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2025-12-189p: fix cache/debug options printing in v9fs_show_optionsEric Sandeen1-2/+2
[ Upstream commit f0445613314f474c1a0ec6fa8a5cd153a618f1b6 ] commit 4eb3117888a92 changed the cache= option to accept either string shortcuts or bitfield values. It also changed /proc/mounts to emit the option as the hexadecimal numeric value rather than the shortcut string. However, by printing "cache=%x" without the leading 0x, shortcuts such as "cache=loose" will emit "cache=f" and 'f' is not a string that is parseable by kstrtoint(), so remounting may fail if a remount with "cache=f" is attempted. debug=%x has had the same problem since options have been displayed in c4fac9100456 ("9p: Implement show_options") Fix these by adding the 0x prefix to the hexadecimal value shown in /proc/mounts. Fixes: 4eb3117888a92 ("fs/9p: Rework cache modes and add new options to Documentation") Signed-off-by: Eric Sandeen <sandeen@redhat.com> Message-ID: <54b93378-dcf1-4b04-922d-c8b4393da299@redhat.com> [Dominique: use %#x at Al Viro's suggestion, also handle debug] Tested-by: Remi Pommarel <repk@triplefau.lt> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-12-18fs/9p: Don't open remote file with APPEND mode when writeback cache is usedTingmao Wang3-6/+10
[ Upstream commit a63dd8fd137933551bfd9aeeeaa942f04c7aad65 ] When page cache is used, writebacks are done on a page granularity, and it is expected that the underlying filesystem (such as v9fs) should respect the write position. However, currently v9fs will passthrough O_APPEND to the server even on cached mode. This causes data corruption if a sync or fstat gets between two writes to the same file. This patch removes the APPEND flag from the open request we send to the server when writeback caching is involved. I believe keeping server-side APPEND is probably fine for uncached mode (even if two fds are opened, one without O_APPEND and one with it, this should still be fine since they would use separate fid for the writes). Signed-off-by: Tingmao Wang <m@maowtm.org> Fixes: 4eb3117888a9 ("fs/9p: Rework cache modes and add new options to Documentation") Message-ID: <20251102235631.8724-1-m@maowtm.org> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-139p: sysfs_init: don't hardcode error to ENOMEMRandall P. Embry1-2/+5
[ Upstream commit 528f218b31aac4bbfc58914d43766a22ab545d48 ] v9fs_sysfs_init() always returned -ENOMEM on failure; return the actual sysfs_create_group() error instead. Signed-off-by: Randall P. Embry <rpembry@gmail.com> Message-ID: <20250926-v9fs_misc-v1-3-a8b3907fc04d@codewreck.org> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-139p: fix /sys/fs/9p/caches overwriting itselfRandall P. Embry1-1/+1
[ Upstream commit 86db0c32f16c5538ddb740f54669ace8f3a1f3d7 ] caches_show() overwrote its buffer on each iteration, so only the last cache tag was visible in sysfs output. Properly append with snprintf(buf + count, …). Signed-off-by: Randall P. Embry <rpembry@gmail.com> Message-ID: <20250926-v9fs_misc-v1-2-a8b3907fc04d@codewreck.org> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-199p: Add a migrate_folio methodMatthew Wilcox (Oracle)1-0/+1
commit 03ddd7725ed1b39cf9251e1a420559f25dac49b3 upstream. The migration code used to be able to migrate dirty 9p folios by writing them back using writepage. When the writepage method was removed, we neglected to add a migrate_folio method, which means that dirty 9p folios have been unmovable ever since. This reduced our success at defragmenting memory on machines which use 9p heavily. Fixes: 80105ed2fd27 (9p: Use netfslib read/write_iter) Cc: stable@vger.kernel.org Cc: David Howells <dhowells@redhat.com> Cc: v9fs@lists.linux.dev Signed-off-by: "Matthew Wilcox (Oracle)" <willy@infradead.org> Link: https://lore.kernel.org/r/20250402150005.2309458-2-willy@infradead.org Acked-by: Dominique Martinet <asmadeus@codewreck.org> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-10fs/9p: fix NULL pointer dereference on mkdirChristian Schoenebeck1-1/+1
[ Upstream commit 3f61ac7c65bdb26accb52f9db66313597e759821 ] When a 9p tree was mounted with option 'posixacl', parent directory had a default ACL set for its subdirectories, e.g.: setfacl -m default:group:simpsons:rwx parentdir then creating a subdirectory crashed 9p client, as v9fs_fid_add() call in function v9fs_vfs_mkdir_dotl() sets the passed 'fid' pointer to NULL (since dafbe689736) even though the subsequent v9fs_set_create_acl() call expects a valid non-NULL 'fid' pointer: [ 37.273191] BUG: kernel NULL pointer dereference, address: 0000000000000000 ... [ 37.322338] Call Trace: [ 37.323043] <TASK> [ 37.323621] ? __die (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:434) [ 37.324448] ? page_fault_oops (arch/x86/mm/fault.c:714) [ 37.325532] ? search_module_extables (kernel/module/main.c:3733) [ 37.326742] ? p9_client_walk (net/9p/client.c:1165) 9pnet [ 37.328006] ? search_bpf_extables (kernel/bpf/core.c:804) [ 37.329142] ? exc_page_fault (./arch/x86/include/asm/paravirt.h:686 arch/x86/mm/fault.c:1488 arch/x86/mm/fault.c:1538) [ 37.330196] ? asm_exc_page_fault (./arch/x86/include/asm/idtentry.h:574) [ 37.331330] ? p9_client_walk (net/9p/client.c:1165) 9pnet [ 37.332562] ? v9fs_fid_xattr_get (fs/9p/xattr.c:30) 9p [ 37.333824] v9fs_fid_xattr_set (fs/9p/fid.h:23 fs/9p/xattr.c:121) 9p [ 37.335077] v9fs_set_acl (fs/9p/acl.c:276) 9p [ 37.336112] v9fs_set_create_acl (fs/9p/acl.c:307) 9p [ 37.337326] v9fs_vfs_mkdir_dotl (fs/9p/vfs_inode_dotl.c:411) 9p [ 37.338590] vfs_mkdir (fs/namei.c:4313) [ 37.339535] do_mkdirat (fs/namei.c:4336) [ 37.340465] __x64_sys_mkdir (fs/namei.c:4354) [ 37.341455] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) [ 37.342447] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Fix this by simply swapping the sequence of these two calls in v9fs_vfs_mkdir_dotl(), i.e. calling v9fs_set_create_acl() before v9fs_fid_add(). Fixes: dafbe689736f ("9p fid refcount: cleanup p9_fid_put calls") Reported-by: syzbot+5b667f9a1fee4ba3775a@syzkaller.appspotmail.com Signed-off-by: Christian Schoenebeck <linux_oss@crudebyte.com> Message-ID: <E1tsiI6-002iMG-Kh@kylie.crudebyte.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-10-26Merge tag '9p-for-6.12-rc5' of https://github.com/martinetd/linuxLinus Torvalds5-87/+192
Pull more 9p reverts from Dominique Martinet: "Revert patches causing inode collision problems. The code simplification introduced significant regressions on servers that do not remap inode numbers when exporting multiple underlying filesystems with colliding inodes. See the top-most revert (commit be2ca3825372) for details. This problem had been ignored for too long and the reverts will also head to stable (6.9+). I'm confident this set of patches gets us back to previous behaviour (another related patch had already been reverted back in April and we're almost back to square 1, and the rest didn't touch inode lifecycle)" * tag '9p-for-6.12-rc5' of https://github.com/martinetd/linux: Revert "fs/9p: simplify iget to remove unnecessary paths" Revert "fs/9p: fix uaf in in v9fs_stat2inode_dotl" Revert "fs/9p: remove redundant pointer v9ses" Revert " fs/9p: mitigate inode collisions"
2024-10-25Revert "fs/9p: simplify iget to remove unnecessary paths"Dominique Martinet5-45/+180
This reverts commit 724a08450f74b02bd89078a596fd24857827c012. This code simplification introduced significant regressions on servers that do not remap inode numbers when exporting multiple underlying filesystems with colliding inodes, as can be illustrated with simple tmpfs exports in qemu with remapping disabled: ``` # host side cd /tmp/linux-test mkdir m1 m2 mount -t tmpfs tmpfs m1 mount -t tmpfs tmpfs m2 mkdir m1/dir m2/dir echo foo > m1/dir/foo echo bar > m2/dir/bar # guest side # started with -virtfs local,path=/tmp/linux-test,mount_tag=tmp,security_model=mapped-file mount -t 9p -o trans=virtio,debug=1 tmp /mnt/t ls /mnt/t/m1/dir # foo ls /mnt/t/m2/dir # bar (works ok if directry isn't open) # cd to keep first dir's inode alive cd /mnt/t/m1/dir ls /mnt/t/m2/dir # foo (should be bar) ``` Other examples can be crafted with regular files with fscache enabled, in which case I/Os just happen to the wrong file leading to corruptions, or guest failing to boot with: | VFS: Lookup of 'com.android.runtime' in 9p 9p would have caused loop In theory, we'd want the servers to be smart enough and ensure they never send us two different files with the same 'qid.path', but while qemu has an option to remap that is recommended (and qemu prints a warning if this case happens), there are many other servers which do not (kvmtool, nfs-ganesha, probably diod...), we should at least ensure we don't cause regressions on this: - assume servers can't be trusted and operations that should get a 'new' inode properly do so. commit d05dcfdf5e16 (" fs/9p: mitigate inode collisions") attempted to do this, but v9fs_fid_iget_dotl() was not called so some higher level of caching got in the way; this needs to be fixed properly before we can re-apply the patches. - if we ever want to really simplify this code, we will need to add some negotiation with the server at mount time where the server could claim they handle this properly, at which point we could optimize this out. (but that might not be needed at all if we properly handle the 'new' check?) Fixes: 724a08450f74 ("fs/9p: simplify iget to remove unnecessary paths") Reported-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/all/20240408141436.GA17022@redhat.com/ Link: https://lkml.kernel.org/r/20240923100508.GA32066@willie-the-truck Cc: stable@vger.kernel.org # v6.9+ Message-ID: <20241024-revert_iget-v1-4-4cac63d25f72@codewreck.org> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2024-10-25Revert "fs/9p: fix uaf in in v9fs_stat2inode_dotl"Dominique Martinet1-1/+1
This reverts commit 11763a8598f888dec631a8a903f7ada32181001f. This is a requirement to revert commit 724a08450f74 ("fs/9p: simplify iget to remove unnecessary paths"), see that revert for details. Fixes: 724a08450f74 ("fs/9p: simplify iget to remove unnecessary paths") Reported-by: Will Deacon <will@kernel.org> Link: https://lkml.kernel.org/r/20240923100508.GA32066@willie-the-truck Cc: stable@vger.kernel.org # v6.9+ Message-ID: <20241024-revert_iget-v1-3-4cac63d25f72@codewreck.org> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2024-10-25Revert "fs/9p: remove redundant pointer v9ses"Dominique Martinet1-0/+4
This reverts commit 10211b4a23cf4a3df5c11a10e5b3d371f16a906f. This is a requirement to revert commit 724a08450f74 ("fs/9p: simplify iget to remove unnecessary paths"), see that revert for details. Fixes: 724a08450f74 ("fs/9p: simplify iget to remove unnecessary paths") Reported-by: Will Deacon <will@kernel.org> Link: https://lkml.kernel.org/r/20240923100508.GA32066@willie-the-truck Cc: stable@vger.kernel.org # v6.9+ Message-ID: <20241024-revert_iget-v1-2-4cac63d25f72@codewreck.org> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2024-10-25Revert " fs/9p: mitigate inode collisions"Dominique Martinet4-56/+22
This reverts commit d05dcfdf5e1659b2949d13060284eff3888b644e. This is a requirement to revert commit 724a08450f74 ("fs/9p: simplify iget to remove unnecessary paths"), see that revert for details. Fixes: 724a08450f74 ("fs/9p: simplify iget to remove unnecessary paths") Reported-by: Will Deacon <will@kernel.org> Link: https://lkml.kernel.org/r/20240923100508.GA32066@willie-the-truck Cc: stable@vger.kernel.org # v6.9+ Message-ID: <20241024-revert_iget-v1-1-4cac63d25f72@codewreck.org> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2024-10-24Revert "9p: Enable multipage folios"Dominique Martinet1-1/+0
This reverts commit 1325e4a91a405f88f1b18626904d37860a4f9069. using multipage folios apparently break some madvise operations like MADV_PAGEOUT which do not reliably unload the specified page anymore, Revert the patch until that is figured out. Reported-by: Andrii Nakryiko <andrii@kernel.org> Fixes: 1325e4a91a40 ("9p: Enable multipage folios") Signed-off-by: Dominique Martinet <asmadeus@codewreck.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-10-19Merge tag '9p-for-6.12-rc4' of https://github.com/martinetd/linuxLinus Torvalds2-3/+3
Pull 9p fixes from Dominique Martinet: "Mashed-up update that I sat on too long: - fix for multiple slabs created with the same name - enable multipage folios - theorical fix to also look for opened fids by inode if none was found by dentry" [ Enabling multi-page folios should have been done during the merge window, but it's a one-liner, and the actual meat of the enablement is in netfs and already in use for other filesystems... - Linus ] * tag '9p-for-6.12-rc4' of https://github.com/martinetd/linux: 9p: Avoid creating multiple slab caches with the same name 9p: Enable multipage folios 9p: v9fs_fid_find: also lookup by inode if not found dentry
2024-09-229p: Enable multipage foliosDavid Howells1-0/+1
Enable support for multipage folios on the 9P filesystem. This is all handled through netfslib and is already enabled on AFS and CIFS also. Signed-off-by: David Howells <dhowells@redhat.com> cc: Eric Van Hensbergen <ericvh@kernel.org> cc: Latchesar Ionkov <lucho@ionkov.net> cc: Dominique Martinet <asmadeus@codewreck.org> cc: Christian Schoenebeck <linux_oss@crudebyte.com> cc: Jeff Layton <jlayton@kernel.org> cc: Matthew Wilcox <willy@infradead.org> cc: v9fs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org Message-ID: <20240620173137.610345-7-dhowells@redhat.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2024-09-229p: v9fs_fid_find: also lookup by inode if not found dentryDominique Martinet1-3/+2
It's possible for v9fs_fid_find "find by dentry" branch to not turn up anything despite having an entry set (because e.g. uid doesn't match), in which case the calling code will generally make an extra lookup to the server. In this case we might have had better luck looking by inode, so fall back to look up by inode if we have one and the lookup by dentry failed. Message-Id: <20240523210024.1214386-1-asmadeus@codewreck.org> Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2024-09-12netfs: Speed up buffered readingDavid Howells1-3/+8
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>
2024-08-139p: Fix DIO read through netfsDominique Martinet1-1/+2
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>
2024-05-29Merge tag '9p-for-6.10-rc2' of https://github.com/martinetd/linuxLinus Torvalds1-2/+7
Pull 9p fixes from Dominique Martinet: "Two fixes headed to stable trees: - a trace event was dumping uninitialized values - a missing lock that was thought to have exclusive access, and it turned out not to" * tag '9p-for-6.10-rc2' of https://github.com/martinetd/linux: 9p: add missing locking around taking dentry fid list net/9p: fix uninit-value in p9_client_rpc()
2024-05-27netfs, 9p: Fix race between umount and async request completionDavid Howells1-0/+1
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>
2024-05-239p: add missing locking around taking dentry fid listDominique Martinet1-2/+7
Fix a use-after-free on dentry's d_fsdata fid list when a thread looks up a fid through dentry while another thread unlinks it: UAF thread: refcount_t: addition on 0; use-after-free. p9_fid_get linux/./include/net/9p/client.h:262 v9fs_fid_find+0x236/0x280 linux/fs/9p/fid.c:129 v9fs_fid_lookup_with_uid linux/fs/9p/fid.c:181 v9fs_fid_lookup+0xbf/0xc20 linux/fs/9p/fid.c:314 v9fs_vfs_getattr_dotl+0xf9/0x360 linux/fs/9p/vfs_inode_dotl.c:400 vfs_statx+0xdd/0x4d0 linux/fs/stat.c:248 Freed by: p9_fid_destroy (inlined) p9_client_clunk+0xb0/0xe0 linux/net/9p/client.c:1456 p9_fid_put linux/./include/net/9p/client.h:278 v9fs_dentry_release+0xb5/0x140 linux/fs/9p/vfs_dentry.c:55 v9fs_remove+0x38f/0x620 linux/fs/9p/vfs_inode.c:518 vfs_unlink+0x29a/0x810 linux/fs/namei.c:4335 The problem is that d_fsdata was not accessed under d_lock, because d_release() normally is only called once the dentry is otherwise no longer accessible but since we also call it explicitly in v9fs_remove that lock is required: move the hlist out of the dentry under lock then unref its fids once they are no longer accessible. Fixes: 154372e67d40 ("fs/9p: fix create-unlink-getattr idiom") Cc: stable@vger.kernel.org Reported-by: Meysam Firouzi Reported-by: Amirmohammad Eftekhar Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com> Message-ID: <20240521122947.1080227-1-asmadeus@codewreck.org> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2024-05-01netfs: Remove the old writeback codeDavid Howells1-34/+0
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 Howells1-4/+2
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, 9p: Implement helpers for new write codeDavid Howells1-0/+48
Implement the helpers for the new write code in 9p. 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: Eric Van Hensbergen <ericvh@kernel.org> cc: Latchesar Ionkov <lucho@ionkov.net> cc: Dominique Martinet <asmadeus@codewreck.org> cc: Christian Schoenebeck <linux_oss@crudebyte.com> cc: v9fs@lists.linux.dev cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org
2024-05-019p: Use alternative invalidation to using launder_folioDavid Howells1-2/+0
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: 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: Jeff Layton <jlayton@kernel.org> cc: v9fs@lists.linux.dev cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org
2024-04-22 fs/9p: mitigate inode collisionsEric Van Hensbergen4-22/+56
Detect and mitigate inode collsions that now occur since we fixed 9p generating duplicate inode structures. Underlying cause of these appears to be a race condition between reuse of inode numbers in underlying file system and cleanup of inode numbers in the client. Enabling caching makes this much more likely to happen as it increases cleanup latency due to writebacks. Reported-by: Kent Overstreet <kent.overstreet@linux.dev> Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-04-12fs/9p: drop inodes immediately on non-.L tooJoakim Sindholt1-0/+1
Signed-off-by: Joakim Sindholt <opensource@zhasha.com> Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-04-12fs/9p: Revert "fs/9p: fix dups even in uncached mode"Eric Van Hensbergen1-0/+16
This reverts commit be57855f505003c5cafff40338d5d0f23b00ba4d. It caused a regression involving duplicate inode numbers in some tester trees. The bad behavior seems to be dependent on inode reuse policy in underlying file system, so it did not trigger in my test setup. Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-04-10fs/9p: remove erroneous nlink init from legacy stat2inodeEric Van Hensbergen1-2/+0
In 9p2000 legacy mode, stat2inode initializes nlink to 1, which is redundant with what alloc_inode should have already set. 9p2000.u overrides this with extensions if present in the stat structure, and 9p2000.L incorporates nlink into its stat structure. At the very least this probably messes with directory nlink accounting in legacy mode. Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-03-289p: explicitly deny setlease attemptsJeff Layton1-0/+2
9p is a remote network protocol, and it doesn't support asynchronous notifications from the server. Ensure that we don't hand out any leases since we can't guarantee they'll be broken when a file's contents change. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-03-28fs/9p: fix the cache always being enabled on files with qid flagsJoakim Sindholt1-3/+0
I'm not sure why this check was ever here. After updating to 6.6 I suddenly found caching had been turned on by default and neither cache=none nor the new directio would turn it off. After walking through the new code very manually I realized that it's because the caching has to be, in effect, turned off explicitly by setting P9L_DIRECT and whenever a file has a flag, in my case QTAPPEND, it doesn't get set. Setting aside QTDIR which seems to ignore the new fid->mode entirely, the rest of these either should be subject to the same cache rules as every other QTFILE or perhaps very explicitly not cached in the case of QTAUTH. Signed-off-by: Joakim Sindholt <opensource@zhasha.com> Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-03-28fs/9p: translate O_TRUNC into OTRUNCJoakim Sindholt1-0/+3
This one hits both 9P2000 and .u as it appears v9fs has never translated the O_TRUNC flag. Signed-off-by: Joakim Sindholt <opensource@zhasha.com> Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-03-28fs/9p: only translate RWX permissions for plain 9P2000Joakim Sindholt1-1/+1
Garbage in plain 9P2000's perm bits is allowed through, which causes it to be able to set (among others) the suid bit. This was presumably not the intent since the unix extended bits are handled explicitly and conditionally on .u. Signed-off-by: Joakim Sindholt <opensource@zhasha.com> Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-03-25fs/9p: fix uninitialized values during inode evictEric Van Hensbergen1-6/+10
If an iget fails due to not being able to retrieve information from the server then the inode structure is only partially initialized. When the inode gets evicted, references to uninitialized structures (like fscache cookies) were being made. This patch checks for a bad_inode before doing anything other than clearing the inode from the cache. Since the inode is bad, it shouldn't have any state associated with it that needs to be written back (and there really isn't a way to complete those anyways). Reported-by: syzbot+eb83fe1cce5833cd66a0@syzkaller.appspotmail.com Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-03-25fs/9p: remove redundant pointer v9sesColin Ian King1-4/+0
Pointer v9ses is being assigned the value from the return of inlined function v9fs_inode2v9ses (which just returns inode->i_sb->s_fs_info). The pointer is not used after the assignment, so the variable is redundant and can be removed. Cleans up clang scan warnings such as: fs/9p/vfs_inode_dotl.c:300:28: warning: variable 'v9ses' set but not used [-Wunused-but-set-variable] Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Reviewed-by: Dominique Martinet <asmadeus@codewreck.org> Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-03-25fs/9p: fix uaf in in v9fs_stat2inode_dotlLizhi Xu1-1/+1
The incorrect logical order of accessing the st object code in v9fs_fid_iget_dotl is causing this uaf. Fixes: 724a08450f74 ("fs/9p: simplify iget to remove unnecessary paths") Reported-and-tested-by: syzbot+7a3d75905ea1a830dbe5@syzkaller.appspotmail.com Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com> Tested-by: Breno Leitao <leitao@debian.org> Reviewed-by: Dominique Martinet <asmadeus@codewreck.org> Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-03-15Merge tag '9p-for-6.9' of ↵Linus Torvalds6-364/+71
git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs Pull 9p updates from Eric Van Hensbergen: "This includes a number of patches addressing improvements in the cache portions of the 9p client. The biggest improvements have to do with fixing handling of inodes and eliminating duplicate structures and unnecessary allocation/release of inode structures and many associated unnecessary protocol traffic. This also dramatically reduced code complexity across the code and sets us up to add proper temporal cache capabilities" * tag '9p-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs: fs/9p: fix dups even in uncached mode fs/9p: simplify iget to remove unnecessary paths fs/9p: rework qid2ino logic fs/9p: Eliminate now unused v9fs_get_inode fs/9p: Eliminate redundant non-cache path in mknod fs/9p: remove walk and inode allocation from symlink fs/9p: convert mkdir to use get_new_inode fs/9p: switch vfsmount to use v9fs_get_new_inode
2024-03-13mm, slab: remove last vestiges of SLAB_MEM_SPREADLinus Torvalds1-1/+1
Yes, yes, I know the slab people were planning on going slow and letting every subsystem fight this thing on their own. But let's just rip off the band-aid and get it over and done with. I don't want to see a number of unnecessary pull requests just to get rid of a flag that no longer has any meaning. This was mainly done with a couple of 'sed' scripts and then some manual cleanup of the end result. Link: https://lore.kernel.org/all/CAHk-=wji0u+OOtmAOD-5JV3SXcRJF___k_+8XNKmak0yd5vW1Q@mail.gmail.com/ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-02-059p: adapt to breakup of struct file_lockJeff Layton1-20/+19
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-v3-34-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 Layton1-0/+1
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>
2024-02-059p: rename fl_type variable in v9fs_file_do_lockJeff Layton1-3/+3
In later patches, we're going to introduce some macros that conflict with the variable name here. Rename it. Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20240131-flsplit-v3-5-c6129007ee8d@kernel.org Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-01-26fs/9p: fix dups even in uncached modeEric Van Hensbergen1-16/+0
In uncached mode we were still seeing duplicate getattr requests because of aggressive dropping of inodes. Inode "freshness" is guarded by other mechanisms when caches are disabled so this is unnecessary and increases overhead of almost every operation. Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-01-26fs/9p: simplify iget to remove unnecessary pathsEric Van Hensbergen5-180/+45
Remove the additional comparison operators and switch to simply lookup by inode number (aka qid.path). Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-01-26fs/9p: rework qid2ino logicEric Van Hensbergen4-31/+12
This changes from a function to a macro because we can figure out if we are 32 or 64 bit at compile time. Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-01-26fs/9p: Eliminate now unused v9fs_get_inodeEric Van Hensbergen2-32/+0
Now with all inode allocation going through get_from_fid functions we can remove v9fs_get_inode and reduce us down to a single inode allocation path. Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-01-26fs/9p: Eliminate redundant non-cache path in mknodEric Van Hensbergen1-26/+10
Like symlink, mknod had a seperate path with different inode allocation -- but this seems unnecessary, so eliminating this path. Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-01-26fs/9p: remove walk and inode allocation from symlinkEric Van Hensbergen1-33/+0
Symlink had a bunch of extra operations which essentially end up discarded. It was walking the fid to the new file and creating an inode for it, but those semantics are part of tsymlink. This did prepopulate the cache, but that also seems potentially unnecessary and frought with peril. Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-01-26fs/9p: convert mkdir to use get_new_inodeEric Van Hensbergen1-25/+10
mkdir had different code paths for inode creation, cache used the get_new_inode_from_fid helper, but non-cached used v9fs_get_inode. Collapsed into a single implementation across both as there should be no difference. Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-01-26fs/9p: switch vfsmount to use v9fs_get_new_inodeEric Van Hensbergen1-28/+1
In the process of cleaning up inode number allocation, I noticed several functions which didn't use the standard helper allocators. This patch fixes the allocation in the mount entrypoint. Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-01-049p: Use length of data written to the server in preference to errorDavid Howells1-4/+3
In v9fs_upload_to_server(), we pass the error to netfslib to terminate the subreq rather than the amount of data written - even if we did actually write something. Further, we assume that the write is always entirely done if successful - but it might have been partially complete - as returned by p9_client_write(), but we ignore that. Fix this by indicating the amount written by preference and only returning the error if we didn't write anything. (We might want to return both in future if both are available as this might be useful as to whether we retry or not.) Suggested-by: Dominique Martinet <asmadeus@codewreck.org> Link: https://lore.kernel.org/r/ZZULNQAZ0n0WQv7p@codewreck.org/ Signed-off-by: David Howells <dhowells@redhat.com> Acked-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: v9fs@lists.linux.dev cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org
2024-01-049p: Do a couple of cleanupsDavid Howells1-8/+9
Do a couple of cleanups to 9p: (1) Remove a couple of unused variables. (2) Turn a BUG_ON() into a warning, consolidate with another warning and make the warning message include the inode number rather than whatever's in i_private (which will get hashed anyway). Suggested-by: Dominique Martinet <asmadeus@codewreck.org> Link: https://lore.kernel.org/r/ZZULNQAZ0n0WQv7p@codewreck.org/ Signed-off-by: David Howells <dhowells@redhat.com> Acked-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: v9fs@lists.linux.dev cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org