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2024-03-11Merge tag 'vfs-6.9.file' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull file locking updates from Christian Brauner: "A few years ago struct file_lock_context was added to allow for separate lists to track different types of file locks instead of using a singly-linked list for all of them. Now leases no longer need to be tracked using struct file_lock. However, a lot of the infrastructure is identical for leases and locks so separating them isn't trivial. This splits a group of fields used by both file locks and leases into a new struct file_lock_core. The new core struct is embedded in struct file_lock. Coccinelle was used to convert a lot of the callers to deal with the move, with the remaining 25% or so converted by hand. Afterwards several internal functions in fs/locks.c are made to work with struct file_lock_core. Ultimately this allows to split struct file_lock into struct file_lock and struct file_lease. The file lease APIs are then converted to take struct file_lease" * tag 'vfs-6.9.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (51 commits) filelock: fix deadlock detection in POSIX locking filelock: always define for_each_file_lock() smb: remove redundant check filelock: don't do security checks on nfsd setlease calls filelock: split leases out of struct file_lock filelock: remove temporary compatibility macros smb/server: adapt to breakup of struct file_lock smb/client: adapt to breakup of struct file_lock ocfs2: adapt to breakup of struct file_lock nfsd: adapt to breakup of struct file_lock nfs: adapt to breakup of struct file_lock lockd: adapt to breakup of struct file_lock fuse: adapt to breakup of struct file_lock gfs2: adapt to breakup of struct file_lock dlm: adapt to breakup of struct file_lock ceph: adapt to breakup of struct file_lock afs: adapt to breakup of struct file_lock 9p: adapt to breakup of struct file_lock filelock: convert seqfile handling to use file_lock_core filelock: convert locks_translate_pid to take file_lock_core ...
2024-02-05afs: adapt to breakup of struct file_lockJeff Layton1-2/+2
Most of the existing APIs have remained the same, but subsystems that access file_lock fields directly need to reach into struct file_lock_core now. Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20240131-flsplit-v3-35-c6129007ee8d@kernel.org Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-01-22afs: Fix error handling with lookup via FS.InlineBulkStatusDavid Howells1-0/+25
When afs does a lookup, it tries to use FS.InlineBulkStatus to preemptively look up a bunch of files in the parent directory and cache this locally, on the basis that we might want to look at them too (for example if someone does an ls on a directory, they may want want to then stat every file listed). FS.InlineBulkStatus can be considered a compound op with the normal abort code applying to the compound as a whole. Each status fetch within the compound is then given its own individual abort code - but assuming no error that prevents the bulk fetch from returning the compound result will be 0, even if all the constituent status fetches failed. At the conclusion of afs_do_lookup(), we should use the abort code from the appropriate status to determine the error to return, if any - but instead it is assumed that we were successful if the op as a whole succeeded and we return an incompletely initialised inode, resulting in ENOENT, no matter the actual reason. In the particular instance reported, a vnode with no permission granted to be accessed is being given a UAEACCES abort code which should be reported as EACCES, but is instead being reported as ENOENT. Fix this by abandoning the inode (which will be cleaned up with the op) if file[1] has an abort code indicated and turn that abort code into an error instead. Whilst we're at it, add a tracepoint so that the abort codes of the individual subrequests of FS.InlineBulkStatus can be logged. At the moment only the container abort code can be 0. Fixes: e49c7b2f6de7 ("afs: Build an abstraction around an "operation" concept") Reported-by: Jeffrey Altman <jaltman@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2024-01-19Merge tag 'vfs-6.8.netfs' of ↵Linus Torvalds1-31/+0
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 ...
2024-01-01afs: trace: Log afs_make_call(), including server addressDavid Howells1-0/+36
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 fileserver rotationDavid Howells1-12/+69
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 Howells1-4/+0
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 Howells1-1/+29
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: Apply server breaks to mmap'd files in the call processorDavid Howells1-0/+2
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: Keep a record of the current fileserver endpoint stateDavid Howells1-15/+54
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 Howells1-0/+34
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 Howells1-0/+33
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
2023-12-28afs: Use the netfs write helpersDavid Howells1-23/+0
Make afs use the netfs write helpers. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org
2023-12-24afs: Fold the afs_addr_cursor struct inDavid Howells1-4/+14
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: Add a tracepoint for struct afs_addr_listDavid Howells1-0/+47
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: Don't use folio->private to record partial modificationDavid Howells1-12/+4
AFS currently uses folio->private to store the range of bytes within a folio that have been modified - the idea being that if we have, say, a 2MiB folio and someone writes a single byte, we only have to write back that single page and not the whole 2MiB folio - thereby saving on network bandwidth. Remove this, at least for now, and accept the extra network load (which doesn't matter in the common case of writing a whole file at a time from beginning to end). This makes folio->private available for netfslib to use. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org
2023-12-24afs: Automatically generate trace tag enumsDavid Howells1-206/+27
Automatically generate trace tag enums from the symbol -> string mapping tables rather than having the enums as well, thereby reducing duplicated data. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Jeff Layton <jlayton@kernel.org> cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org
2023-12-24afs: Remove whitespace before most ')' from the trace headerDavid Howells1-121/+121
checkpatch objects to whitespace before ')', so remove most of it from the afs trace header. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Jeff Layton <jlayton@kernel.org> cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org
2022-08-02afs: Fix access after dec in put functionsDavid Howells1-6/+6
Reference-putting functions should not access the object being put after decrementing the refcount unless they reduce the refcount to zero. Fix a couple of instances of this in afs by copying the information to be logged by tracepoint to local variables before doing the decrement. [Fixed a bit in afs_put_server() that I'd missed but Marc caught] Fixes: 341f741f04be ("afs: Refcount the afs_call struct") Fixes: 452181936931 ("afs: Trace afs_server usage") Fixes: 977e5f8ed0ab ("afs: Split the usage count on struct afs_server") 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/165911278430.3745403.16526310736054780645.stgit@warthog.procyon.org.uk/ # v1
2022-08-02afs: Use refcount_t rather than atomic_tDavid Howells1-13/+13
Use refcount_t rather than atomic_t in afs to make use of the count checking facilities provided. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/165911277768.3745403.423349776836296452.stgit@warthog.procyon.org.uk/ # v1
2021-11-10netfs, 9p, afs, ceph: Use foliosDavid Howells1-10/+11
Convert the netfs helper library to use folios throughout, convert the 9p and afs filesystems to use folios in their file I/O paths and convert the ceph filesystem to use just enough folios to compile. With these changes, afs passes -g quick xfstests. Changes ======= ver #5: - Got rid of folio_end{io,_read,_write}() and inlined the stuff it does instead (Willy decided he didn't want this after all). ver #4: - Fixed a bug in afs_redirty_page() whereby it didn't set the next page index in the loop and returned too early. - Simplified a check in v9fs_vfs_write_folio_locked()[1]. - Undid a change to afs_symlink_readpage()[1]. - Used offset_in_folio() in afs_write_end()[1]. - Changed from using page_endio() to folio_end{io,_read,_write}()[1]. ver #2: - Add 9p foliation. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Tested-by: Jeff Layton <jlayton@kernel.org> Tested-by: Dominique Martinet <asmadeus@codewreck.org> Tested-by: kafs-testing@auristor.com cc: Matthew Wilcox (Oracle) <willy@infradead.org> cc: Marc Dionne <marc.dionne@auristor.com> cc: Ilya Dryomov <idryomov@gmail.com> cc: Dominique Martinet <asmadeus@codewreck.org> cc: v9fs-developer@lists.sourceforge.net cc: linux-afs@lists.infradead.org cc: ceph-devel@vger.kernel.org cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/YYKa3bfQZxK5/wDN@casper.infradead.org/ [1] Link: https://lore.kernel.org/r/2408234.1628687271@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/162877311459.3085614.10601478228012245108.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/162981153551.1901565.3124454657133703341.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/163005745264.2472992.9852048135392188995.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163584187452.4023316.500389675405550116.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/163649328026.309189.1124218109373941936.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/163657852454.834781.9265101983152100556.stgit@warthog.procyon.org.uk/ # v5
2021-09-13afs: Try to avoid taking RCU read lock when checking vnode validityDavid Howells1-2/+6
Try to avoid taking the RCU read lock when checking the validity of a vnode's callback state. The only thing it's needed for is to pin the parent volume's server list whilst we search it to find the record of the server we're currently using to see if it has been reinitialised (ie. it sent us a CB.InitCallBackState* RPC). Do this by the following means: (1) Keep an additional per-cell counter (fs_s_break) that's incremented each time any of the fileservers in the cell reinitialises. Since the new counter can be accessed without RCU from the vnode, we can check that first - and only if it differs, get the RCU read lock and check the volume's server list. (2) Replace afs_get_s_break_rcu() with afs_check_server_good() which now indicates whether the callback promise is still expected to be present on the server. This does the checks as described in (1). (3) Restructure afs_check_validity() to take account of the change in (2). We can also get rid of the valid variable and just use the need_clear variable with the addition of the afs_cb_break_no_promise reason. (4) afs_check_validity() probably shouldn't be altering vnode->cb_v_break and vnode->cb_s_break when it doesn't have cb_lock exclusively locked. Move the change to vnode->cb_v_break to __afs_break_callback(). Delegate the change to vnode->cb_s_break to afs_select_fileserver() and set vnode->cb_fs_s_break there also. (5) afs_validate() no longer needs to get the RCU read lock around its call to afs_check_validity() - and can skip the call entirely if we don't have a promise. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Markus Suvanto <markus.suvanto@gmail.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/163111669583.283156.1397603105683094563.stgit@warthog.procyon.org.uk/
2021-07-21afs: Fix tracepoint string placement with built-in AFSDavid Howells1-5/+62
To quote Alexey[1]: I was adding custom tracepoint to the kernel, grabbed full F34 kernel .config, disabled modules and booted whole shebang as VM kernel. Then did perf record -a -e ... It crashed: general protection fault, probably for non-canonical address 0x435f5346592e4243: 0000 [#1] SMP PTI CPU: 1 PID: 842 Comm: cat Not tainted 5.12.6+ #26 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014 RIP: 0010:t_show+0x22/0xd0 Then reproducer was narrowed to # cat /sys/kernel/tracing/printk_formats Original F34 kernel with modules didn't crash. So I started to disable options and after disabling AFS everything started working again. The root cause is that AFS was placing char arrays content into a section full of _pointers_ to strings with predictable consequences. Non canonical address 435f5346592e4243 is "CB.YFS_" which came from CM_NAME macro. Steps to reproduce: CONFIG_AFS=y CONFIG_TRACING=y # cat /sys/kernel/tracing/printk_formats Fix this by the following means: (1) Add enum->string translation tables in the event header with the AFS and YFS cache/callback manager operations listed by RPC operation ID. (2) Modify the afs_cb_call tracepoint to print the string from the translation table rather than using the string at the afs_call name pointer. (3) Switch translation table depending on the service we're being accessed as (AFS or YFS) in the tracepoint print clause. Will this cause problems to userspace utilities? Note that the symbolic representation of the YFS service ID isn't available to this header, so I've put it in as a number. I'm not sure if this is the best way to do this. (4) Remove the name wrangling (CM_NAME) macro and put the names directly into the afs_call_type structs in cmservice.c. Fixes: 8e8d7f13b6d5a9 ("afs: Add some tracepoints") Reported-by: Alexey Dobriyan (SK hynix) <adobriyan@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> cc: Andrew Morton <akpm@linux-foundation.org> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/YLAXfvZ+rObEOdc%2F@localhost.localdomain/ [1] Link: https://lore.kernel.org/r/643721.1623754699@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/162430903582.2896199.6098150063997983353.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/162609463957.3133237.15916579353149746363.stgit@warthog.procyon.org.uk/ # v1 (repost) Link: https://lore.kernel.org/r/162610726860.3408253.445207609466288531.stgit@warthog.procyon.org.uk/ # v2
2021-04-23afs: Use ITER_XARRAY for writingDavid Howells1-32/+19
Use a single ITER_XARRAY iterator to describe the portion of a file to be transmitted to the server rather than generating a series of small ITER_BVEC iterators on the fly. This will make it easier to implement AIO in afs. In theory we could maybe use one giant ITER_BVEC, but that means potentially allocating a huge array of bio_vec structs (max 256 per page) when in fact the pagecache already has a structure listing all the relevant pages (radix_tree/xarray) that can be walked over. Signed-off-by: David Howells <dhowells@redhat.com> Tested-By: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/153685395197.14766.16289516750731233933.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/158861251312.340223.17924900795425422532.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/159465828607.1377938.6903132788463419368.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/160588535018.3465195.14509994354240338307.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161118152415.1232039.6452879415814850025.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161161048194.2537118.13763612220937637316.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/161340411602.1303470.4661108879482218408.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/161539555629.286939.5241869986617154517.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/161653811456.2770958.7017388543246759245.stgit@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/161789095005.6155.6789055030327407928.stgit@warthog.procyon.org.uk/ # v6
2021-04-23afs: Pass page into dirty region helpers to provide THP sizeDavid Howells1-10/+13
Pass a pointer to the page being accessed into the dirty region helpers so that the size of the page can be determined in case it's a transparent huge page. This also required the page to be passed into the afs_page_dirty trace point - so there's no need to specifically pass in the index or private data as these can be retrieved directly from the page struct. Signed-off-by: David Howells <dhowells@redhat.com> Tested-By: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/160588527183.3465195.16107942526481976308.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161118144921.1232039.11377711180492625929.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161161040747.2537118.11435394902674511430.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/161340404553.1303470.11414163641767769882.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/161539548385.286939.8864598314493255313.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/161653804285.2770958.3497360004849598038.stgit@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/161789087043.6155.16922142208140170528.stgit@warthog.procyon.org.uk/ # v6
2021-01-04afs: Fix directory entry size calculationDavid Howells1-0/+2
The number of dirent records used by an AFS directory entry should be calculated using the assumption that there is a 16-byte name field in the first block, rather than a 20-byte name field (which is actually the case). This miscalculation is historic and effectively standard, so we have to use it. The calculation we need to use is: 1 + (((strlen(name) + 1) + 15) >> 5) where we are adding one to the strlen() result to account for the NUL termination. Fix this by the following means: (1) Create an inline function to do the calculation for a given name length. (2) Use the function to calculate the number of records used for a dirent in afs_dir_iterate_block(). Use this to move the over-end check out of the loop since it only needs to be done once. Further use this to only go through the loop for the 2nd+ records composing an entry. The only test there now is for if the record is allocated - and we already checked the first block at the top of the outer loop. (3) Add a max name length check in afs_dir_iterate_block(). (4) Make afs_edit_dir_add() and afs_edit_dir_remove() use the function from (1) to calculate the number of blocks rather than doing it incorrectly themselves. Fixes: 63a4681ff39c ("afs: Locally edit directory data for mkdir/create/unlink/...") Fixes: ^1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Marc Dionne <marc.dionne@auristor.com>
2020-10-29afs: Fix afs_invalidatepage to adjust the dirty regionDavid Howells1-2/+3
Fix afs_invalidatepage() to adjust the dirty region recorded in page->private when truncating a page. If the dirty region is entirely removed, then the private data is cleared and the page dirty state is cleared. Without this, if the page is truncated and then expanded again by truncate, zeros from the expanded, but no-longer dirty region may get written back to the server if the page gets laundered due to a conflicting 3rd-party write. It mustn't, however, shorten the dirty region of the page if that page is still mmapped and has been marked dirty by afs_page_mkwrite(), so a flag is stored in page->private to record this. Fixes: 4343d00872e1 ("afs: Get rid of the afs_writeback record") Signed-off-by: David Howells <dhowells@redhat.com>
2020-10-29afs: Wrap page->private manipulations in inline functionsDavid Howells1-16/+3
The afs filesystem uses page->private to store the dirty range within a page such that in the event of a conflicting 3rd-party write to the server, we write back just the bits that got changed locally. However, there are a couple of problems with this: (1) I need a bit to note if the page might be mapped so that partial invalidation doesn't shrink the range. (2) There aren't necessarily sufficient bits to store the entire range of data altered (say it's a 32-bit system with 64KiB pages or transparent huge pages are in use). So wrap the accesses in inline functions so that future commits can change how this works. Also move them out of the tracing header into the in-directory header. There's not really any need for them to be in the tracing header. Signed-off-by: David Howells <dhowells@redhat.com>
2020-10-16afs: Don't assert on unpurgeable server recordsDavid Howells1-0/+2
Don't give an assertion failure on unpurgeable afs_server records - which kills the thread - but rather emit a trace line when we are purging a record (which only happens during network namespace removal or rmmod) and print a notice of the problem. Signed-off-by: David Howells <dhowells@redhat.com>
2020-10-16afs: Add tracing for cell refcount and active user countDavid Howells1-0/+107
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>
2020-06-04afs: Add a tracepoint to track the lifetime of the afs_volume structDavid Howells1-0/+56
Add a tracepoint to track the lifetime of the afs_volume struct. Signed-off-by: David Howells <dhowells@redhat.com>
2020-06-04afs: Implement client support for the YFSVL.GetCellName RPC opDavid Howells1-0/+4
Implement client support for the YFSVL.GetCellName RPC operation by which YFS permits the canonical cell name to be queried from a VL server. Signed-off-by: David Howells <dhowells@redhat.com>
2020-06-04afs: Build an abstraction around an "operation" conceptDavid Howells1-11/+8
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>
2020-05-31afs: Remove the error argument from afs_protocol_error()David Howells1-6/+4
Remove the error argument from afs_protocol_error() as it's always -EBADMSG. Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-31afs: Actively poll fileservers to maintain NAT or firewall openingsDavid Howells1-0/+4
When an AFS client accesses a file, it receives a limited-duration callback promise that the server will notify it if another client changes a file. This callback duration can be a few hours in length. If a client mounts a volume and then an application prevents it from being unmounted, say by chdir'ing into it, but then does nothing for some time, the rxrpc_peer record will expire and rxrpc-level keepalive will cease. If there is NAT or a firewall between the client and the server, the route back for the server may close after a comparatively short duration, meaning that attempts by the server to notify the client may then bounce. The client, however, may (so far as it knows) still have a valid unexpired promise and will then rely on its cached data and will not see changes made on the server by a third party until it incidentally rechecks the status or the promise needs renewal. To deal with this, the client needs to regularly probe the server. This has two effects: firstly, it keeps a route open back for the server, and secondly, it causes the server to disgorge any notifications that got queued up because they couldn't be sent. Fix this by adding a mechanism to emit regular probes. Two levels of probing are made available: Under normal circumstances the 'slow' queue will be used for a fileserver - this just probes the preferred address once every 5 mins or so; however, if server fails to respond to any probes, the server will shift to the 'fast' queue from which all its interfaces will be probed every 30s. When it finally responds, the record will switch back to the slow queue. Further notes: (1) Probing is now no longer driven from the fileserver rotation algorithm. (2) Probes are dispatched to all interfaces on a fileserver when that an afs_server object is set up to record it. (3) The afs_server object is removed from the probe queues when we start to probe it. afs_is_probing_server() returns true if it's not listed - ie. it's undergoing probing. (4) The afs_server object is added back on to the probe queue when the final outstanding probe completes, but the probed_at time is set when we're about to launch a probe so that it's not dependent on the probe duration. (5) The timer and the work item added for this must be handed a count on net->servers_outstanding, which they hand on or release. This makes sure that network namespace cleanup waits for them. Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation") Reported-by: Dave Botsch <botsch@cnf.cornell.edu> Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-31afs: Split the usage count on struct afs_serverDavid Howells1-6/+12
Split the usage count on the afs_server struct to have an active count that registers who's actually using it separately from the reference count on the object. This allows a future patch to dispatch polling probes without advancing the "unuse" time into the future each time we emit a probe, which would otherwise prevent unused server records from expiring. Included in this: (1) The latter part of afs_destroy_server() in which the RCU destruction of afs_server objects is invoked and the outstanding server count is decremented is split out into __afs_put_server(). (2) afs_put_server() now calls __afs_put_server() rather then setting the management timer. (3) The calls begun by afs_fs_give_up_all_callbacks() and afs_fs_get_capabilities() can now take a ref on the server record, so afs_destroy_server() can just drop its ref and needn't wait for the completion of these calls. They'll put the ref when they're done. (4) Because of (3), afs_fs_probe_done() no longer needs to wake up afs_destroy_server() with server->probe_outstanding. (5) afs_gc_servers can be simplified. It only needs to check if server->active is 0 rather than playing games with the refcount. (6) afs_manage_servers() can propose a server for gc if