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2026-07-03netfs: Fix barriering when walking subrequest listDavid Howells2-2/+12
Fix the barriering used when walking the subrequest list in retry as there's a possibility of seeing a subreq that's just been added by the application thread. Fixes: ee4cdf7ba857 ("netfs: Speed up buffered reading") Fixes: 288ace2f57c9 ("netfs: New writeback implementation") Link: https://sashiko.dev/#/patchset/20260608145432.681865-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/138807.1782980582@warthog.procyon.org.uk Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> cc: Paulo Alcantara <pc@manguebit.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-07-01netfs: Fix DIO write retry for filesystems without a ->prepare_write()David Howells1-11/+7
Fix netfs_unbuffered_write() so that it doesn't re-issue a write twice when the filesystem doesn't have a ->prepare_write(). The resetting of the iterator and the call to netfs_reissue_write() should just be removed as almost everything it does is done again when the loop it's in goes back to the top. It does, however, still need the IN_PROGRESS flag setting, so that (and the stat inc) are moved out of the if-statement. Further, the MADE_PROGRESS flags should be cleared and wreq->transferred should be updated, so fix those too. Reported-by: syzbot+3c74b1f0c372e98efc32@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=3c74b1f0c372e98efc32 Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260625140640.3116900-16-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: hongao <hongao@uniontech.com> cc: ChenXiaoSong <chenxiaosong@chenxiaosong.com> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-07-01netfs: Fix folio state after ENOMEM whilst under writeback iterationDavid Howells1-0/+4
Fix the state of the current folio when ENOMEM occurs during writeback iteration. The folio needs to be redirtied and unlocked before the terminal writeback_iter() is invoked. Fixes: 06fa229ceb36 ("netfs: Abstract out a rolling folio buffer implementation") Link: https://sashiko.dev/#/patchset/20260619140646.2633762-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260625140640.3116900-15-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: Matthew Wilcox <willy@infradead.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-07-01netfs: Fix writeback error handlingDavid Howells1-3/+8
Fix the error handling in writeback_iter() loop. If an error occurs, writeback_iter() needs to be called again with *error set to the error so that it can clean up iteration state. Further, the current folio needs unlocking and redirtying. Fixes: 288ace2f57c9 ("netfs: New writeback implementation") Link: https://sashiko.dev/#/patchset/20260619140646.2633762-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260625140640.3116900-14-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: Matthew Wilcox <willy@infradead.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-07-01netfs: Fix writethrough to use collection offloadDavid Howells1-0/+1
Fix writethrough write to set NETFS_RREQ_OFFLOAD_COLLECTION on the request so that collection is processed asynchronously rather than only right at the end - and also so that asynchronous O_SYNC writes get collected at all. Fixes: 288ace2f57c9 ("netfs: New writeback implementation") Closes: https://sashiko.dev/#/patchset/20260616100821.2062304-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260625140640.3116900-13-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-07-01netfs: Replace wb_lock with a bit lock for asynchronicityDavid Howells3-27/+115
The netfs_inode::wb_lock mutex is used to prevent multiple simultaneous writebacks from fighting each other (a writeback thread will write multiple discontiguous regions within the same request). The mutex, however, only serialises the issuing of subrequests; it doesn't serialise the collection of results, and, in particular, the updating of file size information and fscache populatedness data. Unfortunately, the mutex cannot be held around the entire process as it has to be unlocked in the same thread in which it is locked - and we don't want to hold up the allocator whilst we complete the writeback. Fix this by replacing the mutex with a bit flag and a list of lock waiters so that the lock can be dropped in the collector thread after collection is complete. Link: https://sashiko.dev/#/patchset/20260608145432.681865-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260625140640.3116900-12-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-07-01netfs: Fix netfs_create_write_req() to handle async cache object creationDavid Howells1-1/+1
netfs_create_write_req() will skip caching if the fscache cookie is disabled, but this is a problem because async cache object creation might not have got far enough yet that has been enabled - thereby causing the call to fscache_begin_write_operation() to be skipped. Fix this by removing the checks on the cookie and delegating this to fscache_begin_write_operation(). Fixes: 7b589a9b45ae ("netfs: Fix handling of USE_PGPRIV2 and WRITE_TO_CACHE flags") Closes: https://sashiko.dev/#/patchset/20260624115737.2964520-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260625140640.3116900-3-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-07-01netfs: Fix decision whether to disallow write-streaming due to fscache useDavid Howells3-2/+14
netfs_perform_write() buffers data by writing it into the pagecache for later writeback. If the folio it wants to write to isn't present, it uses "write streaming" in which is will store partial data in a non-uptodate, but dirty folio. However, when fscache is in use, this is a potential problem as writes to the cache have to be aligned to the cache backend's DIO granularity, and so netfs_perform_write() attempts to suppress write-streaming in such a case, requiring the folio content to be fetched first unless the entire folio is going to be overwritten. This allows the content to be written to the cache too. Unfortunately, the test netfs_perform_write() uses isn't correct because it doesn't take into account the fact that the object lookup is asynchronous and farmed off to a work queue, so there's a short window in which the cache is doing a lookup but the test fails because the answer is undefined. This can be triggered by the generic/464 xfstest, and causes a warning to be emitted in cachefiles (in code not yet upstream) because it sees a write that doesn't have its bounds rounded out to DIO alignment. Fix this by changing the condition to whether FSCACHE_COOKIE_IS_CACHING is set on a cookie rather than whether the cookie is marked enabled. Note that this is really just a hint as to whether we allow write streaming or not and no other aspects of the cookie or cache object are accessed. Also apply the same fix to netfs_write_begin(). Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260625140640.3116900-2-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-05-12netfs, afs: Fix write skipping in dir/link writepagesDavid Howells1-1/+6
Fix netfs_write_single() and afs_single_writepages() to better handle a write that would be skipped due to lock contention and WB_SYNC_NONE by returning 1 from netfs_write_single() if it skipped and making afs_single_writepages() skip also. If a skip occurs, the inode must be re-marked as the VFS may have cleared the mark. This is really only theoretical for directories in netfs_write_single() as the only path to that is through afs_single_writepages() that takes the ->validate_lock around it, thereby serialising it. Fixes: 6dd80936618c ("afs: Use netfslib for directories") Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-24-dhowells@redhat.com cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: Fix netfs_read_folio() to wait on writebackDavid Howells1-0/+2
Fix netfs_read_folio() to wait for an ongoing writeback to complete so that it can trust the dirty flag and whatever is attached to folio->private (folio->private may get cleaned up by the collector before it clears the writeback flag). Fixes: ee4cdf7ba857 ("netfs: Speed up buffered reading") Closes: https://sashiko.dev/#/patchset/20260414082004.3756080-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-23-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: Matthew Wilcox <willy@infradead.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: Fix folio->private handling in netfs_perform_write()David Howells1-53/+81
Under some circumstances, netfs_perform_write() doesn't correctly manipulate folio->private between NULL, NETFS_FOLIO_COPY_TO_CACHE, pointing to a group and pointing to a netfs_folio struct, leading to potential multiple attachments of private data with associated folio ref leaks and also leaks of netfs_folio structs or netfs_group refs. Fix this by consolidating the place at which a folio is marked uptodate in one place and having that look at what's attached to folio->private and decide how to clean it up and then set the new group. Also, the content shouldn't be flushed if group is NULL, even if a group is specified in the netfs_group parameter, as that would be the case for a new folio. A filesystem should always specify netfs_group or never specify netfs_group. The Sashiko auto-review tool noted that it was theoretically possible that the fpos >= ctx->zero_point section might leak if it modified a streaming write folio. This is unlikely, but with a network filesystem, third party changes can happen. It also pointed out that __netfs_set_group() would leak if called multiple times on the same folio from the "whole folio modify section". Fixes: 8f52de0077ba ("netfs: Reduce number of conditional branches in netfs_perform_write()") Closes: https://sashiko.dev/#/patchset/20260414082004.3756080-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-22-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: Matthew Wilcox <willy@infradead.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: Fix partial invalidation of streaming-write folioDavid Howells1-1/+1
In netfs_invalidate_folio(), if the region of a partial invalidation overlaps the front (but not all) of a dirty write cached in a streaming write page (dirty, but not uptodate, with the dirty region tracked by a netfs_folio struct), the function modifies the dirty region - but incorrectly as it moves the region forward by setting the start to the start, not the end, of the invalidation region. Fix this by setting finfo->dirty_offset to the end of the invalidation region (iend). Fixes: cce6bfa6ca0e ("netfs: Fix trimming of streaming-write folios in netfs_inval_folio()") Closes: https://sashiko.dev/#/patchset/20260414082004.3756080-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-21-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: Matthew Wilcox <willy@infradead.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: Fix potential UAF in netfs_unlock_abandoned_read_pages()David Howells3-4/+4
netfs_unlock_abandoned_read_pages(rreq) accesses the index of the folios it is wanting to unlock and compares that to rreq->no_unlock_folio so that it doesn't unlock a folio being read for netfs_perform_write() or netfs_write_begin(). However, given that netfs_unlock_abandoned_read_pages() is called _after_ NETFS_RREQ_IN_PROGRESS is cleared, the one folio that it's not allowed to dereference is the one specified by ->no_unlock_folio as ownership immediately reverts to the caller. Fix this by storing the folio pointer instead and using that rather than the index. Also fix netfs_unlock_read_folio() where the same applies. Fixes: ee4cdf7ba857 ("netfs: Speed up buffered reading") Closes: https://sashiko.dev/#/patchset/20260414082004.3756080-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-20-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com> cc: Matthew Wilcox <willy@infradead.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: Fix leak of request in netfs_write_begin() error handlingDavid Howells1-1/+1
Fix netfs_write_begin() to not leak our ref on the request in the event that we get an error from netfs_wait_for_read(). Fixes: 4090b31422a6 ("netfs: Add a function to consolidate beginning a read") Closes: https://sashiko.dev/#/patchset/20260414082004.3756080-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-19-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: Matthew Wilcox <willy@infradead.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: Fix early put of sink folio in netfs_read_gaps()David Howells1-3/+3
Fix netfs_read_gaps() to release the sink page it uses after waiting for the request to complete. The way the sink page is used is that an ITER_BVEC-class iterator is created that has the gaps from the target folio at either end, but has the sink page tiled over the middle so that a single read op can fill in both gaps. The bug was found by KASAN detecting a UAF on the generic/075 xfstest in the cifsd kernel thread that handles reception of data from the TCP socket: BUG: KASAN: use-after-free in _copy_to_iter+0x48a/0xa20 Write of size 885 at addr ffff888107f92000 by task cifsd/1285 CPU: 2 UID: 0 PID: 1285 Comm: cifsd Not tainted 7.0.0 #6 PREEMPT(lazy) Call Trace: dump_stack_lvl+0x5d/0x80 print_report+0x17f/0x4f1 kasan_report+0x100/0x1e0 kasan_check_range+0x10f/0x1e0 __asan_memcpy+0x3c/0x60 _copy_to_iter+0x48a/0xa20 __skb_datagram_iter+0x2c9/0x430 skb_copy_datagram_iter+0x6e/0x160 tcp_recvmsg_locked+0xce0/0x1130 tcp_recvmsg+0xeb/0x300 inet_recvmsg+0xcf/0x3a0 sock_recvmsg+0xea/0x100 cifs_readv_from_socket+0x3a6/0x4d0 [cifs] cifs_read_iter_from_socket+0xdd/0x130 [cifs] cifs_readv_receive+0xaad/0xb10 [cifs] cifs_demultiplex_thread+0x1148/0x1740 [cifs] kthread+0x1cf/0x210 Fixes: ee4cdf7ba857 ("netfs: Speed up buffered reading") Reported-by: Steve French <sfrench@samba.org> Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-18-dhowells@redhat.com Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> cc: Paulo Alcantara <pc@manguebit.org> cc: Matthew Wilcox <willy@infradead.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: Fix write streaming disablement if fd open O_RDWRDavid Howells1-10/+7
In netfs_perform_write(), "write streaming" (the caching of dirty data in dirty but !uptodate folios) is performed to avoid the need to read data that is just going to get immediately overwritten. However, this is/will be disabled in three circumstances: if the fd is open O_RDWR, if fscache is in use (as we need to round out the blocks for DIO) or if content encryption is enabled (again for rounding out purposes). The idea behind disabling it if the fd is open O_RDWR is that we'd need to flush the write-streaming page before we could read the data, particularly through mmap. But netfs now fills in the gaps if ->read_folio() is called on the page, so that is unnecessary. Further, this doesn't actually work if a separate fd is open for reading. Fix this by removing the check for O_RDWR, thereby allowing streaming writes even when we might read. This caused a number of problems with the generic/522 xfstest, but those are now fixed. Fixes: c38f4e96e605 ("netfs: Provide func to copy data to pagecache for buffered write") Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-17-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: Matthew Wilcox <willy@infradead.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: Fix read-gaps to remove netfs_folio from filled folioDavid Howells1-3/+8
Fix netfs_read_gaps() to remove the netfs_folio record from the folio record before marking the folio uptodate if it successfully fills the gaps around the dirty data in a streaming write folio (dirty, but not uptodate). Found with: fsx -q -N 1000000 -p 10000 -o 128000 -l 600000 \ /xfstest.test/junk --replay-ops=junk.fsxops using the following as junk.fsxops: truncate 0x0 0x138b1 0x8b15d * write 0x507ee 0x10df7 0x927c0 write 0x19993 0x10e04 0x927c0 * mapwrite 0x66214 0x1a253 0x927c0 copy_range 0xb704 0x89b9 0x24429 0x79380 write 0x2402b 0x144a2 0x90660 * mapwrite 0x204d5 0x140a0 0x927c0 * copy_range 0x1f72c 0x137d0 0x7a906 0x927c0 * read 0 0x9157c 0x9157c on cifs with the default cache option. It shows folio 0x24 misbehaving if the FMODE_READ check is commented out in netfs_perform_write(): if (//(file->f_mode & FMODE_READ) || netfs_is_cache_enabled(ctx)) { and no fscache. This was initially found with the generic/522 xfstest. Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-16-dhowells@redhat.com Fixes: ee4cdf7ba857 ("netfs: Speed up buffered reading") cc: Paulo Alcantara <pc@manguebit.org> cc: Matthew Wilcox <willy@infradead.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: Fix potential deadlock in write-through modeDavid Howells1-14/+25
Fix netfs_advance_writethrough() to always unlock the supplied folio and to mark it dirty if it isn't yet written to the end. Unfortunately, it can't be marked for writeback until the folio is done with as that may cause a deadlock against mmapped reads and writes. Even though it has been marked dirty, premature writeback can't occur as the caller is holding both inode->i_rwsem (which will prevent concurrent truncation, fallocation, DIO and other writes) and ictx->wb_lock (which will cause flushing to wait and writeback to skip or wait). Note that this may be easier to deal with once the queuing of folios is split from the generation of subrequests. Fixes: 288ace2f57c9 ("netfs: New writeback implementation") Closes: https://sashiko.dev/#/patchset/20260427154639.180684-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-15-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: Fix streaming write being overwrittenDavid Howells1-13/+34
In order to avoid reading whilst writing, netfslib will allow "streaming writes" in which dirty data is stored directly into folios without reading them first. Such folios are marked dirty but may not be marked uptodate. If a folio is entirely written by a streaming write, uptodate will be set, otherwise it will have a netfs_folio struct attached to ->private recording the dirty region. In the event that a partially written streaming write page is to be overwritten entirely by a single write(), netfs_perform_write() will try to copy over it, but doesn't discard the netfs_folio if it succeeds; further, it doesn't correctly handle a partial copy that overwrites some of the dirty data. Fix this by the following: (1) If the folio is successfully overwritten, free the netfs_folio struct before marking the page uptodate. (2) If the copy to the folio partially fails, but short of the dirty data, just ignore the copy. (3) If the copy partially fails and overwrites some of the dirty data, accept the copy, update the netfs_folio struct to record the new data. If the folio is now filled, free the netfs_folio and set uptodate, otherwise return a partial write. Found with: fsx -q -N 1000000 -p 10000 -o 128000 -l 600000 \ /xfstest.test/junk --replay-ops=junk.fsxops using the following as junk.fsxops: truncate 0x0 0 0x927c0 write 0x63fb8 0x53c8 0 copy_range 0xb704 0x19b9 0x24429 0x79380 write 0x2402b 0x144a2 0x90660 * write 0x204d5 0x140a0 0x927c0 * copy_range 0x1f72c 0x137d0 0x7a906 0x927c0 * read 0x00000 0x20000 0x9157c read 0x20000 0x20000 0x9157c read 0x40000 0x20000 0x9157c read 0x60000 0x20000 0x9157c read 0x7e1a0 0xcfb9 0x9157c on cifs with the default cache option. It shows folio 0x24 misbehaving if the FMODE_READ check is commented out in netfs_perform_write(): if (//(file->f_mode & FMODE_READ) || netfs_is_cache_enabled(ctx)) { and no fscache. This was initially found with the generic/522 xfstest. Fixes: 8f52de0077ba ("netfs: Reduce number of conditional branches in netfs_perform_write()") Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-14-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: Matthew Wilcox <willy@infradead.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: Defer the emission of trace_netfs_folio()David Howells1-8/+10
Change netfs_perform_write() to keep the netfs_folio trace value in a variable and emit it later to make it easier to choose the value displayed. This is a prerequisite for a subsequent patch. Closes: https://sashiko.dev/#/patchset/20260414082004.3756080-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-13-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: Matthew Wilcox <willy@infradead.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: Fix netfs_invalidate_folio() to clear dirty bit if all changes goneDavid Howells1-1/+5
If a streaming write is made, this will leave the relevant modified folio in a not-uptodate, but dirty state with a netfs_folio struct hung off of folio->private indicating the dirty range. Subsequently truncating the file such that the dirty data in the folio is removed, but the first part of the folio theoretically remains will cause the netfs_folio struct to be discarded... but will leave the dirty flag set. If the folio is then read via mmap(), netfs_read_folio() will see that the page is dirty and jump to netfs_read_gaps() to fill in the missing bits. netfs_read_gaps(), however, expects there to be a netfs_folio struct present and can oops because truncate removed it. Fix this by calling folio_cancel_dirty() in netfs_invalidate_folio() in the event that all the dirty data in the folio is erased (as nfs does). Also add some tracepoints to log modifications to a dirty page. This can be reproduced with something like: dd if=/dev/zero of=/xfstest.test/foo bs=1M count=1 umount /xfstest.test mount /xfstest.test xfs_io -c "w 0xbbbf 0xf96c" \ -c "truncate 0xbbbf" \ -c "mmap -r 0xb000 0x11000" \ -c "mr 0xb000 0x11000" \ /xfstest.test/foo with fscaching disabled (otherwise streaming writes are suppressed) and a change to netfs_perform_write() to disallow streaming writes if the fd is open O_RDWR: if (//(file->f_mode & FMODE_READ) || <--- comment this out netfs_is_cache_enabled(ctx)) { It should be reproducible even without this change, but if prevents the above trivial xfs_io command from reproducing it. Note that the initial dd is important: the file must start out sufficiently large that the zero-point logic doesn't just clear the gaps because it knows there's nothing in the file to read yet. Unmounting and mounting is needed to clear the pagecache (there are other ways to do that that may also work). This was initially reproduced with the generic/522 xfstest on some patches that remove the FMODE_READ restriction. Fixes: 9ebff83e6481 ("netfs: Prep to use folio->private for write grouping and streaming write") Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-12-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: Matthew Wilcox <willy@infradead.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: Fix overrun check in netfs_extract_user_iter()David Howells1-9/+17
Fix netfs_extract_user_iter() so that if iov_iter_extract_pages() overfills pages[], then those pages don't get included in the iterator constructed at the end of the function. If there was an overfill, memory corruption has already happened. Fixes: 85dd2c8ff368 ("netfs: Add a function to extract a UBUF or IOVEC into a BVEC iterator") Closes: https://sashiko.dev/#/patchset/20260427154639.180684-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-11-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: fix error handling in netfs_extract_user_iter()Paulo Alcantara1-3/+10
In netfs_extract_user_iter(), if iov_iter_extract_pages() failed to extract user pages, bail out on -ENOMEM, otherwise return the error code only if @npages == 0, allowing short DIO reads and writes to be issued. This fixes mmapstress02 from LTP tests against CIFS. Fixes: 85dd2c8ff368 ("netfs: Add a function to extract a UBUF or IOVEC into a BVEC iterator") Reported-by: Xiaoli Feng <xifeng@redhat.com> Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-10-dhowells@redhat.com Cc: netfs@lists.linux.dev Cc: stable@vger.kernel.org Cc: linux-cifs@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: Fix potential uninitialised var in netfs_extract_user_iter()David Howells1-1/+1
In netfs_extract_user_iter(), if it's given a zero-length iterator, it will fall through the loop without setting ret, and so the error handling behaviour will be undefined, depending on whether ret happens to be negative. The value of ret then propagates back up the callstack. Fix this by presetting ret to 0. Fixes: 85dd2c8ff368 ("netfs: Add a function to extract a UBUF or IOVEC into a BVEC iterator") Closes: https://sashiko.dev/#/patchset/20260414082004.3756080-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-9-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: Matthew Wilcox <willy@infradead.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: fix VM_BUG_ON_FOLIO() issue in netfs_write_begin() callViacheslav Dubeyko1-2/+9
The multiple runs of generic/013 test-case is capable to reproduce a kernel BUG at mm/filemap.c:1504 with probability of 30%. while true; do sudo ./check generic/013 done [ 9849.452376] page: refcount:3 mapcount:0 mapping:00000000e58ff252 index:0x10781 pfn:0x1c322 [ 9849.452412] memcg:ffff8881a1915800 [ 9849.452417] aops:ceph_aops ino:1000058db9e dentry name(?):"f9XXXXXX" [ 9849.452432] flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff) [ 9849.452441] raw: 0017ffffc0000000 0000000000000000 dead000000000122 ffff88816110d248 [ 9849.452445] raw: 0000000000010781 0000000000000000 00000003ffffffff ffff8881a1915800 [ 9849.452447] page dumped because: VM_BUG_ON_FOLIO(!folio_test_locked(folio)) [ 9849.452474] ------------[ cut here ]------------ [ 9849.452476] kernel BUG at mm/filemap.c:1504! [ 9849.478635] Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI [ 9849.481772] CPU: 2 UID: 0 PID: 84223 Comm: fsstress Not tainted 7.0.0-rc1+ #18 PREEMPT(full) [ 9849.482881] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-9.fc43 06/1 0/2025 [ 9849.484539] RIP: 0010:folio_unlock+0x85/0xa0 [ 9849.485076] Code: 89 df 31 f6 e8 1c f3 ff ff 48 8b 5d f8 c9 31 c0 31 d2 31 f6 31 ff c3 cc cc cc cc 48 c7 c6 80 6c d9 a7 48 89 df e8 4b b3 10 00 <0f> 0b 48 89 df e8 21 e6 2c 00 eb 9d 0f 1f 40 00 66 66 2e 0f 1f 84 [ 9849.493818] RSP: 0018:ffff8881bb8076b0 EFLAGS: 00010246 [ 9849.495740] RAX: 0000000000000000 RBX: ffffea00070c8980 RCX: 0000000000000000 [ 9849.498678] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 9849.500559] RBP: ffff8881bb8076b8 R08: 0000000000000000 R09: 0000000000000000 [ 9849.501097] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000010782000 [ 9849.502108] R13: ffff8881935de738 R14: ffff88816110d010 R15: 0000000000001000 [ 9849.502516] FS: 00007e36cbe94740(0000) GS:ffff88824a899000(0000) knlGS:0000000000000000 [ 9849.502996] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 9849.503810] CR2: 000000c0002b0000 CR3: 000000011bbf6004 CR4: 0000000000772ef0 [ 9849.504459] PKRU: 55555554 [ 9849.504626] Call Trace: [ 9849.505242] <TASK> [ 9849.505379] netfs_write_begin+0x7c8/0x10a0 [ 9849.505877] ? __kasan_check_read+0x11/0x20 [ 9849.506384] ? __pfx_netfs_write_begin+0x10/0x10 [ 9849.507178] ceph_write_begin+0x8c/0x1c0 [ 9849.507934] generic_perform_write+0x391/0x8f0 [ 9849.508503] ? __pfx_generic_perform_write+0x10/0x10 [ 9849.509062] ? file_update_time_flags+0x19a/0x4b0 [ 9849.509581] ? ceph_get_caps+0x63/0xf0 [ 9849.510259] ? ceph_get_caps+0x63/0xf0 [ 9849.510530] ceph_write_iter+0xe79/0x1ae0 [ 9849.511282] ? __pfx_ceph_write_iter+0x10/0x10 [ 9849.511839] ? lock_acquire+0x1ad/0x310 [ 9849.512334] ? ksys_write+0xf9/0x230 [ 9849.512582] ? lock_is_held_type+0xaa/0x140 [ 9849.513128] vfs_write+0x512/0x1110 [ 9849.513634] ? __fget_files+0x33/0x350 [ 9849.513893] ? __pfx_vfs_write+0x10/0x10 [ 9849.514143] ? mutex_lock_nested+0x1b/0x30 [ 9849.514394] ksys_write+0xf9/0x230 [ 9849.514621] ? __pfx_ksys_write+0x10/0x10 [ 9849.514887] ? do_syscall_64+0x25e/0x1520 [ 9849.515122] ? __kasan_check_read+0x11/0x20 [ 9849.515366] ? trace_hardirqs_on_prepare+0x178/0x1c0 [ 9849.515655] __x64_sys_write+0x72/0xd0 [ 9849.515885] ? trace_hardirqs_on+0x24/0x1c0 [ 9849.516130] x64_sys_call+0x22f/0x2390 [ 9849.516341] do_syscall_64+0x12b/0x1520 [ 9849.516545] ? do_syscall_64+0x27c/0x1520 [ 9849.516783] ? do_syscall_64+0x27c/0x1520 [ 9849.517003] ? lock_release+0x318/0x480 [ 9849.517220] ? __x64_sys_io_getevents+0x143/0x2d0 [ 9849.517479] ? percpu_ref_put_many.constprop.0+0x8f/0x210 [ 9849.517779] ? entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 9849.518073] ? do_syscall_64+0x25e/0x1520 [ 9849.518291] ? __kasan_check_read+0x11/0x20 [ 9849.518519] ? trace_hardirqs_on_prepare+0x178/0x1c0 [ 9849.518799] ? do_syscall_64+0x27c/0x1520 [ 9849.519024] ? local_clock_noinstr+0xf/0x120 [ 9849.519262] ? entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 9849.519544] ? do_syscall_64+0x25e/0x1520 [ 9849.519781] ? __kasan_check_read+0x11/0x20 [ 9849.520008] ? trace_hardirqs_on_prepare+0x178/0x1c0 [ 9849.520273] ? do_syscall_64+0x27c/0x1520 [ 9849.520491] ? trace_hardirqs_on_prepare+0x178/0x1c0 [ 9849.520767] ? irqentry_exit+0x10c/0x6c0 [ 9849.520984] ? trace_hardirqs_off+0x86/0x1b0 [ 9849.521224] ? exc_page_fault+0xab/0x130 [ 9849.521472] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 9849.521766] RIP: 0033:0x7e36cbd14907 [ 9849.521989] Code: 10 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24 [ 9849.523057] RSP: 002b:00007ffff2d2a968 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 9849.523484] RAX: ffffffffffffffda RBX: 000000000000e549 RCX: 00007e36cbd14907 [ 9849.523885] RDX: 000000000000e549 RSI: 00005bd797ec6370 RDI: 0000000000000004 [ 9849.524277] RBP: 0000000000000004 R08: 0000000000000047 R09: 00005bd797ec6370 [ 9849.524652] R10: 0000000000000078 R11: 0000000000000246 R12: 0000000000000049 [ 9849.525062] R13: 0000000010781a37 R14: 00005bd797ec6370 R15: 0000000000000000 [ 9849.525447] </TASK> [ 9849.525574] Modules linked in: intel_rapl_msr intel_rapl_common intel_uncore_frequency_common intel_pmc_core pmt_telemetry pmt_discovery pmt_class intel_pmc_ssram_telemetry intel_vsec kvm_intel joydev kvm irqbypass ghash_clmulni_intel aesni_intel input_leds rapl mac_hid psmouse vga16fb serio_raw vgastate floppy i2c_piix4 bochs qemu_fw_cfg i2c_smbus pata_acpi sch_fq_codel rbd msr parport_pc ppdev lp parport efi_pstore [ 9849.529150] ---[ end trace 0000000000000000 ]--- [ 9849.529502] RIP: 0010:folio_unlock+0x85/0xa0 [ 9849.530813] Code: 89 df 31 f6 e8 1c f3 ff ff 48 8b 5d f8 c9 31 c0 31 d2 31 f6 31 ff c3 cc cc cc cc 48 c7 c6 80 6c d9 a7 48 89 df e8 4b b3 10 00 <0f> 0b 48 89 df e8 21 e6 2c 00 eb 9d 0f 1f 40 00 66 66 2e 0f 1f 84 [ 9849.534986] RSP: 0018:ffff8881bb8076b0 EFLAGS: 00010246 [ 9849.536198] RAX: 0000000000000000 RBX: ffffea00070c8980 RCX: 0000000000000000 [ 9849.537718] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 9849.539321] RBP: ffff8881bb8076b8 R08: 0000000000000000 R09: 0000000000000000 [ 9849.540862] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000010782000 [ 9849.542438] R13: ffff8881935de738 R14: ffff88816110d010 R15: 0000000000001000 [ 9849.543996] FS: 00007e36cbe94740(0000) GS:ffff88824b899000(0000) knlGS:0000000000000000 [ 9849.545854] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 9849.547092] CR2: 00007e36cb3ff000 CR3: 000000011bbf6006 CR4: 0000000000772ef0 [ 9849.548679] PKRU: 55555554 The race sequence: 1. Read completes -> netfs_read_collection() runs 2. netfs_wake_rreq_flag(rreq, NETFS_RREQ_IN_PROGRESS, ...) 3. netfs_wait_for_read() returns -EFAULT to netfs_write_begin() 4. The netfs_unlock_abandoned_read_pages() unlocks the folio 5. netfs_write_begin() calls folio_unlock(folio) -> VM_BUG_ON_FOLIO() The key reason of the issue that netfs_unlock_abandoned_read_pages() doesn't check the flag NETFS_RREQ_NO_UNLOCK_FOLIO and executes folio_unlock() unconditionally. This patch implements in netfs_unlock_abandoned_read_pages() logic similar to netfs_unlock_read_folio(). Fixes: ee4cdf7ba857 ("netfs: Speed up buffered reading") Signed-off-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com> Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-8-dhowells@redhat.com Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org cc: Ceph Development <ceph-devel@vger.kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: Fix zeropoint update where i_size > remote_i_sizeDavid Howells1-2/+2
Fix the update of the zero point[*] by netfs_release_folio() when there is uncommitted data in the pagecache beyond the folio being released but the on-server EOF is in this folio (ie. i_size > remote_i_size). The update needs to limit zero_point to remote_i_size, not i_size as i_size is a local phenomenon reflecting updates made locally to the pagecache, not stuff written to the server. remote_i_size tracks the server's i_size. [*] The zero point is the file position from which we can assume that the server will just return zeros, so we can avoid generating reads. Note that netfs_invalidate_folio() probably doesn't need fixing as zero_point should be updated by setattr after truncation or fallocate. Found with: fsx -q -N 1000000 -p 10000 -o 128000 -l 600000 \ /xfstest.test/junk --replay-ops=junk.fsxops using the following as junk.fsxops: truncate 0x0 0x1bbae 0x82864 write 0x3ef2e 0xf9c8 0x1bbae write 0x67e05 0xcb5a 0x4e8f6 mapread 0x57781 0x85b6 0x7495f copy_range 0x5d3d 0x10329 0x54fac 0x7495f write 0x64710 0x1c2b 0x7495f mapread 0x64000 0x1000 0x7495f on cifs with the default cache option. It shows read-gaps on folio 0x64 failing with a short read (ie. it hits EOF) if the FMODE_READ check is commented out in netfs_perform_write(): if (//(file->f_mode & FMODE_READ) || netfs_is_cache_enabled(ctx)) { and no fscache. This was initially found with the generic/522 xfstest. Fixes: cce6bfa6ca0e ("netfs: Fix trimming of streaming-write folios in netfs_inval_folio()") Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-7-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: Matthew Wilcox <willy@infradead.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: Fix potential for tearing in ->remote_i_size and ->zero_pointDavid Howells5-18/+37
Fix potential tearing in using ->remote_i_size and ->zero_point by copying i_size_read() and i_size_write() and using the same seqcount as for i_size. We need to make sure that netfslib and the filesystems that use it always hold i_lock whilst updating any of the sizes to prevent i_size_seqcount from getting corrupted. Fixes: 4058f742105e ("netfs: Keep track of the actual remote file size") Fixes: 100ccd18bb41 ("netfs: Optimise away reads above the point at which there can be no data") Closes: https://sashiko.dev/#/patchset/20260414082004.3756080-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-6-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: Matthew Wilcox <willy@infradead.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: Fix netfs_read_to_pagecache() to pause on subreq failureDavid Howells1-0/+5
Fix netfs_read_to_pagecache() so that it pauses the generation of new subrequests if an already-issued subrequest fails. Fixes: ee4cdf7ba857 ("netfs: Speed up buffered reading") Closes: https://sashiko.dev/#/patchset/20260425125426.3855807-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-5-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: Fix missing barriers when accessing stream->subrequests locklesslyDavid Howells5-6/+13
The list of subrequests attached to stream->subrequests is accessed without locks by netfs_collect_read_results() and netfs_collect_write_results(), and then they access subreq->flags without taking a barrier after getting the subreq pointer from the list. Relatedly, the functions that build the list don't use any sort of write barrier when constructing the list to make sure that the NETFS_SREQ_IN_PROGRESS flag is perceived to be set first if no lock is taken. Fix this by: (1) Add a new list_add_tail_release() function that uses a release barrier to set the pointer to the new member of the list. (2) Add a new list_first_entry_or_null_acquire() function that uses an acquire barrier to read the pointer to the first member in a list (or return NULL). (3) Use list_add_tail_release() when adding a subreq to ->subrequests. (4) Use list_first_entry_or_null_acquire() when initially accessing the front of the list (when an item is removed, the pointer to the new front iterm is obtained under the same lock). Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item") Fixes: 288ace2f57c9 ("netfs: New writeback implementation") Link: https://sashiko.dev/#/patchset/20260326104544.509518-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-4-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: Fix missing locking around retry adding new subreqsDavid Howells2-2/+10
Fix netfs_retry_read_subrequests() and netfs_retry_write_stream() to take the appropriate lock when adding extra subrequests into stream->subrequests. Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item") Fixes: 288ace2f57c9 ("netfs: New writeback implementation") Closes: https://sashiko.dev/#/patchset/20260425125426.3855807-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-3-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-12netfs: Fix cancellation of a DIO and single read subrequestsDavid Howells5-63/+50
When the preparation of a new subrequest for a read fails, if the subrequest has already been added to the stream->subrequests list, it can't simply be put and abandoned as the collector may see it. Also, if it hasn't been queued yet, it has two outstanding refs that both need to be put. Both DIO read and single-read dispatch fail at this; further, both differ in the order they do things to the way buffered read works. Fix cancellation of both DIO-read and single-read subrequests that failed preparation by the following steps: (1) Harmonise all three reads (buffered, dio, single) to queue the subreq before prepping it. (2) Make all three call netfs_queue_read() to do the queuing. (3) Set NETFS_RREQ_ALL_QUEUED independently of the queuing as we don't know the length of the subreq at this point. (4) In all cases, set the error and NETFS_SREQ_FAILED flag on the subreq and then call netfs_read_subreq_terminated() to deal with it. This will pass responsibility off to the collector for dealing with it. Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item") Closes: https://sashiko.dev/#/patchset/20260425125426.3855807-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260512123404.719402-2-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-04-15Merge tag 'mm-stable-2026-04-13-21-45' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - "maple_tree: Replace big node with maple copy" (Liam Howlett) Mainly prepararatory work for ongoing development but it does reduce stack usage and is an improvement. - "mm, swap: swap table phase III: remove swap_map" (Kairui Song) Offers memory savings by removing the static swap_map. It also yields some CPU savings and implements several cleanups. - "mm: memfd_luo: preserve file seals" (Pratyush Yadav) File seal preservation to LUO's memfd code - "mm: zswap: add per-memcg stat for incompressible pages" (Jiayuan Chen) Additional userspace stats reportng to zswap - "arch, mm: consolidate empty_zero_page" (Mike Rapoport) Some cleanups for our handling of ZERO_PAGE() and zero_pfn - "mm/kmemleak: Improve scan_should_stop() implementation" (Zhongqiu Han) A robustness improvement and some cleanups in the kmemleak code - "Improve khugepaged scan logic" (Vernon Yang) Improve khugepaged scan logic and reduce CPU consumption by prioritizing scanning tasks that access memory frequently - "Make KHO Stateless" (Jason Miu) Simplify Kexec Handover by transitioning KHO from an xarray-based metadata tracking system with serialization to a radix tree data structure that can be passed directly to the next kernel - "mm: vmscan: add PID and cgroup ID to vmscan tracepoints" (Thomas Ballasi and Steven Rostedt) Enhance vmscan's tracepointing - "mm: arch/shstk: Common shadow stack mapping helper and VM_NOHUGEPAGE" (Catalin Marinas) Cleanup for the shadow stack code: remove per-arch code in favour of a generic implementation - "Fix KASAN support for KHO restored vmalloc regions" (Pasha Tatashin) Fix a WARN() which can be emitted the KHO restores a vmalloc area - "mm: Remove stray references to pagevec" (Tal Zussman) Several cleanups, mainly udpating references to "struct pagevec", which became folio_batch three years ago - "mm: Eliminate fake head pages from vmemmap optimization" (Kiryl Shutsemau) Simplify the HugeTLB vmemmap optimization (HVO) by changing how tail pages encode their relationship to the head page - "mm/damon/core: improve DAMOS quota efficiency for core layer filters" (SeongJae Park) Improve two problematic behaviors of DAMOS that makes it less efficient when core layer filters are used - "mm/damon: strictly respect min_nr_regions" (SeongJae Park) Improve DAMON usability by extending the treatment of the min_nr_regions user-settable parameter - "mm/page_alloc: pcp locking cleanup" (Vlastimil Babka) The proper fix for a previously hotfixed SMP=n issue. Code simplifications and cleanups ensued - "mm: cleanups around unmapping / zapping" (David Hildenbrand) A bunch of cleanups around unmapping and zapping. Mostly simplifications, code movements, documentation and renaming of zapping functions - "support batched checking of the young flag for MGLRU" (Baolin Wang) Batched checking of the young flag for MGLRU. It's part cleanups; one benchmark shows large performance benefits for arm64 - "memcg: obj stock and slab stat caching cleanups" (Johannes Weiner) memcg cleanup and robustness improvements - "Allow order zero pages in page reporting" (Yuvraj Sakshith) Enhance free page reporting - it is presently and undesirably order-0 pages when reporting free memory. - "mm: vma flag tweaks" (Lorenzo Stoakes) Cleanup work following from the recent conversion of the VMA flags to a bitmap - "mm/damon: add optional debugging-purpose sanity checks" (SeongJae Park) Add some more developer-facing debug checks into DAMON core - "mm/damon: test and document power-of-2 min_region_sz requirement" (SeongJae Park) An additional DAMON kunit test and makes some adjustments to the addr_unit parameter handling - "mm/damon/core: make passed_sample_intervals comparisons overflow-safe" (SeongJae Park) Fix a hard-to-hit time overflow issue in DAMON core - "mm/damon: improve/fixup/update ratio calculation, test and documentation" (SeongJae Park) A batch of misc/minor improvements and fixups for DAMON - "mm: move vma_(kernel|mmu)_pagesize() out of hugetlb.c" (David Hildenbrand) F