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authorDavid Howells <dhowells@redhat.com>2021-09-14 11:47:45 +0300
committerDavid Howells <dhowells@redhat.com>2022-01-07 12:22:19 +0300
commit3a11b3a86366ccbf0818b088ffecadf8b2d61177 (patch)
treefa50fc236e1872716dd6a31c48c3f7611fea983a /include/linux/netfs.h
parented1235eb78a7421cd0ac2ad09e931f8f07ccdc7c (diff)
downloadlinux-3a11b3a86366ccbf0818b088ffecadf8b2d61177.tar.xz
netfs: Pass more information on how to deal with a hole in the cache
Pass more information to the cache on how to deal with a hole if it encounters one when trying to read from the cache. Three options are provided: (1) NETFS_READ_HOLE_IGNORE. Read the hole along with the data, assuming it to be a punched-out extent by the backing filesystem. (2) NETFS_READ_HOLE_CLEAR. If there's a hole, erase the requested region of the cache and clear the read buffer. (3) NETFS_READ_HOLE_FAIL. Fail the read if a hole is detected. 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/163819612321.215744.9738308885948264476.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906914460.143852.6284247083607910189.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967119923.1823006.15637375885194297582.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021519762.640689.16994364383313159319.stgit@warthog.procyon.org.uk/ # v4
Diffstat (limited to 'include/linux/netfs.h')
-rw-r--r--include/linux/netfs.h11
1 files changed, 10 insertions, 1 deletions
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index 5a46fde65759..b46c39d98bbd 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -197,6 +197,15 @@ struct netfs_read_request_ops {
};
/*
+ * How to handle reading from a hole.
+ */
+enum netfs_read_from_hole {
+ NETFS_READ_HOLE_IGNORE,
+ NETFS_READ_HOLE_CLEAR,
+ NETFS_READ_HOLE_FAIL,
+};
+
+/*
* Table of operations for access to a cache. This is obtained by
* rreq->ops->begin_cache_operation().
*/
@@ -208,7 +217,7 @@ struct netfs_cache_ops {
int (*read)(struct netfs_cache_resources *cres,
loff_t start_pos,
struct iov_iter *iter,
- bool seek_data,
+ enum netfs_read_from_hole read_hole,
netfs_io_terminated_t term_func,
void *term_func_priv);