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* Merge tag 'netfs-prep-20220318' of ↵Linus Torvalds2022-04-011-11/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull netfs updates from David Howells: "Netfs prep for write helpers. Having had a go at implementing write helpers and content encryption support in netfslib, it seems that the netfs_read_{,sub}request structs and the equivalent write request structs were almost the same and so should be merged, thereby requiring only one set of alloc/get/put functions and a common set of tracepoints. Merging the structs also has the advantage that if a bounce buffer is added to the request struct, a read operation can be performed to fill the bounce buffer, the contents of the buffer can be modified and then a write operation can be performed on it to send the data wherever it needs to go using the same request structure all the way through. The I/O handlers would then transparently perform any required crypto. This should make it easier to perform RMW cycles if needed. The potentially common functions and structs, however, by their names all proclaim themselves to be associated with the read side of things. The bulk of these changes alter this in the following ways: - Rename struct netfs_read_{,sub}request to netfs_io_{,sub}request. - Rename some enums, members and flags to make them more appropriate. - Adjust some comments to match. - Drop "read"/"rreq" from the names of common functions. For instance, netfs_get_read_request() becomes netfs_get_request(). - The ->init_rreq() and ->issue_op() methods become ->init_request() and ->issue_read(). I've kept the latter as a read-specific function and in another branch added an ->issue_write() method. The driver source is then reorganised into a number of files: fs/netfs/buffered_read.c Create read reqs to the pagecache fs/netfs/io.c Dispatchers for read and write reqs fs/netfs/main.c Some general miscellaneous bits fs/netfs/objects.c Alloc, get and put functions fs/netfs/stats.c Optional procfs statistics. and future development can be fitted into this scheme, e.g.: fs/netfs/buffered_write.c Modify the pagecache fs/netfs/buffered_flush.c Writeback from the pagecache fs/netfs/direct_read.c DIO read support fs/netfs/direct_write.c DIO write support fs/netfs/unbuffered_write.c Write modifications directly back Beyond the above changes, there are also some changes that affect how things work: - Make fscache_end_operation() generally available. - In the netfs tracing header, generate enums from the symbol -> string mapping tables rather than manually coding them. - Add a struct for filesystems that uses netfslib to put into their inode wrapper structs to hold extra state that netfslib is interested in, such as the fscache cookie. This allows netfslib functions to be set in filesystem operation tables and jumped to directly without having to have a filesystem wrapper. - Add a member to the struct added above to track the remote inode length as that may differ if local modifications are buffered. We may need to supply an appropriate EOF pointer when storing data (in AFS for example). - Pass extra information to netfs_alloc_request() so that the ->init_request() hook can access it and retain information to indicate the origin of the operation. - Make the ->init_request() hook return an error, thereby allowing a filesystem that isn't allowed to cache an inode (ceph or cifs, for example) to skip readahead. - Switch to using refcount_t for subrequests and add tracepoints to log refcount changes for the request and subrequest structs. - Add a function to consolidate dispatching a read request. Similar code is used in three places and another couple are likely to be added in the future" Link: https://lore.kernel.org/all/2639515.1648483225@warthog.procyon.org.uk/ * tag 'netfs-prep-20220318' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: afs: Maintain netfs_i_context::remote_i_size netfs: Keep track of the actual remote file size netfs: Split some core bits out into their own file netfs: Split fs/netfs/read_helper.c netfs: Rename read_helper.c to io.c netfs: Prepare to split read_helper.c netfs: Add a function to consolidate beginning a read netfs: Add a netfs inode context ceph: Make ceph_init_request() check caps on readahead netfs: Change ->init_request() to return an error code netfs: Refactor arguments for netfs_alloc_read_request netfs: Adjust the netfs_failure tracepoint to indicate non-subreq lines netfs: Trace refcounting on the netfs_io_subrequest struct netfs: Trace refcounting on the netfs_io_request struct netfs: Adjust the netfs_rreq tracepoint slightly netfs: Split netfs_io_* object handling out netfs: Finish off rename of netfs_read_request to netfs_io_request netfs: Rename netfs_read_*request to netfs_io_*request netfs: Generate enums from trace symbol mapping lists fscache: export fscache_end_operation()
| * fscache: export fscache_end_operation()Jeffle Xu2022-03-181-11/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Export fscache_end_operation() to avoid code duplication. Besides, considering the paired fscache_begin_read_operation() is already exported, it shall make sense to also export fscache_end_operation(). Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/20220302125134.131039-2-jefflexu@linux.alibaba.com/ # Jeffle's v4 Link: https://lore.kernel.org/r/164622971432.3564931.12184135678781328146.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/164678190346.1200972.7453733431978569479.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/164692888334.2099075.5166283293894267365.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/20220316131723.111553-2-jefflexu@linux.alibaba.com/ # v5
* | fscache: Convert fscache_set_page_dirty() to fscache_dirty_folio()Matthew Wilcox (Oracle)2022-03-151-13/+15
|/ | | | | | | | | | Convert all users of fscache_set_page_dirty to use fscache_dirty_folio. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs Tested-by: David Howells <dhowells@redhat.com> # afs
* fscache: Fix the volume collision wait conditionDavid Howells2022-01-211-2/+2
| | | | | | | | | | | | | | | | | The condition that the waits in fscache_wait_on_volume_collision() are waiting until are inverted. This suddenly started happening on the upstream kernel with something like the following appearing in dmesg when running xfstests: CacheFiles: cachefiles: Inode already in use: Iafs,example.com,100055 Fix them by inverting the conditions. Fixes: 62ab63352350 ("fscache: Implement volume registration") Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/164251398010.3435901.943876048104930939.stgit@warthog.procyon.org.uk/ # v1
* fscache: Add a tracepoint for cookie use/unuseDavid Howells2022-01-111-4/+25
| | | | | | | | | Add a tracepoint to track fscache_use/unuse_cookie(). Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/164021588628.640689.12942919367404043608.stgit@warthog.procyon.org.uk/ # v4
* nfs: Implement cache I/O by accessing the cache directlyDavid Howells2022-01-101-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move NFS to using fscache DIO API instead of the old upstream I/O API as that has been removed. This is a stopgap solution as the intention is that at sometime in the future, the cache will move to using larger blocks and won't be able to store individual pages in order to deal with the potential for data corruption due to the backing filesystem being able insert/remove bridging blocks of zeros into its extent list[1]. NFS then reads and writes cache pages synchronously and one page at a time. The preferred change would be to use the netfs lib, but the new I/O API can be used directly. It's just that as the cache now needs to track data for itself, caching blocks may exceed page size... This code is somewhat borrowed from my "fallback I/O" patchset[2]. Changes ======= ver #3: - Restore lost =n fallback for nfs_fscache_release_page()[2]. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Dave Wysochanski <dwysocha@redhat.com> Acked-by: Jeff Layton <jlayton@kernel.org> cc: Trond Myklebust <trond.myklebust@hammerspace.com> cc: Anna Schumaker <anna.schumaker@netapp.com> cc: linux-nfs@vger.kernel.org cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/YO17ZNOcq+9PajfQ@mit.edu [1] Link: https://lore.kernel.org/r/202112100957.2oEDT20W-lkp@intel.com/ [2] Link: https://lore.kernel.org/r/163189108292.2509237.12615909591150927232.stgit@warthog.procyon.org.uk/ [2] Link: https://lore.kernel.org/r/163906981318.143852.17220018647843475985.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967184451.1823006.6450645559828329590.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021577632.640689.11069627070150063812.stgit@warthog.procyon.org.uk/ # v4
* fscache, cachefiles: Display stat of culling eventsDavid Howells2022-01-071-2/+5
| | | | | | | | | | | | | | Add a stat counter of culling events whereby the cache backend culls a file to make space (when asked by cachefilesd in this case) and display in /proc/fs/fscache/stats. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819654165.215744.3797804661644212436.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906961387.143852.9291157239960289090.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967168266.1823006.14436200166581605746.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021567619.640689.4339228906248763197.stgit@warthog.procyon.org.uk/ # v4
* fscache, cachefiles: Display stats of no-space eventsDavid Howells2022-01-071-0/+8
| | | | | | | | | | | | | Add stat counters of no-space events that caused caching not to happen and display in /proc/fs/fscache/stats. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819653216.215744.17210522251617386509.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906958369.143852.7257100711818401748.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967166917.1823006.14842444049198947892.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021566184.640689.4417328329632709265.stgit@warthog.procyon.org.uk/ # v4
* fscache, cachefiles: Store the volume coherency dataDavid Howells2022-01-071-2/+12
| | | | | | | | | | | | | | | | Store the volume coherency data in an xattr and check it when we rebind the volume. If it doesn't match the cache volume is moved to the graveyard and rebuilt anew. Changes ======= ver #4: - Remove a couple of debugging prints. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/163967164397.1823006.2950539849831291830.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021563138.640689.15851092065380543119.stgit@warthog.procyon.org.uk/ # v4
* fscache: Provide a function to resize a cookieDavid Howells2022-01-073-2/+35
| | | | | | | | | | | | | | | | | | | | Provide a function to change the size of the storage attached to a cookie, to match the size of the file being cached when it's changed by truncate or fallocate: void fscache_resize_cookie(struct fscache_cookie *cookie, loff_t new_size); This acts synchronously and is expected to run under the inode lock of the caller. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819621839.215744.7895597119803515402.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906922387.143852.16394459879816147793.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967128998.1823006.10740669081985775576.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021527861.640689.3466382085497236267.stgit@warthog.procyon.org.uk/ # v4
* vfs, fscache: Implement pinning of cache usage for writebackDavid Howells2022-01-071-0/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Cachefiles has a problem in that it needs to keep the backing file for a cookie open whilst there are local modifications pending that need to be written to it. However, we don't want to keep the file open indefinitely, as that causes EMFILE/ENFILE/ENOMEM problems. Reopening the cache file, however, is a problem if this is being done due to writeback triggered by exit(). Some filesystems will oops if we try to open a file in that context because they want to access current->fs or other resources that have already been dismantled. To get around this, I added the following: (1) An inode flag, I_PINNING_FSCACHE_WB, to be set on a network filesystem inode to indicate that we have a usage count on the cookie caching that inode. (2) A flag in struct writeback_control, unpinned_fscache_wb, that is set when __writeback_single_inode() clears the last dirty page from i_pages - at which point it clears I_PINNING_FSCACHE_WB and sets this flag. This has to be done here so that clearing I_PINNING_FSCACHE_WB can be done atomically with the check of PAGECACHE_TAG_DIRTY that clears I_DIRTY_PAGES. (3) A function, fscache_set_page_dirty(), which if it is not set, sets I_PINNING_FSCACHE_WB and calls fscache_use_cookie() to pin the cache resources. (4) A function, fscache_unpin_writeback(), to be called by ->write_inode() to unuse the cookie. (5) A function, fscache_clear_inode_writeback(), to be called when the inode is evicted, before clear_inode() is called. This cleans up any lingering I_PINNING_FSCACHE_WB. The network filesystem can then use these tools to make sure that fscache_write_to_cache() can write locally modified data to the cache as well as to the server. For the future, I'm working on write helpers for netfs lib that should allow this facility to be removed by keeping track of the dirty regions separately - but that's incomplete at the moment and is also going to be affected by folios, one way or another, since it deals with pages Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819615157.215744.17623791756928043114.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906917856.143852.8224898306177154573.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967124567.1823006.14188359004568060298.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021524705.640689.17824932021727663017.stgit@warthog.procyon.org.uk/ # v4
* fscache: Implement higher-level write I/O interfaceDavid Howells2022-01-071-0/+104
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide a higher-level function than fscache_write() to perform a write from an inode's pagecache to the cache, whilst fending off concurrent writes by means of the PG_fscache mark on a page: void fscache_write_to_cache(struct fscache_cookie *cookie, struct address_space *mapping, loff_t start, size_t len, loff_t i_size, netfs_io_terminated_t term_func, void *term_func_priv, bool caching); If caching is false, this function does nothing except call (*term_func)() if given. It assumes that, in such a case, PG_fscache will not have been set on the pages. Otherwise, if caching is true, this function requires the source pages to have had PG_fscache set on them before calling. start and len define the region of the file to be modified and i_size indicates the new file size. The source pages are extracted from the mapping. term_func and term_func_priv work as for fscache_write(). The PG_fscache marks will be cleared at the end of the operation, before term_func is called or the function otherwise returns. There is an additonal helper function to clear the PG_fscache bits from a range of pages: void fscache_clear_page_bits(struct fscache_cookie *cookie, struct address_space *mapping, loff_t start, size_t len, bool caching); If caching is true, the pages to be managed are expected to be located on mapping in the range defined by start and len. If caching is false, it does nothing. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819614155.215744.5528123235123721230.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906916346.143852.15632773570362489926.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967123599.1823006.12946816026724657428.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021522672.640689.4381958316198807813.stgit@warthog.procyon.org.uk/ # v4
* fscache: Provide read/write stat counters for the cacheDavid Howells2022-01-071-0/+9
| | | | | | | | | | | | Provide read/write stat counters for the cache backend to use. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819609532.215744.10821082637727410554.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906912598.143852.12960327989649429069.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967113830.1823006.3222957649202368162.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021517502.640689.6077928311710357342.stgit@warthog.procyon.org.uk/ # v4
* fscache: Count data storage objects in a cacheDavid Howells2022-01-071-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Count the data storage objects that are currently allocated in a cache. This is used to pin certain cache structures until cache withdrawal is complete. Three helpers are provided to manage and make use of the count: (1) void fscache_count_object(struct fscache_cache *cache); This should be called by the cache backend to note that an object has been allocated and attached to the cache. (2) void fscache_uncount_object(struct fscache_cache *cache); This should be called by the backend to note that an object has been destroyed. This sends a wakeup event that allows cache withdrawal to proceed if it was waiting for that object. (3) void fscache_wait_for_objects(struct fscache_cache *cache); This can be used by the backend to wait for all outstanding cache object to be destroyed. Each cache's counter is displayed as part of /proc/fs/fscache/caches. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819608594.215744.1812706538117388252.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906911646.143852.168184059935530127.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967111846.1823006.9868154941573671255.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021516219.640689.4934796654308958158.stgit@warthog.procyon.org.uk/ # v4
* fscache: Provide a means to begin an operationDavid Howells2022-01-073-0/+163
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide a function to begin a read operation: int fscache_begin_read_operation( struct netfs_cache_resources *cres, struct fscache_cookie *cookie) This is primarily intended to be called by network filesystems on behalf of netfslib, but may also be called to use the I/O access functions directly. It attaches the resources required by the cache to cres struct from the supplied cookie. This holds access to the cache behind the cookie for the duration of the operation and forces cache withdrawal and cookie invalidation to perform synchronisation on the operation. cres->inval_counter is set from the cookie at this point so that it can be compared at the end of the operation. Note that this does not guarantee that the cache state is fully set up and able to perform I/O immediately; looking up and creation may be left in progress in the background. The operations intended to be called by the network filesystem, such as reading and writing, are expected to wait for the cookie to move to the correct state. This will, however, potentially sleep, waiting for a certain minimum state to be set or for operations such as invalidate to advance far enough that I/O can resume. Also provide a function for the cache to call to wait for the cache object to get to a state where it can be used for certain things: bool fscache_wait_for_operation(struct netfs_cache_resources *cres, enum fscache_want_stage stage); This looks at the cache resources provided by the begin function and waits for them to get to an appropriate stage. There's a choice of wanting just some parameters (FSCACHE_WANT_PARAM) or the ability to do I/O (FSCACHE_WANT_READ or FSCACHE_WANT_WRITE). Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819603692.215744.146724961588817028.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906910672.143852.13856103384424986357.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967110245.1823006.2239170567540431836.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021513617.640689.16627329360866150606.stgit@warthog.procyon.org.uk/ # v4
* fscache: Implement cookie invalidationDavid Howells2022-01-073-1/+94
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a function to invalidate the cache behind a cookie: void fscache_invalidate(struct fscache_cookie *cookie, const void *aux_data, loff_t size, unsigned int flags) This causes any cached data for the specified cookie to be discarded. If the cookie is marked as being in use, a new cache object will be created if possible and future I/O will use that instead. In-flight I/O should be abandoned (writes) or reconsidered (reads). Each time it is called cookie->inval_counter is incremented and this can be used to detect invalidation at the end of an I/O operation. The coherency data attached to the cookie can be updated and the cookie size should be reset. One flag is available, FSCACHE_INVAL_DIO_WRITE, which should be used to indicate invalidation due to a DIO write on a file. This will temporarily disable caching for this cookie. Changes ======= ver #2: - Should only change to inval state if can get access to cache. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819602231.215744.11206598147269491575.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906909707.143852.18056070560477964891.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967107447.1823006.5945029409592119962.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021512640.640689.11418616313147754172.stgit@warthog.procyon.org.uk/ # v4
* fscache: Implement cookie user counting and resource pinningDavid Howells2022-01-073-1/+234
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide a pair of functions to count the number of users of a cookie (open files, writeback, invalidation, resizing, reads, writes), to obtain and pin resources for the cookie and to prevent culling for the whilst there are users. The first function marks a cookie as being in use: void fscache_use_cookie(struct fscache_cookie *cookie, bool will_modify); The caller should indicate the cookie to use and whether or not the caller is in a context that may modify the cookie (e.g. a file open O_RDWR). If the cookie is not already resourced, fscache will ask the cache backend in the background to do whatever it needs to look up, create or otherwise obtain the resources necessary to access data. This is pinned to the cookie and may not be culled, though it may be withdrawn if the cache as a whole is withdrawn. The second function removes the in-use mark from a cookie and, optionally, updates the coherency data: void fscache_unuse_cookie(struct fscache_cookie *cookie, const void *aux_data, const loff_t *object_size); If non-NULL, the aux_data buffer and/or the object_size will be saved into the cookie and will be set on the backing store when the object is committed. If this removes the last usage on a cookie, the cookie is placed onto an LRU list from which it will be removed and closed after a couple of seconds if it doesn't get reused. This prevents resource overload in the cache - in particular it prevents it from holding too many files open. Changes ======= ver #2: - Fix fscache_unuse_cookie() to use atomic_dec_and_lock() to avoid a potential race if the cookie gets reused before it completes the unusement. - Added missing transition to LRU_DISCARDING state. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819600612.215744.13678350304176542741.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906907567.143852.16979631199380722019.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967106467.1823006.6790864931048582667.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021511674.640689.10084988363699111860.stgit@warthog.procyon.org.uk/ # v4
* fscache: Implement simple cookie state machineDavid Howells2022-01-071-42/+271
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement a very simple cookie state machine to handle lookup, invalidation, withdrawal, relinquishment and, to be added later, commit on LRU discard. Three cache methods are provided: ->lookup_cookie() to look up and, if necessary, create a data storage object; ->withdraw_cookie() to free the resources associated with that object and potentially delete it; and ->prepare_to_write(), to do prepare for changes to the cached data to be modified locally. Changes ======= ver #3: - Fix a race between LRU discard and relinquishment whereby the former would override the latter and thus the latter would never happen[1]. ver #2: - Don't hold n_accesses elevated whilst cache is bound to a cookie, but rather add a flag that prevents the state machine from being queued when n_accesses reaches 0. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/599331.1639410068@warthog.procyon.org.uk/ [1] Link: https://lore.kernel.org/r/163819599657.215744.15799615296912341745.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906903925.143852.1805855338154353867.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967105456.1823006.14730395299835841776.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021510706.640689.7961423370243272583.stgit@warthog.procyon.org.uk/ # v4
* fscache: Add a function for a cache backend to note an I/O errorDavid Howells2022-01-071-0/+20
| | | | | | | | | | | | Add a function to the backend API to note an I/O error in a cache. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819598741.215744.891281275151382095.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906901316.143852.15225412215771586528.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967100721.1823006.16435671567428949398.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021508840.640689.11902836226570620424.stgit@warthog.procyon.org.uk/ # v4
* fscache: Provide and use cache methods to lookup/create/free a volumeDavid Howells2022-01-071-3/+86
| | | | | | | | | | | | | | | | | | Add cache methods to lookup, create and remove a volume. Looking up or creating the volume requires the cache pinning for access; freeing the volume requires the volume pinning for access. The ->acquire_volume() method is used to ask the cache backend to lookup and, if necessary, create a volume; the ->free_volume() method is used to free the resources for a volume. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819597821.215744.5225318658134989949.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906898645.143852.8537799955945956818.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967099771.1823006.1455197910571061835.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021507345.640689.4073511598838843040.stgit@warthog.procyon.org.uk/ # v4
* fscache: Implement functions add/remove a cacheDavid Howells2022-01-071-0/+70
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement functions to allow the cache backend to add or remove a cache: (1) Declare a cache to be live: int fscache_add_cache(struct fscache_cache *cache, const struct fscache_cache_ops *ops, void *cache_priv); Take a previously acquired cache cookie, set the operations table and private data and mark the cache open for access. (2) Withdraw a cache from service: void fscache_withdraw_cache(struct fscache_cache *cache); This marks the cache as withdrawn and thus prevents further cache-level and volume-level accesses. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819596022.215744.8799712491432238827.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906896599.143852.17049208999019262884.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967097870.1823006.3470041000971522030.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021505541.640689.1819714759326331054.stgit@warthog.procyon.org.uk/ # v4
* fscache: Implement cookie-level access helpersDavid Howells2022-01-073-0/+102
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a number of helper functions to manage access to a cookie, pinning the cache object in place for the duration to prevent cache withdrawal from removing it: (1) void fscache_init_access_gate(struct fscache_cookie *cookie); This function initialises the access count when a cache binds to a cookie. An extra ref is taken on the access count to prevent wakeups while the cache is active. We're only interested in the wakeup when a cookie is being withdrawn and we're waiting for it to quiesce - at which point the counter will be decremented before the wait. The FSCACHE_COOKIE_NACC_ELEVATED flag is set on the cookie to keep track of the extra ref in order to handle a race between relinquishment and withdrawal both trying to drop the extra ref. (2) bool fscache_begin_cookie_access(struct fscache_cookie *cookie, enum fscache_access_trace why); This function attempts to begin access upon a cookie, pinning it in place if it's cached. If successful, it returns true and leaves a the access count incremented. (3) void fscache_end_cookie_access(struct fscache_cookie *cookie, enum fscache_access_trace why); This function drops the access count obtained by (2), permitting object withdrawal to take place when it reaches zero. A tracepoint is provided to track changes to the access counter on a cookie. Changes ======= ver #2: - Don't hold n_accesses elevated whilst cache is bound to a cookie, but rather add a flag that prevents the state machine from being queued when n_accesses reaches 0. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819595085.215744.1706073049250505427.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906895313.143852.10141619544149102193.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967095980.1823006.1133648159424418877.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021503063.640689.8870918985269528670.stgit@warthog.procyon.org.uk/ # v4
* fscache: Implement volume-level access helpersDavid Howells2022-01-073-0/+88
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a pair of helper functions to manage access to a volume, pinning the volume in place for the duration to prevent cache withdrawal from removing it: bool fscache_begin_volume_access(struct fscache_volume *volume, enum fscache_access_trace why); void fscache_end_volume_access(struct fscache_volume *volume, enum fscache_access_trace why); The way the access gate on the volume works/will work is: (1) If the cache tests as not live (state is not FSCACHE_CACHE_IS_ACTIVE), then we return false to indicate access was not permitted. (2) If the cache tests as live, then we increment the volume's n_accesses count and then recheck the cache liveness, ending the access if it ceased to be live. (3) When we end the access, we decrement the volume's n_accesses and wake up the any waiters if it reaches 0. (4) Whilst the cache is caching, the volume's n_accesses is kept artificially incremented to prevent wakeups from happening. (5) When the cache is taken offline, the state is changed to prevent new accesses, the volume's n_accesses is decremented and we wait for it to become 0. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819594158.215744.8285859817391683254.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906894315.143852.5454793807544710479.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967095028.1823006.9173132503876627466.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021501546.640689.9631510472149608443.stgit@warthog.procyon.org.uk/ # v4
* fscache: Implement cache-level access helpersDavid Howells2022-01-073-0/+66
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a pair of functions to pin/unpin a cache that we're wanting to do a high-level access to (such as creating or removing a volume): bool fscache_begin_cache_access(struct fscache_cache *cache, enum fscache_access_trace why); void fscache_end_cache_access(struct fscache_cache *cache, enum fscache_access_trace why); The way the access gate works/will work is: (1) If the cache tests as not live (state is not FSCACHE_CACHE_IS_ACTIVE), then we return false to indicate access was not permitted. (2) If the cache tests as live, then we increment the n_accesses count and then recheck the liveness, ending the access if it ceased to be live. (3) When we end the access, we decrement n_accesses and wake up the any waiters if it reaches 0. (4) Whilst the cache is caching, n_accesses is kept artificially incremented to prevent wakeups from happening. (5) When the cache is taken offline, the state is changed to prevent new accesses, n_accesses is decremented and we wait for n_accesses to become 0. Note that some of this is implemented in a later patch. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819593239.215744.7537428720603638088.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906893368.143852.14164004598465617981.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967093977.1823006.6967886507023056409.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021499995.640689.18286203753480287850.stgit@warthog.procyon.org.uk/ # v4
* fscache: Implement cookie registrationDavid Howells2022-01-076-1/+564
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add functions to the fscache API to allow data file cookies to be acquired and relinquished by the network filesystem. It is intended that the filesystem will create such cookies per-inode under a volume. To request a cookie, the filesystem should call: struct fscache_cookie * fscache_acquire_cookie(struct fscache_volume *volume, u8 advice, const void *index_key, size_t index_key_len, const void *aux_data, size_t aux_data_len, loff_t object_size) The filesystem must first have created a volume cookie, which is passed in here. If it passes in NULL then the function will just return a NULL cookie. A binary key should be passed in index_key and is of size index_key_len. This is saved in the cookie and is used to locate the associated data in the cache. A coherency data buffer of size aux_data_len will be allocated and initialised from the buffer pointed to by aux_data. This is used to validate cache objects when they're opened and is stored on disk with them when they're committed. The data is stored in the cookie and will be updateable by various functions in later patches. The object_size must also be given. This is also used to perform a coherency check and to size the backing storage appropriately. This function disallows a cookie from being acquired twice in parallel, though it will cause the second user to wait if the first is busy relinquishing its cookie. When a network filesystem has finished with a cookie, it should call: void fscache_relinquish_cookie(struct fscache_volume *volume, bool retire) If retire is true, any backing data will be discarded immediately. Changes ======= ver #3: - fscache_hash()'s size parameter is now in bytes. Use __le32 as the unit to round up to. - When comparing cookies, simply see if the attributes are the same rather than subtracting them to produce a strcmp-style return[1]. - Add a check to see if the cookie is still hashed at the point of freeing. ver #2: - Don't hold n_accesses elevated whilst cache is bound to a cookie, but rather add a flag that prevents the state machine from being queued when n_accesses reaches 0. - Remove the unused cookie pointer field from the fscache_acquire tracepoint. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/CAHk-=whtkzB446+hX0zdLsdcUJsJ=8_-0S1mE_R+YurThfUbLA@mail.gmail.com/ [1] Link: https://lore.kernel.org/r/163819590658.215744.14934902514281054323.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906891983.143852.6219772337558577395.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967088507.1823006.12659006350221417165.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021498432.640689.12743483856927722772.stgit@warthog.procyon.org.uk/ # v4
* fscache: Implement volume registrationDavid Howells2022-01-075-1/+372
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add functions to the fscache API to allow volumes to be acquired and relinquished by the network filesystem. A volume is an index of data storage cache objects. A volume is represented by a volume cookie in the API. A filesystem would typically create a volume for a superblock and then create per-inode cookies within it. To request a volume, the filesystem calls: struct fscache_volume * fscache_acquire_volume(const char *volume_key, const char *cache_name, const void *coherency_data, size_t coherency_len) The volume_key is a printable string used to match the volume in the cache. It should not contain any '/' characters. For AFS, for example, this would be "afs,<cellname>,<volume_id>", e.g. "afs,example.com,523001". The cache_name can be NULL, but if not it should be a string indicating the name of the cache to use if there's more than one available. The coherency data, if given, is an arbitrarily-sized blob that's attached to the volume and is compared when the volume is looked up. If it doesn't match, the old volume is judged to be out of date and it and everything within it is discarded. Acquiring a volume twice concurrently is disallowed, though the function will wait if an old volume cookie is being relinquishing. When a network filesystem has finished with a volume, it should return the volume cookie by calling: void fscache_relinquish_volume(struct fscache_volume *volume, const void *coherency_data, bool invalidate) If invalidate is true, the entire volume will be discarded; if false, the volume will be synced and the coherency data will be updated. Changes ======= ver #4: - Removed an extraneous param from kdoc on fscache_relinquish_volume()[3]. ver #3: - fscache_hash()'s size parameter is now in bytes. Use __le32 as the unit to round up to. - When comparing cookies, simply see if the attributes are the same rather than subtracting them to produce a strcmp-style return[2]. - Make the coherency data an arbitrary blob rather than a u64, but don't store it for the moment. ver #2: - Fix error check[1]. - Make a fscache_acquire_volume() return errors, including EBUSY if a conflicting volume cookie already exists. No error is printed now - that's left to the netfs. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/20211203095608.GC2480@kili/ [1] Link: https://lore.kernel.org/r/CAHk-=whtkzB446+hX0zdLsdcUJsJ=8_-0S1mE_R+YurThfUbLA@mail.gmail.com/ [2] Link: https://lore.kernel.org/r/20211220224646.30e8205c@canb.auug.org.au/ [3] Link: https://lore.kernel.org/r/163819588944.215744.1629085755564865996.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906890630.143852.13972180614535611154.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967086836.1823006.8191672796841981763.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021495816.640689.4403156093668590217.stgit@warthog.procyon.org.uk/ # v4
* fscache: Implement cache registrationDavid Howells2022-01-074-0/+312
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement a register of caches and provide functions to manage it. Two functions are provided for the cache backend to use: (1) Acquire a cache cookie: struct fscache_cache *fscache_acquire_cache(const char *name) This gets the cache cookie for a cache of the specified name and moves it to the preparation state. If a nameless cache cookie exists, that will be given this name and used. (2) Relinquish a cache cookie: void fscache_relinquish_cache(struct fscache_cache *cache); This relinquishes a cache cookie, cleans it and makes it available if it's still referenced by a network filesystem. Note that network filesystems don't deal with cache cookies directly, but rather go straight to the volume registration. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819587157.215744.13523139317322503286.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906889665.143852.10378009165231294456.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967085081.1823006.2218944206363626210.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021494847.640689.10109692261640524343.stgit@warthog.procyon.org.uk/ # v4
* fscache: Implement a hash functionDavid Howells2022-01-072-0/+42
| | | | | | | | | | | | | | | | | | | | | | | | | Implement a function to generate hashes. It needs to be stable over time and endianness-independent as the hashes will appear on disk in future patches. It can assume that its input is a multiple of four bytes in size and alignment. This is borrowed from the VFS and simplified. le32_to_cpu() is added to make it endianness-independent. Changes ======= ver #3: - Read the data being hashed in an endianness-independent way[1]. - Change the size parameter to be in bytes rather than words. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/CAHk-=whtkzB446+hX0zdLsdcUJsJ=8_-0S1mE_R+YurThfUbLA@mail.gmail.com [1] Link: https://lore.kernel.org/r/163819586113.215744.1699465806130102367.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906888735.143852.10944614318596881429.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967082342.1823006.8915671045444488742.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021493624.640689.9990442668811178628.stgit@warthog.procyon.org.uk/ # v4
* fscache: Introduce new driverDavid Howells2022-01-076-0/+363
| | | | | | | | | | | | | | | | | | Introduce basic skeleton of the new, rewritten fscache driver. Changes ======= ver #3: - Use remove_proc_subtree(), not remove_proc_entry() to remove a populated dir. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819584034.215744.4290533472390439030.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906887770.143852.3577888294989185666.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967080039.1823006.5702921801104057922.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021491014.640689.4292699878317589512.stgit@warthog.procyon.org.uk/ # v4
* fscache: Remove the contents of the fscache driver, pending rewriteDavid Howells2022-01-0714-5879/+0
| | | | | | | | | | | | | | | | | Remove the code that comprises the fscache driver as it's going to be substantially rewritten, with the majority of the code being erased in the rewrite. A small piece of linux/fscache.h is left as that is #included by a bunch of network filesystems. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819578724.215744.18210619052245724238.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906884814.143852.6727245089843862889.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967077097.1823006.1377665951499979089.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021485548.640689.13876080567388696162.stgit@warthog.procyon.org.uk/ # v4
* fscache, cachefiles: Disable configurationDavid Howells2022-01-071-0/+3
| | | | | | | | | | | | Disable fscache and cachefiles in Kconfig whilst it is rewritten. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819576672.215744.12444272479560406780.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906882835.143852.11073015983885872901.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967075113.1823006.277316290062782998.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021481179.640689.2004199594774033658.stgit@warthog.procyon.org.uk/ # v4
* fscache: Remove an unused static variableDavid Howells2021-10-041-1/+0
| | | | | | | | | | | | The fscache object CREATE_OBJECT work state isn't ever referred to, so remove it and avoid the unused variable warning caused by W=1. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-fsdevel@vger.kernel.org cc: linux-doc@vger.kernel.org Link: https://lore.kernel.org/r/163214005516.2945267.7000234432243167892.stgit@warthog.procyon.org.uk/ # rfc v1 Link: https://lore.kernel.org/r/163281899704.2790286.9177774252843775348.stgit@warthog.procyon.org.uk/ # rfc v2
* fscache: Fix some kerneldoc warnings shown up by W=1David Howells2021-10-042-0/+4
| | | | | | | | | | | | Fix some kerneldoc warnings in the fscache driver that are shown up by W=1. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: Mauro Carvalho Chehab <mchehab@kernel.org> cc: linux-fsdevel@vger.kernel.org cc: linux-doc@vger.kernel.org Link: https://lore.kernel.org/r/163214005516.2945267.7000234432243167892.stgit@warthog.procyon.org.uk/ # rfc v1 Link: https://lore.kernel.org/r/163281899704.2790286.9177774252843775348.stgit@warthog.procyon.org.uk/ # rfc v2
* fscache: Use refcount_t for the cookie refcount instead of atomic_tDavid Howells2021-08-274-20/+32
| | | | | | | | | | | Use refcount_t for the fscache_cookie refcount instead of atomic_t and rename the 'usage' member to 'ref' in such cases. The tracepoints that reference it change from showing "u=%d" to "r=%d". Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/162431204358.2908479.8006938388213098079.stgit@warthog.procyon.org.uk/
* fscache: Fix fscache_cookie_put() to not deref after decDavid Howells2021-08-273-6/+8
| | | | | | | | | | | | | | | | | | fscache_cookie_put() accesses the cookie it has just put inside the tracepoint that monitors the change - but this is something it's not allowed to do if we didn't reduce the count to zero. Fix this by dropping most of those values from the tracepoint and grabbing the cookie debug ID before doing the dec. Also take the opportunity to switch over the usage and where arguments on the tracepoint to put the reason last. Fixes: a18feb55769b ("fscache: Add tracepoints") Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/162431203107.2908479.3259582550347000088.stgit@warthog.procyon.org.uk/
* fscache: Fix cookie key hashingDavid Howells2021-08-273-13/+42
| | | | | | | | | | | | | | | | | | | | | | The current hash algorithm used for hashing cookie keys is really bad, producing almost no dispersion (after a test kernel build, ~30000 files were split over just 18 out of the 32768 hash buckets). Borrow the full_name_hash() hash function into fscache to do the hashing for cookie keys and, in the future, volume keys. I don't want to use full_name_hash() as-is because I want the hash value to be consistent across arches and over time as the hash value produced may get used on disk. I can also optimise parts of it away as the key will always be a padded array of aligned 32-bit words. Fixes: ec0328e46d6e ("fscache: Maintain a catalogue of allocated cookies") Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/162431201844.2908479.8293647220901514696.stgit@warthog.procyon.org.uk/
* fscache: Change %p in format strings to something elseDavid Howells2021-08-273-14/+11
| | | | | | | | | | | | Change plain %p in format strings in fscache code to something more useful, since %p is now hashed before printing and thus no longer matches the contents of an oops register dump. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/160588474843.3465195.5446072310069374803.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/162431199509.2908479.2950631488219944294.stgit@warthog.procyon.org.uk/
* fscache: Remove the object list procfileDavid Howells2021-08-277-440/+0
| | | | | | | | | | Remove the object list procfile from fscache as objects will become entirely internal to the cache. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/162431198332.2908479.5847286163455099669.stgit@warthog.procyon.org.uk/
* fscache, cachefiles: Remove the histogram stuffDavid Howells2021-08-278-156/+0
| | | | | | | | | Remove the histogram stuff as it's mostly going to be outdated. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/162431195953.2908479.16770977195634296638.stgit@warthog.procyon.org.uk/
* fscache: Procfile to display cookiesDavid Howells2021-08-273-0/+111
| | | | | | | | | | | | Add /proc/fs/fscache/cookies to display active cookies. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/158861211871.340223.7223853943667440807.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/159465771021.1376105.6933857529128238020.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/160588460994.3465195.16963417803501149328.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/162431194785.2908479.786917990782538164.stgit@warthog.procyon.org.uk/
* fscache: Add a cookie debug ID and use that in tracesDavid Howells2021-08-273-16/+28
| | | | | | | | | | | | | | | | | | | | | Add a cookie debug ID and use that in traces and in procfiles rather than displaying the (hashed) pointer to the cookie. This is easier to correlate and we don't lose anything when interpreting oops output since that shows unhashed addresses and registers that aren't comparable to the hashed values. Changes: ver #2: - Fix the fscache_op tracepoint to handle a NULL cookie pointer. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/158861210988.340223.11688464116498247790.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/159465769844.1376105.14119502774019865432.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/160588459097.3465195.1273313637721852165.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/162431193544.2908479.17556704572948300790.stgit@warthog.procyon.org.uk/
* fscache: Select netfs stats if fscache stats are enabledDavid Howells2021-08-251-0/+1
| | | | | | | | | | | Unconditionally select the stats produced by the netfs lib if fscache stats are enabled as the former are displayed in the latter's procfile. Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-cachefs@redhat.com Reviewed-by: Jeff Layton <jlayton@redhat.com> Link: https://lore.kernel.org/r/162280352566.3319242.10615341893991206961.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/162431189627.2908479.9165349423842063755.stgit@warthog.procyon.org.uk/
* fscache, cachefiles: Add alternate API to use kiocb for read/write to cacheDavid Howells2021-04-236-1/+124
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add an alternate API by which the cache can be accessed through a kiocb, doing async DIO, rather than using the current API that tells the cache where all the pages are. The new API is intended to be used in conjunction with the netfs helper library. A filesystem must pick one or the other and not mix them. Filesystems wanting to use the new API must #define FSCACHE_USE_NEW_IO_API before #including the header. This prevents them from continuing to use the old API at the same time as there are incompatibilities in how the PG_fscache page bit is used. Changes: v6: - Provide a routine to shape a write so that the start and length can be aligned for DIO[3]. v4: - Use the vfs_iocb_iter_read/write() helpers[1] - Move initial definition of fscache_begin_read_operation() here. - Remove a commented-out line[2] - Combine ki->term_func calls in cachefiles_read_complete()[2]. - Remove explicit NULL initialiser[2]. - Remove extern on func decl[2]. - Put in param names on func decl[2]. - Remove redundant else[2]. - Fill out the kdoc comment for fscache_begin_read_operation(). - Rename fs/fscache/page2.c to io.c to match later patches. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-and-tested-by: Jeff Layton <jlayton@kernel.org> Tested-by: Dave Wysochanski <dwysocha@redhat.com> Tested-By: Marc Dionne <marc.dionne@auristor.com> cc: Christoph Hellwig <hch@lst.de> cc: linux-cachefs@redhat.com cc: linux-afs@lists.infradead.org cc: linux-nfs@vger.kernel.org cc: linux-cifs@vger.kernel.org cc: ceph-devel@vger.kernel.org cc: v9fs-developer@lists.sourceforge.net cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/20210216102614.GA27555@lst.de/ [1] Link: https://lore.kernel.org/r/20210216084230.GA23669@lst.de/ [2] Link: https://lore.kernel.org/r/161781047695.463527.7463536103593997492.stgit@warthog.procyon.org.uk/ [3] Link: https://lore.kernel.org/r/161118142558.1232039.17993829899588971439.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161161037850.2537118.8819808229350326503.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/161340402057.1303470.8038373593844486698.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/161539545919.286939.14573472672781434757.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/161653801477.2770958.10543270629064934227.stgit@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/161789084517.6155.12799689829859169640.stgit@warthog.procyon.org.uk/ # v6
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextLinus Torvalds2020-06-041-2/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking updates from David Miller: 1) Allow setting bluetooth L2CAP modes via socket option, from Luiz Augusto von Dentz. 2) Add GSO partial support to igc, from Sasha Neftin. 3) Several cleanups and improvements to r8169 from Heiner Kallweit. 4) Add IF_OPER_TESTING link state and use it when ethtool triggers a device self-test. From Andrew Lunn. 5) Start moving away from custom driver versions, use the globally defined kernel version instead, from Leon Romanovsky. 6) Support GRO vis gro_cells in DSA layer, from Alexander Lobakin. 7) Allow hard IRQ deferral during NAPI, from Eric Dumazet. 8) Add sriov and vf support to hinic, from Luo bin. 9) Support Media Redundancy Protocol (MRP) in the bridging code, from Horatiu Vultur. 10) Support netmap in the nft_nat code, from Pablo Neira Ayuso. 11) Allow UDPv6 encapsulation of ESP in the ipsec code, from Sabrina Dubroca. Also add ipv6 support for espintcp. 12) Lots of ReST conversions of the networking documentation, from Mauro Carvalho Chehab. 13) Support configuration of ethtool rxnfc flows in bcmgenet driver, from Doug Berger. 14) Allow to dump cgroup id and filter by it in inet_diag code, from Dmitry Yakunin. 15) Add infrastructure to export netlink attribute policies to userspace, from Johannes Berg. 16) Several optimizations to sch_fq scheduler, from Eric Dumazet. 17) Fallback to the default qdisc if qdisc init fails because otherwise a packet scheduler init failure will make a device inoperative. From Jesper Dangaard Brouer. 18) Several RISCV bpf jit optimizations, from Luke Nelson. 19) Correct the return type of the ->ndo_start_xmit() method in several drivers, it's netdev_tx_t but many drivers were using 'int'. From Yunjian Wang. 20) Add an ethtool interface for PHY master/slave config, from Oleksij Rempel. 21) Add BPF iterators, from Yonghang Song. 22) Add cable test infrastructure, including ethool interfaces, from Andrew Lunn. Marvell PHY driver is the first to support this facility. 23) Remove zero-length arrays all over, from Gustavo A. R. Silva. 24) Calculate and maintain an explicit frame size in XDP, from Jesper Dangaard Brouer. 25) Add CAP_BPF, from Alexei Starovoitov. 26) Support terse dumps in the packet scheduler, from Vlad Buslov. 27) Support XDP_TX bulking in dpaa2 driver, from Ioana Ciornei. 28) Add devm_register_netdev(), from Bartosz Golaszewski. 29) Minimize qdisc resets, from Cong Wang. 30) Get rid of kernel_getsockopt and kernel_setsockopt in order to eliminate set_fs/get_fs calls. From Christoph Hellwig. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2517 commits) selftests: net: ip_defrag: ignore EPERM net_failover: fixed rollback in net_failover_open() Revert "tipc: Fix potential tipc_aead refcnt leak in tipc_crypto_rcv" Revert "tipc: Fix potential tipc_node refcnt leak in tipc_rcv" vmxnet3: allow rx flow hash ops only when rss is enabled hinic: add set_channels ethtool_ops support selftests/bpf: Add a default $(CXX) value tools/bpf: Don't use $(COMPILE.c) bpf, selftests: Use bpf_probe_read_kernel s390/bpf: Use bcr 0,%0 as tail call nop filler s390/bpf: Maintain 8-byte stack alignment selftests/bpf: Fix verifier test selftests/bpf: Fix sample_cnt shared between two threads bpf, selftests: Adapt cls_redirect to call csum_level helper bpf: Add csum_level helper for fixing up csum levels bpf: Fix up bpf_skb_adjust_room helper's skb csum setting sfc: add missing annotation for efx_ef10_try_update_nic_stats_vf() crypto/chtls: IPv6 support for inline TLS Crypto/chcr: Fixes a coccinile check error Crypto/chcr: Fixes compilations warnings ...
| * sysctl: pass kernel pointers to ->proc_handlerChristoph Hellwig2020-04-271-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of having all the sysctl handlers deal with user pointers, which is rather hairy in terms of the BPF interaction, copy the input to and from userspace in common code. This also means that the strings are always NUL-terminated by the common code, making the API a little bit safer. As most handler just pass through the data to one of the common handlers a lot of the changes are mechnical. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | docs: filesystems: caching/backend-api.txt: convert it to ReSTMauro Carvalho Chehab2020-05-052-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | - Add a SPDX header; - Adjust document and section titles; - Some whitespace fixes and new line breaks; - Mark literal blocks as such; - Add table markups; - Add it to filesystems/caching/index.rst. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/5d0a61abaa87bfe913b9e2f321e74ef7af0f3dfc.1588021877.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* | docs: filesystems: caching/operations.txt: convert it to ReSTMauro Carvalho Chehab2020-05-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | - Add a SPDX header; - Adjust document and section titles; - Comment out text ToC for html/pdf output; - Mark literal blocks as such; - Add it to filesystems/caching/index.rst. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/97e71cc598a4f61df484ebda3ec06b63530ceb62.1588021877.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* | docs: filesystems: caching/netfs-api.txt: convert it to ReSTMauro Carvalho Chehab2020-05-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | - Add a SPDX header; - Adjust document and section titles; - Some whitespace fixes and new line breaks; - Mark literal blocks as such; - Add it to filesystems/caching/index.rst. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/cfe4cb1bf8e1f0093d44c30801ec42e74721e543.1588021877.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* | docs: filesystems: convert caching/fscache.txt to ReST formatMauro Carvalho Chehab2020-05-051-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | - Add a SPDX header; - Adjust document and section titles; - Comment out text ToC for html/pdf output; - Some whitespace fixes and new line breaks; - Add table markups; - Add it to filesystems/index.rst. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/e33ec382a53cf10ffcbd802f6de3f384159cddba.1588021877.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* | docs: filesystems: convert caching/object.txt to ReSTMauro Carvalho Chehab2020-05-051-1/+1
|/ | | | | | | | | | | | | - Add a SPDX header; - Adjust document and section titles; - Comment out text ToC for html/pdf output; - Some whitespace fixes and new line breaks; - Adjust the events list to make them look better for html output; - Add it to filesystems/index.rst. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/49026a8ea7e714c2e0f003aa26b975b1025476b7.1588021877.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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