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2024-12-20afs: Use netfslib for directoriesDavid Howells
In the AFS ecosystem, directories are just a special type of file that is downloaded and parsed locally. Download is done by the same mechanism as ordinary files and the data can be cached. There is one important semantic restriction on directories over files: the client must download the entire directory in one go because, for example, the server could fabricate the contents of the blob on the fly with each download and give a different image each time. So that we can cache the directory download, switch AFS directory support over to using the netfslib single-object API, thereby allowing directory content to be stored in the local cache. To make this work, the following changes are made: (1) A directory's contents are now stored in a folio_queue chain attached to the afs_vnode (inode) struct rather than its associated pagecache, though multipage folios are still used to hold the data. The folio queue is discarded when the directory inode is evicted. This also helps with the phasing out of ITER_XARRAY. (2) Various directory operations are made to use and unuse the cache cookie. (3) The content checking, content dumping and content iteration are now performed with a standard iov_iter iterator over the contents of the folio queue. (4) Iteration and modification must be done with the vnode's validate_lock held. In conjunction with (1), this means that the iteration can be done without the need to lock pages or take extra refs on them, unlike when accessing ->i_pages. (5) Convert to using netfs_read_single() to read data. (6) Provide a ->writepages() to call netfs_writeback_single() to save the data to the cache according to the VM's scheduling whilst holding the validate_lock read-locked as (4). (7) Change local directory image editing functions: (a) Provide a function to get a specific block by number from the folio_queue as we can no longer use the i_pages xarray to locate folios by index. This uses a cursor to remember the current position as we need to iterate through the directory contents. The block is kmapped before being returned. (b) Make the function in (a) extend the directory by an extra folio if we run out of space. (c) Raise the check of the block free space counter, for those blocks that have one, higher in the function to eliminate a call to get a block. (d) Remove the page unlocking and putting done during the editing loops. This is no longer necessary as the folio_queue holds the references and the pages are no longer in the pagecache. (e) Mark the inode dirty and pin the cache usage till writeback at the end of a successful edit. (8) Don't set the large_folios flag on the inode as we do the allocation ourselves rather than the VM doing it automatically. (9) Mark the inode as being a single object that isn't uploaded to the server. (10) Enable caching on directories. (11) Only set the upload key for writeback for regular files. Notes: (*) We keep the ->release_folio(), ->invalidate_folio() and ->migrate_folio() ops as we set the mapping pointer on the folio. Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20241216204124.3752367-22-dhowells@redhat.com cc: Marc Dionne <marc.dionne@auristor.com> cc: Jeff Layton <jlayton@kernel.org> cc: linux-afs@lists.infradead.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-12-20afs: Make afs_init_request() get a key if not given a fileDavid Howells
In a future patch, AFS directory caching will go through netfslib and this will involve, at times, running on behalf of ->lookup(), which doesn't provide us with a file from which we can get an authentication key. If a file isn't provided, make afs_init_request() get a key from the process's keyrings instead when setting up a read. Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20241216204124.3752367-21-dhowells@redhat.com cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-12-20afs: Add more tracepoints to do with tracking validityDavid Howells
Add wrappers to set and clear the callback promise and to mark a directory as invalidated, and add tracepoints to track these events: (1) afs_cb_promise: Log when a callback promise is set on a vnode. (2) afs_vnode_invalid: Log when the server's callback promise for a vnode is no longer valid and we need to refetch the vnode metadata. (3) afs_dir_invalid: Log when the contents of a directory are marked invalid and requiring refetching from the server and the cache invalidating. and two tracepoints to record data version number management: (4) afs_set_dv: Log when the DV is recorded on a vnode. (5) afs_dv_mismatch: Log when the DV recorded on a vnode plus the expected delta for the operation does not match the DV we got back from the server. Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20241216204124.3752367-18-dhowells@redhat.com cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-12-20netfs: Remove some extraneous directory invalidationsDavid Howells
In the directory editing code, we shouldn't re-invalidate the directory if it is already invalidated. Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20241216204124.3752367-15-dhowells@redhat.com cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-12-20afs: Fix directory format encoding structDavid Howells
The AFS directory format structure, union afs_xdr_dir_block::meta, has too many alloc counter slots declared and so pushes the hash table along and over the data. This doesn't cause a problem at the moment because I'm currently ignoring the hash table and only using the correct number of alloc_ctrs in the code anyway. In future, however, I should start using the hash table to try and speed up afs_lookup(). Fix this by using the correct constant to declare the counter array. Fixes: 4ea219a839bf ("afs: Split the directory content defs into a header") Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20241216204124.3752367-14-dhowells@redhat.com cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-12-20afs: Fix EEXIST error returned from afs_rmdir() to be ENOTEMPTYDavid Howells
AFS servers pass back a code indicating EEXIST when they're asked to remove a directory that is not empty rather than ENOTEMPTY because not all the systems that an AFS server can run on have the latter error available and AFS preexisted the addition of that error in general. Fix afs_rmdir() to translate EEXIST to ENOTEMPTY. Fixes: 260a980317da ("[AFS]: Add "directory write" support.") Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20241216204124.3752367-13-dhowells@redhat.com cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-12-20afs: Don't use mutex for I/O operation lockDavid Howells
Don't use the standard mutex for the I/O operation lock, but rather implement our own as the standard mutex must be released in the same thread as locked it. This is a problem when it comes to doing async FetchData where the lock will be dropped from the workqueue that processed the incoming data and not from the issuing thread. Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20241216204124.3752367-12-dhowells@redhat.com cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-12-20netfs: Drop the was_async arg from netfs_read_subreq_terminated()David Howells
Drop the was_async argument from netfs_read_subreq_terminated(). Almost every caller is either in process context and passes false. Some filesystems delegate the call to a workqueue to avoid doing the work in their network message queue parsing thread. The only exception is netfs_cache_read_terminated() which handles completion in the cache - which is usually a callback from the backing filesystem in softirq context, though it can be from process context if an error occurred. In this case, delegate to a workqueue. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/CAHk-=wiVC5Cgyz6QKXFu6fTaA6h4CjexDR-OV9kL6Vo5x9v8=A@mail.gmail.com/ Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20241216204124.3752367-10-dhowells@redhat.com cc: Jeff Layton <jlayton@kernel.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-12-20netfs: Drop the error arg from netfs_read_subreq_terminated()David Howells
Drop the error argument from netfs_read_subreq_terminated() in favour of passing the value in subreq->error. Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20241216204124.3752367-9-dhowells@redhat.com cc: Jeff Layton <jlayton@kernel.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-12-20netfs: Work around recursion by abandoning retry if nothing readDavid Howells
syzkaller reported recursion with a loop of three calls (netfs_rreq_assess, netfs_retry_reads and netfs_rreq_terminated) hitting the limit of the stack during an unbuffered or direct I/O read. There are a number of issues: (1) There is no limit on the number of retries. (2) A subrequest is supposed to be abandoned if it does not transfer anything (NETFS_SREQ_NO_PROGRESS), but that isn't checked under all circumstances. (3) The actual root cause, which is this: if (atomic_dec_and_test(&rreq->nr_outstanding)) netfs_rreq_terminated(rreq, ...); When we do a retry, we bump the rreq->nr_outstanding counter to prevent the final cleanup phase running before we've finished dispatching the retries. The problem is if we hit 0, we have to do the cleanup phase - but we're in the cleanup phase and end up repeating the retry cycle, hence the recursion. Work around the problem by limiting the number of retries. This is based on Lizhi Xu's patch[1], and makes the following changes: (1) Replace NETFS_SREQ_NO_PROGRESS with NETFS_SREQ_MADE_PROGRESS and make the filesystem set it if it managed to read or write at least one byte of data. Clear this bit before issuing a subrequest. (2) Add a ->retry_count member to the subrequest and increment it any time we do a retry. (3) Remove the NETFS_SREQ_RETRYING flag as it is superfluous with ->retry_count. If the latter is non-zero, we're doing a retry. (4) Abandon a subrequest if retry_count is non-zero and we made no progress. (5) Use ->retry_count in both the write-side and the read-size. [?] Question: Should I set a hard limit on retry_count in both read and write? Say it hits 50, we always abandon it. The problem is that these changes only mitigate the issue. As long as it made at least one byte of progress, the recursion is still an issue. This patch mitigates the problem, but does not fix the underlying cause. I have patches that will do that, but it's an intrusive fix that's currently pending for the next merge window. The oops generated by KASAN looks something like: BUG: TASK stack guard page was hit at ffffc9000482ff48 (stack is ffffc90004830000..ffffc90004838000) Oops: stack guard page: 0000 [#1] PREEMPT SMP KASAN NOPTI ... RIP: 0010:mark_lock+0x25/0xc60 kernel/locking/lockdep.c:4686 ... mark_usage kernel/locking/lockdep.c:4646 [inline] __lock_acquire+0x906/0x3ce0 kernel/locking/lockdep.c:5156 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ___slab_alloc+0x123/0x1880 mm/slub.c:3695 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3908 __slab_alloc_node mm/slub.c:3961 [inline] slab_alloc_node mm/slub.c:4122 [inline] kmem_cache_alloc_noprof+0x2a7/0x2f0 mm/slub.c:4141 radix_tree_node_alloc.constprop.0+0x1e8/0x350 lib/radix-tree.c:253 idr_get_free+0x528/0xa40 lib/radix-tree.c:1506 idr_alloc_u32+0x191/0x2f0 lib/idr.c:46 idr_alloc+0xc1/0x130 lib/idr.c:87 p9_tag_alloc+0x394/0x870 net/9p/client.c:321 p9_client_prepare_req+0x19f/0x4d0 net/9p/client.c:644 p9_client_zc_rpc.constprop.0+0x105/0x880 net/9p/client.c:793 p9_client_read_once+0x443/0x820 net/9p/client.c:1570 p9_client_read+0x13f/0x1b0 net/9p/client.c:1534 v9fs_issue_read+0x115/0x310 fs/9p/vfs_addr.c:74 netfs_retry_read_subrequests fs/netfs/read_retry.c:60 [inline] netfs_retry_reads+0x153a/0x1d00 fs/netfs/read_retry.c:232 netfs_rreq_assess+0x5d3/0x870 fs/netfs/read_collect.c:371 netfs_rreq_terminated+0xe5/0x110 fs/netfs/read_collect.c:407 netfs_retry_reads+0x155e/0x1d00 fs/netfs/read_retry.c:235 netfs_rreq_assess+0x5d3/0x870 fs/netfs/read_collect.c:371 netfs_rreq_terminated+0xe5/0x110 fs/netfs/read_collect.c:407 netfs_retry_reads+0x155e/0x1d00 fs/netfs/read_retry.c:235 netfs_rreq_assess+0x5d3/0x870 fs/netfs/read_collect.c:371 ... netfs_rreq_terminated+0xe5/0x110 fs/netfs/read_collect.c:407 netfs_retry_reads+0x155e/0x1d00 fs/netfs/read_retry.c:235 netfs_rreq_assess+0x5d3/0x870 fs/netfs/read_collect.c:371 netfs_rreq_terminated+0xe5/0x110 fs/netfs/read_collect.c:407 netfs_retry_reads+0x155e/0x1d00 fs/netfs/read_retry.c:235 netfs_rreq_assess+0x5d3/0x870 fs/netfs/read_collect.c:371 netfs_rreq_terminated+0xe5/0x110 fs/netfs/read_collect.c:407 netfs_dispatch_unbuffered_reads fs/netfs/direct_read.c:103 [inline] netfs_unbuffered_read fs/netfs/direct_read.c:127 [inline] netfs_unbuffered_read_iter_locked+0x12f6/0x19b0 fs/netfs/direct_read.c:221 netfs_unbuffered_read_iter+0xc5/0x100 fs/netfs/direct_read.c:256 v9fs_file_read_iter+0xbf/0x100 fs/9p/vfs_file.c:361 do_iter_readv_writev+0x614/0x7f0 fs/read_write.c:832 vfs_readv+0x4cf/0x890 fs/read_write.c:1025 do_preadv fs/read_write.c:1142 [inline] __do_sys_preadv fs/read_write.c:1192 [inline] __se_sys_preadv fs/read_write.c:1187 [inline] __x64_sys_preadv+0x22d/0x310 fs/read_write.c:1187 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 Fixes: ee4cdf7ba857 ("netfs: Speed up buffered reading") Closes: https://syzkaller.appspot.com/bug?extid=1fc6f64c40a9d143cfb6 Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20241108034020.3695718-1-lizhi.xu@windriver.com/ [1] Link: https://lore.kernel.org/r/20241213135013.2964079-9-dhowells@redhat.com Tested-by: syzbot+885c03ad650731743489@syzkaller.appspotmail.com Suggested-by: Lizhi Xu <lizhi.xu@windriver.com> cc: Dominique Martinet <asmadeus@codewreck.org> cc: Jeff Layton <jlayton@kernel.org> cc: v9fs@lists.linux.dev cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Reported-by: syzbot+885c03ad650731743489@syzkaller.appspotmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-11-01Merge tag 'vfs-6.12-rc6.fixes' of ↵Linus Torvalds
gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs Pull filesystem fixes from Christian Brauner: "VFS: - Fix copy_page_from_iter_atomic() if KMAP_LOCAL_FORCE_MAP=y is set - Add a get_tree_bdev_flags() helper that allows to modify e.g., whether errors are logged into the filesystem context during superblock creation. This is used by erofs to fix a userspace regression where an error is currently logged when its used on a regular file which is an new allowed mode in erofs. netfs: - Fix the sysfs debug path in the documentation. - Fix iov_iter_get_pages*() for folio queues by skipping the page extracation if we're at the end of a folio. afs: - Fix moving subdirectories to different parent directory. autofs: - Fix handling of AUTOFS_DEV_IOCTL_TIMEOUT_CMD ioctl in validate_dev_ioctl(). The actual ioctl number, not the ioctl command needs to be checked for autofs" * tag 'vfs-6.12-rc6.fixes' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: iov_iter: fix copy_page_from_iter_atomic() if KMAP_LOCAL_FORCE_MAP autofs: fix thinko in validate_dev_ioctl() iov_iter: Fix iov_iter_get_pages*() for folio_queue afs: Fix missing subdir edit when renamed between parent dirs doc: correcting the debug path for cachefiles erofs: use get_tree_bdev_flags() to avoid misleading messages fs/super.c: introduce get_tree_bdev_flags()
2024-10-24afs: Fix missing subdir edit when renamed between parent dirsDavid Howells
When rename moves an AFS subdirectory between parent directories, the subdir also needs a bit of editing: the ".." entry needs updating to point to the new parent (though I don't make use of the info) and the DV needs incrementing by 1 to reflect the change of content. The server also sends a callback break notification on the subdirectory if we have one, but we can take care of recovering the promise next time we access the subdir. This can be triggered by something like: mount -t afs %example.com:xfstest.test20 /xfstest.test/ mkdir /xfstest.test/{aaa,bbb,aaa/ccc} touch /xfstest.test/bbb/ccc/d mv /xfstest.test/{aaa/ccc,bbb/ccc} touch /xfstest.test/bbb/ccc/e When the pathwalk for the second touch hits "ccc", kafs spots that the DV is incorrect and downloads it again (so the fix is not critical). Fix this, if the rename target is a directory and the old and new parents are different, by: (1) Incrementing the DV number of the target locally. (2) Editing the ".." entry in the target to refer to its new parent's vnode ID and uniquifier. Link: https://lore.kernel.org/r/3340431.1729680010@warthog.procyon.org.uk Fixes: 63a4681ff39c ("afs: Locally edit directory data for mkdir/create/unlink/...") cc: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-10-17afs: Fix lock recursionDavid Howells
afs_wake_up_async_call() can incur lock recursion. The problem is that it is called from AF_RXRPC whilst holding the ->notify_lock, but it tries to take a ref on the afs_call struct in order to pass it to a work queue - but if the afs_call is already queued, we then have an extraneous ref that must be put... calling afs_put_call() may call back down into AF_RXRPC through rxrpc_kernel_shutdown_call(), however, which might try taking the ->notify_lock again. This case isn't very common, however, so defer it to a workqueue. The oops looks something like: BUG: spinlock recursion on CPU#0, krxrpcio/7001/1646 lock: 0xffff888141399b30, .magic: dead4ead, .owner: krxrpcio/7001/1646, .owner_cpu: 0 CPU: 0 UID: 0 PID: 1646 Comm: krxrpcio/7001 Not tainted 6.12.0-rc2-build3+ #4351 Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014 Call Trace: <TASK> dump_stack_lvl+0x47/0x70 do_raw_spin_lock+0x3c/0x90 rxrpc_kernel_shutdown_call+0x83/0xb0 afs_put_call+0xd7/0x180 rxrpc_notify_socket+0xa0/0x190 rxrpc_input_split_jumbo+0x198/0x1d0 rxrpc_input_data+0x14b/0x1e0 ? rxrpc_input_call_packet+0xc2/0x1f0 rxrpc_input_call_event+0xad/0x6b0 rxrpc_input_packet_on_conn+0x1e1/0x210 rxrpc_input_packet+0x3f2/0x4d0 rxrpc_io_thread+0x243/0x410 ? __pfx_rxrpc_io_thread+0x10/0x10 kthread+0xcf/0xe0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x24/0x40 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/1394602.1729162732@warthog.procyon.org.uk 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>
2024-09-27afs: Fix the setting of the server responding flagDavid Howells
In afs_wait_for_operation(), we set transcribe the call responded flag to the server record that we used after doing the fileserver iteration loop - but it's possible to exit the loop having had a response from the server that we've discarded (e.g. it returned an abort or we started receiving data, but the call didn't complete). This means that op->server might be NULL, but we don't check that before attempting to set the server flag. Fixes: 98f9fda2057b ("afs: Fold the afs_addr_cursor struct in") Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20240923150756.902363-7-dhowells@redhat.com cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-09-27afs: Remove unused struct and function prototypeThorsten Blum
The struct afs_address_list and the function prototype afs_put_address_list() are not used anymore and can be removed. Remove them. Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com> Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20240911095046.3749-2-thorsten.blum@toblux.com/ Link: https://lore.kernel.org/r/20240923150756.902363-5-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>
2024-09-27afs: Fix possible infinite loop with unresponsive serversMarc Dionne
A return code of 0 from afs_wait_for_one_fs_probe is an indication that the endpoint state attached to the operation is stale and has been superseded. In that case the iteration needs to be restarted so that the newer probe result state gets used. Failure to do so can result in an tight infinite loop around the iterate_address label, where all addresses are thought to be responsive and have been tried, with nothing to refresh the endpoint state. Fixes: 495f2ae9e355 ("afs: Fix fileserver rotation") Reported-by: Markus Suvanto <markus.suvanto@gmail.com> Link: https://lists.infradead.org/pipermail/linux-afs/2024-July/008628.html cc: linux-afs@lists.infradead.org Signed-off-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20240906134019.131553-1-marc.dionne@auristor.com/ Link: https://lore.kernel.org/r/20240923150756.902363-6-dhowells@redhat.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-09-27afs: Fix missing wire-up of afs_retry_request()David Howells
afs_retry_request() is supposed to be pointed to by the afs_req_ops netfs operations table, but the pointer got lost somewhere. The function is used during writeback to rotate through the authentication keys that were in force when the file was modified locally. Fix this by adding the pointer to the function. Fixes: 1ecb146f7cd8 ("netfs, afs: Use writeback retry to deal with alternate keys") Reported-by: Dr. David Alan Gilbert <linux@treblig.org> Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/1690847.1726346402@warthog.procyon.org.uk cc: Marc Dionne <marc.dionne@auristor.com> cc: Jeff Layton <jlayton@kernel.org> cc: linux-afs@lists.infradead.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-09-12netfs: Speed up buffered readingDavid Howells
Improve the efficiency of buffered reads in a number of ways: (1) Overhaul the algorithm in general so that it's a lot more compact and split the read submission code between buffered and unbuffered versions. The unbuffered version can be vastly simplified. (2) Read-result collection is handed off to a work queue rather than being done in the I/O thread. Multiple subrequests can be processes simultaneously. (3) When a subrequest is collected, any folios it fully spans are collected and "spare" data on either side is donated to either the previous or the next subrequest in the sequence. Notes: (*) Readahead expansion is massively slows down fio, presumably because it causes a load of extra allocations, both folio and xarray, up front before RPC requests can be transmitted. (*) RDMA with cifs does appear to work, both with SIW and RXE. (*) PG_private_2-based reading and copy-to-cache is split out into its own file and altered to use folio_queue. Note that the copy to the cache now creates a new write transaction against the cache and adds the folios to be copied into it. This allows it to use part of the writeback I/O code. Signed-off-by: David Howells <dhowells@redhat.com> cc: Jeff Layton <jlayton@kernel.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/20240814203850.2240469-20-dhowells@redhat.com/ # v2 Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-09-12afs: Make read subreqs asyncDavid Howells
Perform AFS read subrequests in a work item rather than in the calling thread. For normal buffered reads, this will allow the calling thread to copy data from the pagecache to the application at the same time as the demarshalling thread is shovelling data from skbuffs into the pagecache. This will also allow the RA mark to trigger a new read before we've finished shovelling the data from the current one. Note: This would be a bit safer if the FS.FetchData RPC ops returned the metadata (including the data version number) before returning the data. This would allow me to flush the pagecache before installing the new data. In future, it may be possible to asynchronously flush the pagecache either side of the region being read. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Jeff Layton <jlayton@kernel.org> cc: linux-afs@lists.infradead.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/20240814203850.2240469-19-dhowells@redhat.com/ # v2 Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-09-05netfs: Move max_len/max_nr_segs from netfs_io_subrequest to netfs_io_streamDavid Howells
Move max_len/max_nr_segs from struct netfs_io_subrequest to struct netfs_io_stream as we only issue one subreq at a time and then don't need these values again for that subreq unless and until we have to retry it - in which case we want to renegotiate them. Signed-off-by: David Howells <dhowells@redhat.com> cc: Jeff Layton <jlayton@kernel.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/20240814203850.2240469-8-dhowells@redhat.com/ # v2 Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-24afs: Fix post-setattr file edit to do truncation correctlyDavid Howells
At the end of an kAFS RPC operation, there is an "edit" phase (originally intended for post-directory modification ops to edit the local image) that the setattr VFS op uses to fix up the pagecache if the RPC that requested truncation of a file was successful. afs_setattr_edit_file() calls truncate_setsize() which sets i_size, expands the pagecache if needed and truncates the pagecache. The first two of those, however, are redundant as they've already been done by afs_setattr_success() under the io_lock and the first is also done under the callback lock (cb_lock). Fix afs_setattr_edit_file() to call truncate_pagecache() instead (which is called by truncate_setsize(), thereby skipping the redundant parts. Fixes: 100ccd18bb41 ("netfs: Optimise away reads above the point at which there can be no data") Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20240823200819.532106-3-dhowells@redhat.com cc: Matthew Wilcox (Oracle) <willy@infradead.org> cc: Pankaj Raghav <p.raghav@samsung.com> cc: Jeff Layton <jlayton@kernel.org> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: netfs@lists.linux.dev cc: linux-mm@kvack.org cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-139p: Fix DIO read through netfsDominique Martinet
If a program is watching a file on a 9p mount, it won't see any change in size if the file being exported by the server is changed directly in the source filesystem, presumably because 9p doesn't have change notifications, and because netfs skips the reads if the file is empty. Fix this by attempting to read the full size specified when a DIO read is requested (such as when 9p is operating in unbuffered mode) and dealing with a short read if the EOF was less than the expected read. To make this work, filesystems using netfslib must not set NETFS_SREQ_CLEAR_TAIL if performing a DIO read where that read hit the EOF. I don't want to mandatorily clear this flag in netfslib for DIO because, say, ceph might make a read from an object that is not completely filled, but does not reside at the end of file - and so we need to clear the excess. This can be tested by watching an empty file over 9p within a VM (such as in the ktest framework): while true; do read content; if [ -n "$content" ]; then echo $content; break; fi; done < /host/tmp/foo then writing something into the empty file. The watcher should immediately display the file content and break out of the loop. Without this fix, it remains in the loop indefinitely. Fixes: 80105ed2fd27 ("9p: Use netfslib read/write_iter") Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218916 Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/1229195.1723211769@warthog.procyon.org.uk cc: Eric Van Hensbergen <ericvh@kernel.org> cc: Latchesar Ionkov <lucho@ionkov.net> cc: Christian Schoenebeck <linux_oss@crudebyte.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Ilya Dryomov <idryomov@gmail.com> cc: Steve French <sfrench@samba.org> cc: Paulo Alcantara <pc@manguebit.com> cc: Trond Myklebust <trond.myklebust@hammerspace.com> cc: v9fs@lists.linux.dev cc: linux-afs@lists.infradead.org cc: ceph-devel@vger.kernel.org cc: linux-cifs@vger.kernel.org cc: linux-nfs@vger.kernel.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Dominique Martinet <asmadeus@codewreck.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-07-21Merge tag 'mm-stable-2024-07-21-14-50' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - In the series "mm: Avoid possible overflows in dirty throttling" Jan Kara addresses a couple of issues in the writeback throttling code. These fixes are also targetted at -stable kernels. - Ryusuke Konishi's series "nilfs2: fix potential issues related to reserved inodes" does that. This should actually be in the mm-nonmm-stable tree, along with the many other nilfs2 patches. My bad. - More folio conversions from Kefeng Wang in the series "mm: convert to folio_alloc_mpol()" - Kemeng Shi has sent some cleanups to the writeback code in the series "Add helper functions to remove repeated code and improve readability of cgroup writeback" - Kairui Song has made the swap code a little smaller and a little faster in the series "mm/swap: clean up and optimize swap cache index". - In the series "mm/memory: cleanly support zeropage in vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David Hildenbrand has reworked the rather sketchy handling of the use of the zeropage in MAP_SHARED mappings. I don't see any runtime effects here - more a cleanup/understandability/maintainablity thing. - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling of higher addresses, for aarch64. The (poorly named) series is "Restructure va_high_addr_switch". - The core TLB handling code gets some cleanups and possible slight optimizations in Bang Li's series "Add update_mmu_tlb_range() to simplify code". - Jane Chu has improved the handling of our fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in the series "Enhance soft hwpoison handling and injection". - Jeff Johnson has sent a billion patches everywhere to add MODULE_DESCRIPTION() to everything. Some landed in this pull. - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang has simplified migration's use of hardware-offload memory copying. - Yosry Ahmed performs more folio API conversions in his series "mm: zswap: trivial folio conversions". - In the series "large folios swap-in: handle refault cases first", Chuanhua Han inches us forward in the handling of large pages in the swap code. This is a cleanup and optimization, working toward the end objective of full support of large folio swapin/out. - In the series "mm,swap: cleanup VMA based swap readahead window calculation", Huang Ying has contributed some cleanups and a possible fixlet to his VMA based swap readahead code. - In the series "add mTHP support for anonymous shmem" Baolin Wang has taught anonymous shmem mappings to use multisize THP. By default this is a no-op - users must opt in vis sysfs controls. Dramatic improvements in pagefault latency are realized. - David Hildenbrand has some cleanups to our remaining use of page_mapcount() in the series "fs/proc: move page_mapcount() to fs/proc/internal.h". - David also has some highmem accounting cleanups in the series "mm/highmem: don't track highmem pages manually". - Build-time fixes and cleanups from John Hubbard in the series "cleanups, fixes, and progress towards avoiding "make headers"". - Cleanups and consolidation of the core pagemap handling from Barry Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers and utilize them". - Lance Yang's series "Reclaim lazyfree THP without splitting" has reduced the latency of the reclaim of pmd-mapped THPs under fairly common circumstances. A 10x speedup is seen in a microbenchmark. It does this by punting to aother CPU but I guess that's a win unless all CPUs are pegged. - hugetlb_cgroup cleanups from Xiu Jianfeng in the series "mm/hugetlb_cgroup: rework on cftypes". - Miaohe Lin's series "Some cleanups for memory-failure" does just that thing. - Someone other than SeongJae has developed a DAMON feature in Honggyu Kim's series "DAMON based tiered memory management for CXL memory". This adds DAMON features which may be used to help determine the efficiency of our placement of CXL/PCIe attached DRAM. - DAMON user API centralization and simplificatio work in SeongJae Park's series "mm/damon: introduce DAMON parameters online commit function". - In the series "mm: page_type, zsmalloc and page_mapcount_reset()" David Hildenbrand does some maintenance work on zsmalloc - partially modernizing its use of pageframe fields. - Kefeng Wang provides more folio conversions in the series "mm: remove page_maybe_dma_pinned() and page_mkclean()". - More cleanup from David Hildenbrand, this time in the series "mm/memory_hotplug: use PageOffline() instead of PageReserved() for !ZONE_DEVICE". It "enlightens memory hotplug more about PageOffline() pages" and permits the removal of some virtio-mem hacks. - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and __folio_add_anon_rmap()" is a cleanup to the anon folio handling in preparation for mTHP (multisize THP) swapin. - Kefeng Wang's series "mm: improve clear and copy user folio" implements more folio conversions, this time in the area of large folio userspace copying. - The series "Docs/mm/damon/maintaier-profile: document a mailing tool and community meetup series" tells people how to get better involved with other DAMON developers. From SeongJae Park. - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does that. - David Hildenbrand sends along more cleanups, this time against the migration code. The series is "mm/migrate: move NUMA hinting fault folio isolation + checks under PTL". - Jan Kara has found quite a lot of strangenesses and minor errors in the readahead code. He addresses this in the series "mm: Fix various readahead quirks". - SeongJae Park's series "selftests/damon: test DAMOS tried regions and {min,max}_nr_regions" adds features and addresses errors in DAMON's self testing code. - Gavin Shan has found a userspace-triggerable WARN in the pagecache code. The series "mm/filemap: Limit page cache size to that supported by xarray" addresses this. The series is marked cc:stable. - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations and cleanup" cleans up and slightly optimizes KSM. - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of code motion. The series (which also makes the memcg-v1 code Kconfigurable) are "mm: memcg: separate legacy cgroup v1 code and put under config option" and "mm: memcg: put cgroup v1-specific memcg data under CONFIG_MEMCG_V1" - Dan Schatzberg's series "Add swappiness argument to memory.reclaim" adds an additional feature to this cgroup-v2 control file. - The series "Userspace controls soft-offline pages" from Jiaqi Yan permits userspace to stop the kernel's automatic treatment of excessive correctable memory errors. In order to permit userspace to monitor and handle this situation. - Kefeng Wang's series "mm: migrate: support poison recover from migrate folio" teaches the kernel to appropriately handle migration from poisoned source folios rather than simply panicing. - SeongJae Park's series "Docs/damon: minor fixups and improvements" does those things. - In the series "mm/zsmalloc: change back to per-size_class lock" Chengming Zhou improves zsmalloc's scalability and memory utilization. - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for pinning memfd folios" makes the GUP code use FOLL_PIN rather than bare refcount increments. So these paes can first be moved aside if they reside in the movable zone or a CMA block. - Andrii Nakryiko has added a binary ioctl()-based API to /proc/pid/maps for much faster reading of vma information. The series is "query VMAs from /proc/<pid>/maps". - In the series "mm: introduce per-order mTHP split counters" Lance Yang improves the kernel's presentation of developer information related to multisize THP splitting. - Michael Ellerman has developed the series "Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64)". This permits userspace to use all available huge page sizes. - In the series "revert unconditional slab and page allocator fault injection calls" Vlastimil Babka removes a performance-affecting and not very useful feature from slab fault injection. * tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (411 commits) mm/mglru: fix ineffective protection calculation mm/zswap: fix a white space issue mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folio mm/hugetlb: fix possible recursive locking detected warning mm/gup: clear the LRU flag of a page before adding to LRU batch mm/numa_balancing: teach mpol_to_str about the balancing mode mm: memcg1: convert charge move flags to unsigned long long alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting lib: reuse page_ext_data() to obtain codetag_ref lib: add missing newline character in the warning message mm/mglru: fix overshooting shrinker memory mm/mglru: fix div-by-zero in vmpressure_calc_level() mm/kmemleak: replace strncpy() with strscpy() mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB mm: ignore data-race in __swap_writepage hugetlbfs: ensure generic_hugetlb_get_unmapped_area() returns higher address than mmap_min_addr mm: shmem: rename mTHP shmem counters mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async() mm/migrate: putback split folios when numa hint migration fails ...
2024-07-03afs: drop usage of folio_file_posKairui Song
folio_file_pos is only needed for mixed usage of page cache and swap cache, for pure page cache usage, the caller can just use folio_pos instead. It can't be a swap cache page here. Swap mapping may only call into fs through swap_rw and that is not supported for afs. So just drop it and use folio_pos instead. Link: https://lkml.kernel.org/r/20240521175854.96038-6-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Cc: David Howells <dhowells@redhat.com> Cc: Marc Dionne <marc.dionne@auristor.com> Cc: Anna Schumaker <anna@kernel.org> Cc: Barry Song <v-songbaohua@oppo.com> Cc: Chao Yu <chao@kernel.org> Cc: Chris Li <chrisl@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ilya Dryomov <idryomov@gmail.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Jeff Layton <jlayton@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: NeilBrown <neilb@suse.de> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Xiubo Li <xiubli@redhat.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-02afs: Convert comma to semicolonChen Ni
Replace a comma between expression statements by a semicolon. Signed-off-by: Chen Ni <nichen@iscas.ac.cn> Link: https://lore.kernel.org/r/20240702024055.1411407-1-nichen@iscas.ac.cn/ Link: https://lore.kernel.org/r/20240702024055.1411407-1-nichen@iscas.ac.cn Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-05-27netfs, 9p: Fix race between umount and async request completionDavid Howells
There's a problem in 9p's interaction with netfslib whereby a crash occurs because the 9p_fid structs get forcibly destroyed during client teardown (without paying attention to their refcounts) before netfslib has finished with them. However, it's not a simple case of deferring the clunking that p9_fid_put() does as that requires the p9_client record to still be present. The problem is that netfslib has to unlock pages and clear the IN_PROGRESS flag before destroying the objects involved - including the fid - and, in any case, nothing checks to see if writeback completed barring looking at the page flags. Fix this by keeping a count of outstanding I/O requests (of any type) and waiting for it to quiesce during inode eviction. Reported-by: syzbot+df038d463cca332e8414@syzkaller.appspotmail.com Link: https://lore.kernel.org/all/0000000000005be0aa061846f8d6@google.com/ Reported-by: syzbot+d7c7a495a5e466c031b6@syzkaller.appspotmail.com Link: https://lore.kernel.org/all/000000000000b86c5e06130da9c6@google.com/ Reported-by: syzbot+1527696d41a634cc1819@syzkaller.appspotmail.com Link: https://lore.kernel.org/all/000000000000041f960618206d7e@google.com/ Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/755891.1716560771@warthog.procyon.org.uk Tested-by: syzbot+d7c7a495a5e466c031b6@syzkaller.appspotmail.com Reviewed-by: Dominique Martinet <asmadeus@codewreck.org> cc: Eric Van Hensbergen <ericvh@kernel.org> cc: Latchesar Ionkov <lucho@ionkov.net> cc: Christian Schoenebeck <linux_oss@crudebyte.com> cc: Jeff Layton <jlayton@kernel.org> cc: Steve French <sfrench@samba.org> cc: Hillf Danton <hdanton@sina.com> cc: v9fs@lists.linux.dev cc: linux-afs@lists.infradead.org cc: linux-cifs@vger.kernel.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Reported-and-tested-by: syzbot+d7c7a495a5e466c031b6@syzkaller.appspotmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-05-25afs: Don't cross .backup mountpoint from backup volumeMarc Dionne
Don't cross a mountpoint that explicitly specifies a backup volume (target is <vol>.backup) when starting from a backup volume. It it not uncommon to mount a volume's backup directly in the volume itself. This can cause tools that are not paying attention to get into a loop mounting the volume onto itself as they attempt to traverse the tree, leading to a variety of problems. This doesn't prevent the general case of loops in a sequence of mountpoints, but addresses a common special case in the same way as other afs clients. Reported-by: Jan Henrik Sylvester <jan.henrik.sylvester@uni-hamburg.de> Link: http://lists.infradead.org/pipermail/linux-afs/2024-May/008454.html Reported-by: Markus Suvanto <markus.suvanto@gmail.com> Link: http://lists.infradead.org/pipermail/linux-afs/2024-February/008074.html Signed-off-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/768760.1716567475@warthog.procyon.org.uk Reviewed-by: Jeffrey Altman <jaltman@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-05-13Merge tag 'vfs-6.10.netfs' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull netfs updates from Christian Brauner: "This reworks the netfslib writeback implementation so that pages read from the cache are written to the cache through ->writepages(), thereby allowing the fscache page flag to be retired. The reworking also: - builds on top of the new writeback_iter() infrastructure - makes it possible to use vectored write RPCs as discontiguous streams of pages can be accommodated - makes it easier to do simultaneous content crypto and stream division - provides support for retrying writes and re-dividing a stream - replaces the ->launder_folio() op, so that ->writepages() is used instead - uses mempools to allocate the netfs_io_request and netfs_io_subrequest structs to avoid allocation failure in the writeback path Some code that uses the fscache page flag is retained for compatibility purposes with nfs and ceph. The code is switched to using the synonymous private_2 label instead and marked with deprecation comments. The merge commit contains additional details on the new algorithm that I've left out of here as it would probably be excessively detailed. On top of the netfslib infrastructure this contains the work to convert cifs over to netfslib" * tag 'vfs-6.10.netfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (38 commits) cifs: Enable large folio support cifs: Remove some code that's no longer used, part 3 cifs: Remove some code that's no longer used, part 2 cifs: Remove some code that's no longer used, part 1 cifs: Cut over to using netfslib cifs: Implement netfslib hooks cifs: Make add_credits_and_wake_if() clear deducted credits cifs: Add mempools for cifs_io_request and cifs_io_subrequest structs cifs: Set zero_point in the copy_file_range() and remap_file_range() cifs: Move cifs_loose_read_iter() and cifs_file_write_iter() to file.c cifs: Replace the writedata replay bool with a netfs sreq flag cifs: Make wait_mtu_credits take size_t args cifs: Use more fields from netfs_io_subrequest cifs: Replace cifs_writedata with a wrapper around netfs_io_subrequest cifs: Replace cifs_readdata with a wrapper around netfs_io_subrequest cifs: Use alternative invalidation to using launder_folio netfs, afs: Use writeback retry to deal with alternate keys netfs: Miscellaneous tidy ups netfs: Remove the old writeback code netfs: Cut over to using new writeback code ...
2024-05-10afs: Fix fileserver rotation getting stuckDavid Howells
Fix the fileserver rotation code in a couple of ways: (1) op->server_states is an array, not a pointer to a single record, so fix the places that access it to index it. (2) In the places that go through an address list to work out which one has the best priority, fix the loops to skip known failed addresses. Without this, the rotation algorithm may get stuck on addresses that are inaccessible or don't respond. This can be triggered manually by finding a server that advertises a non-routable address and giving it a higher priority, eg.: echo "add udp 192.168.0.0/16 3000" >/proc/fs/afs/addr_prefs if the server, say, includes the address 192.168.7.7 in its address list, and then attempting to access a volume on that server. Fixes: 495f2ae9e355 ("afs: Fix fileserver rotation") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/4005300.1712309731@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/998836.1714746152@warthog.procyon.org.uk Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-05-01netfs, afs: Use writeback retry to deal with alternate keysDavid Howells
Use a hook in the new writeback code's retry algorithm to rotate the keys once all the outstanding subreqs have failed rather than doing it separately on each subreq. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org
2024-05-01netfs: Remove the old writeback codeDavid Howells
Remove the old writeback code. Signed-off-by: David Howells <dhowells@redhat.com> cc: Jeff Layton <jlayton@kernel.org> 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: Marc Dionne <marc.dionne@auristor.com> cc: v9fs@lists.linux.dev cc: linux-afs@lists.infradead.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org
2024-05-01netfs: Cut over to using new writeback codeDavid Howells
Cut over to using the new writeback code. The old code is #ifdef'd out or otherwise removed from compilation to avoid conflicts and will be removed in a future patch. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> 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: Marc Dionne <marc.dionne@auristor.com> cc: v9fs@lists.linux.dev cc: linux-afs@lists.infradead.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org
2024-05-01netfs, afs: Implement helpers for new write codeDavid Howells
Implement the helpers for the new write code in afs. There's now an optional ->prepare_write() that allows the filesystem to set the parameters for the next write, such as maximum size and maximum segment count, and an ->issue_write() that is called to initiate an (asynchronous) write operation. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org
2024-05-01afs: Use alternative invalidation to using launder_folioDavid Howells
Use writepages-based flushing invalidation instead of invalidate_inode_pages2() and ->launder_folio(). This will allow ->launder_folio() to be removed eventually. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Jeff Layton <jlayton@kernel.org> cc: linux-afs@lists.infradead.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org
2024-03-14afs: Fix occasional rmdir-then-VNOVNODE with generic/011David Howells
Sometimes generic/011 causes kafs to follow up an FS.RemoveDir RPC call by spending around a second sending a slew of FS.FetchStatus RPC calls to the directory just deleted that then abort with VNOVNODE, indicating deletion of the target directory. This seems to stem from userspace attempting to stat the directory or something in it: afs_select_fileserver+0x46d/0xaa2 afs_wait_for_operation+0x12/0x17e afs_fetch_status+0x56/0x75 afs_validate+0xfb/0x240 afs_permission+0xef/0x1b0 inode_permission+0x90/0x139 link_path_walk.part.0.constprop.0+0x6f/0x2f0 path_lookupat+0x4c/0xfa filename_lookup+0x63/0xd7 vfs_statx+0x62/0x13f vfs_fstatat+0x72/0x8a The issue appears to be that afs_dir_remove_subdir() marks the callback promise as being cancelled by setting the expiry time to AFS_NO_CB_PROMISE - which then confuses afs_validate() which sends the FetchStatus to try and get a new one before it checks for the AFS_VNODE_DELETED flag which indicates that we know the directory got deleted. Fix this by: (1) Make afs_check_validity() return true if AFS_VNODE_DELETED is set, and then tweak the return from afs_validate() if the DELETED flag is set. (2) Move the AFS_VNODE_DELETED check in afs_validate() up above the expiration check to immediately after we've grabbed the validate_lock. Fixes: 453924de6212 ("afs: Overhaul invalidation handling to better support RO volumes") Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20240313081505.3060173-3-dhowells@redhat.com Reviewed-by: Marc Dionne <marc.dionne@auristor.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-03-14afs: Don't cache preferred addressDavid Howells
In the AFS fileserver rotation algorithm, don't cache the preferred address for the server as that will override the explicit preference if a non-preferred address responds first. Fixes: 495f2ae9e355 ("afs: Fix fileserver rotation") Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20240313081505.3060173-2-dhowells@redhat.com Reviewed-by: Marc Dionne <marc.dionne@auristor.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-03-14afs: Revert "afs: Hide silly-rename files from userspace"David Howells
This reverts commit 57e9d49c54528c49b8bffe6d99d782ea051ea534. This undoes the hiding of .__afsXXXX silly-rename files. The problem with hiding them is that rm can't then manually delete them. This also reverts commit 5f7a07646655fb4108da527565dcdc80124b14c4 ("afs: Fix endless loop in directory parsing") as that's a bugfix for the above. Fixes: 57e9d49c5452 ("afs: Hide silly-rename files from userspace") Reported-by: Markus Suvanto <markus.suvanto@gmail.com> Link: https://lists.infradead.org/pipermail/linux-afs/2024-February/008102.html Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/3085695.1710328121@warthog.procyon.org.uk Reviewed-by: Jeffrey E Altman <jaltman@auristor.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-03-11Merge tag 'vfs-6.9.file' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull file locking updates from Christian Brauner: "A few years ago struct file_lock_context was added to allow for separate lists to track different types of file locks instead of using a singly-linked list for all of them. Now leases no longer need to be tracked using struct file_lock. However, a lot of the infrastructure is identical for leases and locks so separating them isn't trivial. This splits a group of fields used by both file locks and leases into a new struct file_lock_core. The new core struct is embedded in struct file_lock. Coccinelle was used to convert a lot of the callers to deal with the move, with the remaining 25% or so converted by hand. Afterwards several internal functions in fs/locks.c are made to work with struct file_lock_core. Ultimately this allows to split struct file_lock into struct file_lock and struct file_lease. The file lease APIs are then converted to take struct file_lease" * tag 'vfs-6.9.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (51 commits) filelock: fix deadlock detection in POSIX locking filelock: always define for_each_file_lock() smb: remove redundant check filelock: don't do security checks on nfsd setlease calls filelock: split leases out of struct file_lock filelock: remove temporary compatibility macros smb/server: adapt to breakup of struct file_lock smb/client: adapt to breakup of struct file_lock ocfs2: adapt to breakup of struct file_lock nfsd: adapt to breakup of struct file_lock nfs: adapt to breakup of struct file_lock lockd: adapt to breakup of struct file_lock fuse: adapt to breakup of struct file_lock gfs2: adapt to breakup of struct file_lock dlm: adapt to breakup of struct file_lock ceph: adapt to breakup of struct file_lock afs: adapt to breakup of struct file_lock 9p: adapt to breakup of struct file_lock filelock: convert seqfile handling to use file_lock_core filelock: convert locks_translate_pid to take file_lock_core ...
2024-02-27afs: Fix endless loop in directory parsingDavid Howells
If a directory has a block with only ".__afsXXXX" files in it (from uncompleted silly-rename), these .__afsXXXX files are skipped but without advancing the file position in the dir_context. This leads to afs_dir_iterate() repeating the block again and again. Fix this by making the code that skips the .__afsXXXX file also manually advance the file position. The symptoms are a soft lookup: watchdog: BUG: soft lockup - CPU#3 stuck for 52s! [check:5737] ... RIP: 0010:afs_dir_iterate_block+0x39/0x1fd ... ? watchdog_timer_fn+0x1a6/0x213 ... ? asm_sysvec_apic_timer_interrupt+0x16/0x20 ? afs_dir_iterate_block+0x39/0x1fd afs_dir_iterate+0x10a/0x148 afs_readdir+0x30/0x4a iterate_dir+0x93/0xd3 __do_sys_getdents64+0x6b/0xd4 This is almost certainly the actual fix for: https://bugzilla.kernel.org/show_bug.cgi?id=218496 Fixes: 57e9d49c5452 ("afs: Hide silly-rename files from userspace") Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/786185.1708694102@warthog.procyon.org.uk Reviewed-by: Marc Dionne <marc.dionne@auristor.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Markus Suvanto <markus.suvanto@gmail.com> cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-02-25Merge tag 'pull-fixes.pathwalk-rcu-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull RCU pathwalk fixes from Al Viro: "We still have some races in filesystem methods when exposed to RCU pathwalk. This series is a result of code audit (the second round of it) and it should deal with most of that stuff. Still pending: ntfs3 ->d_hash()/->d_compare() and ceph_d_revalidate(). Up to maintainers (a note for NTFS folks - when documentation says that a method may not block, it *does* imply that blocking allocations are to be avoided. Really)" [ More explanations for people who aren't familiar with the vagaries of RCU path walking: most of it is hidden from filesystems, but if a filesystem actively participates in the low-level path walking it needs to make sure the fields involved in that walk are RCU-safe. That "actively participate in low-level path walking" includes things like having its own ->d_hash()/->d_compare() routines, or by having its own directory permission function that doesn't just use the common helpers. Having a ->d_revalidate() function will also have this issue. Note that instead of making everything RCU safe you can also choose to abort the RCU pathwalk if your operation cannot be done safely under RCU, but that obviously comes with a performance penalty. One common pattern is to allow the simple cases under RCU, and abort only if you need to do something more complicated. So not everything needs to be RCU-safe, and things like the inode etc that the VFS itself maintains obviously already are. But these fixes tend to be about properly RCU-delaying things like ->s_fs_info that are maintained by the filesystem and that got potentially released too early. - Linus ] * tag 'pull-fixes.pathwalk-rcu-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: ext4_get_link(): fix breakage in RCU mode cifs_get_link(): bail out in unsafe case fuse: fix UAF in rcu pathwalks procfs: make freeing proc_fs_info rcu-delayed procfs: move dropping pde and pid from ->evict_inode() to ->free_inode() nfs: fix UAF on pathwalk running into umount nfs: make nfs_set_verifier() safe for use in RCU pathwalk afs: fix __afs_break_callback() / afs_drop_open_mmap() race hfsplus: switch to rcu-delayed unloading of nls and freeing ->s_fs_info exfat: move freeing sbi, upcase table and dropping nls into rcu-delayed helper affs: free affs_sb_info with kfree_rcu() rcu pathwalk: prevent bogus hard errors from may_lookup() fs/super.c: don't drop ->s_user_ns until we free struct super_block itself
2024-02-25afs: fix __afs_break_callback() / afs_drop_open_mmap() raceAl Viro
In __afs_break_callback() we might check ->cb_nr_mmap and if it's non-zero do queue_work(&vnode->cb_work). In afs_drop_open_mmap() we decrement ->cb_nr_mmap and do flush_work(&vnode->cb_work) if it reaches zero. The trouble is, there's nothing to prevent __afs_break_callback() from seeing ->cb_nr_mmap before the decrement and do queue_work() after both the decrement and flush_work(). If that happens, we might be in trouble - vnode might get freed before the queued work runs. __afs_break_callback() is always done under ->cb_lock, so let's make sure that ->cb_nr_mmap can change from non-zero to zero while holding ->cb_lock (the spinlock component of it - it's a seqlock and we don't need to mess with the counter). Acked-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-20afs: Increase buffer size in afs_update_volume_status()Daniil Dulov
The max length of volume->vid value is 20 characters. So increase idbuf[] size up to 24 to avoid overflow. Found by Linux Verification Center (linuxtesting.org) with SVACE. [DH: Actually, it's 20 + NUL, so increase it to 24 and use snprintf()] Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation") Signed-off-by: Daniil Dulov <d.dulov@aladdin.ru> Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20240211150442.3416-1-d.dulov@aladdin.ru/ # v1 Link: https://lore.kernel.org/r/20240212083347.10742-1-d.dulov@aladdin.ru/ # v2 Link: https://lore.kernel.org/r/20240219143906.138346-3-dhowells@redhat.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-02-20afs: Fix ignored callbacks over ipv4Marc Dionne
When searching for a matching peer, all addresses need to be searched, not just the ipv6 ones in the fs_addresses6 list. Given that the lists no longer contain addresses, there is little reason to splitting things between separate lists, so unify them into a single list. When processing an incoming callback from an ipv4 address, this would lead to a failure to set call->server, resulting in the callback being ignored and the client seeing stale contents. Fixes: 72904d7b9bfb ("rxrpc, afs: Allow afs to pin rxrpc_peer objects") Reported-by: Markus Suvanto <markus.suvanto@gmail.com> Link: https://lists.infradead.org/pipermail/linux-afs/2024-February/008035.html Signed-off-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lists.infradead.org/pipermail/linux-afs/2024-February/008037.html # v1 Link: https://lists.infradead.org/pipermail/linux-afs/2024-February/008066.html # v2 Link: https://lore.kernel.org/r/20240219143906.138346-2-dhowells@redhat.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-02-05afs: adapt to breakup of struct file_lockJeff Layton
Most of the existing APIs have remained the same, but subsystems that access file_lock fields directly need to reach into struct file_lock_core now. Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20240131-flsplit-v3-35-c6129007ee8d@kernel.org Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-02-05filelock: split common fields into struct file_lock_coreJeff Layton
In a future patch, we're going to split file leases into their own structure. Since a lot of the underlying machinery uses the same fields move those into a new file_lock_core, and embed that inside struct file_lock. For now, add some macros to ensure that we can continue to build while the conversion is in progress. Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20240131-flsplit-v3-17-c6129007ee8d@kernel.org Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-02-05afs: convert to using new filelock helpersJeff Layton
Convert to using the new file locking helper functions. Also, in later patches we're going to introduce macros that conflict with the variable name in afs_next_locker. Rename it. Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20240131-flsplit-v3-6-c6129007ee8d@kernel.org Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-01-22afs: Fix missing/incorrect unlocking of RCU read lockDavid Howells
In afs_proc_addr_prefs_show(), we need to unlock the RCU read lock in both places before returning (and not lock it again). Fixes: f94f70d39cc2 ("afs: Provide a way to configure address priorities") Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202401172243.cd53d5f6-oliver.sang@intel.com Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org
2024-01-22afs: Remove afs_dynroot_d_revalidate() as it is redundantDavid Howells
Remove afs_dynroot_d_revalidate() as it is redundant as all it does is return 1 and the caller assumes that if the op is not given. Suggested-by: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org
2024-01-22afs: Fix error handling with lookup via FS.InlineBulkStatusDavid Howells
When afs does a lookup, it tries to use FS.InlineBulkStatus to preemptively look up a bunch of files in the parent directory and cache this locally, on the basis that we might want to look at them too (for example if someone does an ls on a directory, they may want want to then stat every file listed). FS.InlineBulkStatus can be considered a compound op with the normal abort code applying to the compound as a whole. Each status fetch within the compound is then given its own individual abort code - but assuming no error that prevents the bulk fetch from returning the compound result will be 0, even if all the constituent status fetches failed. At the conclusion of afs_do_lookup(), we should use the abort code from the appropriate status to determine the error to return, if any - but instead it is assumed that we were successful if the op as a whole succeeded and we return an incompletely initialised inode, resulting in ENOENT, no matter the actual reason. In the particular instance reported, a vnode with no permission granted to be accessed is being given a UAEACCES abort code which should be reported as EACCES, but is instead being reported as ENOENT. Fix this by abandoning the inode (which will be cleaned up with the op) if file[1] has an abort code indicated and turn that abort code into an error instead. Whilst we're at it, add a tracepoint so that the abort codes of the individual subrequests of FS.InlineBulkStatus can be logged. At the moment only the container abort code can be 0. Fixes: e49c7b2f6de7 ("afs: Build an abstraction around an "operation" concept") Reported-by: Jeffrey Altman <jaltman@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2024-01-22afs: Hide silly-rename files from userspaceDavid Howells
There appears to be a race between silly-rename files being created/removed and various userspace tools iterating over the contents of a directory, leading to such errors as: find: './kernel/.tmp_cpio_dir/include/dt-bindings/reset/.__afs2080': No such file or directory tar: ./include/linux/greybus/.__afs3C95: File removed before we read it when building a kernel. Fix afs_readdir() so that it doesn't return .__afsXXXX silly-rename files to userspace. This doesn't stop them being looked up directly by name as we need to be able to look them up from within the kernel as part of the silly-rename algorithm. Fixes: 79ddbfa500b3 ("afs: Implement sillyrename for unlink and rename") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org