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* afs: Remove afs_dynroot_d_revalidate() as it is redundantDavid Howells2024-01-221-9/+0
| | | | | | | | | | | Remove afs_dynroot_d_revalidate() as it is redundant as all it does is return 1 and the caller assumes that if the op is not given. Suggested-by: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org
* Merge tag 'vfs-6.8.netfs' of ↵Linus Torvalds2024-01-191-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs Pull netfs updates from Christian Brauner: "This extends the netfs helper library that network filesystems can use to replace their own implementations. Both afs and 9p are ported. cifs is ready as well but the patches are way bigger and will be routed separately once this is merged. That will remove lots of code as well. The overal goal is to get high-level I/O and knowledge of the page cache and ouf of the filesystem drivers. This includes knowledge about the existence of pages and folios The pull request converts afs and 9p. This removes about 800 lines of code from afs and 300 from 9p. For 9p it is now possible to do writes in larger than a page chunks. Additionally, multipage folio support can be turned on for 9p. Separate patches exist for cifs removing another 2000+ lines. I've included detailed information in the individual pulls I took. Summary: - Add NFS-style (and Ceph-style) locking around DIO vs buffered I/O calls to prevent these from happening at the same time. - Support for direct and unbuffered I/O. - Support for write-through caching in the page cache. - O_*SYNC and RWF_*SYNC writes use write-through rather than writing to the page cache and then flushing afterwards. - Support for write-streaming. - Support for write grouping. - Skip reads for which the server could only return zeros or EOF. - The fscache module is now part of the netfs library and the corresponding maintainer entry is updated. - Some helpers from the fscache subsystem are renamed to mark them as belonging to the netfs library. - Follow-up fixes for the netfs library. - Follow-up fixes for the 9p conversion" * tag 'vfs-6.8.netfs' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (50 commits) netfs: Fix wrong #ifdef hiding wait cachefiles: Fix signed/unsigned mixup netfs: Fix the loop that unmarks folios after writing to the cache netfs: Fix interaction between write-streaming and cachefiles culling netfs: Count DIO writes netfs: Mark netfs_unbuffered_write_iter_locked() static netfs: Fix proc/fs/fscache symlink to point to "netfs" not "../netfs" netfs: Rearrange netfs_io_subrequest to put request pointer first 9p: Use length of data written to the server in preference to error 9p: Do a couple of cleanups 9p: Fix initialisation of netfs_inode for 9p cachefiles: Fix __cachefiles_prepare_write() 9p: Use netfslib read/write_iter afs: Use the netfs write helpers netfs: Export the netfs_sreq tracepoint netfs: Optimise away reads above the point at which there can be no data netfs: Implement a write-through caching option netfs: Provide a launder_folio implementation netfs: Provide a writepages implementation netfs, cachefiles: Pass upper bound length to allow expansion ...
| * netfs: Optimise away reads above the point at which there can be no dataDavid Howells2023-12-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* | Merge tag 'pull-dcache' of ↵Linus Torvalds2024-01-111-2/+3
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull dcache updates from Al Viro: "Change of locking rules for __dentry_kill(), regularized refcounting rules in that area, assorted cleanups and removal of weird corner cases (e.g. now ->d_iput() on child is always called before the parent might hit __dentry_kill(), etc)" * tag 'pull-dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits) dcache: remove unnecessary NULL check in dget_dlock() kill DCACHE_MAY_FREE __d_unalias() doesn't use inode argument d_alloc_parallel(): in-lookup hash insertion doesn't need an RCU variant get rid of DCACHE_GENOCIDE d_genocide(): move the extern into fs/internal.h simple_fill_super(): don't bother with d_genocide() on failure nsfs: use d_make_root() d_alloc_pseudo(): move setting ->d_op there from the (sole) caller kill d_instantate_anon(), fold __d_instantiate_anon() into remaining caller retain_dentry(): introduce a trimmed-down lockless variant __dentry_kill(): new locking scheme d_prune_aliases(): use a shrink list switch select_collect{,2}() to use of to_shrink_list() to_shrink_list(): call only if refcount is 0 fold dentry_kill() into dput() don't try to cut corners in shrink_lock_dentry() fold the call of retain_dentry() into fast_dput() Call retain_dentry() with refcount 0 dentry_kill(): don't bother with retain_dentry() on slow path ...
| * dentry: switch the lists of children to hlistAl Viro2023-11-251-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | Saves a pointer per struct dentry and actually makes the things less clumsy. Cleaned the d_walk() and dcache_readdir() a bit by use of hlist_for_... iterators. A couple of new helpers - d_first_child() and d_next_sibling(), to make the expressions less awful. Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | afs: Fix dynamic root lookup DNS checkDavid Howells2023-12-201-2/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the afs dynamic root directory, the ->lookup() function does a DNS check on the cell being asked for and if the DNS upcall reports an error it will report an error back to userspace (typically ENOENT). However, if a failed DNS upcall returns a new-style result, it will return a valid result, with the status field set appropriately to indicate the type of failure - and in that case, dns_query() doesn't return an error and we let stat() complete with no error - which can cause confusion in userspace as subsequent calls that trigger d_automount then fail with ENOENT. Fix this by checking the status result from a valid dns_query() and returning an error if it indicates a failure. Fixes: bbb4c4323a4d ("dns: Allow the dns resolver to retrieve a server set") Reported-by: Markus Suvanto <markus.suvanto@gmail.com> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=216637 Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Markus Suvanto <markus.suvanto@gmail.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* | afs: Fix the dynamic root's d_delete to always delete unused dentriesDavid Howells2023-12-201-12/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Fix the afs dynamic root's d_delete function to always delete unused dentries rather than only deleting them if they're positive. With things as they stand upstream, negative dentries stemming from failed DNS lookups stick around preventing retries. Fixes: 66c7e1d319a5 ("afs: Split the dynroot stuff out and give it its own ops tables") Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Markus Suvanto <markus.suvanto@gmail.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* | afs: Make error on cell lookup failure consistent with OpenAFSDavid Howells2023-11-171-2/+2
|/ | | | | | | | | | | | | | | | | | | | When kafs tries to look up a cell in the DNS or the local config, it will translate a lookup failure into EDESTADDRREQ whereas OpenAFS translates it into ENOENT. Applications such as West expect the latter behaviour and fail if they see the former. This can be seen by trying to mount an unknown cell: # mount -t afs %example.com:cell.root /mnt mount: /mnt: mount(2) system call failed: Destination address required. Fixes: 4d673da14533 ("afs: Support the AFS dynamic root") Reported-by: Markus Suvanto <markus.suvanto@gmail.com> Link: https://bugzilla.kernel.org/show_bug.cgi?id=216637 Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeffrey Altman <jaltman@auristor.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
* afs: convert to new timestamp accessorsJeff Layton2023-10-181-1/+1
| | | | | | | | Convert to using the new inode timestamp accessor functions. Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20231004185347.80880-16-jlayton@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
* afs: convert to ctime accessor functionsJeff Layton2023-07-131-1/+1
| | | | | | | | | | | In later patches, we're going to change how the inode's ctime field is used. Switch to using accessor functions instead of raw accesses of inode->i_ctime. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jeff Layton <jlayton@kernel.org> Message-Id: <20230705190309.579783-22-jlayton@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
* netfs: Further cleanups after struct netfs_inode wrapper introducedLinus Torvalds2022-06-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Change the signature of netfs helper functions to take a struct netfs_inode pointer rather than a struct inode pointer where appropriate, thereby relieving the need for the network filesystem to convert its internal inode format down to the VFS inode only for netfslib to bounce it back up. For type safety, it's better not to do that (and it's less typing too). Give netfs_write_begin() an extra argument to pass in a pointer to the netfs_inode struct rather than deriving it internally from the file pointer. Note that the ->write_begin() and ->write_end() ops are intended to be replaced in the future by netfslib code that manages this without the need to call in twice for each page. netfs_readpage() and similar are intended to be pointed at directly by the address_space_operations table, so must stick to the signature dictated by the function pointers there. Changes ======= - Updated the kerneldoc comments and documentation [DH]. Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/CAHk-=wgkwKyNmNdKpQkqZ6DnmUL-x9hp0YBnUGjaPFEAdxDTbw@mail.gmail.com/
* netfs: Fix gcc-12 warning by embedding vfs inode in netfs_i_contextDavid Howells2022-06-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <jlayton@kernel.org> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Xiubo Li <xiubli@redhat.com> cc: Jonathan Corbet <corbet@lwn.net> cc: Eric Van Hensbergen <ericvh@gmail.com> 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: Ilya Dryomov <idryomov@gmail.com> cc: Steve French <smfrench@gmail.com> cc: William Kucharski <william.kucharski@oracle.com> cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> cc: Dave Chinner <david@fromorbit.com> 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 <torvalds@linux-foundation.org>
* netfs: Add a netfs inode contextDavid Howells2022-03-181-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a netfs_i_context struct that should be included in the network filesystem's own inode struct wrapper, directly after the VFS's inode struct, e.g.: struct my_inode { struct { /* These must be contiguous */ struct inode vfs_inode; struct netfs_i_context netfs_ctx; }; }; The netfs_i_context struct so far contains a single field for the network filesystem to use - the cache cookie: struct netfs_i_context { ... struct fscache_cookie *cache; }; Three functions are provided to help with this: (1) void netfs_i_context_init(struct inode *inode, const struct netfs_request_ops *ops); Initialise the netfs context and set the operations. (2) struct netfs_i_context *netfs_i_context(struct inode *inode); Find the netfs context from the VFS inode. (3) struct inode *netfs_inode(struct netfs_i_context *ctx); Find the VFS inode from the netfs context. Changes ======= ver #4) - Fix netfs_is_cache_enabled() to check cookie->cache_priv to see if a cache is present[3]. - Fix netfs_skip_folio_read() to zero out all of the page, not just some of it[3]. ver #3) - Split out the bit to move ceph cap-getting on readahead into ceph_init_request()[1]. - Stick in a comment to the netfs inode structs indicating the contiguity requirements[2]. ver #2) - Adjust documentation to match. - Use "#if IS_ENABLED()" in netfs_i_cookie(), not "#ifdef". - Move the cap check from ceph_readahead() to ceph_init_request() to be called from netfslib. - Remove ceph_readahead() and use netfs_readahead() directly instead. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/8af0d47f17d89c06bbf602496dd845f2b0bf25b3.camel@kernel.org/ [1] Link: https://lore.kernel.org/r/beaf4f6a6c2575ed489adb14b257253c868f9a5c.camel@kernel.org/ [2] Link: https://lore.kernel.org/r/3536452.1647421585@warthog.procyon.org.uk/ [3] Link: https://lore.kernel.org/r/164622984545.3564931.15691742939278418580.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/164678213320.1200972.16807551936267647470.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/164692909854.2099075.9535537286264248057.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/306388.1647595110@warthog.procyon.org.uk/ # v4
* afs: Add tracing for cell refcount and active user countDavid Howells2020-10-161-2/+2
| | | | | | | | | | | Add a tracepoint to log the cell refcount and active user count and pass in a reason code through various functions that manipulate these counters. Additionally, a helper function, afs_see_cell(), is provided to log interesting places that deal with a cell without actually doing any accounting directly. Signed-off-by: David Howells <dhowells@redhat.com>
* afs: Fix cell refcounting by splitting the usage counterDavid Howells2020-10-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Management of the lifetime of afs_cell struct has some problems due to the usage counter being used to determine whether objects of that type are in use in addition to whether anyone might be interested in the structure. This is made trickier by cell objects being cached for a period of time in case they're quickly reused as they hold the result of a setup process that may be slow (DNS lookups, AFS RPC ops). Problems include the cached root volume from alias resolution pinning its parent cell record, rmmod occasionally hanging and occasionally producing assertion failures. Fix this by splitting the count of active users from the struct reference count. Things then work as follows: (1) The cell cache keeps +1 on the cell's activity count and this has to be dropped before the cell can be removed. afs_manage_cell() tries to exchange the 1 to a 0 with the cells_lock write-locked, and if successful, the record is removed from the net->cells. (2) One struct ref is 'owned' by the activity count. That is put when the active count is reduced to 0 (final_destruction label). (3) A ref can be held on a cell whilst it is queued for management on a work queue without confusing the active count. afs_queue_cell() is added to wrap this. (4) The queue's ref is dropped at the end of the management. This is split out into a separate function, afs_manage_cell_work(). (5) The root volume record is put after a cell is removed (at the final_destruction label) rather then in the RCU destruction routine. (6) Volumes hold struct refs, but aren't active users. (7) Both counts are displayed in /proc/net/afs/cells. There are some management function changes: (*) afs_put_cell() now just decrements the refcount and triggers the RCU destruction if it becomes 0. It no longer sets a timer to have the manager do this. (*) afs_use_cell() and afs_unuse_cell() are added to increase and decrease the active count. afs_unuse_cell() sets the management timer. (*) afs_queue_cell() is added to queue a cell with approprate refs. There are also some other fixes: (*) Don't let /proc/net/afs/cells access a cell's vllist if it's NULL. (*) Make sure that candidate cells in lookups are properly destroyed rather than being simply kfree'd. This ensures the bits it points to are destroyed also. (*) afs_dec_cells_outstanding() is now called in cell destruction rather than at "final_destruction". This ensures that cell->net is still valid to the end of the destructor. (*) As a consequence of the previous two changes, move the increment of net->cells_outstanding that was at the point of insertion into the tree to the allocation routine to correctly balance things. Fixes: 989782dcdc91 ("afs: Overhaul cell database management") Signed-off-by: David Howells <dhowells@redhat.com>
* afs: Fix rapid cell addition/removal by not using RCU on cells treeDavid Howells2020-10-161-13/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are a number of problems that are being seen by the rapidly mounting and unmounting an afs dynamic root with an explicit cell and volume specified (which should probably be rejected, but that's a separate issue): What the tests are doing is to look up/create a cell record for the name given and then tear it down again without actually using it to try to talk to a server. This is repeated endlessly, very fast, and the new cell collides with the old one if it's not quick enough to reuse it. It appears (as suggested by Hillf Danton) that the search through the RB tree under a read_seqbegin_or_lock() under RCU conditions isn't safe and that it's not blocking the write_seqlock(), despite taking two passes at it. He suggested that the code should take a ref on the cell it's attempting to look at - but this shouldn't be necessary until we've compared the cell names. It's possible that I'm missing a barrier somewhere. However, using an RCU search for this is overkill, really - we only need to access the cell name in a few places, and they're places where we're may end up sleeping anyway. Fix this by switching to an R/W semaphore instead. Additionally, draw the down_read() call inside the function (renamed to afs_find_cell()) since all the callers were taking the RCU read lock (or should've been[*]). [*] afs_probe_cell_name() should have been, but that doesn't appear to be involved in the bug reports. The symptoms of this look like: general protection fault, probably for non-canonical address 0xf27d208691691fdb: 0000 [#1] PREEMPT SMP KASAN KASAN: maybe wild-memory-access in range [0x93e924348b48fed8-0x93e924348b48fedf] ... RIP: 0010:strncasecmp lib/string.c:52 [inline] RIP: 0010:strncasecmp+0x5f/0x240 lib/string.c:43 afs_lookup_cell_rcu+0x313/0x720 fs/afs/cell.c:88 afs_lookup_cell+0x2ee/0x1440 fs/afs/cell.c:249 afs_parse_source fs/afs/super.c:290 [inline] ... Fixes: 989782dcdc91 ("afs: Overhaul cell database management") Reported-by: syzbot+459a5dce0b4cb70fd076@syzkaller.appspotmail.com Signed-off-by: David Howells <dhowells@redhat.com> cc: Hillf Danton <hdanton@sina.com> cc: syzkaller-bugs@googlegroups.com
* afs: Fix NULL deref in afs_dynroot_depopulate()David Howells2020-08-211-9/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If an error occurs during the construction of an afs superblock, it's possible that an error occurs after a superblock is created, but before we've created the root dentry. If the superblock has a dynamic root (ie. what's normally mounted on /afs), the afs_kill_super() will call afs_dynroot_depopulate() to unpin any created dentries - but this will oops if the root hasn't been created yet. Fix this by skipping that bit of code if there is no root dentry. This leads to an oops looking like: general protection fault, ... KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f] ... RIP: 0010:afs_dynroot_depopulate+0x25f/0x529 fs/afs/dynroot.c:385 ... Call Trace: afs_kill_super+0x13b/0x180 fs/afs/super.c:535 deactivate_locked_super+0x94/0x160 fs/super.c:335 afs_get_tree+0x1124/0x1460 fs/afs/super.c:598 vfs_get_tree+0x89/0x2f0 fs/super.c:1547 do_new_mount fs/namespace.c:2875 [inline] path_mount+0x1387/0x2070 fs/namespace.c:3192 do_mount fs/namespace.c:3205 [inline] __do_sys_mount fs/namespace.c:3413 [inline] __se_sys_mount fs/namespace.c:3390 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3390 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 which is oopsing on this line: inode_lock(root->d_inode); presumably because sb->s_root was NULL. Fixes: 0da0b7fd73e4 ("afs: Display manually added cells in dynamic root mount") Reported-by: syzbot+c1eff8205244ae7e11a6@syzkaller.appspotmail.com Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* afs: Build an abstraction around an "operation" conceptDavid Howells2020-06-041-0/+93
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Turn the afs_operation struct into the main way that most fileserver operations are managed. Various things are added to the struct, including the following: (1) All the parameters and results of the relevant operations are moved into it, removing corresponding fields from the afs_call struct. afs_call gets a pointer to the op. (2) The target volume is made the main focus of the operation, rather than the target vnode(s), and a bunch of op->vnode->volume are made op->volume instead. (3) Two vnode records are defined (op->file[]) for the vnode(s) involved in most operations. The vnode record (struct afs_vnode_param) contains: - The vnode pointer. - The fid of the vnode to be included in the parameters or that was returned in the reply (eg. FS.MakeDir). - The status and callback information that may be returned in the reply about the vnode. - Callback break and data version tracking for detecting simultaneous third-parth changes. (4) Pointers to dentries to be updated with new inodes. (5) An operations table pointer. The table includes pointers to functions for issuing AFS and YFS-variant RPCs, handling the success and abort of an operation and handling post-I/O-lock local editing of a directory. To make this work, the following function restructuring is made: (A) The rotation loop that issues calls to fileservers that can be found in each function that wants to issue an RPC (such as afs_mkdir()) is extracted out into common code, in a new file called fs_operation.c. (B) The rotation loops, such as the one in afs_mkdir(), are replaced with a much smaller piece of code that allocates an operation, sets the parameters and then calls out to the common code to do the actual work. (C) The code for handling the success and failure of an operation are moved into operation functions (as (5) above) and these are called from the core code at appropriate times. (D) The pseudo inode getting stuff used by the dynamic root code is moved over into dynroot.c. (E) struct afs_iget_data is absorbed into the operation struct and afs_iget() expects to be given an op pointer and a vnode record. (F) Point (E) doesn't work for the root dir of a volume, but we know the FID in advance (it's always vnode 1, unique 1), so a separate inode getter, afs_root_iget(), is provided to special-case that. (G) The inode status init/update functions now also take an op and a vnode record. (H) The RPC marshalling functions now, for the most part, just take an afs_operation struct as their only argument. All the data they need is held there. The result delivery functions write their answers there as well. (I) The call is attached to the operation and then the operation core does the waiting. And then the new operation code is, for the moment, made to just initialise the operation, get the appropriate vnode I/O locks and do the same rotation loop as before. This lays the foundation for the following changes in the future: (*) Overhauling the rotation (again). (*) Support for asynchronous I/O, where the fileserver rotation must be done asynchronously also. Signed-off-by: David Howells <dhowells@redhat.com>
* afs: Fix creation calls in the dynamic root to fail with EOPNOTSUPPDavid Howells2019-12-111-0/+3
| | | | | | | | | | | | | Fix the lookup method on the dynamic root directory such that creation calls, such as mkdir, open(O_CREAT), symlink, etc. fail with EOPNOTSUPP rather than failing with some odd error (such as EEXIST). lookup() itself tries to create automount directories when it is invoked. These are cached locally in RAM and not committed to storage. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> Tested-by: Jonathan Billings <jsbillings@jsbillings.org>
* afs dynroot: switch to simple_dir_operationsAl Viro2019-09-151-7/+0
| | | | | | no point reinventing it (with wrong ->read(), BTW). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge tag 'keys-namespace-20190627' of ↵Linus Torvalds2019-07-081-3/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull keyring namespacing from David Howells: "These patches help make keys and keyrings more namespace aware. Firstly some miscellaneous patches to make the process easier: - Simplify key index_key handling so that the word-sized chunks assoc_array requires don't have to be shifted about, making it easier to add more bits into the key. - Cache the hash value in the key so that we don't have to calculate on every key we examine during a search (it involves a bunch of multiplications). - Allow keying_search() to search non-recursively. Then the main patches: - Make it so that keyring names are per-user_namespace from the point of view of KEYCTL_JOIN_SESSION_KEYRING so that they're not accessible cross-user_namespace. keyctl_capabilities() shows KEYCTL_CAPS1_NS_KEYRING_NAME for this. - Move the user and user-session keyrings to the user_namespace rather than the user_struct. This prevents them propagating directly across user_namespaces boundaries (ie. the KEY_SPEC_* flags will only pick from the current user_namespace). - Make it possible to include the target namespace in which the key shall operate in the index_key. This will allow the possibility of multiple keys with the same description, but different target domains to be held in the same keyring. keyctl_capabilities() shows KEYCTL_CAPS1_NS_KEY_TAG for this. - Make it so that keys are implicitly invalidated by removal of a domain tag, causing them to be garbage collected. - Institute a network namespace domain tag that allows keys to be differentiated by the network namespace in which they operate. New keys that are of a type marked 'KEY_TYPE_NET_DOMAIN' are assigned the network domain in force when they are created. - Make it so that the desired network namespace can be handed down into the request_key() mechanism. This allows AFS, NFS, etc. to request keys specific to the network namespace of the superblock. This also means that the keys in the DNS record cache are thenceforth namespaced, provided network filesystems pass the appropriate network namespace down into dns_query(). For DNS, AFS and NFS are good, whilst CIFS and Ceph are not. Other cache keyrings, such as idmapper keyrings, also need to set the domain tag - for which they need access to the network namespace of the superblock" * tag 'keys-namespace-20190627' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: keys: Pass the network namespace into request_key mechanism keys: Network namespace domain tag keys: Garbage collect keys for which the domain has been removed keys: Include target namespace in match criteria keys: Move the user and user-session keyrings to the user_namespace keys: Namespace keyring names keys: Add a 'recurse' flag for keyring searches keys: Cache the hash value to avoid lots of recalculation keys: Simplify key description management
| * keys: Pass the network namespace into request_key mechanismDavid Howells2019-06-271-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | Create a request_key_net() function and use it to pass the network namespace domain tag into DNS revolver keys and rxrpc/AFS keys so that keys for different domains can coexist in the same keyring. Signed-off-by: David Howells <dhowells@redhat.com> cc: netdev@vger.kernel.org cc: linux-nfs@vger.kernel.org cc: linux-cifs@vger.kernel.org cc: linux-afs@lists.infradead.org
* | treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36Thomas Gleixner2019-05-241-5/+1
|/ | | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public licence as published by the free software foundation either version 2 of the licence or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 114 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190520170857.552531963@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* afs: Make dynamic root population wait uninterruptibly for proc_cells_lockDavid Howells2019-05-161-2/+1
| | | | | | Make dynamic root population wait uninterruptibly for proc_cells_lock. Signed-off-by: David Howells <dhowells@redhat.com>
* dns_resolver: Allow used keys to be invalidatedDavid Howells2019-05-151-1/+1
| | | | | | | | | | | | | Allow used DNS resolver keys to be invalidated after use if the caller is doing its own caching of the results. This reduces the amount of resources required. Fix AFS to invalidate DNS results to kill off permanent failure records that get lodged in the resolver keyring and prevent future lookups from happening. Fixes: 0a5143f2f89c ("afs: Implement VL server rotation") Signed-off-by: David Howells <dhowells@redhat.com>
* afs: Increase to 64-bit volume ID and 96-bit vnode ID for YFSDavid Howells2018-10-241-1/+1
| | | | | | | | | | | | | | Increase the sizes of the volume ID to 64 bits and the vnode ID (inode number equivalent) to 96 bits to allow the support of YFS. This requires the iget comparator to check the vnode->fid rather than i_ino and i_generation as i_ino is not sufficiently capacious. It also requires this data to be placed into the vnode cache key for fscache. For the moment, just discard the top 32 bits of the vnode ID when returning it though stat. Signed-off-by: David Howells <dhowells@redhat.com>
* afs: Implement VL server rotationDavid Howells2018-10-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Track VL servers as independent entities rather than lumping all their addresses together into one set and implement server-level rotation by: (1) Add the concept of a VL server list, where each server has its own separate address list. This code is similar to the FS server list. (2) Use the DNS resolver to retrieve a set of servers and their associated addresses, ports, preference and weight ratings. (3) In the case of a legacy DNS resolver or an address list given directly through /proc/net/afs/cells, create a list containing just a dummy server record and attach all the addresses to that. (4) Implement a simple rotation policy, for the moment ignoring the priorities and weights assigned to the servers. (5) Show the address list through /proc/net/afs/<cell>/vlservers. This also displays the source and status of the data as indicated by the upcall. Signed-off-by: David Howells <dhowells@redhat.com>
* afs: Fix cell proc listDavid Howells2018-10-121-1/+1
| | | | | | | | | | | | | | | | | | | | | Access to the list of cells by /proc/net/afs/cells has a couple of problems: (1) It should be checking against SEQ_START_TOKEN for the keying the header line. (2) It's only holding the RCU read lock, so it can't just walk over the list without following the proper RCU methods. Fix these by using an hlist instead of an ordinary list and using the appropriate accessor functions to follow it with RCU. Since the code that adds a cell to the list must also necessarily change, sort the list on insertion whilst we're at it. Fixes: 989782dcdc91 ("afs: Overhaul cell database management") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* afs_try_auto_mntpt(): return NULL instead of ERR_PTR(-ENOENT)Al Viro2018-08-051-11/+2
| | | | | | | simpler logics in callers that way Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* afs: switch dynroot lookups to d_splice_alias()Al Viro2018-08-051-15/+3
| | | | | | | | | ->lookup() methods can (and should) use d_splice_alias() instead of d_add(). Even if they are not going to be hit by open_by_handle(), code does get copied around... Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* afs: Display manually added cells in dynamic root mountDavid Howells2018-06-151-1/+123
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Alter the dynroot mount so that cells created by manipulation of /proc/fs/afs/cells and /proc/fs/afs/rootcell and by specification of a root cell as a module parameter will cause directories for those cells to be created in the dynamic root superblock for the network namespace[*]. To this end: (1) Only one dynamic root superblock is now created per network namespace and this is shared between all attempts to mount it. This makes it easier to find the superblock to modify. (2) When a dynamic root superblock is created, the list of cells is walked and directories created for each cell already defined. (3) When a new cell is added, if a dynamic root superblock exists, a directory is created for it. (4) When a cell is destroyed, the directory is removed. (5) These directories are created by calling lookup_one_len() on the root dir which automatically creates them if they don't exist. [*] Inasmuch as network namespaces are currently supported here. Signed-off-by: David Howells <dhowells@redhat.com>
* afs: Enable IPv6 DNS lookupsDavid Howells2018-06-151-1/+1
| | | | | | | Remove the restriction on DNS lookup upcalls that prevents ipv6 addresses from being looked up. Signed-off-by: David Howells <dhowells@redhat.com>
* afs: Split the dynroot stuff out and give it its own ops tablesDavid Howells2018-04-091-0/+209
Split the AFS dynamic root stuff out of the main directory handling file and into its own file as they share little in common. The dynamic root code also gets its own dentry and inode ops tables. Signed-off-by: David Howells <dhowells@redhat.com>