linux-stable/fs
David Howells 23e12e285a fscache: Implement cache-level access helpers
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
2022-01-07 09:22:19 +00:00
..
9p fscache: Remove the contents of the fscache driver, pending rewrite 2022-01-07 09:22:19 +00:00
adfs mm: require ->set_page_dirty to be explicitly wired up 2021-06-29 10:53:48 -07:00
affs affs: use bdev_nr_sectors instead of open coding it 2021-10-18 14:43:22 -06:00
afs fscache: Remove the contents of the fscache driver, pending rewrite 2022-01-07 09:22:19 +00:00
autofs autofs: fix wait name hash calculation in autofs_wait() 2021-10-20 21:09:02 -04:00
befs isystem: ship and use stdarg.h 2021-08-19 09:02:55 +09:00
bfs mm: require ->set_page_dirty to be explicitly wired up 2021-06-29 10:53:48 -07:00
btrfs for-5.16-rc2-tag 2021-11-26 11:24:32 -08:00
ceph fscache, cachefiles: Disable configuration 2022-01-07 09:21:44 +00:00
cifs fscache, cachefiles: Disable configuration 2022-01-07 09:21:44 +00:00
coda coda: bump module version to 7.2 2021-11-09 10:02:51 -08:00
configfs configfs: fix a race in configfs_lookup() 2021-08-25 07:58:49 +02:00
cramfs cramfs: use bdev_nr_bytes instead of open coding it 2021-10-18 14:43:22 -06:00
crypto fscrypt: improve a few comments 2021-10-25 19:11:50 -07:00
debugfs debugfs: debugfs_create_file_size(): use IS_ERR to check for error 2021-09-21 09:09:06 +02:00
devpts
dlm fs: dlm: avoid comms shutdown delay in release_lockspace 2021-09-01 11:29:14 -05:00
ecryptfs mm: require ->set_page_dirty to be explicitly wired up 2021-06-29 10:53:48 -07:00
efivarfs
efs
erofs erofs: fix deadlock when shrink erofs slab 2021-11-23 14:58:16 +08:00
exfat exfat: fix incorrect loading of i_blocks for large files 2021-11-01 07:49:21 +09:00
exportfs
ext2 ext2: fix sleeping in atomic bugs on error 2021-09-22 13:05:23 +02:00
ext4 Only bug fixes and cleanups for ext4 this merge window. Of note are 2021-11-10 17:05:37 -08:00
f2fs Update to zstd-1.4.10 2021-11-13 15:32:30 -08:00
fat for-5.16/inode-sync-2021-10-29 2021-11-01 10:25:27 -07:00
freevxfs
fscache fscache: Implement cache-level access helpers 2022-01-07 09:22:19 +00:00
fuse fuse: release pipe buf after last use 2021-11-25 14:05:18 +01:00
gfs2 gfs2: gfs2_create_inode rework 2021-12-02 12:41:10 +01:00
hfs Merge branch 'akpm' (patches from Andrew) 2021-11-09 10:11:53 -08:00
hfsplus Merge branch 'akpm' (patches from Andrew) 2021-11-09 10:11:53 -08:00
hostfs hostfs: support splice_write 2021-08-26 22:28:02 +02:00
hpfs treewide: Replace open-coded flex arrays in unions 2021-10-18 12:28:53 -07:00
hugetlbfs mm,hugetlb: remove mlock ulimit for SHM_HUGETLB 2021-11-09 10:02:48 -08:00
iomap iomap: iomap_read_inline_data cleanup 2021-11-24 10:15:47 -08:00
isofs isofs: Fix out of bound access for corrupted isofs image 2021-10-19 12:51:02 +02:00
jbd2 jbd2: add sparse annotations for add_transaction_credits() 2021-08-30 23:36:50 -04:00
jffs2 vfs: add rcu argument to ->get_acl() callback 2021-08-18 22:08:24 +02:00
jfs Just one JFS patch 2021-11-03 09:23:25 -07:00
kernfs Merge 5.15-rc6 into driver-core-next 2021-10-18 09:43:37 +02:00
ksmbd ksmbd: fix memleak in get_file_stream_info() 2021-11-25 00:09:26 -06:00
lockd A slow cycle for nfsd: mainly cleanup, including Neil's patch dropping 2021-11-10 16:45:54 -08:00
minix mm: require ->set_page_dirty to be explicitly wired up 2021-06-29 10:53:48 -07:00
netfs netfs: Pass a flag to ->prepare_write() to say if there's no alloc'd space 2022-01-07 09:22:19 +00:00
nfs fscache, cachefiles: Disable configuration 2022-01-07 09:21:44 +00:00
nfs_common nfs: Fix kerneldoc warning shown up by W=1 2021-10-04 22:02:17 +01:00
nfsd This is just one bugfix for a bufferflow in knfsd's xdr decoding. 2021-11-17 08:38:00 -08:00
nilfs2 Merge branch 'akpm' (patches from Andrew) 2021-11-09 10:11:53 -08:00
nls
notify fanotify: Allow users to request FAN_FS_ERROR events 2021-10-27 12:53:45 +02:00
ntfs fs: ntfs: Limit NTFS_RW to page sizes smaller than 64k 2021-11-27 14:34:41 -08:00
ntfs3 gfs2: Fix mmap + page fault deadlocks 2021-11-02 12:25:03 -07:00
ocfs2 Merge branch 'exit-cleanups-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2021-11-10 16:15:54 -08:00
omfs mm: require ->set_page_dirty to be explicitly wired up 2021-06-29 10:53:48 -07:00
openpromfs
orangefs orangefs: three fixes from other folks... 2021-11-09 10:34:06 -08:00
overlayfs overlayfs update for 5.16 2021-11-09 10:51:12 -08:00
proc proc/vmcore: fix clearing user buffer by properly using clear_user() 2021-11-20 10:35:55 -08:00
pstore pstore/blk: Use "%lu" to format unsigned long 2021-11-21 09:44:19 -08:00
qnx4 qnx4: work around gcc false positive warning bug 2021-09-21 08:36:48 -07:00
qnx6
quota \n 2021-11-06 16:40:48 -07:00
ramfs Merge branch 'akpm' (patches from Andrew) 2021-11-09 10:11:53 -08:00
reiserfs \n 2021-11-06 16:40:48 -07:00
romfs
smbfs_common cifs: Move SMB2_Create definitions to the shared area 2021-11-05 09:55:36 -05:00
squashfs lib: zstd: Add kernel-specific API 2021-11-08 16:55:21 -08:00
sysfs fs/sysfs/dir.c: replace S_IRWXU|S_IRUGO|S_IXUGO with 0755 sysfs_create_dir_ns() 2021-10-05 16:35:05 +02:00
sysv sysv: use BUILD_BUG_ON instead of runtime check 2021-11-09 10:02:52 -08:00
tracefs tracefs: Have tracefs directories not set OTH permission bits by default 2021-10-08 18:08:43 -04:00
ubifs fscrypt: remove fscrypt_operations::max_namelen 2021-09-20 19:32:33 -07:00
udf udf: Fix crash after seekdir 2021-11-09 12:53:58 +01:00
ufs isystem: ship and use stdarg.h 2021-08-19 09:02:55 +09:00
unicode
vboxsf vboxfs: fix broken legacy mount signature checking 2021-09-27 11:26:21 -07:00
verity fs-verity: fix signed integer overflow with i_size near S64_MAX 2021-09-22 10:56:34 -07:00
xfs xfs: remove incorrect ASSERT in xfs_rename 2021-12-01 17:27:48 -08:00
zonefs gfs2: Fix mmap + page fault deadlocks 2021-11-02 12:25:03 -07:00
aio.c Various hardening fixes and cleanups for 5.16-rc1 2021-11-01 17:29:10 -07:00
anon_inodes.c fs: add anon_inode_getfile_secure() similar to anon_inode_getfd_secure() 2021-09-19 22:35:37 -04:00
attr.c fs: handle circular mappings correctly 2021-11-17 09:26:09 +01:00
bad_inode.c vfs: add rcu argument to ->get_acl() callback 2021-08-18 22:08:24 +02:00
binfmt_aout.c binfmt: a.out: Fix bogus semicolon 2021-09-05 10:15:05 -07:00
binfmt_elf.c Merge branch 'akpm' (patches from Andrew) 2021-11-09 10:11:53 -08:00
binfmt_elf_fdpic.c coredump: Limit coredumps to a single thread group 2021-10-08 12:06:02 -05:00
binfmt_flat.c binfmt: remove in-tree usage of MAP_EXECUTABLE 2021-06-29 10:53:50 -07:00
binfmt_misc.c
binfmt_script.c
buffer.c fs: simplify init_page_buffers 2021-10-18 14:43:22 -06:00
char_dev.c
compat_binfmt_elf.c
coredump.c coredump: Limit coredumps to a single thread group 2021-10-08 12:06:02 -05:00
d_path.c d_path: fix Kernel doc validator complaining 2021-11-06 13:30:32 -07:00
dax.c New code for 5.15: 2021-08-31 11:13:35 -07:00
dcache.c
direct-io.c fs: get rid of the res2 iocb->ki_complete argument 2021-10-25 10:36:24 -06:00
drop_caches.c fs: drop_caches: fix skipping over shadow cache inodes 2021-09-03 09:58:10 -07:00
eventfd.c eventfd: Export eventfd_wake_count to modules 2021-09-06 07:20:56 -04:00
eventpoll.c ARM development updates for 5.15: 2021-09-09 13:25:49 -07:00
exec.c Merge branch 'exit-cleanups-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2021-11-10 16:15:54 -08:00
fcntl.c Merge branch 'akpm' (patches from Andrew) 2021-09-03 10:08:28 -07:00
fhandle.c
file.c fget: check that the fd still exists after getting a ref to it 2021-12-03 10:06:58 -08:00
file_table.c
filesystems.c fs: simplify get_filesystem_list / get_all_fs_names 2021-08-23 01:25:40 -04:00
fs-writeback.c Various hardening fixes and cleanups for 5.16-rc1 2021-11-01 17:29:10 -07:00
fs_context.c memcg: charge fs_context and legacy_fs_context 2021-09-03 09:58:12 -07:00
fs_parser.c namei: Standardize callers of filename_lookup() 2021-09-07 16:07:47 -04:00
fs_pin.c
fs_struct.c
fs_types.c
fsopen.c
init.c
inode.c fs: Remove FS_THP_SUPPORT 2021-11-17 10:36:35 -05:00
internal.h Merge branch 'akpm' (patches from Andrew) 2021-11-09 10:11:53 -08:00
io-wq.c io-wq: don't retry task_work creation failure on fatal conditions 2021-12-03 06:27:32 -07:00
io-wq.h io_uring: optimise INIT_WQ_LIST 2021-10-19 05:49:54 -06:00
io_uring.c io_uring: Fix undefined-behaviour in io_issue_sqe 2021-11-27 06:41:38 -07:00
ioctl.c New code for 5.15: 2021-08-31 11:06:32 -07:00
Kconfig cachefiles: Delete the cachefiles driver pending rewrite 2022-01-07 09:22:19 +00:00
Kconfig.binfmt binfmt: remove support for em86 (alpha only) 2021-07-25 22:33:03 -07:00
kernel_read_file.c vfs: check fd has read access in kernel_read_file_from_fd() 2021-10-18 20:22:03 -10:00
libfs.c libfs: Support RENAME_EXCHANGE in simple_rename() 2021-11-03 15:43:08 +01:00
locks.c locks: remove changelog comments 2021-10-19 14:11:39 -04:00
Makefile fscache: Introduce new driver 2022-01-07 09:22:19 +00:00
mbcache.c
mount.h
mpage.c
namei.c File locking changes for v5.16 2021-11-01 09:06:53 -07:00
namespace.c Merge branch 'akpm' (patches from Andrew) 2021-09-03 10:08:28 -07:00
no-block.c
nsfs.c
open.c Merge branch 'akpm' (patches from Andrew) 2021-11-06 14:08:17 -07:00
pipe.c Revert "mm/gup: remove try_get_page(), call try_get_compound_head() directly" 2021-09-07 11:03:45 -07:00
pnode.c
pnode.h
posix_acl.c fs/posix_acl.c: avoid -Wempty-body warning 2021-11-06 13:30:32 -07:00
proc_namespace.c
read_write.c fs: remove leftover comments from mandatory locking removal 2021-10-26 12:20:50 -04:00
readdir.c
remap_range.c fs: remove mandatory file locking support 2021-08-23 06:15:36 -04:00
select.c Revert "memcg: enable accounting for pollfd and select bits arrays" 2021-09-07 11:26:23 -07:00
seq_file.c seq_file: move seq_escape() to a header 2021-11-09 10:02:52 -08:00
signalfd.c signal: Rename SIL_PERF_EVENT SIL_FAULT_PERF_EVENT for consistency 2021-07-23 13:16:43 -05:00
splice.c
stack.c
stat.c fs: add generic helper for filling statx attribute flags 2021-08-17 11:47:43 +02:00
statfs.c
super.c fs: explicitly unregister per-superblock BDIs 2021-11-06 13:30:34 -07:00
sync.c block: simplify the block device syncing code 2021-10-22 08:36:55 -06:00
timerfd.c timerfd: Provide timerfd_resume() 2021-08-10 17:57:22 +02:00
userfaultfd.c userfaultfd: fix a race between writeprotect and exit_mmap() 2021-10-18 20:22:02 -10:00
utimes.c
xattr.c