This series cleans up some of the special user copy functions naming and
semantics. In particular, get rid of the (very traditional) double
underscore names and behavior: the whole "optimize away the range check"
model has been largely excised from the other user accessors because
it's so subtle and can be unsafe, but also because it's just not a
relevant optimization any more.
To do that, a couple of drivers that misused the "user" copies as kernel
copies in order to get non-temporal stores had to be fixed up, but that
kind of code should never have been allowed anyway.
The x86-only "nocache" version was also renamed to more accurately
reflect what it actually does.
This was all done because I looked at this code due to a report by Jann
Horn, and I just couldn't stand the inconsistent naming, the horrible
semantics, and the random misuse of these functions. This code should
probably be cleaned up further, but it's at least slightly closer to
normal semantics.
I had a more intrusive series that went even further in trying to
normalize the semantics, but that ended up hitting so many other
inconsistencies between different architectures in this area (eg
'size_t' vs 'unsigned long' vs 'int' as size arguments, and various
iovec check differences that Vasily Gorbik pointed out) that I ended up
with this more limited version that fixed the worst of the issues.
Reported-by: Jann Horn <jannh@google.com>
Tested-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/all/CAHk-=wgg1QVWNWG-UCFo1hx0zqrPnB3qhPzUTrWNft+MtXQXig@mail.gmail.com/
* nocache-cleanup:
x86-64/arm64/powerpc: clean up and rename __copy_from_user_flushcache
x86: rename and clean up __copy_from_user_inatomic_nocache()
x86-64: rename misleadingly named '__copy_user_nocache()' function
This finishes the work on these odd functions that were only implemented
by a handful of architectures.
The 'flushcache' function was only used from the iterator code, and
let's make it do the same thing that the nontemporal version does:
remove the two underscores and add the user address checking.
Yes, yes, the user address checking is also done at iovec import time,
but we have long since walked away from the old double-underscore thing
where we try to avoid address checking overhead at access time, and
these functions shouldn't be so special and old-fashioned.
The arm64 version already did the address check, in fact, so there it's
just a matter of renaming it. For powerpc and x86-64 we now do the
proper user access boilerplate.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Similarly to the previous commit, this renames the somewhat confusingly
named function. But in this case, it was at least less confusing: the
__copy_from_user_inatomic_nocache is indeed copying from user memory,
and it is indeed ok to be used in an atomic context, so it will not warn
about it.
But the previous commit also removed the NTB mis-use of the
__copy_from_user_inatomic_nocache() function, and as a result every
call-site is now _actually_ doing a real user copy. That means that we
can now do the proper user pointer verification too.
End result: add proper address checking, remove the double underscores,
and change the "nocache" to "nontemporal" to more accurately describe
what this x86-only function actually does. It might be worth noting
that only the target is non-temporal: the actual user accesses are
normal memory accesses.
Also worth noting is that non-x86 targets (and on older 32-bit x86 CPU's
before XMM2 in the Pentium III) we end up just falling back on a regular
user copy, so nothing can actually depend on the non-temporal semantics,
but that has always been true.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
Massage __bio_iov_iter_get_pages so that it doesn't need the bio, and
move it to lib/iov_iter.c so that it can be used by block code for
other things than filling a bio and by other subsystems like netfs.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
copy_from_user_iter() lacks a speculation barrier, which will degrade
performance on some architecture like x86, which would be unfortunate as
copy_from_user_iter() is a critical hotpath function.
Convert copy_from_user_iter() to using masked user access on architecture
that support it. This allows to add the speculation barrier without
impacting performance.
This is similar to what was done for copy_from_user() in commit
0fc810ae3a ("x86/uaccess: Avoid barrier_nospec() in 64-bit
copy_from_user()")
[ tglx: Massage change log ]
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://patch.msgid.link/58e4b07d469ca68a2b9477fe2c1ccc8a44cef131.1763396724.git.christophe.leroy@csgroup.eu
If iov_offset is non-zero, then we need to consider iov_offset in length
calculation, otherwise we might pass smaller IOs such as 512 bytes, in
below scenario [1].
This issue is reproducible using lib-uring test/fixed-seg.c application
with fixed buffer on a 512 LBA formatted device.
[1]
At present we pass the alignment check, for 512 LBA formatted devices,
len_mask = 511 when IO is smaller, i->count = 512 has an offset,
i->io_offset = 3584 with bvec values, bvec->bv_offset = 256,
bvec->bv_len = 3840. In short, the first 256 bytes are in the current
page, next 256 bytes are in the another page. Ideally we expect to
fail the IO.
I can think of 2 userspace scenarios where we experience this.
a: From userspace, we observe a different behaviour when device LBA
size is 512 vs 4096 bytes. For 4096 LBA formatted device, I see the
same liburing test [2] failing, whereas 512 the test passes without
this. This is reproducible everytime.
[2] https://github.com/axboe/liburing/
b: Although I was not able to reproduce the below condition, but I
suspect below case should be possible from user space for devices
with 512 LBA formatted device. Lets say from userspace while
allocating a virtually single chunk of memory, if we get 2 physical
chunk of memory, and IO happens to be at the boundary of first
physical chunk with length crossing first chunk, then we allow IOs
to proceed and hence we might map wrong physical address length and
proceed with IO rather than failing.
: --- a/test/fixed-seg.c
: +++ b/test/fixed-seg.c
: @@ -64,7 +64,7 @@ static int test(struct io_uring *ring, int fd, int
: vec_off)
: return T_EXIT_FAIL;
: }
:
: - ret = read_it(ring, fd, 4096, vec_off);
: + ret = read_it(ring, fd, 4096, 7*512 + 256);
: if (ret) {
: fprintf(stderr, "4096 0 failed\n");
: return T_EXIT_FAIL;
Effectively this is a write crossing the page boundary.
Link: https://lkml.kernel.org/r/20250428095849.11709-1-nj.shetty@samsung.com
Fixes: 2263639f96 ("iov_iter: streamline iovec/bvec alignment iteration")
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Signed-off-by: Nitesh Shetty <nj.shetty@samsung.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Keith Busch <kbusch@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When testing EROFS file-backed mount over v9fs on qemu, I encountered a
folio UAF issue. The page sanity check reports the following call trace.
The root cause is that pages in bvec are coalesced across a folio bounary.
The refcount of all non-slab folios should be increased to ensure
p9_releas_pages can put them correctly.
BUG: Bad page state in process md5sum pfn:18300
page: refcount:0 mapcount:0 mapping:00000000d5ad8e4e index:0x60 pfn:0x18300
head: order:0 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
aops:z_erofs_aops ino:30b0f dentry name(?):"GoogleExtServicesCn.apk"
flags: 0x100000000000041(locked|head|node=0|zone=1)
raw: 0100000000000041 dead000000000100 dead000000000122 ffff888014b13bd0
raw: 0000000000000060 0000000000000020 00000000ffffffff 0000000000000000
head: 0100000000000041 dead000000000100 dead000000000122 ffff888014b13bd0
head: 0000000000000060 0000000000000020 00000000ffffffff 0000000000000000
head: 0100000000000000 0000000000000000 ffffffffffffffff 0000000000000000
head: 0000000000000010 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
Call Trace:
dump_stack_lvl+0x53/0x70
bad_page+0xd4/0x220
__free_pages_ok+0x76d/0xf30
__folio_put+0x230/0x320
p9_release_pages+0x179/0x1f0
p9_virtio_zc_request+0xa2a/0x1230
p9_client_zc_rpc.constprop.0+0x247/0x700
p9_client_read_once+0x34d/0x810
p9_client_read+0xf3/0x150
v9fs_issue_read+0x111/0x360
netfs_unbuffered_read_iter_locked+0x927/0x1390
netfs_unbuffered_read_iter+0xa2/0xe0
vfs_iocb_iter_read+0x2c7/0x460
erofs_fileio_rq_submit+0x46b/0x5b0
z_erofs_runqueue+0x1203/0x21e0
z_erofs_readahead+0x579/0x8b0
read_pages+0x19f/0xa70
page_cache_ra_order+0x4ad/0xb80
filemap_readahead.isra.0+0xe7/0x150
filemap_get_pages+0x7aa/0x1890
filemap_read+0x320/0xc80
vfs_read+0x6c6/0xa30
ksys_read+0xf9/0x1c0
do_syscall_64+0x9e/0x1a0
entry_SYSCALL_64_after_hwframe+0x71/0x79
Link: https://lkml.kernel.org/r/20250401144712.1377719-1-shengyong1@xiaomi.com
Fixes: b9c0e49abf ("mm: decline to manipulate the refcount on a slab page")
Signed-off-by: Sheng Yong <shengyong1@xiaomi.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Slab pages now have a refcount of 0, so nobody should be trying to
manipulate the refcount on them. Doing so has little effect; the object
could be freed and reallocated to a different purpose, although the slab
itself would not be until the refcount was put making it behave rather
like TYPESAFE_BY_RCU.
Unfortunately, __iov_iter_get_pages_alloc() does take a refcount. Fix
that to not change the refcount, and make put_page() silently not change
the refcount. get_page() warns so that we can fix any other callers that
need to be changed.
Long-term, networking needs to stop taking a refcount on the pages that it
uses and rely on the caller to hold whatever references are necessary to
make the memory stable. In the medium term, more page types are going to
hav a zero refcount, so we'll want to move get_page() and put_page() out
of line.
Link: https://lkml.kernel.org/r/20250310143544.1216127-1-willy@infradead.org
Fixes: 9aec2fb0fd (slab: allocate frozen pages)
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: Hannes Reinecke <hare@suse.de>
Closes: https://lore.kernel.org/all/08c29e4b-2f71-4b6d-8046-27e407214d8c@suse.com/
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull block updates from Jens Axboe:
- NVMe updates via Keith:
- Use uring_cmd helper (Pavel)
- Host Memory Buffer allocation enhancements (Christoph)
- Target persistent reservation support (Guixin)
- Persistent reservation tracing (Guixen)
- NVMe 2.1 specification support (Keith)
- Rotational Meta Support (Matias, Wang, Keith)
- Volatile cache detection enhancment (Guixen)
- MD updates via Song:
- Maintainers update
- raid5 sync IO fix
- Enhance handling of faulty and blocked devices
- raid5-ppl atomic improvement
- md-bitmap fix
- Support for manually defining embedded partition tables
- Zone append fixes and cleanups
- Stop sending the queued requests in the plug list to the driver
->queue_rqs() handle in reverse order.
- Zoned write plug cleanups
- Cleanups disk stats tracking and add support for disk stats for
passthrough IO
- Add preparatory support for file system atomic writes
- Add lockdep support for queue freezing. Already found a bunch of
issues, and some fixes for that are in here. More will be coming.
- Fix race between queue stopping/quiescing and IO queueing
- ublk recovery improvements
- Fix ublk mmap for 64k pages
- Various fixes and cleanups
* tag 'for-6.13/block-20241118' of git://git.kernel.dk/linux: (118 commits)
MAINTAINERS: Update git tree for mdraid subsystem
block: make struct rq_list available for !CONFIG_BLOCK
block/genhd: use seq_put_decimal_ull for diskstats decimal values
block: don't reorder requests in blk_mq_add_to_batch
block: don't reorder requests in blk_add_rq_to_plug
block: add a rq_list type
block: remove rq_list_move
virtio_blk: reverse request order in virtio_queue_rqs
nvme-pci: reverse request order in nvme_queue_rqs
btrfs: validate queue limits
block: export blk_validate_limits
nvmet: add tracing of reservation commands
nvme: parse reservation commands's action and rtype to string
nvmet: report ns's vwc not present
md/raid5: Increase r5conf.cache_name size
block: remove the ioprio field from struct request
block: remove the write_hint field from struct request
nvme: check ns's volatile write cache not present
nvme: add rotational support
nvme: use command set independent id ns if available
...
.bi_size of bvec iterator should be initialized as real max size for
walking, and .bi_bvec_done just counts how many bytes need to be
skipped in the 1st bvec, so .bi_size isn't related with .bi_bvec_done.
This patch fixes bvec iterator initialization, and the inner `size`
check isn't needed any more, so revert Eric Dumazet's commit
7bc802acf193 ("iov-iter: do not return more bytes than requested in
iov_iter_extract_bvec_pages()").
Cc: Eric Dumazet <edumazet@google.com>
Fixes: e4e535bff2 ("iov_iter: don't require contiguous pages in iov_iter_extract_bvec_pages")
Reported-by: syzbot+71abe7ab2b70bca770fd@syzkaller.appspotmail.com
Tested-by: syzbot+71abe7ab2b70bca770fd@syzkaller.appspotmail.com
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Initialize bi.bi_idx as 0 before iterating over bvec, otherwise
garbage data can be used as ->bi_idx.
Cc: Christoph Hellwig <hch@lst.de>
Reported-and-tested-by: Klara Modin <klarasmodin@gmail.com>
Fixes: e4e535bff2 ("iov_iter: don't require contiguous pages in iov_iter_extract_bvec_pages")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The iov_iter_extract_pages interface allows to return physically
discontiguous pages, as long as all but the first and last page
in the array are page aligned and page size. Rewrite
iov_iter_extract_bvec_pages to take advantage of that instead of only
returning ranges of physically contiguous pages.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
[hch: minor cleanups, new commit log]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20241024050021.627350-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
generic/077 on x86_32 CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP=y with highmem,
on huge=always tmpfs, issues a warning and then hangs (interruptibly):
WARNING: CPU: 5 PID: 3517 at mm/highmem.c:622 kunmap_local_indexed+0x62/0xc9
CPU: 5 UID: 0 PID: 3517 Comm: cp Not tainted 6.12.0-rc4 #2
...
copy_page_from_iter_atomic+0xa6/0x5ec
generic_perform_write+0xf6/0x1b4
shmem_file_write_iter+0x54/0x67
Fix copy_page_from_iter_atomic() by limiting it in that case
(include/linux/skbuff.h skb_frag_must_loop() does similar).
But going forward, perhaps CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP is too
surprising, has outlived its usefulness, and should just be removed?
Fixes: 908a1ad894 ("iov_iter: Handle compound highmem pages in copy_page_from_iter_atomic()")
Signed-off-by: Hugh Dickins <hughd@google.com>
Link: https://lore.kernel.org/r/dd5f0c89-186e-18e1-4f43-19a60f5a9774@google.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
p9_get_mapped_pages() uses iov_iter_get_pages_alloc2() to extract pages
from an iterator when performing a zero-copy request and under some
circumstances, this crashes with odd page errors[1], for example, I see:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xbcf0
flags: 0x2000000000000000(zone=1)
...
page dumped because: VM_BUG_ON_FOLIO(((unsigned int) folio_ref_count(folio) + 127u <= 127u))
------------[ cut here ]------------
kernel BUG at include/linux/mm.h:1444!
This is because, unlike in iov_iter_extract_folioq_pages(), the
iter_folioq_get_pages() helper function doesn't skip the current folio
when iov_offset points to the end of it, but rather extracts the next
page beyond the end of the folio and adds it to the list. Reading will
then clobber the contents of this page, leading to system corruption,
and if the page is not in use, put_page() may try to clean up the unused
page.
This can be worked around by copying the iterator before each
extraction[2] and using iov_iter_advance() on the original as the
advance function steps over the page we're at the end of.
Fix this by skipping the page extraction if we're at the end of the
folio.
This was reproduced in the ktest environment[3] by forcing 9p to use the
fscache caching mode and then reading a file through 9p.
Fixes: db0aa2e956 ("mm: Define struct folio_queue and ITER_FOLIOQ to handle a sequence of folios")
Reported-by: Antony Antony <antony@phenome.org>
Closes: https://lore.kernel.org/r/ZxFQw4OI9rrc7UYc@Antony2201.local/
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Eric Van Hensbergen <ericvh@kernel.org>
cc: Latchesar Ionkov <lucho@ionkov.net>
cc: Dominique Martinet <asmadeus@codewreck.org>
cc: Christian Schoenebeck <linux_oss@crudebyte.com>
cc: v9fs@lists.linux.dev
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/ZxFEi1Tod43pD6JC@moon.secunet.de/ [1]
Link: https://lore.kernel.org/r/2299159.1729543103@warthog.procyon.org.uk/ [2]
Link: https://github.com/koverstreet/ktest.git [3]
Tested-by: Antony Antony <antony.antony@secunet.com>
Link: https://lore.kernel.org/r/3327438.1729678025@warthog.procyon.org.uk
Signed-off-by: Christian Brauner <brauner@kernel.org>
Define a data structure, struct folio_queue, to represent a sequence of
folios and a kernel-internal I/O iterator type, ITER_FOLIOQ, to allow a
list of folio_queue structures to be used to provide a buffer to
iov_iter-taking functions, such as sendmsg and recvmsg.
The folio_queue structure looks like:
struct folio_queue {
struct folio_batch vec;
u8 orders[PAGEVEC_SIZE];
struct folio_queue *next;
struct folio_queue *prev;
unsigned long marks;
unsigned long marks2;
};
It does not use a list_head so that next and/or prev can be set to NULL at
the ends of the list, allowing iov_iter-handling routines to determine that
they *are* the ends without needing to store a head pointer in the iov_iter
struct.
A folio_batch struct is used to hold the folio pointers which allows the
batch to be passed to batch handling functions. Two mark bits are
available per slot. The intention is to use at least one of them to mark
folios that need putting, but that might not be ultimately necessary.
Accessor functions are used to access the slots to do the masking and an
additional accessor function is used to indicate the size of the array.
The order of each folio is also stored in the structure to avoid the need
for iov_iter_advance() and iov_iter_revert() to have to query each folio to
find its size.
With careful barriering, this can be used as an extending buffer with new
folios inserted and new folio_queue structs added without the need for a
lock. Further, provided we always keep at least one struct in the buffer,
we can also remove consumed folios and consumed structs from the head end
as we without the need for locks.
[Questions/thoughts]
(1) To manage this, I need a head pointer, a tail pointer, a tail slot
number (assuming insertion happens at the tail end and the next
pointers point from head to tail). Should I put these into a struct
of their own, say "folio_queue_head" or "rolling_buffer"?
I will end up with two of these in netfs_io_request eventually, one
keeping track of the pagecache I'm dealing with for buffered I/O and
the other to hold a bounce buffer when we need one.
(2) Should I make the slots {folio,off,len} or bio_vec?
(3) This is intended to replace ITER_XARRAY eventually. Using an xarray
in I/O iteration requires the taking of the RCU read lock, doing
copying under the RCU read lock, walking the xarray (which may change
under us), handling retries and dealing with special values.
The advantage of ITER_XARRAY is that when we're dealing with the
pagecache directly, we don't need any allocation - but if we're doing
encrypted comms, there's a good chance we'd be using a bounce buffer
anyway.
This will require afs, erofs, cifs, orangefs and fscache to be
converted to not use this. afs still uses it for dirs and symlinks;
some of erofs usages should be easy to change, but there's one which
won't be so easy; ceph's use via fscache can be fixed by porting ceph
to netfslib; cifs is using xarray as a bounce buffer - that can be
moved to use sheaves instead; and orangefs has a similar problem to
erofs - maybe orangefs could use netfslib?
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Matthew Wilcox <willy@infradead.org>
cc: Jeff Layton <jlayton@kernel.org>
cc: Steve French <sfrench@samba.org>
cc: Ilya Dryomov <idryomov@gmail.com>
cc: Gao Xiang <xiang@kernel.org>
cc: Mike Marshall <hubcap@omnibond.com>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
cc: linux-afs@lists.infradead.org
cc: linux-cifs@vger.kernel.org
cc: ceph-devel@vger.kernel.org
cc: linux-erofs@lists.ozlabs.org
cc: devel@lists.orangefs.org
Link: https://lore.kernel.org/r/20240814203850.2240469-13-dhowells@redhat.com/ # v2
Signed-off-by: Christian Brauner <brauner@kernel.org>
Pull misc vfs updates from Christian Brauner:
"Misc features, cleanups, and fixes for vfs and individual filesystems.
Features:
- Support idmapped mounts for hugetlbfs.
- Add RWF_NOAPPEND flag for pwritev2(). This allows us to fix a bug
where the passed offset is ignored if the file is O_APPEND. The new
flag allows a caller to enforce that the offset is honored to
conform to posix even if the file was opened in append mode.
- Move i_mmap_rwsem in struct address_space to avoid false sharing
between i_mmap and i_mmap_rwsem.
- Convert efs, qnx4, and coda to use the new mount api.
- Add a generic is_dot_dotdot() helper that's used by various
filesystems and the VFS code instead of open-coding it multiple
times.
- Recently we've added stable offsets which allows stable ordering
when iterating directories exported through NFS on e.g., tmpfs
filesystems. Originally an xarray was used for the offset map but
that caused slab fragmentation issues over time. This switches the
offset map to the maple tree which has a dense mode that handles
this scenario a lot better. Includes tests.
- Finally merge the case-insensitive improvement series Gabriel has
been working on for a long time. This cleanly propagates case
insensitive operations through ->s_d_op which in turn allows us to
remove the quite ugly generic_set_encrypted_ci_d_ops() operations.
It also improves performance by trying a case-sensitive comparison
first and then fallback to case-insensitive lookup if that fails.
This also fixes a bug where overlayfs would be able to be mounted
over a case insensitive directory which would lead to all sort of
odd behaviors.
Cleanups:
- Make file_dentry() a simple accessor now that ->d_real() is
simplified because of the backing file work we did the last two
cycles.
- Use the dedicated file_mnt_idmap helper in ntfs3.
- Use smp_load_acquire/store_release() in the i_size_read/write
helpers and thus remove the hack to handle i_size reads in the
filemap code.
- The SLAB_MEM_SPREAD is a nop now. Remove it from various places in
fs/
- It's no longer necessary to perform a second built-in initramfs
unpack call because we retain the contents of the previous
extraction. Remove it.
- Now that we have removed various allocators kfree_rcu() always
works with kmem caches and kmalloc(). So simplify various places
that only use an rcu callback in order to handle the kmem cache
case.
- Convert the pipe code to use a lockdep comparison function instead
of open-coding the nesting making lockdep validation easier.
- Move code into fs-writeback.c that was located in a header but can
be made static as it's only used in that one file.
- Rewrite the alignment checking iterators for iovec and bvec to be
easier to read, and also significantly more compact in terms of
generated code. This saves 270 bytes of text on x86-64 (with
clang-18) and 224 bytes on arm64 (with gcc-13). In profiles it also
saves a bit of time for the same workload.
- Switch various places to use KMEM_CACHE instead of
kmem_cache_create().
- Use inode_set_ctime_to_ts() in inode_set_ctime_current()
- Use kzalloc() in name_to_handle_at() to avoid kernel infoleak.
- Various smaller cleanups for eventfds.
Fixes:
- Fix various comments and typos, and unneeded initializations.
- Fix stack allocation hack for clang in the select code.
- Improve dump_mapping() debug code on a best-effort basis.
- Fix build errors in various selftests.
- Avoid wrap-around instrumentation in various places.
- Don't allow user namespaces without an idmapping to be used for
idmapped mounts.
- Fix sysv sb_read() call.
- Fix fallback implementation of the get_name() export operation"
* tag 'vfs-6.9.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (70 commits)
hugetlbfs: support idmapped mounts
qnx4: convert qnx4 to use the new mount api
fs: use inode_set_ctime_to_ts to set inode ctime to current time
libfs: Drop generic_set_encrypted_ci_d_ops
ubifs: Configure dentry operations at dentry-creation time
f2fs: Configure dentry operations at dentry-creation time
ext4: Configure dentry operations at dentry-creation time
libfs: Add helper to choose dentry operations at mount-time
libfs: Merge encrypted_ci_dentry_ops and ci_dentry_ops
fscrypt: Drop d_revalidate once the key is added
fscrypt: Drop d_revalidate for valid dentries during lookup
fscrypt: Factor out a helper to configure the lookup dentry
ovl: Always reject mounting over case-insensitive directories
libfs: Attempt exact-match comparison first during casefolded lookup
efs: remove SLAB_MEM_SPREAD flag usage
jfs: remove SLAB_MEM_SPREAD flag usage
minix: remove SLAB_MEM_SPREAD flag usage
openpromfs: remove SLAB_MEM_SPREAD flag usage
proc: remove SLAB_MEM_SPREAD flag usage
qnx6: remove SLAB_MEM_SPREAD flag usage
...
