summaryrefslogtreecommitdiffstats
path: root/fs/cachefiles
diff options
context:
space:
mode:
authorJingbo Xu <jefflexu@linux.alibaba.com>2022-11-24 04:42:11 +0100
committerGao Xiang <hsiangkao@linux.alibaba.com>2022-12-07 03:56:29 +0100
commit8669247524c73e16e4d3384c4ff882e5c5d06194 (patch)
tree5229c6304c4f89b9ea2def556b1ae2a6a2eb51cb /fs/cachefiles
parenterofs: clean up cached I/O strategies (diff)
downloadlinux-8669247524c73e16e4d3384c4ff882e5c5d06194.tar.xz
linux-8669247524c73e16e4d3384c4ff882e5c5d06194.zip
fscache,cachefiles: add prepare_ondemand_read() callback
Add prepare_ondemand_read() callback dedicated for the on-demand read scenario, so that callers from this scenario can be decoupled from netfs_io_subrequest. The original cachefiles_prepare_read() is now refactored to a generic routine accepting a parameter list instead of netfs_io_subrequest. There's no logic change, except that the debug id of subrequest and request is removed from trace_cachefiles_prep_read(). Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com> Acked-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20221124034212.81892-2-jefflexu@linux.alibaba.com Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Diffstat (limited to 'fs/cachefiles')
-rw-r--r--fs/cachefiles/io.c77
1 files changed, 50 insertions, 27 deletions
diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c
index 000a28f46e59..175a25fcade8 100644
--- a/fs/cachefiles/io.c
+++ b/fs/cachefiles/io.c
@@ -385,38 +385,35 @@ static int cachefiles_write(struct netfs_cache_resources *cres,
term_func, term_func_priv);
}
-/*
- * Prepare a read operation, shortening it to a cached/uncached
- * boundary as appropriate.
- */
-static enum netfs_io_source cachefiles_prepare_read(struct netfs_io_subrequest *subreq,
- loff_t i_size)
+static inline enum netfs_io_source
+cachefiles_do_prepare_read(struct netfs_cache_resources *cres,
+ loff_t start, size_t *_len, loff_t i_size,
+ unsigned long *_flags, ino_t netfs_ino)
{
enum cachefiles_prepare_read_trace why;
- struct netfs_io_request *rreq = subreq->rreq;
- struct netfs_cache_resources *cres = &rreq->cache_resources;
- struct cachefiles_object *object;
+ struct cachefiles_object *object = NULL;
struct cachefiles_cache *cache;
struct fscache_cookie *cookie = fscache_cres_cookie(cres);
const struct cred *saved_cred;
struct file *file = cachefiles_cres_file(cres);
enum netfs_io_source ret = NETFS_DOWNLOAD_FROM_SERVER;
+ size_t len = *_len;
loff_t off, to;
ino_t ino = file ? file_inode(file)->i_ino : 0;
int rc;
- _enter("%zx @%llx/%llx", subreq->len, subreq->start, i_size);
+ _enter("%zx @%llx/%llx", len, start, i_size);
- if (subreq->start >= i_size) {
+ if (start >= i_size) {
ret = NETFS_FILL_WITH_ZEROES;
why = cachefiles_trace_read_after_eof;
goto out_no_object;
}
if (test_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags)) {
- __set_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags);
+ __set_bit(NETFS_SREQ_COPY_TO_CACHE, _flags);
why = cachefiles_trace_read_no_data;
- if (!test_bit(NETFS_SREQ_ONDEMAND, &subreq->flags))
+ if (!test_bit(NETFS_SREQ_ONDEMAND, _flags))
goto out_no_object;
}
@@ -437,7 +434,7 @@ static enum netfs_io_source cachefiles_prepare_read(struct netfs_io_subrequest *
retry:
off = cachefiles_inject_read_error();
if (off == 0)
- off = vfs_llseek(file, subreq->start, SEEK_DATA);
+ off = vfs_llseek(file, start, SEEK_DATA);
if (off < 0 && off >= (loff_t)-MAX_ERRNO) {
if (off == (loff_t)-ENXIO) {
why = cachefiles_trace_read_seek_nxio;
@@ -449,21 +446,22 @@ retry:
goto out;
}
- if (off >= subreq->start + subreq->len) {
+ if (off >= start + len) {
why = cachefiles_trace_read_found_hole;
goto download_and_store;
}
- if (off > subreq->start) {
+ if (off > start) {
off = round_up(off, cache->bsize);
- subreq->len = off - subreq->start;
+ len = off - start;
+ *_len = len;
why = cachefiles_trace_read_found_part;
goto download_and_store;
}
to = cachefiles_inject_read_error();
if (to == 0)
- to = vfs_llseek(file, subreq->start, SEEK_HOLE);
+ to = vfs_llseek(file, start, SEEK_HOLE);
if (to < 0 && to >= (loff_t)-MAX_ERRNO) {
trace_cachefiles_io_error(object, file_inode(file), to,
cachefiles_trace_seek_error);
@@ -471,12 +469,13 @@ retry:
goto out;
}
- if (to < subreq->start + subreq->len) {
- if (subreq->start + subreq->len >= i_size)
+ if (to < start + len) {
+ if (start + len >= i_size)
to = round_up(to, cache->bsize);
else
to = round_down(to, cache->bsize);
- subreq->len = to - subreq->start;
+ len = to - start;
+ *_len = len;
}
why = cachefiles_trace_read_have_data;
@@ -484,12 +483,11 @@ retry:
goto out;
download_and_store:
- __set_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags);
- if (test_bit(NETFS_SREQ_ONDEMAND, &subreq->flags)) {
- rc = cachefiles_ondemand_read(object, subreq->start,
- subreq->len);
+ __set_bit(NETFS_SREQ_COPY_TO_CACHE, _flags);
+ if (test_bit(NETFS_SREQ_ONDEMAND, _flags)) {
+ rc = cachefiles_ondemand_read(object, start, len);
if (!rc) {
- __clear_bit(NETFS_SREQ_ONDEMAND, &subreq->flags);
+ __clear_bit(NETFS_SREQ_ONDEMAND, _flags);
goto retry;
}
ret = NETFS_INVALID_READ;
@@ -497,11 +495,35 @@ download_and_store:
out:
cachefiles_end_secure(cache, saved_cred);
out_no_object:
- trace_cachefiles_prep_read(subreq, ret, why, ino);
+ trace_cachefiles_prep_read(object, start, len, *_flags, ret, why, ino, netfs_ino);
return ret;
}
/*
+ * Prepare a read operation, shortening it to a cached/uncached
+ * boundary as appropriate.
+ */
+static enum netfs_io_source cachefiles_prepare_read(struct netfs_io_subrequest *subreq,
+ loff_t i_size)
+{
+ return cachefiles_do_prepare_read(&subreq->rreq->cache_resources,
+ subreq->start, &subreq->len, i_size,
+ &subreq->flags, subreq->rreq->inode->i_ino);
+}
+
+/*
+ * Prepare an on-demand read operation, shortening it to a cached/uncached
+ * boundary as appropriate.
+ */
+static enum netfs_io_source
+cachefiles_prepare_ondemand_read(struct netfs_cache_resources *cres,
+ loff_t start, size_t *_len, loff_t i_size,
+ unsigned long *_flags, ino_t ino)
+{
+ return cachefiles_do_prepare_read(cres, start, _len, i_size, _flags, ino);
+}
+
+/*
* Prepare for a write to occur.
*/
int __cachefiles_prepare_write(struct cachefiles_object *object,
@@ -621,6 +643,7 @@ static const struct netfs_cache_ops cachefiles_netfs_cache_ops = {
.write = cachefiles_write,
.prepare_read = cachefiles_prepare_read,
.prepare_write = cachefiles_prepare_write,
+ .prepare_ondemand_read = cachefiles_prepare_ondemand_read,
.query_occupancy = cachefiles_query_occupancy,
};