@@ -273,6 +273,7 @@ static enum netfs_read_source cachefiles_prepare_read(struct netfs_read_subreque
struct cachefiles_cache *cache;
const struct cred *saved_cred;
struct file *file = subreq->rreq->cache_resources.cache_priv2;
+ enum netfs_read_source ret = NETFS_DOWNLOAD_FROM_SERVER;
loff_t off, to;
_enter("%zx @%llx/%llx", subreq->len, subreq->start, i_size);
@@ -281,19 +282,24 @@ static enum netfs_read_source cachefiles_prepare_read(struct netfs_read_subreque
cache = container_of(object->fscache.cache,
struct cachefiles_cache, cache);
- if (!file)
- goto cache_fail_nosec;
+ cachefiles_begin_secure(cache, &saved_cred);
- if (subreq->start >= i_size)
- return NETFS_FILL_WITH_ZEROES;
+ if (subreq->start >= i_size) {
+ ret = NETFS_FILL_WITH_ZEROES;
+ goto out;
+ }
- cachefiles_begin_secure(cache, &saved_cred);
+ if (!file)
+ goto out;
+
+ if (test_bit(FSCACHE_COOKIE_NO_DATA_YET, &object->fscache.cookie->flags))
+ goto download_and_store;
off = vfs_llseek(file, subreq->start, SEEK_DATA);
if (off < 0 && off >= (loff_t)-MAX_ERRNO) {
if (off == (loff_t)-ENXIO)
goto download_and_store;
- goto cache_fail;
+ goto out;
}
if (off >= subreq->start + subreq->len)
@@ -307,7 +313,7 @@ static enum netfs_read_source cachefiles_prepare_read(struct netfs_read_subreque
to = vfs_llseek(file, subreq->start, SEEK_HOLE);
if (to < 0 && to >= (loff_t)-MAX_ERRNO)
- goto cache_fail;
+ goto out;
if (to < subreq->start + subreq->len) {
if (subreq->start + subreq->len >= i_size)
@@ -317,16 +323,15 @@ static enum netfs_read_source cachefiles_prepare_read(struct netfs_read_subreque
subreq->len = to - subreq->start;
}
- cachefiles_end_secure(cache, saved_cred);
- return NETFS_READ_FROM_CACHE;
+ ret = NETFS_READ_FROM_CACHE;
+ goto out;
download_and_store:
if (cachefiles_has_space(cache, 0, (subreq->len + PAGE_SIZE - 1) / PAGE_SIZE) == 0)
__set_bit(NETFS_SREQ_WRITE_TO_CACHE, &subreq->flags);
-cache_fail:
+out:
cachefiles_end_secure(cache, saved_cred);
-cache_fail_nosec:
- return NETFS_DOWNLOAD_FROM_SERVER;
+ return ret;
}
/*
In cachefiles_prepare_read(), always indicate to the netfs lib that a page beyond the EOF should be filled with zeros, even if we don't have a cache file attached because it's still being created. This avoids confusion in netfs_rreq_prepare_read() where it sees source == NETFS_DOWNLOAD_FROM_SERVER, where it consequently sees the read after the EOF getting reduced to 0 size and thus triggers the WARN_ON and marking the read invalid. Also don't try to check for data if there's a flag set indicating we don't yet have anything stored in the cache. Signed-off-by: David Howells <dhowells@redhat.com> --- fs/cachefiles/io.c | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-)