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2024-01-11Merge tag 'pull-dcache' of ↵Linus Torvalds
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 ...
2024-01-10Merge tag 'hardening-v6.8-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardening updates from Kees Cook: - Introduce the param_unknown_fn type and other clean ups (Andy Shevchenko) - Various __counted_by annotations (Christophe JAILLET, Gustavo A. R. Silva, Kees Cook) - Add KFENCE test to LKDTM (Stephen Boyd) - Various strncpy() refactorings (Justin Stitt) - Fix qnx4 to avoid writing into the smaller of two overlapping buffers - Various strlcpy() refactorings * tag 'hardening-v6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: qnx4: Use get_directory_fname() in qnx4_match() qnx4: Extract dir entry filename processing into helper atags_proc: Add __counted_by for struct buffer and use struct_size() tracing/uprobe: Replace strlcpy() with strscpy() params: Fix multi-line comment style params: Sort headers params: Use size_add() for kmalloc() params: Do not go over the limit when getting the string length params: Introduce the param_unknown_fn type lkdtm: Add kfence read after free crash type nvme-fc: replace deprecated strncpy with strscpy nvdimm/btt: replace deprecated strncpy with strscpy nvme-fabrics: replace deprecated strncpy with strscpy drm/modes: replace deprecated strncpy with strscpy_pad afs: Add __counted_by for struct afs_acl and use struct_size() VMCI: Annotate struct vmci_handle_arr with __counted_by i40e: Annotate struct i40e_qvlist_info with __counted_by HID: uhid: replace deprecated strncpy with strscpy samples: Replace strlcpy() with strscpy() SUNRPC: Replace strlcpy() with strscpy()
2024-01-10Merge tag 'afs-fix-rotation-20240105' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull afs updates from David Howells: "The majority of the patches are aimed at fixing and improving the AFS filesystem's rotation over server IP addresses, but there are also some fixes from Oleg Nesterov for the use of read_seqbegin_or_lock(). - Fix fileserver probe handling so that the next round of probes doesn't break ongoing server/address rotation by clearing all the probe result tracking. This could occasionally cause the rotation algorithm to drop straight through, give a 'successful' result without actually emitting any RPC calls, leaving the reply buffer in an undefined state. Instead, detach the probe results into a separate struct and allocate a new one each time we start probing and update the pointer to it. Probes are also sent in order of address preference to try and improve the chance that the preferred one will complete first. - Fix server rotation so that it uses configurable address preferences across on the probes that have completed so far than ranking them by RTT as the latter doesn't necessarily give the best route. The preference list can be altered by writing into /proc/net/afs/addr_prefs. - Fix the handling of Read-Only (and Backup) volume callbacks as there is one per volume, not one per file, so if someone performs a command that, say, offlines the volume but doesn't change it, when it comes back online we don't spam the server with a status fetch for every vnode we're using. Instead, check the Creation timestamp in the VolSync record when prompted by a callback break. - Handle volume regression (ie. a RW volume being restored from a backup) by scrubbing all cache data for that volume. This is detected from the VolSync creation timestamp. - Adjust abort handling and abort -> error mapping to match better with what other AFS clients do. - Fix offline and busy volume state handling as they only apply to individual server instances and not entire volumes and the rotation algorithm should go and look at other servers if available. Also make it sleep briefly before each retry if all the volume instances are unavailable" * tag 'afs-fix-rotation-20240105' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: (40 commits) afs: trace: Log afs_make_call(), including server address afs: Fix offline and busy message emission afs: Fix fileserver rotation afs: Overhaul invalidation handling to better support RO volumes afs: Parse the VolSync record in the reply of a number of RPC ops afs: Don't leave DONTUSE/NEWREPSITE servers out of server list afs: Fix comment in afs_do_lookup() afs: Apply server breaks to mmap'd files in the call processor afs: Move the vnode/volume validity checking code into its own file afs: Defer volume record destruction to a workqueue afs: Make it possible to find the volumes that are using a server afs: Combine the endpoint state bools into a bitmask afs: Keep a record of the current fileserver endpoint state afs: Dispatch vlserver probes in priority order afs: Dispatch fileserver probes in priority order afs: Mark address lists with configured priorities afs: Provide a way to configure address priorities afs: Remove the unimplemented afs_cmp_addr_list() afs: Add some more info to /proc/net/afs/servers rxrpc: Create a procfile to display outstanding client conn bundles ...
2024-01-09Merge tag 'mm-stable-2024-01-08-15-31' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "Many singleton patches against the MM code. The patch series which are included in this merge do the following: - Peng Zhang has done some mapletree maintainance work in the series 'maple_tree: add mt_free_one() and mt_attr() helpers' 'Some cleanups of maple tree' - In the series 'mm: use memmap_on_memory semantics for dax/kmem' Vishal Verma has altered the interworking between memory-hotplug and dax/kmem so that newly added 'device memory' can more easily have its memmap placed within that newly added memory. - Matthew Wilcox continues folio-related work (including a few fixes) in the patch series 'Add folio_zero_tail() and folio_fill_tail()' 'Make folio_start_writeback return void' 'Fix fault handler's handling of poisoned tail pages' 'Convert aops->error_remove_page to ->error_remove_folio' 'Finish two folio conversions' 'More swap folio conversions' - Kefeng Wang has also contributed folio-related work in the series 'mm: cleanup and use more folio in page fault' - Jim Cromie has improved the kmemleak reporting output in the series 'tweak kmemleak report format'. - In the series 'stackdepot: allow evicting stack traces' Andrey Konovalov to permits clients (in this case KASAN) to cause eviction of no longer needed stack traces. - Charan Teja Kalla has fixed some accounting issues in the page allocator's atomic reserve calculations in the series 'mm: page_alloc: fixes for high atomic reserve caluculations'. - Dmitry Rokosov has added to the samples/ dorectory some sample code for a userspace memcg event listener application. See the series 'samples: introduce cgroup events listeners'. - Some mapletree maintanance work from Liam Howlett in the series 'maple_tree: iterator state changes'. - Nhat Pham has improved zswap's approach to writeback in the series 'workload-specific and memory pressure-driven zswap writeback'. - DAMON/DAMOS feature and maintenance work from SeongJae Park in the series 'mm/damon: let users feed and tame/auto-tune DAMOS' 'selftests/damon: add Python-written DAMON functionality tests' 'mm/damon: misc updates for 6.8' - Yosry Ahmed has improved memcg's stats flushing in the series 'mm: memcg: subtree stats flushing and thresholds'. - In the series 'Multi-size THP for anonymous memory' Ryan Roberts has added a runtime opt-in feature to transparent hugepages which improves performance by allocating larger chunks of memory during anonymous page faults. - Matthew Wilcox has also contributed some cleanup and maintenance work against eh buffer_head code int he series 'More buffer_head cleanups'. - Suren Baghdasaryan has done work on Andrea Arcangeli's series 'userfaultfd move option'. UFFDIO_MOVE permits userspace heap compaction algorithms to move userspace's pages around rather than UFFDIO_COPY'a alloc/copy/free. - Stefan Roesch has developed a 'KSM Advisor', in the series 'mm/ksm: Add ksm advisor'. This is a governor which tunes KSM's scanning aggressiveness in response to userspace's current needs. - Chengming Zhou has optimized zswap's temporary working memory use in the series 'mm/zswap: dstmem reuse optimizations and cleanups'. - Matthew Wilcox has performed some maintenance work on the writeback code, both code and within filesystems. The series is 'Clean up the writeback paths'. - Andrey Konovalov has optimized KASAN's handling of alloc and free stack traces for secondary-level allocators, in the series 'kasan: save mempool stack traces'. - Andrey also performed some KASAN maintenance work in the series 'kasan: assorted clean-ups'. - David Hildenbrand has gone to town on the rmap code. Cleanups, more pte batching, folio conversions and more. See the series 'mm/rmap: interface overhaul'. - Kinsey Ho has contributed some maintenance work on the MGLRU code in the series 'mm/mglru: Kconfig cleanup'. - Matthew Wilcox has contributed lruvec page accounting code cleanups in the series 'Remove some lruvec page accounting functions'" * tag 'mm-stable-2024-01-08-15-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (361 commits) mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER mm, treewide: introduce NR_PAGE_ORDERS selftests/mm: add separate UFFDIO_MOVE test for PMD splitting selftests/mm: skip test if application doesn't has root privileges selftests/mm: conform test to TAP format output selftests: mm: hugepage-mmap: conform to TAP format output selftests/mm: gup_test: conform test to TAP format output mm/selftests: hugepage-mremap: conform test to TAP format output mm/vmstat: move pgdemote_* out of CONFIG_NUMA_BALANCING mm: zsmalloc: return -ENOSPC rather than -EINVAL in zs_malloc while size is too large mm/memcontrol: remove __mod_lruvec_page_state() mm/khugepaged: use a folio more in collapse_file() slub: use a folio in __kmalloc_large_node slub: use folio APIs in free_large_kmalloc() slub: use alloc_pages_node() in alloc_slab_page() mm: remove inc/dec lruvec page state functions mm: ratelimit stat flush from workingset shrinker kasan: stop leaking stack trace handles mm/mglru: remove CONFIG_TRANSPARENT_HUGEPAGE mm/mglru: add dummy pmd_dirty() ...
2024-01-01afs: trace: Log afs_make_call(), including server addressDavid Howells
Add a tracepoint to log calls to afs_make_call(), including the destination server address. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2024-01-01afs: Fix offline and busy message emissionDavid Howells
The current code assumes that offline and busy volume states apply to all instances of a volume, not just the one on the server that returned VOFFLINE or VBUSY and will emit a notice to dmesg suggesting that the entire volume is unavailable. Fix that by moving the flags recording this to the afs_server_entry struct that is used to represent a particular instance of a volume on a specific server. The notice is altered to include the server UUID also. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2024-01-01afs: Fix fileserver rotationDavid Howells
Fix the fileserver rotation so that it doesn't use RTT as the basis for deciding which server and address to use as this doesn't necessarily give a good indication of the best path. Instead, use the configurable preference list in conjunction with whatever probes have succeeded at the time of looking. To this end, make the following changes: (1) Keep an array of "server states" to track what addresses we've tried on each server and move the waitqueue entries there that we'll need for probing. (2) Each afs_server_state struct is made to pin the corresponding server's endpoint state rather than the afs_operation struct carrying a pin on the server we're currently looking at. (3) Drop the server list preference; we now always rescan the server list. (4) afs_wait_for_probes() now uses the server state list to guide it in what it waits for (and to provide the waitqueue entries) and returns an indication of whether we'd got a response, run out of responsive addresses or the endpoint state had been superseded and we need to restart the iteration. (5) Call afs_get_address_preferences*() occasionally to refresh the preference values. (6) When picking a server, scan the addresses of the servers for which we have as-yet untested communications, looking for the highest priority one and use that instead of trying all the addresses for a particular server in ascending-RTT order. (7) When a Busy or Offline state is seen across all available servers, do a short sleep. (8) If we detect that we accessed a future RO volume version whilst it is undergoing replication, reissue the op against the older version until at least half of the servers are replicated. (9) Whilst RO replication is ongoing, increase the frequency of Volume Location server checks for that volume to every ten minutes instead of hourly. Also add a tracepoint to track progress through the rotation algorithm. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2024-01-01afs: Overhaul invalidation handling to better support RO volumesDavid Howells
Overhaul the third party-induced invalidation handling, making use of the previously added volume-level event counters (cb_scrub and cb_ro_snapshot) that are now being parsed out of the VolSync record returned by the fileserver in many of its replies. This allows better handling of RO (and Backup) volumes. Since these are snapshot of a RW volume that are updated atomically simultantanously across all servers that host them, they only require a single callback promise for the entire volume. The currently upstream code assumes that RO volumes operate in the same manner as RW volumes, and that each file has its own individual callback - which means that it does a status fetch for *every* file in a RO volume, whether or not the volume got "released" (volume callback breaks can occur for other reasons too, such as the volumeserver taking ownership of a volume from a fileserver). To this end, make the following changes: (1) Change the meaning of the volume's cb_v_break counter so that it is now a hint that we need to issue a status fetch to work out the state of a volume. cb_v_break is incremented by volume break callbacks and by server initialisation callbacks. (2) Add a second counter, cb_v_check, to the afs_volume struct such that if this differs from cb_v_break, we need to do a check. When the check is complete, cb_v_check is advanced to what cb_v_break was at the start of the status fetch. (3) Move the list of mmap'd vnodes to the volume and trigger removal of PTEs that map to files on a volume break rather than on a server break. (4) When a server reinitialisation callback comes in, use the server-to-volume reverse mapping added in a preceding patch to iterate over all the volumes using that server and clear the volume callback promises for that server and the general volume promise as a whole to trigger reanalysis. (5) Replace the AFS_VNODE_CB_PROMISED flag with an AFS_NO_CB_PROMISE (TIME64_MIN) value in the cb_expires_at field, reducing the number of checks we need to make. (6) Change afs_check_validity() to quickly see if various event counters have been incremented or if the vnode or volume callback promise is due to expire/has expired without making any changes to the state. That is now left to afs_validate() as this may get more complicated in future as we may have to examine server records too. (7) Overhaul afs_validate() so that it does a single status fetch if we need to check the state of either the vnode or the volume - and do so under appropriate locking. The function does the following steps: (A) If the vnode/volume is no longer seen as valid, then we take the vnode validation lock and, if the volume promise has expired, the volume check lock also. The latter prevents redundant checks being made to find out if a new version of the volume got released. (B) If a previous RPC call found that the volsync changed unexpectedly or that a RO volume was updated, then we unmap all PTEs pointing to the file to stop mmap being used for access. (C) If the vnode is still seen to be of uncertain validity, then we perform an FS.FetchStatus RPC op to jointly update the volume status and the vnode status. This assessment is done as part of parsing the reply: If the RO volume creation timestamp advances, cb_ro_snapshot is incremented; if either the creation or update timestamps changes in an unexpected way, the cb_scrub counter is incremented If the Data Version returned doesn't match the copy we have locally, then we ask for the pagecache to be zapped. This takes care of handling RO update. (D) If cb_scrub differs between volume and vnode, the vnode's pagecache is zapped and the vnode's cb_scrub is updated unless the file is marked as having been deleted. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2024-01-01afs: Parse the VolSync record in the reply of a number of RPC opsDavid Howells
A number of fileserver RPC operations return a VolSync record as part of their reply that gives some information about the state of the volume being accessed, including: (1) A volume Creation timestamp. For an RW volume, this is the time at which the volume was created; if it changes, the RW volume was presumably restored from a backup and all cached data should be scrubbed as Data Version numbers could regress on the files in the volume. For an RO volume, this is the time it was last snapshotted from the RW volume. It is expected to advance each time this happens; if it regresses, cached data should be scrubbed. (2) A volume Update timestamp (Auristor only). For an RW volume, this is updated any time any change is made to a volume or its contents. If it regresses, all cached data must be scrubbed. For an RO volume, this is a copy of the RW volume's Update timestamp at the point of snapshotting. It can be used as a version number when checking to see if a callback on a RO volume was due to a snapshot. If it regresses, all cached data must be scrubbed. but this is currently not made use of by the in-kernel afs filesystem. Make the afs filesystem use this by: (1) Add an update time field to the afs_volsync struct and use a value of TIME64_MIN in both that and the creation time to indicate that they are unset. (2) Add creation and update time fields to the afs_volume struct and use this to track the two timestamps. (3) Add a volsync_lock mutex to the afs_volume struct to control modification access for when we detect a change in these values. (3) Add a 'pre-op volsync' struct to the afs_operation struct to record the state of the volume tracking before the op. (4) Add a new counter, cb_scrub, to the afs_volume struct to count events that require all data to be scrubbed. A copy is placed in the afs_vnode struct (inode) and if they no longer match, a scrub takes place. (5) When the result of an operation is being parsed, parse the VolSync data too, if it is provided. Note that the two timestamps are handled separately, since they don't work in quite the same way. - If the afs_volume tracking is unset, just set it and do nothing else. - If the result timestamps are the same as the ones in afs_volume, do nothing. - If the timestamps regress, increment cb_scrub if not already done so. - If the creation timestamp on a RW volume changes, increment cb_scrub if not already done so. - If the creation timestamp on a RO volume advances, update the server list and see if the current server has been excluded, if so reissue the op. Once over half of the replication sites have been updated, increment cb_ro_snapshot to indicate updates may be required and switch over to excluding unupdated replication sites. - If the creation timestamp on a Backup volume advances, just increment cb_ro_snapshot to trigger updates. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2024-01-01afs: Don't leave DONTUSE/NEWREPSITE servers out of server listDavid Howells
Don't leave servers that are marked VLSF_DONTUSE or VLSF_NEWREPSITE out of the server list for a volume; rather, mark DONTUSE ones excluded and mark either NEWREPSITE excluded if the number of updated servers is <50% of the usable servers or mark !NEWREPSITE excluded otherwise. Mark the server list as a whole with a 3-state flag to indicate whether we think the RW volume is being replicated to the RO volume, and, if so, whether we should switch to using updated replication sites (VLSF_NEWREPSITE) or stick with the old for now. This processing is pushed up from the VLDB RPC reply parser to the code that generates the server list from that information. Doing this allows the old list to be kept with just the exclusion flags replaced and to keep the server records pinned and maintained. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2024-01-01afs: Fix comment in afs_do_lookup()David Howells
Fix the comment in afs_do_lookup() that says that slot 0 is used for the fid being looked up and slot 1 is used for the directory. It's actually done the other way round. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2024-01-01afs: Apply server breaks to mmap'd files in the call processorDavid Howells
Apply server breaks to mmap'd files that are being used from that server from the call processor work function rather than punting it off to a workqueue. The work item, afs_server_init_callback(), then bumps each individual inode off to its own work item introducing a potentially lengthy delay. This reduces that delay at the cost of extending the amount of time we delay replying to the CB.InitCallBack3 notification RPC from the server. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2024-01-01afs: Move the vnode/volume validity checking code into its own fileDavid Howells
Move the code that does validity checking of vnodes and volumes with respect to third-party changes into its own file. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2024-01-01afs: Defer volume record destruction to a workqueueDavid Howells
Defer volume record destruction to a workqueue so that afs_put_volume() isn't going to run the destruction process in the callback workqueue whilst the server is holding up other clients whilst waiting for us to reply to a CB.CallBack notification RPC. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2024-01-01afs: Make it possible to find the volumes that are using a serverDavid Howells
Make it possible to find the afs_volume structs that are using an afs_server struct to aid in breaking volume callbacks. The way this is done is that each afs_volume already has an array of afs_server_entry records that point to the servers where that volume might be found. An afs_volume backpointer and a list node is added to each entry and each entry is then added to an RCU-traversable list on the afs_server to which it points. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2024-01-01afs: Combine the endpoint state bools into a bitmaskDavid Howells
Combine the endpoint state bool-type members into a bitmask so that some of them can be waited upon more easily. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2024-01-01afs: Keep a record of the current fileserver endpoint stateDavid Howells
Keep a record of the current fileserver endpoint state, including the probe state, and replace it when a new probe is started rather than just squelching the old state and overwriting it. Clearance of the old state can cause a race if there's another thread also currently trying to communicate with that server. It appears that this race might be the culprit for some occasions where kafs complains about invalid data in the RPC reply because the rotation algorithm fell all the way through without actually issuing an RPC call and the error return got filled in from the probe state (which has a zero error recorded). Whatever happens to be in the caller's reply buffer is then taken as the response. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2024-01-01afs: Dispatch vlserver probes in priority orderDavid Howells
When probing all the addresses for a volume location server, dispatch them in order of descending priority to try and get back highest priority one first. Also add a tracepoint to show the transmission and completion of the probes. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2024-01-01afs: Dispatch fileserver probes in priority orderDavid Howells
When probing all the addresses for a fileserver, dispatch them in order of descending priority to try and get back highest priority one first. Also add a tracepoint to show the transmission and completion of the probes. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2024-01-01afs: Mark address lists with configured prioritiesDavid Howells
Add a field to each address in an address list (afs_addr_list struct) that records the current priority for that address according to the address preference table. We don't want to do this every time we use an address list, so the version number of the address preference table is recorded in the address list too and we only re-mark the list when we see the version change. These numbers are then displayed through /proc/net/afs/servers. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2024-01-01afs: Provide a way to configure address prioritiesDavid Howells
AFS servers may have multiple addresses, but the client can't easily judge between them as to which one is best. For instance, an address that has a larger RTT might actually have a better bandwidth because it goes through a switch rather than being directly connected - but we can't work this out dynamically unless we push through sufficient data that we can measure it. To allow the administrator to configure this, add a list of preference weightings for server addresses by IPv4/IPv6 address or subnet and allow this to be viewed through a procfile and altered by writing text commands to that same file. Preference rules can be added/updated by: echo "add <proto> <addr>[/<subnet>] <prior>" >/proc/fs/afs/addr_prefs echo "add udp 1.2.3.4 1000" >/proc/fs/afs/addr_prefs echo "add udp 192.168.0.0/16 3000" >/proc/fs/afs/addr_prefs echo "add udp 1001:2002:0:6::/64 4000" >/proc/fs/afs/addr_prefs and removed by: echo "del <proto> <addr>[/<subnet>]" >/proc/fs/afs/addr_prefs echo "del udp 1.2.3.4" >/proc/fs/afs/addr_prefs where the priority is a number between 0 and 65535. The list is split between IPv4 and IPv6 addresses and each sublist is kept in numerical order, with rules that would otherwise match but have different subnet masking being ordered with the most specific submatch first. A subsequent patch will apply these rules. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2024-01-01afs: Remove the unimplemented afs_cmp_addr_list()David Howells
Remove afs_cmp_addr_list() as it was never implemented. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2024-01-01afs: Add some more info to /proc/net/afs/serversDavid Howells
In /proc/net/afs/servers, show the cell name and the last error for each address in the server's list. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-12-24afs: Fold the afs_addr_cursor struct inDavid Howells
Fold the afs_addr_cursor struct into the afs_operation struct and the afs_vl_cursor struct and fold its operations into their callers also. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-12-24afs: Use peer + service_id as call addressDavid Howells
Use the rxrpc_peer plus the service ID as the call address instead of passing in a sockaddr_srx down to rxrpc. The peer record is obtained by using rxrpc_kernel_get_peer(). This avoids the need to repeatedly look up the peer and allows rxrpc to hold on to resources for it. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-12-24afs: Rename some fieldsDavid Howells
Rename the ->index and ->untried fields of the afs_vl_cursor and afs_operation struct to ->server_index and ->untried_servers to avoid confusion with address iteration fields when those get folded in. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-12-24afs: Add a tracepoint for struct afs_addr_listDavid Howells
Add a tracepoint to track the lifetime of the afs_addr_list struct. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-12-24afs: Simplify error handlingDavid Howells
Simplify error handling a bit by moving it from the afs_addr_cursor struct to the afs_operation and afs_vl_cursor structs and using the error prioritisation function for accumulating errors from multiple sources (AFS tries to rotate between multiple fileservers, some of which may be inaccessible or in some state of offlinedness). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-12-24afs: Don't put afs_call in afs_wait_for_call_to_complete()David Howells
Don't put the afs_call struct in afs_wait_for_call_to_complete() but rather have the caller do it. This will allow the caller to fish stuff out of the afs_call struct rather than the afs_addr_cursor struct, thereby allowing a subsequent patch to subsume it. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-12-24afs: Wrap most op->error accesses with inline funcsDavid Howells
Wrap most op->error accesses with inline funcs which will make it easier for a subsequent patch to replace op->error with something else. Two functions are added to this end: (1) afs_op_error() - Get the error code. (2) afs_op_set_error() - Set the error code. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-12-24afs: Use op->nr_iterations=-1 to indicate to begin fileserver iterationDavid Howells
Set op->nr_iterations to -1 to indicate that we need to begin fileserver iteration rather than setting error to SHRT_MAX. This makes it easier to eliminate the address cursor. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-12-24afs: Handle the VIO and UAEIO aborts explicitlyDavid Howells
When processing the result of a call, handle the VIO and UAEIO abort specifically rather than leaving it to a default case. Rather than erroring out unconditionally, see if there's another server if the volume has more than one server available, otherwise return -EREMOTEIO. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-12-24afs: Rename addr_list::failed to probe_failedDavid Howells
Rename the failed member of struct addr_list to probe_failed as it's specifically related to probe failures. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-12-24afs: Don't skip server addresses for which we didn't get an RTT readingDavid Howells
In the rotation algorithms for iterating over volume location servers and file servers, don't skip servers from which we got a valid response to a probe (either a reply DATA packet or an ABORT) even if we didn't manage to get an RTT reading. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-12-24rxrpc, afs: Allow afs to pin rxrpc_peer objectsDavid Howells
Change rxrpc's API such that: (1) A new function, rxrpc_kernel_lookup_peer(), is provided to look up an rxrpc_peer record for a remote address and a corresponding function, rxrpc_kernel_put_peer(), is provided to dispose of it again. (2) When setting up a call, the rxrpc_peer object used during a call is now passed in rather than being set up by rxrpc_connect_call(). For afs, this meenat passing it to rxrpc_kernel_begin_call() rather than the full address (the service ID then has to be passed in as a separate parameter). (3) A new function, rxrpc_kernel_remote_addr(), is added so that afs can get a pointer to the transport address for display purposed, and another, rxrpc_kernel_remote_srx(), to gain a pointer to the full rxrpc address. (4) The function to retrieve the RTT from a call, rxrpc_kernel_get_srtt(), is then altered to take a peer. This now returns the RTT or -1 if there are insufficient samples. (5) Rename rxrpc_kernel_get_peer() to rxrpc_kernel_call_get_peer(). (6) Provide a new function, rxrpc_kernel_get_peer(), to get a ref on a peer the caller already has. This allows the afs filesystem to pin the rxrpc_peer records that it is using, allowing faster lookups and pointer comparisons rather than comparing sockaddr_rxrpc contents. It also makes it easier to get hold of the RTT. The following changes are made to afs: (1) The addr_list struct's addrs[] elements now hold a peer struct pointer and a service ID rather than a sockaddr_rxrpc. (2) When displaying the transport address, rxrpc_kernel_remote_addr() is used. (3) The port arg is removed from afs_alloc_addrlist() since it's always overridden. (4) afs_merge_fs_addr4() and afs_merge_fs_addr6() do peer lookup and may now return an error that must be handled. (5) afs_find_server() now takes a peer pointer to specify the address. (6) afs_find_server(), afs_compare_fs_alists() and afs_merge_fs_addr[46]{} now do peer pointer comparison rather than address comparison. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-12-24afs: Turn the afs_addr_list address array into an array of structsDavid Howells
Turn the afs_addr_list address array into an array of structs, thereby allowing per-address (such as RTT) info to be added. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-12-24afs: Add comments on abort handlingDavid Howells
Add some comments on AFS abort code handling in the rotation algorithm and adjust the errors produced to match. Reported-by: Jeffrey E Altman <jaltman@auristor.com> 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
2023-12-24afs: use read_seqbegin() in afs_check_validity() and afs_getattr()Oleg Nesterov
David Howells says: (3) afs_check_validity(). (4) afs_getattr(). These are both pretty short, so your solution is probably good for them. That said, afs_vnode_commit_status() can spend a long time under the write lock - and pretty much every file RPC op returns a status update. Change these functions to use read_seqbegin(). This simplifies the code and doesn't change the current behaviour, the "seq" counter is always even so read_seqbegin_or_lock() can never take the lock. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/20231130115617.GA21584@redhat.com/
2023-12-24afs: fix the usage of read_seqbegin_or_lock() in afs_find_server*()Oleg Nesterov
David Howells says: (5) afs_find_server(). There could be a lot of servers in the list and each server can have multiple addresses, so I think this would be better with an exclusive second pass. The server list isn't likely to change all that often, but when it does change, there's a good chance several servers are going to be added/removed one after the other. Further, this is only going to be used for incoming cache management/callback requests from the server, which hopefully aren't going to happen too often - but it is remotely drivable. (6) afs_find_server_by_uuid(). Similarly to (5), there could be a lot of servers to search through, but they are in a tree not a flat list, so it should be faster to process. Again, it's not likely to change that often and, again, when it does change it's likely to involve multiple changes. This can be driven remotely by an incoming cache management request but is mostly going to be driven by setting up or reconfiguring a volume's server list - something that also isn't likely to happen often. Make the "seq" counter odd on the 2nd pass, otherwise read_seqbegin_or_lock() never takes the lock. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/20231130115614.GA21581@redhat.com/
2023-12-24afs: fix the usage of read_seqbegin_or_lock() in afs_lookup_volume_rcu()Oleg Nesterov
David Howells says: (2) afs_lookup_volume_rcu(). There can be a lot of volumes known by a system. A thousand would require a 10-step walk and this is drivable by remote operation, so I think this should probably take a lock on the second pass too. Make the "seq" counter odd on the 2nd pass, otherwise read_seqbegin_or_lock() never takes the lock. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/20231130115606.GA21571@redhat.com/
2023-12-21afs: Fix use-after-free due to get/remove race in volume treeDavid Howells
When an afs_volume struct is put, its refcount is reduced to 0 before the cell->volume_lock is taken and the volume removed from the cell->volumes tree. Unfortunately, this means that the lookup code can race and see a volume with a zero ref in the tree, resulting in a use-after-free: refcount_t: addition on 0; use-after-free. WARNING: CPU: 3 PID: 130782 at lib/refcount.c:25 refcount_warn_saturate+0x7a/0xda ... RIP: 0010:refcount_warn_saturate+0x7a/0xda ... Call Trace: afs_get_volume+0x3d/0x55 afs_create_volume+0x126/0x1de afs_validate_fc+0xfe/0x130 afs_get_tree+0x20/0x2e5 vfs_get_tree+0x1d/0xc9 do_new_mount+0x13b/0x22e do_mount+0x5d/0x8a __do_sys_mount+0x100/0x12a do_syscall_64+0x3a/0x94 entry_SYSCALL_64_after_hwframe+0x62/0x6a Fix this by: (1) When putting, use a flag to indicate if the volume has been removed from the tree and skip the rb_erase if it has. (2) When looking up, use a conditional ref increment and if it fails because the refcount is 0, replace the node in the tree and set the removal flag. Fixes: 20325960f875 ("afs: Reorganise volume and server trees to be rooted on the cell") 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 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-12-21afs: Fix overwriting of result of DNS queryDavid Howells
In afs_update_cell(), ret is the result of the DNS lookup and the errors are to be handled by a switch - however, the value gets clobbered in between by setting it to -ENOMEM in case afs_alloc_vlserver_list() fails. Fix this by moving the setting of -ENOMEM into the error handling for OOM failure. Further, only do it if we don't have an alternative error to return. Found by Linux Verification Center (linuxtesting.org) with SVACE. Based on a patch from Anastasia Belova [1]. Fixes: d5c32c89b208 ("afs: Fix cell DNS lookup") Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeffrey Altman <jaltman@auristor.com> cc: Anastasia Belova <abelova@astralinux.ru> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: lvc-project@linuxtesting.org Link: https://lore.kernel.org/r/20231221085849.1463-1-abelova@astralinux.ru/ [1] Link: https://lore.kernel.org/r/1700862.1703168632@warthog.procyon.org.uk/ # v1 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-12-20afs: Fix dynamic root lookup DNS checkDavid Howells
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
2023-12-20afs: Fix the dynamic root's d_delete to always delete unused dentriesDavid Howells
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
2023-12-11afs: Fix refcount underflow from error handling raceDavid Howells
If an AFS cell that has an unreachable (eg. ENETUNREACH) server listed (VL server or fileserver), an asynchronous probe to one of its addresses may fail immediately because sendmsg() returns an error. When this happens, a refcount underflow can happen if certain events hit a very small window. The way this occurs is: (1) There are two levels of "call" object, the afs_call and the rxrpc_call. Each of them can be transitioned to a "completed" state in the event of success or failure. (2) Asynchronous afs_calls are self-referential whilst they are active to prevent them from evaporating when they're not being processed. This reference is disposed of when the afs_call is completed. Note that an afs_call may only be completed once; once completed completing it again will do nothing. (3) When a call transmission is made, the app-side rxrpc code queues a Tx buffer for the rxrpc I/O thread to transmit. The I/O thread invokes sendmsg() to transmit it - and in the case of failure, it transitions the rxrpc_call to the completed state. (4) When an rxrpc_call is completed, the app layer is notified. In this case, the app is kafs and it schedules a work item to process events pertaining to an afs_call. (5) When the afs_call event processor is run, it goes down through the RPC-specific handler to afs_extract_data() to retrieve data from rxrpc - and, in this case, it picks up the error from the rxrpc_call and returns it. The error is then propagated to the afs_call and that is completed too. At this point the self-reference is released. (6) If the rxrpc I/O thread manages to complete the rxrpc_call within the window between rxrpc_send_data() queuing the request packet and checking for call completion on the way out, then rxrpc_kernel_send_data() will return the error from sendmsg() to the app. (7) Then afs_make_call() will see an error and will jump to the error handling path which will attempt to clean up the afs_call. (8) The problem comes when the error handling path in afs_make_call() tries to unconditionally drop an async afs_call's self-reference. This self-reference, however, may already have been dropped by afs_extract_data() completing the afs_call (9) The refcount underflows when we return to afs_do_probe_vlserver() and that tries to drop its reference on the afs_call. Fix this by making afs_make_call() attempt to complete the afs_call rather than unconditionally putting it. That way, if afs_extract_data() manages to complete the call first, afs_make_call() won't do anything. The bug can be forced by making do_udp_sendmsg() return -ENETUNREACH and sticking an msleep() in rxrpc_send_data() after the 'success:' label to widen the race window. The error message looks something like: refcount_t: underflow; use-after-free. WARNING: CPU: 3 PID: 720 at lib/refcount.c:28 refcount_warn_saturate+0xba/0x110 ... RIP: 0010:refcount_warn_saturate+0xba/0x110 ... afs_put_call+0x1dc/0x1f0 [kafs] afs_fs_get_capabilities+0x8b/0xe0 [kafs] afs_fs_probe_fileserver+0x188/0x1e0 [kafs] afs_lookup_server+0x3bf/0x3f0 [kafs] afs_alloc_server_list+0x130/0x2e0 [kafs] afs_create_volume+0x162/0x400 [kafs] afs_get_tree+0x266/0x410 [kafs] vfs_get_tree+0x25/0xc0 fc_mount+0xe/0x40 afs_d_automount+0x1b3/0x390 [kafs] __traverse_mounts+0x8f/0x210 step_into+0x340/0x760 path_openat+0x13a/0x1260 do_filp_open+0xaf/0x160 do_sys_openat2+0xaf/0x170 or something like: refcount_t: underflow; use-after-free. ... RIP: 0010:refcount_warn_saturate+0x99/0xda ... afs_put_call+0x4a/0x175 afs_send_vl_probes+0x108/0x172 afs_select_vlserver+0xd6/0x311 afs_do_cell_detect_alias+0x5e/0x1e9 afs_cell_detect_alias+0x44/0x92 afs_validate_fc+0x9d/0x134 afs_get_tree+0x20/0x2e6 vfs_get_tree+0x1d/0xc9 fc_mount+0xe/0x33 afs_d_automount+0x48/0x9d __traverse_mounts+0xe0/0x166 step_into+0x140/0x274 open_last_lookups+0x1c1/0x1df path_openat+0x138/0x1c3 do_filp_open+0x55/0xb4 do_sys_openat2+0x6c/0xb6 Fixes: 34fa47612bfe ("afs: Fix race in async call refcounting") Reported-by: Bill MacAllister <bill@ca-zephyr.org> Closes: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1052304 Suggested-by: Jeffrey E Altman <jaltman@auristor.com> 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 Link: https://lore.kernel.org/r/2633992.1702073229@warthog.procyon.org.uk/ # v1 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-12-10fs: convert error_remove_page to error_remove_folioMatthew Wilcox (Oracle)
There were already assertions that we were not passing a tail page to error_remove_page(), so make the compiler enforce that by converting everything to pass and use a folio. Link: https://lkml.kernel.org/r/20231117161447.2461643-7-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10afs: do not test the return value of folio_start_writeback()Matthew Wilcox (Oracle)
In preparation for removing the return value entirely, stop testing it in afs. Link: https://lkml.kernel.org/r/20231108204605.745109-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: David Howells <dhowells@redhat.com> Cc: Steve French <sfrench@samba.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-01afs: Add __counted_by for struct afs_acl and use struct_size()Gustavo A. R. Silva
Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). While there, use struct_size() helper, instead of the open-coded version, to calculate the size for the allocation of the whole flexible structure, including of course, the flexible-array member. This code was found with the help of Coccinelle, and audited and fixed manually. Signed-off-by: "Gustavo A. R. Silva" <gustavoars@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/ZSVKwBmxQ1amv47E@work Signed-off-by: Kees Cook <keescook@chromium.org>
2023-11-25dentry: switch the lists of children to hlistAl Viro
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>
2023-11-24afs: Mark a superblock for an R/O or Backup volume as SB_RDONLYDavid Howells
Mark a superblock that is for for an R/O or Backup volume as SB_RDONLY when mounting it. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org