diff options
Diffstat (limited to 'Documentation/filesystems/caching')
| -rw-r--r-- | Documentation/filesystems/caching/netfs-api.txt | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/Documentation/filesystems/caching/netfs-api.txt b/Documentation/filesystems/caching/netfs-api.txt index 26c1dd5a6a2..11a0a40ce44 100644 --- a/Documentation/filesystems/caching/netfs-api.txt +++ b/Documentation/filesystems/caching/netfs-api.txt @@ -499,7 +499,7 @@ Else if there's a copy of the page resident in the cache: (*) An argument that's 0 on success or negative for an error code. If an error occurs, it should be assumed that the page contains no usable - data. + data. fscache_readpages_cancel() may need to be called. end_io_func() will be called in process context if the read is results in an error, but it might be called in interrupt context if the read is @@ -623,6 +623,22 @@ some of the pages being read and some being allocated. Those pages will have been marked appropriately and will need uncaching. +CANCELLATION OF UNREAD PAGES +---------------------------- + +If one or more pages are passed to fscache_read_or_alloc_pages() but not then +read from the cache and also not read from the underlying filesystem then +those pages will need to have any marks and reservations removed. This can be +done by calling: + + void fscache_readpages_cancel(struct fscache_cookie *cookie, + struct list_head *pages); + +prior to returning to the caller. The cookie argument should be as passed to +fscache_read_or_alloc_pages(). Every page in the pages list will be examined +and any that have PG_fscache set will be uncached. + + ============== PAGE UNCACHING ============== |