitled
** Checking extents overflow file.
** Checking catalog file.
** Checking catalog hierarchy.
** Checking volume bitmap.
** Checking volume information.
** The volume untitled appears to be OK

Signed-off-by: Viacheslav Dubeyko &lt;slava@dubeyko.com&gt;
Link: https://lore.kernel.org/r/20250610231609.551930-1-slava@dubeyko.com
Signed-off-by: Viacheslav Dubeyko &lt;slava@dubeyko.com&gt;
</content>
</entry>
<entry>
<title>hfs: fix KMSAN uninit-value issue in hfs_find_set_zero_bits()</title>
<updated>2025-09-01T01:13:10+00:00</updated>
<author>
<name>Viacheslav Dubeyko</name>
<email>slava@dubeyko.com</email>
</author>
<published>2025-08-20T23:06:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=2048ec5b98dbdfe0b929d2e42dc7a54c389c53dd'/>
<id>urn:sha1:2048ec5b98dbdfe0b929d2e42dc7a54c389c53dd</id>
<content type='text'>
The syzbot reported issue in hfs_find_set_zero_bits():

=====================================================
BUG: KMSAN: uninit-value in hfs_find_set_zero_bits+0x74d/0xb60 fs/hfs/bitmap.c:45
 hfs_find_set_zero_bits+0x74d/0xb60 fs/hfs/bitmap.c:45
 hfs_vbm_search_free+0x13c/0x5b0 fs/hfs/bitmap.c:151
 hfs_extend_file+0x6a5/0x1b00 fs/hfs/extent.c:408
 hfs_get_block+0x435/0x1150 fs/hfs/extent.c:353
 __block_write_begin_int+0xa76/0x3030 fs/buffer.c:2151
 block_write_begin fs/buffer.c:2262 [inline]
 cont_write_begin+0x10e1/0x1bc0 fs/buffer.c:2601
 hfs_write_begin+0x85/0x130 fs/hfs/inode.c:52
 cont_expand_zero fs/buffer.c:2528 [inline]
 cont_write_begin+0x35a/0x1bc0 fs/buffer.c:2591
 hfs_write_begin+0x85/0x130 fs/hfs/inode.c:52
 hfs_file_truncate+0x1d6/0xe60 fs/hfs/extent.c:494
 hfs_inode_setattr+0x964/0xaa0 fs/hfs/inode.c:654
 notify_change+0x1993/0x1aa0 fs/attr.c:552
 do_truncate+0x28f/0x310 fs/open.c:68
 do_ftruncate+0x698/0x730 fs/open.c:195
 do_sys_ftruncate fs/open.c:210 [inline]
 __do_sys_ftruncate fs/open.c:215 [inline]
 __se_sys_ftruncate fs/open.c:213 [inline]
 __x64_sys_ftruncate+0x11b/0x250 fs/open.c:213
 x64_sys_call+0xfe3/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:78
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4154 [inline]
 slab_alloc_node mm/slub.c:4197 [inline]
 __kmalloc_cache_noprof+0x7f7/0xed0 mm/slub.c:4354
 kmalloc_noprof include/linux/slab.h:905 [inline]
 hfs_mdb_get+0x1cc8/0x2a90 fs/hfs/mdb.c:175
 hfs_fill_super+0x3d0/0xb80 fs/hfs/super.c:337
 get_tree_bdev_flags+0x6e3/0x920 fs/super.c:1681
 get_tree_bdev+0x38/0x50 fs/super.c:1704
 hfs_get_tree+0x35/0x40 fs/hfs/super.c:388
 vfs_get_tree+0xb0/0x5c0 fs/super.c:1804
 do_new_mount+0x738/0x1610 fs/namespace.c:3902
 path_mount+0x6db/0x1e90 fs/namespace.c:4226
 do_mount fs/namespace.c:4239 [inline]
 __do_sys_mount fs/namespace.c:4450 [inline]
 __se_sys_mount+0x6eb/0x7d0 fs/namespace.c:4427
 __x64_sys_mount+0xe4/0x150 fs/namespace.c:4427
 x64_sys_call+0xfa7/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 1 UID: 0 PID: 12609 Comm: syz.1.2692 Not tainted 6.16.0-syzkaller #0 PREEMPT(none)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
=====================================================

The HFS_SB(sb)-&gt;bitmap buffer is allocated in hfs_mdb_get():

HFS_SB(sb)-&gt;bitmap = kmalloc(8192, GFP_KERNEL);

Finally, it can trigger the reported issue because kmalloc()
doesn't clear the allocated memory. If allocated memory contains
only zeros, then everything will work pretty fine.
But if the allocated memory contains the "garbage", then
it can affect the bitmap operations and it triggers
the reported issue.

This patch simply exchanges the kmalloc() on kzalloc()
with the goal to guarantee the correctness of bitmap operations.
Because, newly created allocation bitmap should have all
available blocks free. Potentially, initialization bitmap's read
operation could not fill the whole allocated memory and
"garbage" in the not initialized memory will be the reason of
volume coruptions and file system driver bugs.

Reported-by: syzbot &lt;syzbot+773fa9d79b29bd8b6831@syzkaller.appspotmail.com&gt;
Closes: https://syzkaller.appspot.com/bug?extid=773fa9d79b29bd8b6831
Signed-off-by: Viacheslav Dubeyko &lt;slava@dubeyko.com&gt;
cc: John Paul Adrian Glaubitz &lt;glaubitz@physik.fu-berlin.de&gt;
cc: Yangtao Li &lt;frank.li@vivo.com&gt;
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20250820230636.179085-1-slava@dubeyko.com
Signed-off-by: Viacheslav Dubeyko &lt;slava@dubeyko.com&gt;
</content>
</entry>
<entry>
<title>hfs: make proper initalization of struct hfs_find_data</title>
<updated>2025-09-01T01:11:55+00:00</updated>
<author>
<name>Viacheslav Dubeyko</name>
<email>slava@dubeyko.com</email>
</author>
<published>2025-08-18T22:52:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=c62663a986acee7c4485c1fa9de5fc40194b6290'/>
<id>urn:sha1:c62663a986acee7c4485c1fa9de5fc40194b6290</id>
<content type='text'>
Potenatially, __hfs_ext_read_extent() could operate by
not initialized values of fd-&gt;key after hfs_brec_find() call:

static inline int __hfs_ext_read_extent(struct hfs_find_data *fd, struct hfs_extent *extent,
                                        u32 cnid, u32 block, u8 type)
{
        int res;

        hfs_ext_build_key(fd-&gt;search_key, cnid, block, type);
        fd-&gt;key-&gt;ext.FNum = 0;
        res = hfs_brec_find(fd);
        if (res &amp;&amp; res != -ENOENT)
                return res;
        if (fd-&gt;key-&gt;ext.FNum != fd-&gt;search_key-&gt;ext.FNum ||
            fd-&gt;key-&gt;ext.FkType != fd-&gt;search_key-&gt;ext.FkType)
                return -ENOENT;
        if (fd-&gt;entrylength != sizeof(hfs_extent_rec))
                return -EIO;
        hfs_bnode_read(fd-&gt;bnode, extent, fd-&gt;entryoffset, sizeof(hfs_extent_rec));
        return 0;
}

This patch changes kmalloc() on kzalloc() in hfs_find_init()
and intializes fd-&gt;record, fd-&gt;keyoffset, fd-&gt;keylength,
fd-&gt;entryoffset, fd-&gt;entrylength for the case if hfs_brec_find()
has been found nothing in the b-tree node.

Signed-off-by: Viacheslav Dubeyko &lt;slava@dubeyko.com&gt;
cc: John Paul Adrian Glaubitz &lt;glaubitz@physik.fu-berlin.de&gt;
cc: Yangtao Li &lt;frank.li@vivo.com&gt;
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20250818225252.126427-1-slava@dubeyko.com
Signed-off-by: Viacheslav Dubeyko &lt;slava@dubeyko.com&gt;
</content>
</entry>
<entry>
<title>Merge tag 'hfs-v6.17-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/vdubeyko/hfs</title>
<updated>2025-07-28T23:17:44+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-07-28T23:17:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=cb6bbff7e6fb263dd739514b3f5dfdcd8eaa9836'/>
<id>urn:sha1:cb6bbff7e6fb263dd739514b3f5dfdcd8eaa9836</id>
<content type='text'>
Pull hfs/hfsplus updates from Viacheslav Dubeyko:
 "Johannes Thumshirn has made nice cleanup in hfsplus_submit_bio().

  Tetsuo Handa has fixed the syzbot reported issue in
  hfsplus_create_attributes_file() for the case of corruption the
  Attributes File's metadata.

  Yangtao Li has fixed the syzbot reported issue by removing the
  uneccessary WARN_ON() in hfsplus_free_extents().

  Other fixes:

   - restore generic/001 successful execution by erasing deleted b-tree
     nodes

   - eliminate slab-out-of-bounds issue in hfs_bnode_read() and
     hfsplus_bnode_read() by checking correctness of offset and length
     when accessing b-tree node contents

   - eliminate slab-out-of-bounds read in hfsplus_uni2asc() if the
     b-tree node record has corrupted length of a name that could be
     bigger than HFSPLUS_MAX_STRLEN

   - eliminate general protection fault in hfs_find_init() for the case
     of initial b-tree object creation"

* tag 'hfs-v6.17-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/vdubeyko/hfs:
  hfs: fix general protection fault in hfs_find_init()
  hfs: fix slab-out-of-bounds in hfs_bnode_read()
  hfsplus: fix slab-out-of-bounds in hfsplus_bnode_read()
  hfsplus: fix slab-out-of-bounds read in hfsplus_uni2asc()
  hfsplus: don't use BUG_ON() in hfsplus_create_attributes_file()
  hfsplus: don't set REQ_SYNC for hfsplus_submit_bio()
  hfsplus: remove mutex_lock check in hfsplus_free_extents
  hfs: make splice write available again
  hfsplus: make splice write available again
  hfs: fix not erasing deleted b-tree node issue
</content>
</entry>
<entry>
<title>Merge tag 'vfs-6.17-rc1.mmap_prepare' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs</title>
<updated>2025-07-28T20:43:25+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-07-28T20:43:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=7031769e102b768b3fa0c4c726faf532cb31e973'/>
<id>urn:sha1:7031769e102b768b3fa0c4c726faf532cb31e973</id>
<content type='text'>
Pull mmap_prepare updates from Christian Brauner:
 "Last cycle we introduce f_op-&gt;mmap_prepare() in c84bf6dd2b83 ("mm:
  introduce new .mmap_prepare() file callback").

  This is preferred to the existing f_op-&gt;mmap() hook as it does require
  a VMA to be established yet, thus allowing the mmap logic to invoke
  this hook far, far earlier, prior to inserting a VMA into the virtual
  address space, or performing any other heavy handed operations.

  This allows for much simpler unwinding on error, and for there to be a
  single attempt at merging a VMA rather than having to possibly
  reattempt a merge based on potentially altered VMA state.

  Far more importantly, it prevents inappropriate manipulation of
  incompletely initialised VMA state, which is something that has been
  the cause of bugs and complexity in the past.

  The intent is to gradually deprecate f_op-&gt;mmap, and in that vein this
  series coverts the majority of file systems to using f_op-&gt;mmap_prepare.

  Prerequisite steps are taken - firstly ensuring all checks for mmap
  capabilities use the file_has_valid_mmap_hooks() helper rather than
  directly checking for f_op-&gt;mmap (which is now not a valid check) and
  secondly updating daxdev_mapping_supported() to not require a VMA
  parameter to allow ext4 and xfs to be converted.

  Commit bb666b7c2707 ("mm: add mmap_prepare() compatibility layer for
  nested file systems") handles the nasty edge-case of nested file
  systems like overlayfs, which introduces a compatibility shim to allow
  f_op-&gt;mmap_prepare() to be invoked from an f_op-&gt;mmap() callback.

  This allows for nested filesystems to continue to function correctly
  with all file systems regardless of which callback is used. Once we
  finally convert all file systems, this shim can be removed.

  As a result, ecryptfs, fuse, and overlayfs remain unaltered so they
  can nest all other file systems.

  We additionally do not update resctl - as this requires an update to
  remap_pfn_range() (or an alternative to it) which we defer to a later
  series, equally we do not update cramfs which needs a mixed mapping
  insertion with the same issue, nor do we update procfs, hugetlbfs,
  syfs or kernfs all of which require VMAs for internal state and hooks.
  We shall return to all of these later"

* tag 'vfs-6.17-rc1.mmap_prepare' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  doc: update porting, vfs documentation to describe mmap_prepare()
  fs: replace mmap hook with .mmap_prepare for simple mappings
  fs: convert most other generic_file_*mmap() users to .mmap_prepare()
  fs: convert simple use of generic_file_*_mmap() to .mmap_prepare()
  mm/filemap: introduce generic_file_*_mmap_prepare() helpers
  fs/xfs: transition from deprecated .mmap hook to .mmap_prepare
  fs/ext4: transition from deprecated .mmap hook to .mmap_prepare
  fs/dax: make it possible to check dev dax support without a VMA
  fs: consistently use can_mmap_file() helper
  mm/nommu: use file_has_valid_mmap_hooks() helper
  mm: rename call_mmap/mmap_prepare to vfs_mmap/mmap_prepare
</content>
</entry>
<entry>
<title>Merge tag 'vfs-6.17-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs</title>
<updated>2025-07-28T18:22:56+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-07-28T18:22:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=7879d7aff0ffd969fcb1a59e3f87ebb353e47b7f'/>
<id>urn:sha1:7879d7aff0ffd969fcb1a59e3f87ebb353e47b7f</id>
<content type='text'>
Pull misc VFS updates from Christian Brauner:
 "This contains the usual selections of misc updates for this cycle.

  Features:

   - Add ext4 IOCB_DONTCACHE support

     This refactors the address_space_operations write_begin() and
     write_end() callbacks to take const struct kiocb * as their first
     argument, allowing IOCB flags such as IOCB_DONTCACHE to propagate
     to the filesystem's buffered I/O path.

     Ext4 is updated to implement handling of the IOCB_DONTCACHE flag
     and advertises support via the FOP_DONTCACHE file operation flag.

     Additionally, the i915 driver's shmem write paths are updated to
     bypass the legacy write_begin/write_end interface in favor of
     directly calling write_iter() with a constructed synchronous kiocb.
     Another i915 change replaces a manual write loop with
     kernel_write() during GEM shmem object creation.

  Cleanups:

   - don't duplicate vfs_open() in kernel_file_open()

   - proc_fd_getattr(): don't bother with S_ISDIR() check

   - fs/ecryptfs: replace snprintf with sysfs_emit in show function

   - vfs: Remove unnecessary list_for_each_entry_safe() from
     evict_inodes()

   - filelock: add new locks_wake_up_waiter() helper

   - fs: Remove three arguments from block_write_end()

   - VFS: change old_dir and new_dir in struct renamedata to dentrys

   - netfs: Remove unused declaration netfs_queue_write_request()

  Fixes:

   - eventpoll: Fix semi-unbounded recursion

   - eventpoll: fix sphinx documentation build warning

   - fs/read_write: Fix spelling typo

   - fs: annotate data race between poll_schedule_timeout() and
     pollwake()

   - fs/pipe: set FMODE_NOWAIT in create_pipe_files()

   - docs/vfs: update references to i_mutex to i_rwsem

   - fs/buffer: remove comment about hard sectorsize

   - fs/buffer: remove the min and max limit checks in __getblk_slow()

   - fs/libfs: don't assume blocksize &lt;= PAGE_SIZE in
     generic_check_addressable

   - fs_context: fix parameter name in infofc() macro

   - fs: Prevent file descriptor table allocations exceeding INT_MAX"

* tag 'vfs-6.17-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (24 commits)
  netfs: Remove unused declaration netfs_queue_write_request()
  eventpoll: fix sphinx documentation build warning
  ext4: support uncached buffered I/O
  mm/pagemap: add write_begin_get_folio() helper function
  fs: change write_begin/write_end interface to take struct kiocb *
  drm/i915: Refactor shmem_pwrite() to use kiocb and write_iter
  drm/i915: Use kernel_write() in shmem object create
  eventpoll: Fix semi-unbounded recursion
  vfs: Remove unnecessary list_for_each_entry_safe() from evict_inodes()
  fs/libfs: don't assume blocksize &lt;= PAGE_SIZE in generic_check_addressable
  fs/buffer: remove the min and max limit checks in __getblk_slow()
  fs: Prevent file descriptor table allocations exceeding INT_MAX
  fs: Remove three arguments from block_write_end()
  fs/ecryptfs: replace snprintf with sysfs_emit in show function
  fs: annotate suspected data race between poll_schedule_timeout() and pollwake()
  docs/vfs: update references to i_mutex to i_rwsem
  fs/buffer: remove comment about hard sectorsize
  fs_context: fix parameter name in infofc() macro
  VFS: change old_dir and new_dir in struct renamedata to dentrys
  proc_fd_getattr(): don't bother with S_ISDIR() check
  ...
</content>
</entry>
</feed>
