summaryrefslogtreecommitdiff
path: root/fs/9p
AgeCommit message (Collapse)Author
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>
2024-05-29Merge tag '9p-for-6.10-rc2' of https://github.com/martinetd/linuxLinus Torvalds
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 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>
2024-05-239p: add missing locking around taking dentry fid listDominique Martinet
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 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, 9p: Implement helpers for new write codeDavid Howells
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 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: 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 Hensbergen
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>
2024-04-11fs/9p: drop inodes immediately on non-.L tooJoakim Sindholt
Signed-off-by: Joakim Sindholt <opensource@zhasha.com> Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2024-04-11fs/9p: Revert "fs/9p: fix dups even in uncached mode"Eric Van Hensbergen
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>
2024-04-09fs/9p: remove erroneous nlink init from legacy stat2inodeEric Van Hensbergen
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 Layton
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 Sindholt
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 Sindholt
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 Sindholt
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 Hensbergen
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 King
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 Xu
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 Torvalds
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
2024-03-12mm, slab: remove last vestiges of SLAB_MEM_SPREADLinus Torvalds
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 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-v3-34-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 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>
2024-02-059p: rename fl_type variable in v9fs_file_do_lockJeff Layton
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 Hensbergen
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 Hensbergen
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 Hensbergen
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 Hensbergen
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 Hensbergen
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 Hensbergen
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 Hensbergen
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 Hensbergen
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 Howells
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 Howells
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
2024-01-039p: Fix initialisation of netfs_inode for 9pDavid Howells
The 9p filesystem is calling netfs_inode_init() in v9fs_init_inode() - before the struct inode fields have been initialised from the obtained file stats (ie. after v9fs_stat2inode*() has been called), but netfslib wants to set a couple of its fields from i_size. Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Marc Dionne <marc.dionne@auristor.com> Tested-by: Dominique Martinet <asmadeus@codewreck.org> Acked-by: Dominique Martinet <asmadeus@codewreck.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: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org
2023-12-289p: Use netfslib read/write_iterDavid Howells
Use netfslib's read and write iteration helpers, allowing netfslib to take over the management of the page cache for 9p files and to manage local disk caching. In particular, this eliminates write_begin, write_end, writepage and all mentions of struct page and struct folio from 9p. Note that netfslib now offers the possibility of write-through caching if that is desirable for 9p: just set the NETFS_ICTX_WRITETHROUGH flag in v9inode->netfs.flags in v9fs_set_netfs_context(). Note also this is untested as I can't get ganesha.nfsd to correctly parse the config to turn on 9p support. 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: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org
2023-12-28netfs: Optimise away reads above the point at which there can be no dataDavid Howells
Track the file position above which the server is not expected to have any data (the "zero point") and preemptively assume that we can satisfy requests by filling them with zeroes locally rather than attempting to download them if they're over that line - even if we've written data back to the server. Assume that any data that was written back above that position is held in the local cache. Note that we have to split requests that straddle the line. Make use of this to optimise away some reads from the server. We need to set the zero point in the following circumstances: (1) When we see an extant remote inode and have no cache for it, we set the zero_point to i_size. (2) On local inode creation, we set zero_point to 0. (3) On local truncation down, we reduce zero_point to the new i_size if the new i_size is lower. (4) On local truncation up, we don't change zero_point. (5) On local modification, we don't change zero_point. (6) On remote invalidation, we set zero_point to the new i_size. (7) If stored data is discarded from the pagecache or culled from fscache, we must set zero_point above that if the data also got written to the server. (8) If dirty data is written back to the server, but not fscache, we must set zero_point above that. (9) If a direct I/O write is made, set zero_point above that. Assuming the above, any read from the server at or above the zero_point position will return all zeroes. The zero_point value can be stored in the cache, provided the above rules are applied to it by any code that culls part of the local cache. Signed-off-by: David Howells <dhowells@redhat.com> cc: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org
2023-12-24netfs: Provide invalidate_folio and release_folio callsDavid Howells
Provide default invalidate_folio and release_folio calls. These will need to interact with invalidation correctly at some point. They will be needed if netfslib is to make use of folio->private for its own purposes. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org
2023-12-24netfs: Move pinning-for-writeback from fscache to netfsDavid Howells
Move the resource pinning-for-writeback from fscache code to netfslib code. This is used to keep a cache backing object pinned whilst we have dirty pages on the netfs inode in the pagecache such that VM writeback will be able to reach it. Whilst we're at it, switch the parameters of netfs_unpin_writeback() to match ->write_inode() so that it can be used for that directly. Note that this mechanism could be more generically useful than that for network filesystems. Quite often they have to keep around other resources (e.g. authentication tokens or network connections) until the writeback is complete. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org
2023-12-24netfs, fscache: Remove ->begin_cache_operationDavid Howells
Remove ->begin_cache_operation() in favour of just calling fscache directly. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: Christian Brauner <christian@brauner.io> cc: linux-fsdevel@vger.kernel.org cc: linux-cachefs@redhat.com
2023-11-04Merge tag '9p-for-6.7-rc1' of https://github.com/martinetd/linuxLinus Torvalds
Pull 9p updates from Dominique Martinet: A bunch of small fixes: - three W=1 warning fixes: the NULL -> "" replacement isn't trivial but is serialized identically by the protocol layer and has been tested - one syzbot/KCSAN datarace annotation where we don't care about users messing with the fd they passed to mount -t 9p - removing a declaration without implementation - yet another race fix for trans_fd around connection close: the 'err' field is also used in potentially racy calls and this isn't complete, but it's better than what we had - and finally a theorical memory leak fix on serialization failure" * tag '9p-for-6.7-rc1' of https://github.com/martinetd/linux: 9p/net: fix possible memory leak in p9_check_errors() 9p/fs: add MODULE_DESCRIPTION 9p/net: xen: fix false positive printf format overflow warning 9p: v9fs_listxattr: fix %s null argument warning 9p/trans_fd: Annotate data-racy writes to file::f_flags fs/9p: Remove unused function declaration v9fs_inode2stat() 9p/trans_fd: avoid sending req to a cancelled conn
2023-10-30Merge tag 'vfs-6.7.ctime' of ↵Linus Torvalds
gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs Pull vfs inode time accessor updates from Christian Brauner: "This finishes the conversion of all inode time fields to accessor functions as discussed on list. Changing timestamps manually as we used to do before is error prone. Using accessors function makes this robust. It does not contain the switch of the time fields to discrete 64 bit integers to replace struct timespec and free up space in struct inode. But after this, the switch can be trivially made and the patch should only affect the vfs if we decide to do it" * tag 'vfs-6.7.ctime' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (86 commits) fs: rename inode i_atime and i_mtime fields security: convert to new timestamp accessors selinux: convert to new timestamp accessors apparmor: convert to new timestamp accessors sunrpc: convert to new timestamp accessors mm: convert to new timestamp accessors bpf: convert to new timestamp accessors ipc: convert to new timestamp accessors linux: convert to new timestamp accessors zonefs: convert to new timestamp accessors xfs: convert to new timestamp accessors vboxsf: convert to new timestamp accessors ufs: convert to new timestamp accessors udf: convert to new timestamp accessors ubifs: convert to new timestamp accessors tracefs: convert to new timestamp accessors sysv: convert to new timestamp accessors squashfs: convert to new timestamp accessors server: convert to new timestamp accessors client: convert to new timestamp accessors ...
2023-10-279p/fs: add MODULE_DESCIPTIONDominique Martinet
Fix modpost warning that MODULE_DESCRIPTION is missing in fs/9p/9p.o Signed-off-by: Dominique Martinet <asmadeus@codewreck.org> Message-ID: <20231025223107.1274963-1-asmadeus@codewreck.org> Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com>
2023-10-269p: v9fs_listxattr: fix %s null argument warningDominique Martinet
W=1 warns about null argument to kprintf: In file included from fs/9p/xattr.c:12: In function ‘v9fs_xattr_get’, inlined from ‘v9fs_listxattr’ at fs/9p/xattr.c:142:9: include/net/9p/9p.h:55:2: error: ‘%s’ directive argument is null [-Werror=format-overflow=] 55 | _p9_debug(level, __func__, fmt, ##__VA_ARGS__) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Use an empty string instead of : - this is ok 9p-wise because p9pdu_vwritef serializes a null string and an empty string the same way (one '0' word for length) - since this degrades the print statements, add new single quotes for xattr's name delimter (Old: "file = (null)", new: "file = ''") Link: https://lore.kernel.org/r/20231008060138.517057-1-suhui@nfschina.com Suggested-by: Su Hui <suhui@nfschina.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org> Acked-by: Christian Schoenebeck <linux_oss@crudebyte.com> Message-ID: <20231025103445.1248103-2-asmadeus@codewreck.org>
2023-10-24fs/9p: Remove unused function declaration v9fs_inode2stat()Yue Haibing
Commit 531b1094b743 ("[PATCH] v9fs: zero copy implementation") declared but never implemented this. Signed-off-by: Yue Haibing <yuehaibing@huawei.com> Message-ID: <20230807141726.38860-1-yuehaibing@huawei.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2023-10-189p: convert to new timestamp accessorsJeff Layton
Convert to using the new inode timestamp accessor functions. Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20231004185347.80880-13-jlayton@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-099p: move xattr-related structs to .rodataWedson Almeida Filho
This makes it harder for accidental or malicious changes to v9fs_xattr_user_handler, v9fs_xattr_trusted_handler, v9fs_xattr_security_handler, or v9fs_xattr_handlers at runtime. 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 Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/r/20230930050033.41174-4-wedsonaf@gmail.com Acked-by: Dominique Martinet <asmadeus@codewreck.org> Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-29Merge tag 'mm-stable-2023-08-28-18-26' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Some swap cleanups from Ma Wupeng ("fix WARN_ON in add_to_avail_list") - Peter Xu has a series (mm/gup: Unify hugetlb, speed up thp") which reduces the special-case code for handling hugetlb pages in GUP. It also speeds up GUP handling of transparent hugepages. - Peng Zhang provides some maple tree speedups ("Optimize the fast path of mas_store()"). - Sergey Senozhatsky has improved te performance of zsmalloc during compaction (zsmalloc: small compaction improvements"). - Domenico Cerasuolo has developed additional selftest code for zswap ("selftests: cgroup: add zswap test program"). - xu xin has doe some work on KSM's handling of zero pages. These changes are mainly to enable the user to better understand the effectiveness of KSM's treatment of zero pages ("ksm: support tracking KSM-placed zero-pages"). - Jeff Xu has fixes the behaviour of memfd's MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED sysctl ("mm/memfd: fix sysctl MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED"). - David Howells has fixed an fscache optimization ("mm, netfs, fscache: Stop read optimisation when folio removed from pagecache"). - Axel Rasmussen has given userfaultfd the ability to simulate memory poisoning ("add UFFDIO_POISON to simulate memory poisoning with UFFD"). - Miaohe Lin has contributed some routine maintenance work on the memory-failure code ("mm: memory-failure: remove unneeded PageHuge() check"). - Peng Zhang has contributed some maintenance work on the maple tree code ("Improve the validation for maple tree and some cleanup"). - Hugh Dickins has optimized the collapsing of shmem or file pages into THPs ("mm: free retracted page table by RCU"). - Jiaqi Yan has a patch series which permits us to use the healthy subpages within a hardware poisoned huge page for general purposes ("Improve hugetlbfs read on HWPOISON hugepages"). - Kemeng Shi has done some maintenance work on the pagetable-check code ("Remove unused parameters in page_table_check"). - More folioification work from Matthew Wilcox ("More filesystem folio conversions for 6.6"), ("Followup folio conversions for zswap"). And from ZhangPeng ("Convert several functions in page_io.c to use a folio"). - page_ext cleanups from Kemeng Shi ("minor cleanups for page_ext"). - Baoquan He has converted some architectures to use the GENERIC_IOREMAP ioremap()/iounmap() code ("mm: ioremap: Convert architectures to take GENERIC_IOREMAP way"). - Anshuman Khandual has optimized arm64 tlb shootdown ("arm64: support batched/deferred tlb shootdown during page reclamation/migration"). - Better maple tree lockdep checking from Liam Howlett ("More strict maple tree lockdep"). Liam also developed some efficiency improvements ("Reduce preallocations for maple tree"). - Cleanup and optimization to the secondary IOMMU TLB invalidation, from Alistair Popple ("Invalidate secondary IOMMU TLB on permission upgrade"). - Ryan Roberts fixes some arm64 MM selftest issues ("selftests/mm fixes for arm64"). - Kemeng Shi provides some maintenance work on the compaction code ("Two minor cleanups for compaction"). - Some reduction in mmap_lock pressure from Matthew Wilcox ("Handle most file-backed faults under the VMA lock"). - Aneesh Kumar contributes code to use the vmemmap optimization for DAX on ppc64, under some circumstances ("Add support for DAX vmemmap optimization for ppc64"). - page-ext cleanups from Kemeng Shi ("add page_ext_data to get client data in page_ext"), ("minor cleanups to page_ext header"). - Some zswap cleanups from Johannes Weiner ("mm: zswap: three cleanups"). - kmsan cleanups from ZhangPeng ("minor cleanups for kmsan"). - VMA handling cleanups from Kefeng Wang ("mm: convert to vma_is_initial_heap/stack()"). - DAMON feature work from SeongJae Park ("mm/damon/sysfs-schemes: implement DAMOS tried total bytes file"), ("Extend DAMOS filters for address ranges and DAMON monitoring targets"). - Compaction work from Kemeng Shi ("Fixes and cleanups to compaction"). - Liam Howlett has improved the maple tree node replacement code ("maple_tree: Change replacement strategy"). - ZhangPeng has a general code cleanup - use the K() macro more widely ("cleanup with helper macro K()"). - Aneesh Kumar brings memmap-on-memory to ppc64 ("Add support for memmap on memory feature on ppc64"). - pagealloc cleanups from Kemeng Shi ("Two minor cleanups for pcp list in page_alloc"), ("Two minor cleanups for get pageblock migratetype"). - Vishal Moola introduces a memory descriptor for page table tracking, "struct ptdesc" ("Split ptdesc from struct page"). - memfd selftest maintenance work from Aleksa Sarai ("memfd: cleanups for vm.memfd_noexec"). - MM include file rationalization from Hugh Dickins ("arch: include asm/cacheflush.h in asm/hugetlb.h"). - THP debug output fixes from Hugh Dickins ("mm,thp: fix sloppy text output"). - kmemleak improvements from Xiaolei Wang ("mm/kmemleak: use object_cache instead of kmemleak_initialized"). - More folio-related cleanups from Matthew Wilcox ("Remove _folio_dtor and _folio_order"). - A VMA locking scalability improvement from Suren Baghdasaryan ("Per-VMA lock support for swap and userfaults"). - pagetable handling cleanups from Matthew Wilcox ("New page table range API"). - A batch of swap/thp cleanups from David Hildenbrand ("mm/swap: stop using page->private on tail pages for THP_SWAP + cleanups"). - Cleanups and speedups to the hugetlb fault handling from Matthew Wilcox ("Change calling convention for ->huge_fault"). - Matthew Wilcox has also done some maintenance work on the MM subsystem documentation ("Improve mm documentation"). * tag 'mm-stable-2023-08-28-18-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (489 commits) maple_tree: shrink struct maple_tree maple_tree: clean up mas_wr_append() secretmem: convert page_is_secretmem() to folio_is_secretmem() nios2: fix flush_dcache_page() for usage from irq context hugetlb: add documentation for vma_kernel_pagesize() mm: add orphaned kernel-doc to the rst files. mm: fix clean_record_shared_mapping_range kernel-doc mm: fix get_mctgt_type() kernel-doc mm: fix kernel-doc warning from tlb_flush_rmaps() mm: remove enum page_entry_size mm: allow ->huge_fault() to be called without the mmap_lock held mm: move PMD_ORDER to pgtable.h mm: remove checks for pte_index memcg: remove duplication detection for mem_cgroup_uncharge_swap mm/huge_memory: work on folio->swap instead of page->private when splitting folio mm/swap: inline folio_set_swap_entry() and folio_swap_entry() mm/swap: use dedicated entry for swap in folio mm/swap: stop using page->private on tail pages for THP_SWAP selftests/mm: fix WARNING comparing pointer to 0 selftests: cgroup: fix test_kmem_memcg_deletion kernel mem check ...
2023-08-28Merge tag 'v6.6-vfs.ctime' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs timestamp updates from Christian Brauner: "This adds VFS support for multi-grain timestamps and converts tmpfs, xfs, ext4, and btrfs to use them. This carries acks from all relevant filesystems. The VFS always uses coarse-grained timestamps when updating the ctime and mtime after a change. This has the benefit of allowing filesystems to optimize away a lot of metadata updates, down to around 1 per jiffy, even when a file is under heavy writes. Unfortunately, this has always been an issue when we're exporting via NFSv3, which relies on timestamps to validate caches. A lot of changes can happen in a jiffy, so timestamps aren't sufficient to help the client decide to invalidate the cache. Even with NFSv4, a lot of exported filesystems don't properly support a change attribute and are subject to the same problems with timestamp granularity. Other applications have similar issues with timestamps (e.g., backup applications). If we were to always use fine-grained timestamps, that would improve the situation, but that becomes rather expensive, as the underlying filesystem would have to log a lot more metadata updates. This introduces fine-grained timestamps that are used when they are actively queried. This uses the 31st bit of the ctime tv_nsec field to indicate that something has queried the inode for the mtime or ctime. When this flag is set, on the next mtime or ctime update, the kernel will fetch a fine-grained timestamp instead of the usual coarse-grained one. As POSIX generally mandates that when the mtime changes, the ctime must also change the kernel always stores normalized ctime values, so only the first 30 bits of the tv_nsec field are ever used. Filesytems can opt into this behavior by setting the FS_MGTIME flag in the fstype. Filesystems that don't set this flag will continue to use coarse-grained timestamps. Various preparatory changes, fixes and cleanups are included: - Fixup all relevant places where POSIX requires updating ctime together with mtime. This is a wide-range of places and all maintainers provided necessary Acks. - Add new accessors for inode->i_ctime directly and change all callers to rely on them. Plain accesses to inode->i_ctime are now gone and it is accordingly rename to inode->__i_ctime and commented as requiring accessors. - Extend generic_fillattr() to pass in a request mask mirroring in a sense the statx() uapi. This allows callers to pass in a request mask to only get a subset of attributes filled in. - Rework timestamp updates so it's possible to drop the @now parameter the update_time() inode operation and associated helpers. - Add inode_update_timestamps() and convert all filesystems to it removing a bunch of open-coding" * tag 'v6.6-vfs.ctime' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (107 commits) btrfs: convert to multigrain timestamps ext4: switch to multigrain timestamps xfs: switch to multigrain timestamps tmpfs: add support for multigrain timestamps fs: add infrastructure for multigrain timestamps fs: drop the timespec64 argument from update_time xfs: have xfs_vn_update_time gets its own timestamp fat: make fat_update_time get its own timestamp fat: remove i_version handling from fat_update_time ubifs: have ubifs_update_time use inode_update_timestamps btrfs: have it use inode_update_timestamps fs: drop the timespec64 arg from generic_update_time fs: pass the request_mask to generic_fillattr fs: remove silly warning from current_time gfs2: fix timestamp handling on quota inodes fs: rename i_ctime field to __i_ctime selinux: convert to ctime accessor functions security: convert to ctime accessor functions apparmor: convert to ctime accessor functions sunrpc: convert to ctime accessor functions ...
2023-08-18mm, netfs, fscache: stop read optimisation when folio removed from pagecacheDavid Howells
Fscache has an optimisation by which reads from the cache are skipped until we know that (a) there's data there to be read and (b) that data isn't entirely covered by pages resident in the netfs pagecache. This is done with two flags manipulated by fscache_note_page_release(): if (... test_bit(FSCACHE_COOKIE_HAVE_DATA, &cookie->flags) && test_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags)) clear_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags); where the NO_DATA_TO_READ flag causes cachefiles_prepare_read() to indicate that netfslib should download from the server or clear the page instead. The fscache_note_page_release() function is intended to be called from ->releasepage() - but that only gets called if PG_private or PG_private_2 is set - and currently the former is at the discretion of the network filesystem and the latter is only set whilst a page is being written to the cache, so sometimes we miss clearing the optimisation. Fix this by following Willy's suggestion[1] and adding an address_space flag, AS_RELEASE_ALWAYS, that causes filemap_release_folio() to always call ->release_folio() if it's set, even if PG_private or PG_private_2 aren't set. Note that this would require folio_test_private() and page_has_private() to become more complicated. To avoid that, in the places[*] where these are used to conditionalise calls to filemap_release_folio() and try_to_release_page(), the tests are removed the those functions just jumped to unconditionally and the test is performed there. [*] There are some exceptions in vmscan.c where the check guards more than just a call to the releaser. I've added a function, folio_needs_release() to wrap all the checks for that. AS_RELEASE_ALWAYS should be set if a non-NULL cookie is obtained from fscache and cleared in ->evict_inode() before truncate_inode_pages_final() is called. Additionally, the FSCACHE_COOKIE_NO_DATA_TO_READ flag needs to be cleared and the optimisation cancelled if a cachefiles object already contains data when we open it. [dwysocha@redhat.com: call folio_mapping() inside folio_needs_release()] Link: https://github.com/DaveWysochanskiRH/kernel/commit/902c990e311120179fa5de99d68364b2947b79ec Link: https://lkml.kernel.org/r/20230628104852.3391651-3-dhowells@redhat.com Fixes: 1f67e6d0b188 ("fscache: Provide a function to note the release of a page") Fixes: 047487c947e8 ("cachefiles: Implement the I/O routines") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Reported-by: Rohith Surabattula <rohiths.msft@gmail.com> Suggested-by: Matthew Wilcox <willy@infradead.org> Tested-by: SeongJae Park <sj@kernel.org> Cc: Daire Byrne <daire.byrne@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Steve French <sfrench@samba.org> Cc: Shyam Prasad N <nspmangalore@gmail.com> Cc: Rohith Surabattula <rohiths.msft@gmail.com> Cc: Dave Wysochanski <dwysocha@redhat.com> Cc: Dominique Martinet <asmadeus@codewreck.org> Cc: Ilya Dryomov <idryomov@gmail.com> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jingbo Xu <jefflexu@linux.alibaba.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Xiubo Li <xiubli@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>