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| author | David Howells <dhowells@redhat.com> | 2021-09-14 09:47:45 +0100 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2022-01-07 09:22:19 +0000 |
| commit | 3a11b3a86366ccbf0818b088ffecadf8b2d61177 (patch) | |
| tree | fa50fc236e1872716dd6a31c48c3f7611fea983a | |
| parent | ed1235eb78a7421cd0ac2ad09e931f8f07ccdc7c (diff) | |
| download | linux-stable-3a11b3a86366ccbf0818b088ffecadf8b2d61177.tar.gz linux-stable-3a11b3a86366ccbf0818b088ffecadf8b2d61177.tar.bz2 linux-stable-3a11b3a86366ccbf0818b088ffecadf8b2d61177.zip | |
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
| -rw-r--r-- | fs/netfs/read_helper.c | 8 | ||||
| -rw-r--r-- | include/linux/netfs.h | 11 |
2 files changed, 14 insertions, 5 deletions
diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c index 9dd76b8914f2..6169659857b3 100644 --- a/fs/netfs/read_helper.c +++ b/fs/netfs/read_helper.c @@ -170,7 +170,7 @@ static void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error */ static void netfs_read_from_cache(struct netfs_read_request *rreq, struct netfs_read_subrequest *subreq, - bool seek_data) + enum netfs_read_from_hole read_hole) { struct netfs_cache_resources *cres = &rreq->cache_resources; struct iov_iter iter; @@ -180,7 +180,7 @@ static void netfs_read_from_cache(struct netfs_read_request *rreq, subreq->start + subreq->transferred, subreq->len - subreq->transferred); - cres->ops->read(cres, subreq->start, &iter, seek_data, + cres->ops->read(cres, subreq->start, &iter, read_hole, netfs_cache_read_terminated, subreq); } @@ -461,7 +461,7 @@ static void netfs_rreq_short_read(struct netfs_read_request *rreq, netfs_get_read_subrequest(subreq); atomic_inc(&rreq->nr_rd_ops); if (subreq->source == NETFS_READ_FROM_CACHE) - netfs_read_from_cache(rreq, subreq, true); + netfs_read_from_cache(rreq, subreq, NETFS_READ_HOLE_CLEAR); else netfs_read_from_server(rreq, subreq); } @@ -789,7 +789,7 @@ static bool netfs_rreq_submit_slice(struct netfs_read_request *rreq, netfs_read_from_server(rreq, subreq); break; case NETFS_READ_FROM_CACHE: - netfs_read_from_cache(rreq, subreq, false); + netfs_read_from_cache(rreq, subreq, NETFS_READ_HOLE_IGNORE); break; default: BUG(); 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); |