user/sven/linux.git/include/linux/fscache-cache.h, branch v5.15.19

fscache: Remove the object list procfile

2021-08-27T12:34:02Z

Remove the object list procfile from fscache as objects will become entirely internal to the cache. Signed-off-by: David Howells Reviewed-by: Jeff Layton cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/162431198332.2908479.5847286163455099669.stgit@warthog.procyon.org.uk/

fscache, cachefiles: Remove the histogram stuff

2021-08-27T12:34:02Z

Remove the histogram stuff as it's mostly going to be outdated. Signed-off-by: David Howells Reviewed-by: Jeff Layton cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/162431195953.2908479.16770977195634296638.stgit@warthog.procyon.org.uk/

fscache, cachefiles: Add alternate API to use kiocb for read/write to cache

2021-04-23T09:14:32Z

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 Reviewed-and-tested-by: Jeff Layton Tested-by: Dave Wysochanski Tested-By: Marc Dionne cc: Christoph Hellwig 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

FS-Cache: Replace zero-length array with flexible-array

2020-06-16T04:08:31Z

There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://github.com/KSPP/linux/issues/21 Signed-off-by: Gustavo A. R. Silva

docs: filesystems: caching/backend-api.txt: convert it to ReST

2020-05-05T15:22:21Z

- 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 Link: https://lore.kernel.org/r/5d0a61abaa87bfe913b9e2f321e74ef7af0f3dfc.1588021877.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman

fscache: Fix race in fscache_op_complete() due to split atomic_sub & read

2018-11-28T13:19:20Z

The code in fscache_retrieval_complete is using atomic_sub followed by an atomic_read: atomic_sub(n_pages, &op->n_pages); if (atomic_read(&op->n_pages) <= 0) fscache_op_complete(&op->op, true); This causes two threads doing a decrement of n_pages to race with each other seeing the op->refcount 0 at same time - and they end up calling fscache_op_complete() in both the threads leading to an assertion failure. Fix this by using atomic_sub_return_relaxed() instead of two calls. Note that I'm using 'relaxed' rather than, say, 'release' as there aren't multiple variables that appear to need ordering across the release. The oops looks something like: FS-Cache: Assertion failed FS-Cache: 0 > 0 is false ... kernel BUG at /usr/src/linux-4.4.0/fs/fscache/operation.c:449! ... Workqueue: fscache_operation fscache_op_work_func [fscache] ... RIP: 0010:[] fscache_op_complete+0x10d/0x180 [fscache] ... Call Trace: [] cachefiles_read_copier+0x3a9/0x410 [cachefiles] [] fscache_op_work_func+0x22/0x50 [fscache] [] process_one_work+0x150/0x3f0 [] worker_thread+0x11a/0x470 [] ? __schedule+0x359/0x980 [] ? rescuer_thread+0x310/0x310 [] kthread+0xd6/0xf0 [] ? kthread_park+0x60/0x60 [] ret_from_fork+0x3f/0x70 [] ? kthread_park+0x60/0x60 This seen this in 4.4.x kernels and the same bug affects fscache in latest upstreams kernels. Fixes: 1bb4b7f98f36 ("FS-Cache: The retrieval remaining-pages counter needs to be atomic_t") Signed-off-by: Kiran Kumar Modukuri Signed-off-by: David Howells

fscache: Pass object size in rather than calling back for it

2018-04-06T13:05:14Z

Pass the object size in to fscache_acquire_cookie() and fscache_write_page() rather than the netfs providing a callback by which it can be received. This makes it easier to update the size of the object when a new page is written that extends the object. The current object size is also passed by fscache to the check_aux function, obviating the need to store it in the aux data. Signed-off-by: David Howells Acked-by: Anna Schumaker Tested-by: Steve Dickson

fscache: Add more tracepoints

2018-04-04T12:41:27Z

Add more tracepoints to fscache, including: (*) fscache_page - Tracks netfs pages known to fscache. (*) fscache_check_page - Tracks the netfs querying whether a page is pending storage. (*) fscache_wake_cookie - Tracks cookies being woken up after a page completes/aborts storage in the cache. (*) fscache_op - Tracks operations being initialised. (*) fscache_wrote_page - Tracks return of the backend write_page op. (*) fscache_gang_lookup - Tracks lookup of pages to be stored in the write operation. Signed-off-by: David Howells

fscache: Add tracepoints

2018-04-04T12:41:27Z

Add some tracepoints to fscache: (*) fscache_cookie - Tracks a cookie's usage count. (*) fscache_netfs - Logs registration of a network filesystem, including the pointer to the cookie allocated. (*) fscache_acquire - Logs cookie acquisition. (*) fscache_relinquish - Logs cookie relinquishment. (*) fscache_enable - Logs enablement of a cookie. (*) fscache_disable - Logs disablement of a cookie. (*) fscache_osm - Tracks execution of states in the object state machine. and cachefiles: (*) cachefiles_ref - Tracks a cachefiles object's usage count. (*) cachefiles_lookup - Logs result of lookup_one_len(). (*) cachefiles_mkdir - Logs result of vfs_mkdir(). (*) cachefiles_create - Logs result of vfs_create(). (*) cachefiles_unlink - Logs calls to vfs_unlink(). (*) cachefiles_rename - Logs calls to vfs_rename(). (*) cachefiles_mark_active - Logs an object becoming active. (*) cachefiles_wait_active - Logs a wait for an old object to be destroyed. (*) cachefiles_mark_inactive - Logs an object becoming inactive. (*) cachefiles_mark_buried - Logs the burial of an object. Signed-off-by: David Howells