linux/fs
David Howells 726218fdc2 netfs: Define an interface to talk to a cache
Add an interface to the netfs helper library for reading data from the
cache instead of downloading it from the server and support for writing
data just downloaded or cleared to the cache.

The API passes an iov_iter to the cache read/write routines to indicate the
data/buffer to be used.  This is done using the ITER_XARRAY type to provide
direct access to the netfs inode's pagecache.

When the netfs's ->begin_cache_operation() method is called, this must fill
in the cache_resources in the netfs_read_request struct, including the
netfs_cache_ops used by the helper lib to talk to the cache.  The helper
lib does not directly access the cache.

Changes:
v6:
- Call trace_netfs_read() after beginning the cache op so that the cookie
  debug ID can be logged[3].
- Don't record the error from writing to the cache.  We don't want to pass
  it back to the netfs[4].
- Fix copy-to-cache subreq amalgamation to not round up as it goes along
  otherwise it overcalculates the length of the write[5].

v5:
- Use end_page_fscache() rather than unlock_page_fscache()[2].

v4:
- Added flag to netfs_subreq_terminated() to indicate that the caller may
  have been running async and stuff that might sleep needs punting to a
  workqueue (can't use in_softirq()[1]).
- Add missing inc of netfs_n_rh_read stat.
- Move initial definition of fscache_begin_read_operation() elsewhere.
- Need to call op->begin_cache_operation() from netfs_write_begin().

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: Matthew Wilcox <willy@infradead.org>
cc: linux-mm@kvack.org
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/20210216084230.GA23669@lst.de/ [1]
Link: https://lore.kernel.org/r/2499407.1616505440@warthog.procyon.org.uk/ [2]
Link: https://lore.kernel.org/r/161781045123.463527.14533348855710902201.stgit@warthog.procyon.org.uk/ [3]
Link: https://lore.kernel.org/r/161781046256.463527.18158681600085556192.stgit@warthog.procyon.org.uk/ [4]
Link: https://lore.kernel.org/r/161781047695.463527.7463536103593997492.stgit@warthog.procyon.org.uk/ [5]
Link: https://lore.kernel.org/r/161118141321.1232039.8296910406755622458.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161161036700.2537118.11170748455436854978.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161340399569.1303470.1138884774643385730.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/161539542874.286939.13337898213448136687.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/161653799826.2770958.9015430297426331950.stgit@warthog.procyon.org.uk/ # v5
Link: https://lore.kernel.org/r/161789081462.6155.3853904866933313256.stgit@warthog.procyon.org.uk/ # v6
2021-04-23 10:14:32 +01:00
..
9p Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-02-27 08:07:12 -08:00
adfs fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
affs idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
afs afs: Use wait_on_page_writeback_killable 2021-03-23 20:54:37 +00:00
autofs fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
befs [PATCH] reduce boilerplate in fsid handling 2020-09-18 16:45:50 -04:00
bfs fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
btrfs for-5.12-rc3-tag 2021-03-18 13:38:42 -07:00
cachefiles cachefiles, afs: mm wait fixes 2021-03-24 10:22:00 -07:00
ceph idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
cifs cifs: fix allocation size on newly created files 2021-03-19 11:51:31 -05:00
coda fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
configfs configfs: fix a use-after-free in __configfs_open_file 2021-03-11 12:13:48 +01:00
cramfs cramfs: use %pD instead of messing with file_dentry()->d_name 2021-01-05 23:02:47 -05:00
crypto block: rename BIO_MAX_PAGES to BIO_MAX_VECS 2021-03-11 07:47:48 -07:00
debugfs Driver core / debugfs update for 5.12-rc1 2021-02-24 10:13:55 -08:00
devpts
dlm fs: dlm: check on existing node address 2020-11-10 12:14:20 -06:00
ecryptfs idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
efivarfs fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
efs [PATCH] reduce boilerplate in fsid handling 2020-09-18 16:45:50 -04:00
erofs Change since last update: 2021-03-13 12:26:22 -08:00
exfat idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
exportfs exportfs: Add a function to return the raw output from fh_to_dentry() 2020-12-09 09:39:38 -05:00
ext2 fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
ext4 mm/filemap: Pass the file_ra_state in the ractl 2021-04-23 09:25:00 +01:00
f2fs mm/filemap: Pass the file_ra_state in the ractl 2021-04-23 09:25:00 +01:00
fat idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
freevxfs
fscache
fuse fuse: 32-bit user space ioctl compat for fuse device 2021-03-16 15:20:16 +01:00
gfs2 block-5.12-2021-03-12-v2 2021-03-12 13:25:49 -08:00
hfs fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
hfsplus idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
hostfs idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
hpfs fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
hugetlbfs hugetlbfs: remove unneeded return value of hugetlb_vmtruncate() 2021-02-24 13:38:35 -08:00
iomap Merge branch 'iomap-5.12-fixes' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux 2021-03-18 10:37:30 -07:00
isofs isofs: handle large user and group ID 2021-02-03 19:05:52 +01:00
jbd2 block: use an on-stack bio in blkdev_issue_flush 2021-01-27 09:51:48 -07:00
jffs2 idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
jfs Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-02-27 08:07:12 -08:00
kernfs idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
lockd SUNRPC: Make trace_svc_process() display the RPC procedure symbolically 2021-01-25 09:36:23 -05:00
minix fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
netfs netfs: Define an interface to talk to a cache 2021-04-23 10:14:32 +01:00
nfs nfs: we don't support removing system.nfs4_acl 2021-03-11 13:17:42 -05:00
nfs_common NFSv4_2: SSC helper should use its own config. 2021-01-28 10:55:37 -05:00
nfsd NFSD: fix error handling in NFSv4.0 callbacks 2021-03-11 10:58:49 -05:00
nilfs2 block: rename BIO_MAX_PAGES to BIO_MAX_VECS 2021-03-11 07:47:48 -07:00
nls
notify idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
ntfs ntfs: check for valid standard information attribute 2021-02-24 13:38:26 -08:00
ocfs2 ocfs2: simplify the calculation of variables 2021-02-24 13:38:26 -08:00
omfs fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
openpromfs
orangefs idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
overlayfs idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
proc mm: use is_cow_mapping() across tree where proper 2021-03-13 11:27:30 -08:00
pstore pstore fixes for v5.12-rc2 2021-03-05 17:21:25 -08:00
qnx4 [PATCH] reduce boilerplate in fsid handling 2020-09-18 16:45:50 -04:00
qnx6 [PATCH] reduce boilerplate in fsid handling 2020-09-18 16:45:50 -04:00
quota quota: Fix memory leak when handling corrupted quota file 2021-01-05 14:42:18 +01:00
ramfs ramfs: support O_TMPFILE 2021-02-24 13:38:26 -08:00
reiserfs idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
romfs Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-10-24 12:26:05 -07:00
squashfs block: rename BIO_MAX_PAGES to BIO_MAX_VECS 2021-03-11 07:47:48 -07:00
sysfs sysfs: Support zapping of binary attr mmaps 2021-01-12 14:26:31 +01:00
sysv fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
tracefs fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
ubifs idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
udf idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
ufs fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
unicode unicode: Add utf8_casefold_hash 2020-09-10 14:03:31 -07:00
vboxsf fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
verity idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
xfs xfs: also reject BULKSTAT_SINGLE in a mount user namespace 2021-03-15 08:50:41 -07:00
zonefs zonefs: fix to update .i_wr_refcnt correctly in zonefs_open_zone() 2021-03-17 08:56:50 +09:00
aio.c Merge branch 'akpm' (patches from Andrew) 2020-12-15 12:53:37 -08:00
anon_inodes.c fs: anon_inodes: rephrase to appropriate kernel-doc 2021-01-15 12:17:25 -05:00
attr.c ima: handle idmapped mounts 2021-01-24 14:27:20 +01:00
bad_inode.c fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
binfmt_aout.c
binfmt_elf_fdpic.c Merge branch 'parisc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2021-02-21 13:20:41 -08:00
binfmt_elf.c Merge branch 'parisc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2021-02-21 13:20:41 -08:00
binfmt_em86.c
binfmt_flat.c binfmt_flat: revert "binfmt_flat: don't offset the data start" 2020-08-24 08:49:13 +10:00
binfmt_misc.c binfmt_misc: fix possible deadlock in bm_register_write 2021-03-13 11:27:30 -08:00
binfmt_script.c
block_dev.c block: rename BIO_MAX_PAGES to BIO_MAX_VECS 2021-03-11 07:47:48 -07:00
buffer.c fs: buffer: use raw page_memcg() on locked page 2021-02-24 13:38:30 -08:00
char_dev.c
compat_binfmt_elf.c get rid of COMPAT_ELF_EXEC_PAGESIZE 2021-01-06 08:42:51 -05:00
coredump.c fs/coredump: use kmap_local_page() 2021-02-26 09:41:05 -08:00
d_path.c fs: fix NULL dereference due to data race in prepend_path() 2020-10-14 14:54:45 -07:00
dax.c mm: provide a saner PTE walking API for modules 2021-02-09 07:05:44 -05:00
dcache.c fs: delete repeated words in comments 2021-02-24 13:38:26 -08:00
direct-io.c block-5.12-2021-02-27 2021-02-28 11:23:38 -08:00
drop_caches.c
eventfd.c eventfd: Export eventfd_ctx_do_read() 2020-11-15 09:49:10 -05:00
eventpoll.c kcmp: Support selection of SYS_kcmp without CHECKPOINT_RESTORE 2021-02-16 09:59:41 +01:00
exec.c fs: delete repeated words in comments 2021-02-24 13:38:26 -08:00
fcntl.c idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
fhandle.c fs: delete repeated words in comments 2021-02-24 13:38:26 -08:00
file_table.c epoll: take epitem list out of struct file 2020-10-25 20:02:08 -04:00
file.c fs: provide locked helper variant of close_fd_get_file() 2021-02-01 10:02:42 -07:00
filesystems.c
fs_context.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
fs_parser.c fs_parse: mark fs_param_bad_value() as static 2020-10-13 18:38:27 -07:00
fs_pin.c
fs_struct.c vfs: Use sequence counter with associated spinlock 2020-07-29 16:14:27 +02:00
fs_types.c
fs-writeback.c fs: improve comments for writeback_single_inode() 2021-01-13 17:26:50 +01:00
fsopen.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
init.c init: handle idmapped mounts 2021-01-24 14:27:19 +01:00
inode.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-02-27 08:07:12 -08:00
internal.h idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
io_uring.c io_uring: call req_set_fail_links() on short send[msg]()/recv[msg]() with MSG_WAITALL 2021-03-21 09:41:14 -06:00
io-wq.c io-wq: ensure task is running before processing task_work 2021-03-21 09:41:14 -06:00
io-wq.h io_uring: remove structures from include/linux/io_uring.h 2021-03-18 09:44:35 -06:00
ioctl.c fs: remove ksys_ioctl 2020-07-31 08:16:01 +02:00
Kconfig netfs: Provide readahead and readpage netfs helpers 2021-04-23 10:14:32 +01:00
Kconfig.binfmt Merge branch 'work.elf-compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-02-21 09:29:23 -08:00
kernel_read_file.c fs/kernel_file_read: Add "offset" arg for partial reads 2020-10-05 13:37:04 +02:00
libfs.c idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
locks.c Revert "nfsd4: a client's own opens needn't prevent delegations" 2021-03-09 10:37:34 -05:00
Makefile netfs: Provide readahead and readpage netfs helpers 2021-04-23 10:14:32 +01:00
mbcache.c
mount.h mount: make {lock,unlock}_mount_hash() static 2021-01-24 14:29:34 +01:00
mpage.c block: rename BIO_MAX_PAGES to BIO_MAX_VECS 2021-03-11 07:47:48 -07:00
namei.c idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
namespace.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-02-27 08:07:12 -08:00
no-block.c
nsfs.c
open.c idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
pipe.c fs: delete repeated words in comments 2021-02-24 13:38:26 -08:00
pnode.c
pnode.h mount: fix mounting of detached mounts onto targets that reside on shared mounts 2021-03-08 15:18:43 +01:00
posix_acl.c fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
proc_namespace.c fs: introduce MOUNT_ATTR_IDMAP 2021-01-24 14:43:45 +01:00
read_write.c teach sendfile(2) to handle send-to-pipe directly 2021-01-25 23:29:36 -05:00
readdir.c fs: remove ksys_getdents64 2020-07-31 08:16:00 +02:00
remap_range.c ioctl: handle idmapped mounts 2021-01-24 14:27:19 +01:00
select.c kernel, fs: Introduce and use set_restart_fn() and arch_set_restart_data() 2021-03-16 22:13:10 +01:00
seq_file.c fs: fix kernel-doc markups 2021-01-21 14:06:00 -07:00
signalfd.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
splice.c for-5.12/block-2021-02-17 2021-02-21 11:02:48 -08:00
stack.c
stat.c fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
statfs.c s390,alpha: switch to 64-bit ino_t 2021-02-13 17:17:53 +01:00
super.c It has been a relatively quiet cycle in docsland. 2021-02-22 10:57:46 -08:00
sync.c
timerfd.c
userfaultfd.c userfaultfd: use secure anon inodes for userfaultfd 2021-01-14 17:40:57 -05:00
utimes.c utimes: handle idmapped mounts 2021-01-24 14:27:18 +01:00
xattr.c namei: handle idmapped mounts in may_*() helpers 2021-01-24 14:27:17 +01:00