kernel/linux.git/fs/afs/file.c, branch v6.6.141

afs: fix __afs_break_callback() / afs_drop_open_mmap() race

2024-08-29T15:33:32+00:00

[ Upstream commit 275655d3207b9e65d1561bf21c06a622d9ec1d43 ] 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 Signed-off-by: Al Viro Signed-off-by: Sasha Levin

splice: Use filemap_splice_read() instead of generic_file_splice_read()

2023-05-24T14:42:17+00:00

Replace pointers to generic_file_splice_read() with calls to filemap_splice_read(). Signed-off-by: David Howells Reviewed-by: Christoph Hellwig Reviewed-by: Christian Brauner cc: Jens Axboe cc: Al Viro cc: David Hildenbrand cc: John Hubbard cc: linux-mm@kvack.org cc: linux-block@vger.kernel.org cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/20230522135018.2742245-29-dhowells@redhat.com Signed-off-by: Jens Axboe

afs: Provide a splice-read wrapper

2023-05-24T14:42:16+00:00

Provide a splice_read wrapper for AFS to call afs_validate() before going into generic_file_splice_read() so that we're likely to have a callback promise from the server. Signed-off-by: David Howells cc: Christoph Hellwig cc: Al Viro cc: Jens Axboe cc: Marc Dionne cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org cc: linux-block@vger.kernel.org cc: linux-mm@kvack.org Link: https://lore.kernel.org/r/20230522135018.2742245-16-dhowells@redhat.com Signed-off-by: Jens Axboe

afs: split afs_pagecache_valid() out of afs_validate()

2023-04-06T02:43:00+00:00

For the map_pages() method, we need a test that does not sleep. The page fault handler will continue to call the fault() method where we can sleep and do the full revalidation there. Link: https://lkml.kernel.org/r/20230327174515.1811532-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Acked-by: David Howells Tested-by: David Howells Cc: Darrick J. Wong Cc: Dave Chinner Signed-off-by: Andrew Morton

afs: Stop implementing ->writepage()

2022-12-22T11:40:35+00:00

We're trying to get rid of the ->writepage() hook[1]. Stop afs from using it by unlocking the page and calling afs_writepages_region() rather than folio_write_one(). A flag is passed to afs_writepages_region() to indicate that it should only write a single region so that we don't flush the entire file in ->write_begin(), but do add other dirty data to the region being written to try and reduce the number of RPC ops. This requires ->migrate_folio() to be implemented, so point that at filemap_migrate_folio() for files and also for symlinks and directories. This can be tested by turning on the afs_folio_dirty tracepoint and then doing something like: xfs_io -c "w 2223 7000" -c "w 15000 22222" -c "w 23 7" /afs/my/test/foo and then looking in the trace to see if the write at position 15000 gets stored before page 0 gets dirtied for the write at position 23. Signed-off-by: David Howells cc: Marc Dionne cc: Christoph Hellwig cc: Matthew Wilcox cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/20221113162902.883850-1-hch@lst.de/ [1] Link: https://lore.kernel.org/r/166876785552.222254.4403222906022558715.stgit@warthog.procyon.org.uk/ # v1

use less confusing names for iov_iter direction initializers

2022-11-25T18:01:55+00:00

READ/WRITE proved to be actively confusing - the meanings are "data destination, as used with read(2)" and "data source, as used with write(2)", but people keep interpreting those as "we read data from it" and "we write data to it", i.e. exactly the wrong way. Call them ITER_DEST and ITER_SOURCE - at least that is harder to misinterpret... Signed-off-by: Al Viro

netfs: do not unlock and put the folio twice

2022-07-14T08:10:12+00:00

check_write_begin() will unlock and put the folio when return non-zero. So we should avoid unlocking and putting it twice in netfs layer. Change the way ->check_write_begin() works in the following two ways: (1) Pass it a pointer to the folio pointer, allowing it to unlock and put the folio prior to doing the stuff it wants to do, provided it clears the folio pointer. (2) Change the return values such that 0 with folio pointer set means continue, 0 with folio pointer cleared means re-get and all error codes indicating an error (no special treatment for -EAGAIN). [ bagasdotme: use Sphinx code text syntax for *foliop pointer ] Cc: stable@vger.kernel.org Link: https://tracker.ceph.com/issues/56423 Link: https://lore.kernel.org/r/cf169f43-8ee7-8697-25da-0204d1b4343e@redhat.com Co-developed-by: David Howells Signed-off-by: Xiubo Li Signed-off-by: David Howells Signed-off-by: Bagas Sanjaya Signed-off-by: Ilya Dryomov

netfs: Rename the netfs_io_request cleanup op and give it an op pointer

2022-06-10T19:55:21+00:00

The netfs_io_request cleanup op is now always in a position to be given a pointer to a netfs_io_request struct, so this can be passed in instead of the mapping and private data arguments (both of which are included in the struct). So rename the ->cleanup op to ->free_request (to match ->init_request) and pass in the I/O pointer. Signed-off-by: David Howells Reviewed-by: Jeff Layton cc: linux-cachefs@redhat.com

netfs: Fix gcc-12 warning by embedding vfs inode in netfs_i_context

2022-06-09T20:55:00+00:00

While randstruct was satisfied with using an open-coded "void *" offset cast for the netfs_i_context <-> inode casting, __builtin_object_size() as used by FORTIFY_SOURCE was not as easily fooled. This was causing the following complaint[1] from gcc v12: In file included from include/linux/string.h:253, from include/linux/ceph/ceph_debug.h:7, from fs/ceph/inode.c:2: In function 'fortify_memset_chk', inlined from 'netfs_i_context_init' at include/linux/netfs.h:326:2, inlined from 'ceph_alloc_inode' at fs/ceph/inode.c:463:2: include/linux/fortify-string.h:242:25: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning] 242 | __write_overflow_field(p_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Fix this by embedding a struct inode into struct netfs_i_context (which should perhaps be renamed to struct netfs_inode). The struct inode vfs_inode fields are then removed from the 9p, afs, ceph and cifs inode structs and vfs_inode is then simply changed to "netfs.inode" in those filesystems. Further, rename netfs_i_context to netfs_inode, get rid of the netfs_inode() function that converted a netfs_i_context pointer to an inode pointer (that can now be done with &ctx->inode) and rename the netfs_i_context() function to netfs_inode() (which is now a wrapper around container_of()). Most of the changes were done with: perl -p -i -e 's/vfs_inode/netfs.inode/'g \ `git grep -l 'vfs_inode' -- fs/{9p,afs,ceph,cifs}/*.[ch]` Kees suggested doing it with a pair structure[2] and a special declarator to insert that into the network filesystem's inode wrapper[3], but I think it's cleaner to embed it - and then it doesn't matter if struct randomisation reorders things. Dave Chinner suggested using a filesystem-specific VFS_I() function in each filesystem to convert that filesystem's own inode wrapper struct into the VFS inode struct[4]. Version #2: - Fix a couple of missed name changes due to a disabled cifs option. - Rename nfs_i_context to nfs_inode - Use "netfs" instead of "nic" as the member name in per-fs inode wrapper structs. [ This also undoes commit 507160f46c55 ("netfs: gcc-12: temporarily disable '-Wattribute-warning' for now") that is no longer needed ] Fixes: bc899ee1c898 ("netfs: Add a netfs inode context") Reported-by: Jeff Layton Signed-off-by: David Howells Reviewed-by: Jeff Layton Reviewed-by: Kees Cook Reviewed-by: Xiubo Li cc: Jonathan Corbet cc: Eric Van Hensbergen cc: Latchesar Ionkov cc: Dominique Martinet cc: Christian Schoenebeck cc: Marc Dionne cc: Ilya Dryomov cc: Steve French cc: William Kucharski cc: "Matthew Wilcox (Oracle)" cc: Dave Chinner cc: linux-doc@vger.kernel.org cc: v9fs-developer@lists.sourceforge.net cc: linux-afs@lists.infradead.org cc: ceph-devel@vger.kernel.org cc: linux-cifs@vger.kernel.org cc: samba-technical@lists.samba.org cc: linux-fsdevel@vger.kernel.org cc: linux-hardening@vger.kernel.org Link: https://lore.kernel.org/r/d2ad3a3d7bdd794c6efb562d2f2b655fb67756b9.camel@kernel.org/ [1] Link: https://lore.kernel.org/r/20220517210230.864239-1-keescook@chromium.org/ [2] Link: https://lore.kernel.org/r/20220518202212.2322058-1-keescook@chromium.org/ [3] Link: https://lore.kernel.org/r/20220524101205.GI2306852@dread.disaster.area/ [4] Link: https://lore.kernel.org/r/165296786831.3591209.12111293034669289733.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/165305805651.4094995.7763502506786714216.stgit@warthog.procyon.org.uk # v2 Signed-off-by: Linus Torvalds

afs: Convert to release_folio

2022-05-10T03:12:32+00:00

A straightforward conversion as they already work in terms of folios. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Jeff Layton