Creates an anon_inode_getfile_fmode() function that works similarly to
anon_inode_getfile() with the addition of being able to set the fmode
member.
Signed-off-by: Dawid Osuchowski <linux@osuchow.ski>
Link: https://lore.kernel.org/r/20240426075854.4723-1-linux@osuchow.skiSigned-off-by: Christian Brauner <brauner@kernel.org>

Directories do not support direct I/O and thus no non-blocking direct
I/O either.  Open code the shutdown check and call to generic_file_open
instead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240423124608.537794-4-hch@lst.deReviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Directories have non of the capabilities, so drop the flags.  Note that
the current state is harmless as no one actually checks for the flags
either.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240423124608.537794-3-hch@lst.deReviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Re-wrap the newly added fop_flags fields to not go over 80 characters.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240423124608.537794-2-hch@lst.deReviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Merge patch series 'Fix shmem_rename2 directory offset calculation' of https://lore.kernel.org/r/20240415152057.4605-1-cel@kernel.org

Pull shmem_rename2() offset fixes from Chuck Lever:

The existing code in shmem_rename2() allocates a fresh directory
offset value when renaming over an existing destination entry. User
space does not expect this behavior. In particular, applications
that rename while walking a directory can loop indefinitely because
they never reach the end of the directory.

* 'Fix shmem_rename2 directory offset calculation' of https://lore.kernel.org/r/20240415152057.4605-1-cel@kernel.org: (3 commits)
  shmem: Fix shmem_rename2()
  libfs: Add simple_offset_rename() API
  libfs: Fix simple_offset_rename_exchange()

 fs/libfs.c         | 55 +++++++++++++++++++++++++++++++++++++++++-----
 include/linux/fs.h |  2 ++
 mm/shmem.c         |  3 +--
 3 files changed, 52 insertions(+), 8 deletions(-)
Signed-off-by: Christian Brauner <brauner@kernel.org>

When renaming onto an existing directory entry, user space expects
the replacement entry to have the same directory offset as the
original one.

Link: https://gitlab.alpinelinux.org/alpine/aports/-/issues/15966
Fixes: a2e45955 ("shmem: stable directory offsets")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/20240415152057.4605-4-cel@kernel.orgSigned-off-by: Christian Brauner <brauner@kernel.org>

I'm about to fix a tmpfs rename bug that requires the use of
internal simple_offset helpers that are not available in mm/shmem.c
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/20240415152057.4605-3-cel@kernel.orgSigned-off-by: Christian Brauner <brauner@kernel.org>

User space expects the replacement (old) directory entry to have
the same directory offset after the rename.
Suggested-by: Christian Brauner <brauner@kernel.org>
Fixes: a2e45955 ("shmem: stable directory offsets")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/20240415152057.4605-2-cel@kernel.orgSigned-off-by: Christian Brauner <brauner@kernel.org>

Add a check to make sure that the requested xattr node size is no larger
than the eraseblock minus the cleanmarker.

Unlike the usual inode nodes, the xattr nodes aren't split into parts
and spread across multiple eraseblocks, which means that a xattr node
must not occupy more than one eraseblock. If the requested xattr value is
too large, the xattr node can spill onto the next eraseblock, overwriting
the nodes and causing errors such as:

jffs2: argh. node added in wrong place at 0x0000b050(2)
jffs2: nextblock 0x0000a000, expected at 0000b00c
jffs2: error: (823) do_verify_xattr_datum: node CRC failed at 0x01e050,
read=0xfc892c93, calc=0x000000
jffs2: notice: (823) jffs2_get_inode_nodes: Node header CRC failed
at 0x01e00c. {848f,2fc4,0fef511f,59a3d171}
jffs2: Node at 0x0000000c with length 0x00001044 would run over the
end of the erase block
jffs2: Perhaps the file system was created with the wrong erase size?
jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found
at 0x00000010: 0x1044 instead

This breaks the filesystem and can lead to KASAN crashes such as:

BUG: KASAN: slab-out-of-bounds in jffs2_sum_add_kvec+0x125e/0x15d0
Read of size 4 at addr ffff88802c31e914 by task repro/830
CPU: 0 PID: 830 Comm: repro Not tainted 6.9.0-rc3+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS Arch Linux 1.16.3-1-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xc6/0x120
 print_report+0xc4/0x620
 ? __virt_addr_valid+0x308/0x5b0
 kasan_report+0xc1/0xf0
 ? jffs2_sum_add_kvec+0x125e/0x15d0
 ? jffs2_sum_add_kvec+0x125e/0x15d0
 jffs2_sum_add_kvec+0x125e/0x15d0
 jffs2_flash_direct_writev+0xa8/0xd0
 jffs2_flash_writev+0x9c9/0xef0
 ? __x64_sys_setxattr+0xc4/0x160
 ? do_syscall_64+0x69/0x140
 ? entry_SYSCALL_64_after_hwframe+0x76/0x7e
 [...]

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: aa98d7cf ("[JFFS2][XATTR] XATTR support on JFFS2 (version. 5)")
Signed-off-by: Ilya Denisyev <dev@elkcl.ru>
Link: https://lore.kernel.org/r/20240412155357.237803-1-dev@elkcl.ruSigned-off-by: Christian Brauner <brauner@kernel.org>

No swap support -- no swapfiles possible.
Signed-off-by: Alexey Dobriyan (Yandex) <adobriyan@gmail.com>
Link: https://lore.kernel.org/r/2391c7f5-0f83-4188-ae56-4ec7ccbf2576@p183Signed-off-by: Christian Brauner <brauner@kernel.org>

   "The definition of insanity is doing the same thing over and over
    again and expecting different results”

We've tried to do this before, most recently with commit bb2314b4
("fs: Allow unprivileged linkat(..., AT_EMPTY_PATH) aka flink") about a
decade ago.

But the effort goes back even further than that, eg this thread back
from 1998 that is so old that we don't even have it archived in lore:

    https://lkml.org/lkml/1998/3/10/108

which also points out some of the reasons why it's dangerous.

Or, how about then in 2003:

    https://lkml.org/lkml/2003/4/6/112

where we went through some of the same arguments, just wirh different
people involved.

In particular, having access to a file descriptor does not necessarily
mean that you have access to the path that was used for lookup, and
there may be very good reasons why you absolutely must not have access
to a path to said file.

For example, if we were passed a file descriptor from the outside into
some limited environment (think chroot, but also user namespaces etc) a
'flink()' system call could now make that file visible inside a context
where it's not supposed to be visible.

In the process the user may also be able to re-open it with permissions
that the original file descriptor did not have (eg a read-only file
descriptor may be associated with an underlying file that is writable).

Another variation on this is if somebody else (typically root) opens a
file in a directory that is not accessible to others, and passes the
file descriptor on as a read-only file.  Again, the access to the file
descriptor does not imply that you should have access to a path to the
file in the filesystem.

So while we have tried this several times in the past, it never works.

The last time we did this, that commit bb2314b4 quickly got reverted
again in commit f0cc6ffb (Revert "fs: Allow unprivileged linkat(...,
AT_EMPTY_PATH) aka flink"), with a note saying "We may re-do this once
the whole discussion about the interface is done".

Well, the discussion is long done, and didn't come to any resolution.
There's no question that 'flink()' would be a useful operation, but it's
a dangerous one.

However, it does turn out that since 2008 (commit d76b0d9b: "CRED:
Use creds in file structs") we have had a fairly straightforward way to
check whether the file descriptor was opened by the same credentials as
the credentials of the flink().

That allows the most common patterns that people want to use, which tend
to be to either open the source carefully (ie using the openat2()
RESOLVE_xyz flags, and/or checking ownership with fstat() before
linking), or to use O_TMPFILE and fill in the file contents before it's
exposed to the world with linkat().

But it also means that if the file descriptor was opened by somebody
else, or we've gone through a credentials change since, the operation no
longer works (unless we have CAP_DAC_READ_SEARCH capabilities in the
opener's user namespace, as before).

Note that the credential equality check is done by using pointer
equality, which means that it's not enough that you have effectively the
same user - they have to be literally identical, since our credentials
are using copy-on-write semantics.

So you can't change your credentials to something else and try to change
it back to the same ones between the open() and the linkat().  This is
not meant to be some kind of generic permission check, this is literally
meant as a "the open and link calls are 'atomic' wrt user credentials"
check.

It also means that you can't just move things between namespaces,
because the credentials aren't just a list of uid's and gid's: they
includes the pointer to the user_ns that the capabilities are relative
to.

So let's try this one more time and see if maybe this approach ends up
being workable after all.

Cc: Andrew Lutomirski <luto@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240411001012.12513-1-torvalds@linux-foundation.org
[brauner: relax capability check to opener of the file]
Link: https://lore.kernel.org/all/20231113-undenkbar-gediegen-efde5f1c34bc@braunerSigned-off-by: Christian Brauner <brauner@kernel.org>

The variable retval is being assigned a value that is not being read,
it is being re-assigned later on in the function. The assignment
is redundant and can be removed.

Cleans up clang scan build warning:
fs/direct-io.c:1220:2: warning: Value stored to 'retval' is never
read [deadcode.DeadStores]
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20240410162221.292485-1-colin.i.king@gmail.comReviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Currently, the __d_clear_type_and_inode() writes the value flags to
dentry->d_flags, then immediately re-reads it in order to use it in a if
statement. This re-read is useless because no other update to
dentry->d_flags can occur at this point.

This commit therefore re-use flags in the if statement instead of
re-reading dentry->d_flags.
Signed-off-by: linke li <lilinke99@qq.com>
Link: https://lore.kernel.org/r/tencent_5E187BD0A61BA28605E85405F15228254D0A@qq.comReviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Instead of checking for specific file_operations, add a bit to
file_operations which denotes a file that only contain hugetlb pages.
This lets us make hugetlbfs_file_operations static, and removes
is_file_shm_hugepages() completely.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20240407201122.3783877-1-willy@infradead.orgSigned-off-by: Christian Brauner <brauner@kernel.org>

strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.

There is some care taken to ensure these destination buffers are
NUL-terminated by bounding the strncpy()'s by ORANGEFS_NAME_MAX - 1 or
ORANGEFS_MAX_SERVER_ADDR_LEN - 1. Instead, we can use the new 2-argument
version of strscpy() to guarantee NUL-termination on the destination
buffers while simplifying the code.

Based on usage with printf-likes, we can see these buffers are expected
to be NUL-terminated:
|	gossip_debug(GOSSIP_NAME_DEBUG,
|			"%s: doing lookup on %s under %pU,%d\n",
|			__func__,
|			new_op->upcall.req.lookup.d_name,
|			&new_op->upcall.req.lookup.parent_refn.khandle,
|			new_op->upcall.req.lookup.parent_refn.fs_id);
...
|	gossip_debug(GOSSIP_SUPER_DEBUG,
|			"Attempting ORANGEFS Remount via host %s\n",
|			new_op->upcall.req.fs_mount.orangefs_config_server);

NUL-padding isn't required for any of these destination buffers as
they've all been zero-allocated with op_alloc() or kzalloc().

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20240322-strncpy-fs-orangefs-dcache-c-v1-1-15d12debbf38@google.comReviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

clang-14 points out that v_size is always smaller than a 64KB
page size if that is configured by the CPU architecture:

fs/nilfs2/ioctl.c:63:19: error: result of comparison of constant 65536 with expression of type '__u16' (aka 'unsigned short') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
        if (argv->v_size > PAGE_SIZE)
            ~~~~~~~~~~~~ ^ ~~~~~~~~~

This is ok, so just shut up that warning with a cast.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20240328143051.1069575-7-arnd@kernel.org
Fixes: 3358b4aa ("nilfs2: fix problems of memory allocation in ioctl")
Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reviewed-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Make it easier to see what bits are still available.

Link: https://lore.kernel.org/r/20240406061604.GA538574@ZenIVSigned-off-by: Christian Brauner <brauner@kernel.org>

There's a bunch of flags that are purely based on what the file
operations support while also never being conditionally set or unset.
IOW, they're not subject to change for individual files. Imho, such
flags don't need to live in f_mode they might as well live in the fops
structs itself. And the fops struct already has that lonely
mmap_supported_flags member. We might as well turn that into a generic
fop_flags member and move a few flags from FMODE_* space into FOP_*
space. That gets us four FMODE_* bits back and the ability for new
static flags that are about file ops to not have to live in FMODE_*
space but in their own FOP_* space. It's not the most beautiful thing
ever but it gets the job done. Yes, there'll be an additional pointer
chase but hopefully that won't matter for these flags.

I suspect there's a few more we can move into there and that we can also
redirect a bunch of new flag suggestions that follow this pattern into
the fop_flags field instead of f_mode.

Link: https://lore.kernel.org/r/20240328-gewendet-spargel-aa60a030ef74@braunerReviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for
array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

While there, use struct_size() helper, instead of the open-coded
version.

[brauner@kernel.org: contains a fix by Edward for an OOB access]
Reported-by: syzbot+4139435cb1b34cf759c2@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Link: https://lore.kernel.org/r/tencent_A7845DD769577306D813742365E976E3A205@qq.comSigned-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/ZgImCXTdGDTeBvSS@neatReviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Merge patch series 'fs: aio: more folio conversion' of https://lore.kernel.org/r/20240321131640.948634-1-wangkefeng.wang@huawei.com

Pull aio folio conversion from Kefeng Wang:

Convert to use folio throughout aio.

* series 'fs: aio: more folio conversion' of https://lore.kernel.org/r/20240321131640.948634-1-wangkefeng.wang@huawei.com: (3 commits)
  fs: aio: convert to ring_folios and internal_folios
  fs: aio: use a folio in aio_free_ring()
  fs: aio: use a folio in aio_setup_ring()
Signed-off-by: Christian Brauner <brauner@kernel.org>

Since aio use folios in most functions, convert ring/internal_pages
to ring/internal_folios, let's directly use folio instead of page
throughout aio to remove hidden calls to compound_head(), eg,
flush_dcache_page().
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Link: https://lore.kernel.org/r/20240321131640.948634-4-wangkefeng.wang@huawei.comReviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

The 'TAG 66 Packet Format' description is missing the cipher code and
checksum fields that are packed into the message packet. As a result,
the buffer allocated for the packet is 3 bytes too small and
write_tag_66_packet() will write up to 3 bytes past the end of the
buffer.

Fix this by increasing the size of the allocation so the whole packet
will always fit in the buffer.

This fixes the below kasan slab-out-of-bounds bug:

  BUG: KASAN: slab-out-of-bounds in ecryptfs_generate_key_packet_set+0x7d6/0xde0
  Write of size 1 at addr ffff88800afbb2a5 by task touch/181

  CPU: 0 PID: 181 Comm: touch Not tainted 6.6.13-gnu #1 4c9534092be820851bb687b82d1f92a426598dc6
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2/GNU Guix 04/01/2014
  Call Trace:
   <TASK>
   dump_stack_lvl+0x4c/0x70
   print_report+0xc5/0x610
   ? ecryptfs_generate_key_packet_set+0x7d6/0xde0
   ? kasan_complete_mode_report_info+0x44/0x210
   ? ecryptfs_generate_key_packet_set+0x7d6/0xde0
   kasan_report+0xc2/0x110
   ? ecryptfs_generate_key_packet_set+0x7d6/0xde0
   __asan_store1+0x62/0x80
   ecryptfs_generate_key_packet_set+0x7d6/0xde0
   ? __pfx_ecryptfs_generate_key_packet_set+0x10/0x10
   ? __alloc_pages+0x2e2/0x540
   ? __pfx_ovl_open+0x10/0x10 [overlay 30837f11141636a8e1793533a02e6e2e885dad1d]
   ? dentry_open+0x8f/0xd0
   ecryptfs_write_metadata+0x30a/0x550
   ? __pfx_ecryptfs_write_metadata+0x10/0x10
   ? ecryptfs_get_lower_file+0x6b/0x190
   ecryptfs_initialize_file+0x77/0x150
   ecryptfs_create+0x1c2/0x2f0
   path_openat+0x17cf/0x1ba0
   ? __pfx_path_openat+0x10/0x10
   do_filp_open+0x15e/0x290
   ? __pfx_do_filp_open+0x10/0x10
   ? __kasan_check_write+0x18/0x30
   ? _raw_spin_lock+0x86/0xf0
   ? __pfx__raw_spin_lock+0x10/0x10
   ? __kasan_check_write+0x18/0x30
   ? alloc_fd+0xf4/0x330
   do_sys_openat2+0x122/0x160
   ? __pfx_do_sys_openat2+0x10/0x10
   __x64_sys_openat+0xef/0x170
   ? __pfx___x64_sys_openat+0x10/0x10
   do_syscall_64+0x60/0xd0
   entry_SYSCALL_64_after_hwframe+0x6e/0xd8
  RIP: 0033:0x7f00a703fd67
  Code: 25 00 00 41 00 3d 00 00 41 00 74 37 64 8b 04 25 18 00 00 00 85 c0 75 5b 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 85 00 00 00 48 83 c4 68 5d 41 5c c3 0f 1f
  RSP: 002b:00007ffc088e30b0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
  RAX: ffffffffffffffda RBX: 00007ffc088e3368 RCX: 00007f00a703fd67
  RDX: 0000000000000941 RSI: 00007ffc088e48d7 RDI: 00000000ffffff9c
  RBP: 00007ffc088e48d7 R08: 0000000000000001 R09: 0000000000000000
  R10: 00000000000001b6 R11: 0000000000000246 R12: 0000000000000941
  R13: 0000000000000000 R14: 00007ffc088e48d7 R15: 00007f00a7180040
   </TASK>

  Allocated by task 181:
   kasan_save_stack+0x2f/0x60
   kasan_set_track+0x29/0x40
   kasan_save_alloc_info+0x25/0x40
   __kasan_kmalloc+0xc5/0xd0
   __kmalloc+0x66/0x160
   ecryptfs_generate_key_packet_set+0x6d2/0xde0
   ecryptfs_write_metadata+0x30a/0x550
   ecryptfs_initialize_file+0x77/0x150
   ecryptfs_create+0x1c2/0x2f0
   path_openat+0x17cf/0x1ba0
   do_filp_open+0x15e/0x290
   do_sys_openat2+0x122/0x160
   __x64_sys_openat+0xef/0x170
   do_syscall_64+0x60/0xd0
   entry_SYSCALL_64_after_hwframe+0x6e/0xd8

Fixes: dddfa461 ("[PATCH] eCryptfs: Public key; packet management")
Signed-off-by: Brian Kubisiak <brian@kubisiak.com>
Link: https://lore.kernel.org/r/5j2q56p6qkhezva6b2yuqfrsurmvrrqtxxzrnp3wqu7xrz22i7@hoecdztoplblSigned-off-by: Christian Brauner <brauner@kernel.org>

Use a folio throughout aio_free_ring() to remove calls to compound_head(),
also move pr_debug after folio check to remove unnecessary print.
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Link: https://lore.kernel.org/r/20240321131640.948634-3-wangkefeng.wang@huawei.comReviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Merge series 'Fixes and cleanups to fs-writeback' of https://lore.kernel.org/r/20240228091958.288260-1-shikemeng@huaweicloud.com

Pull writeback fixes and cleanups from Kemeng Shi:

This contains several fixes and cleanups for the writeback code.

* series 'Fixes and cleanups to fs-writeback' of https://lore.kernel.org/r/20240228091958.288260-1-shikemeng@huaweicloud.com: (6 commits)
  fs/writeback: remove unnecessary return in writeback_inodes_sb
  fs/writeback: correct comment of __wakeup_flusher_threads_bdi
  fs/writeback: only calculate dirtied_before when b_io is empty
  fs/writeback: remove unused parameter wb of finish_writeback_work
  fs/writeback: bail out if there is no more inodes for IO and queued once
  fs/writeback: avoid to writeback non-expired inode in kupdate writeback
Signed-off-by: Christian Brauner <brauner@kernel.org>

Use a folio throughout aio_setup_ring() to remove calls to compound_head(),
also use folio_end_read() to simultaneously mark the folio uptodate and
unlock it.
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Link: https://lore.kernel.org/r/20240321131640.948634-2-wangkefeng.wang@huawei.comReviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

writeback_inodes_sb doesn't have return value, just remove unnecessary
return in it.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20240228091958.288260-7-shikemeng@huaweicloud.comReviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Commit e8e8a0c6 ("writeback: move nr_pages == 0 logic to one
location") removed parameter nr_pages of __wakeup_flusher_threads_bdi
and we try to writeback all dirty pages in __wakeup_flusher_threads_bdi
now. Just correct stale comment.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20240228091958.288260-6-shikemeng@huaweicloud.comReviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

The dirtied_before is only used when b_io is not empty, so only calculate
when b_io is not empty.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20240228091958.288260-5-shikemeng@huaweicloud.comReviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Remove unused parameter wb of finish_writeback_work.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20240228091958.288260-4-shikemeng@huaweicloud.comReviewed-by: Tim Chen <tim.c.chen@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

For case there is no more inodes for IO in io list from last wb_writeback,
We may bail out early even there is inode in dirty list should be written
back. Only bail out when we queued once to avoid missing dirtied inode.

This is from code reading...
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20240228091958.288260-3-shikemeng@huaweicloud.comReviewed-by: Jan Kara <jack@suse.cz>
[brauner@kernel.org: fold in memory corruption fix from Jan in [1]]
Link: https://lore.kernel.org/r/20240405132346.bid7gibby3lxxhez@quack3 [1]
Signed-off-by: Christian Brauner <brauner@kernel.org>

This commit adds kernel-doc style comments with complete parameter
descriptions for the function proc_create_net_data_write.
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240315073805.77463-1-yang.lee@linux.alibaba.comSigned-off-by: Christian Brauner <brauner@kernel.org>

In kupdate writeback, only expired inode (have been dirty for longer than
dirty_expire_interval) is supposed to be written back. However, kupdate
writeback will writeback non-expired inode left in b_io or b_more_io from
last wb_writeback. As a result, writeback will keep being triggered
unexpected when we keep dirtying pages even dirty memory is under
threshold and inode is not expired. To be more specific:
Assume dirty background threshold is > 1G and dirty_expire_centisecs is
> 60s. When we running fio -size=1G -invalidate=0 -ioengine=libaio
--time_based -runtime=60... (keep dirtying), the writeback will keep
being triggered as following:
wb_workfn
  wb_do_writeback
    wb_check_background_flush
      /*
       * Wb dirty background threshold starts at 0 if device was idle and
       * grows up when bandwidth of wb is updated. So a background
       * writeback is triggered.
       */
      wb_over_bg_thresh
      /*
       * Dirtied inode will be written back and added to b_more_io list
       * after slice used up (because we keep dirtying the inode).
       */
      wb_writeback

Writeback is triggered per dirty_writeback_centisecs as following:
wb_workfn
  wb_do_writeback
    wb_check_old_data_flush
      /*
       * Write back inode left in b_io and b_more_io from last wb_writeback
       * even the inode is non-expired and it will be added to b_more_io
       * again as slice will be used up (because we keep dirtying the
       * inode)
       */
      wb_writeback

Fix this by moving non-expired inode to dirty list instead of more io
list for kupdate writeback in requeue_inode.

Test as following:
/* make it more easier to observe the issue */
echo 300000 > /proc/sys/vm/dirty_expire_centisecs
echo 100 > /proc/sys/vm/dirty_writeback_centisecs
/* create a idle device */
mkfs.ext4 -F /dev/vdb
mount /dev/vdb /bdi1/
/* run buffer write with fio */
fio -name test -filename=/bdi1/file -size=800M -ioengine=libaio -bs=4K \
-iodepth=1 -rw=write -direct=0 --time_based -runtime=60 -invalidate=0

Fio result before fix (run three tests):
1360MB/s
1329MB/s
1455MB/s

Fio result after fix (run three tests):
1737MB/s
1729MB/s
1789MB/s

Writeback for non-expired inode is gone as expeted. Observe this with trace
writeback_start and writeback_written as following:
echo 1 > /sys/kernel/debug/tracing/events/writeback/writeback_start/enab
echo 1 > /sys/kernel/debug/tracing/events/writeback/writeback_written/enable
cat /sys/kernel/tracing/trace_pipe
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20240228091958.288260-2-shikemeng@huaweicloud.comReviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Since both ext4 and overlayfs define the same macro to specify string
parameters that may allow empty values, define it in an header file so
that this helper can be shared.
Signed-off-by: Luis Henriques (SUSE) <luis.henriques@linux.dev>
Link: https://lore.kernel.org/r/20240312104757.27333-1-luis.henriques@linux.devSigned-off-by: Christian Brauner <brauner@kernel.org>

Add a new statx field for (sub)volume identifiers, as implemented by
btrfs and bcachefs.

This includes bcachefs support; we'll definitely want btrfs support as
well.

Link: https://lore.kernel.org/linux-fsdevel/2uvhm6gweyl7iyyp2xpfryvcu2g3padagaeqcbiavjyiis6prl@yjm725bizncq/Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Link: https://lore.kernel.org/r/20240308022914.196982-1-kent.overstreet@linux.devSigned-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Pull EFI fixes from Ard Biesheuvel:

 - Fix logic that is supposed to prevent placement of the kernel image
   below LOAD_PHYSICAL_ADDR

 - Use the firmware stack in the EFI stub when running in mixed mode

 - Clear BSS only once when using mixed mode

 - Check efi.get_variable() function pointer for NULL before trying to
   call it

* tag 'efi-fixes-for-v6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi: fix panic in kdump kernel
  x86/efistub: Don't clear BSS twice in mixed mode
  x86/efistub: Call mixed mode boot services on the firmware's stack
  efi/libstub: fix efi_random_alloc() to allocate memory at alloc_min or higher address

Pull x86 fixes from Thomas Gleixner:

 - Ensure that the encryption mask at boot is properly propagated on
   5-level page tables, otherwise the PGD entry is incorrectly set to
   non-encrypted, which causes system crashes during boot.

 - Undo the deferred 5-level page table setup as it cannot work with
   memory encryption enabled.

 - Prevent inconsistent XFD state on CPU hotplug, where the MSR is reset
   to the default value but the cached variable is not, so subsequent
   comparisons might yield the wrong result and as a consequence the
   result prevents updating the MSR.

 - Register the local APIC address only once in the MPPARSE enumeration
   to prevent triggering the related WARN_ONs() in the APIC and topology
   code.

 - Handle the case where no APIC is found gracefully by registering a
   fake APIC in the topology code. That makes all related topology
   functions work correctly and does not affect the actual APIC driver
   code at all.

 - Don't evaluate logical IDs during early boot as the local APIC IDs
   are not yet enumerated and the invoked function returns an error
   code. Nothing requires the logical IDs before the final CPUID
   enumeration takes place, which happens after the enumeration.

 - Cure the fallout of the per CPU rework on UP which misplaced the
   copying of boot_cpu_data to per CPU data so that the final update to
   boot_cpu_data got lost which caused inconsistent state and boot
   crashes.

 - Use copy_from_kernel_nofault() in the kprobes setup as there is no
   guarantee that the address can be safely accessed.

 - Reorder struct members in struct saved_context to work around another
   kmemleak false positive

 - Remove the buggy code which tries to update the E820 kexec table for
   setup_data as that is never passed to the kexec kernel.

 - Update the resource control documentation to use the proper units.

 - Fix a Kconfig warning observed with tinyconfig

* tag 'x86-urgent-2024-03-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot/64: Move 5-level paging global variable assignments back
  x86/boot/64: Apply encryption mask to 5-level pagetable update
  x86/cpu: Add model number for another Intel Arrow Lake mobile processor
  x86/fpu: Keep xfd_state in sync with MSR_IA32_XFD
  Documentation/x86: Document that resctrl bandwidth control units are MiB
  x86/mpparse: Register APIC address only once
  x86/topology: Handle the !APIC case gracefully
  x86/topology: Don't evaluate logical IDs during early boot
  x86/cpu: Ensure that CPU info updates are propagated on UP
  kprobes/x86: Use copy_from_kernel_nofault() to read from unsafe address
  x86/pm: Work around false positive kmemleak report in msr_build_context()
  x86/kexec: Do not update E820 kexec table for setup_data
  x86/config: Fix warning for 'make ARCH=x86_64 tinyconfig'

Pull scheduler doc clarification from Thomas Gleixner:
 "A single update for the documentation of the base_slice_ns tunable to
  clarify that any value which is less than the tick slice has no effect
  because the scheduler tick is not guaranteed to happen within the set
  time slice"

* tag 'sched-urgent-2024-03-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/doc: Update documentation for base_slice_ns and CONFIG_HZ relation

Pull dma-mapping fixes from Christoph Hellwig:
 "This has a set of swiotlb alignment fixes for sometimes very long
  standing bugs from Will. We've been discussion them for a while and
  they should be solid now"

* tag 'dma-mapping-6.9-2024-03-24' of git://git.infradead.org/users/hch/dma-mapping:
  swiotlb: Reinstate page-alignment for mappings >= PAGE_SIZE
  iommu/dma: Force swiotlb_max_mapping_size on an untrusted device
  swiotlb: Fix alignment checks when both allocation and DMA masks are present
  swiotlb: Honour dma_alloc_coherent() alignment in swiotlb_alloc()
  swiotlb: Enforce page alignment in swiotlb_alloc()
  swiotlb: Fix double-allocation of slots due to broken alignment handling

Check if get_next_variable() is actually valid pointer before
calling it. In kdump kernel this method is set to NULL that causes
panic during the kexec-ed kernel boot.

Tested with QEMU and OVMF firmware.

Fixes: bad267f9 ("efi: verify that variable services are supported")
Signed-off-by: Oleksandr Tymoshenko <ovt@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>