diff options
| author |   David Howells <dhowells@redhat.com> | 2021-11-17 16:11:07 +0000 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2022-01-07 13:42:24 +0000 |
| commit | 72b957856b0c09eee542afcff29705dd0adda654 (patch) | |
| tree | 2d341270872b1fb0c0e1e3b671d09bc28630fe9e /fs/cachefiles/internal.h | |
| parent | cachefiles: Implement key to filename encoding (diff) | |
| download | linux-dev-72b957856b0c09eee542afcff29705dd0adda654.tar.xz linux-dev-72b957856b0c09eee542afcff29705dd0adda654.zip | |
cachefiles: Implement metadata/coherency data storage in xattrs
Use an xattr on each backing file in the cache to store some metadata, such
as the content type and the coherency data.
Five content types are defined:
(0) No content stored.
(1) The file contains a single monolithic blob and must be all or nothing.
This would be used for something like an AFS directory or a symlink.
(2) The file is populated with content completely up to a point with
nothing beyond that.
(3) The file has a map attached and is sparsely populated. This would be
stored in one or more additional xattrs.
(4) The file is dirty, being in the process of local modification and the
contents are not necessarily represented correctly by the metadata.
The file should be deleted if this is seen on binding.
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/163819641320.215744.16346770087799536862.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906942248.143852.5423738045012094252.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967151734.1823006.9301249989443622576.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021550471.640689.553853918307994335.stgit@warthog.procyon.org.uk/ # v4
Diffstat (limited to 'fs/cachefiles/internal.h')
| -rw-r--r-- | fs/cachefiles/internal.h | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h index dbc37f5d4714..01071e7a7c02 100644 --- a/fs/cachefiles/internal.h +++ b/fs/cachefiles/internal.h @@ -55,6 +55,7 @@ struct cachefiles_object { u8 d_name_len; /* Length of filename */ enum cachefiles_content content_info:8; /* Info about content presence */ unsigned long flags; +#define CACHEFILES_OBJECT_USING_TMPFILE 0 /* Have an unlinked tmpfile */ }; /* @@ -220,6 +221,17 @@ void cachefiles_free_volume(struct fscache_volume *volume); void cachefiles_withdraw_volume(struct cachefiles_volume *volume); /* + * xattr.c + */ +extern int cachefiles_set_object_xattr(struct cachefiles_object *object); +extern int cachefiles_check_auxdata(struct cachefiles_object *object, + struct file *file); +extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache, + struct cachefiles_object *object, + struct dentry *dentry); +extern void cachefiles_prepare_to_write(struct fscache_cookie *cookie); + +/* * Error handling */ #define cachefiles_io_error(___cache, FMT, ...) \ @@ -229,6 +241,15 @@ do { \ set_bit(CACHEFILES_DEAD, &(___cache)->flags); \ } while (0) +#define cachefiles_io_error_obj(object, FMT, ...) \ +do { \ + struct cachefiles_cache *___cache; \ + \ + ___cache = (object)->volume->cache; \ + cachefiles_io_error(___cache, FMT " [o=%08x]", ##__VA_ARGS__, \ + (object)->debug_id); \ +} while (0) + /* * Debug tracing |