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| author | David Howells <dhowells@redhat.com> | 2021-10-21 12:05:53 +0200 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2022-01-07 14:42:44 +0100 |
| commit | 287fd611238dd4b7e32fd3a8985aa387d26c4f29 (patch) | |
| tree | 3b643ab9271c8ac0583840042286355fe27b6592 /fs/cachefiles/interface.c | |
| parent | cachefiles: Implement backing file wrangling (diff) | |
| download | linux-287fd611238dd4b7e32fd3a8985aa387d26c4f29.tar.xz linux-287fd611238dd4b7e32fd3a8985aa387d26c4f29.zip | |
cachefiles: Implement begin and end I/O operation
Implement the methods for beginning and ending an I/O operation.
When called to begin an I/O operation, we are guaranteed that the cookie
has reached a certain stage (we're called by fscache after it has done a
suitable wait).
If a file is available, we paste a ref over into the cache resources for
the I/O routines to use. This means that the object can be invalidated
whilst the I/O is ongoing without the need to synchronise as the file
pointer in the object is replaced, but the file pointer in the cache
resources is unaffected.
Ending the operation just requires ditching any refs we have and dropping
the access guarantee that fscache got for us on the 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/163819645033.215744.2199344081658268312.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906951916.143852.9531384743995679857.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967161222.1823006.4461476204800357263.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021559030.640689.3684291785218094142.stgit@warthog.procyon.org.uk/ # v4
Diffstat (limited to 'fs/cachefiles/interface.c')
| -rw-r--r-- | fs/cachefiles/interface.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c index e47c52c34071..ad9d311413ff 100644 --- a/fs/cachefiles/interface.c +++ b/fs/cachefiles/interface.c @@ -362,5 +362,6 @@ const struct fscache_cache_ops cachefiles_cache_ops = { .lookup_cookie = cachefiles_lookup_cookie, .withdraw_cookie = cachefiles_withdraw_cookie, .invalidate_cookie = cachefiles_invalidate_cookie, + .begin_operation = cachefiles_begin_operation, .prepare_to_write = cachefiles_prepare_to_write, }; |