kernel/include/linux/nfs_page.h, branch linux-3.17.y

nfs: don't sleep with inode lock in lock_and_join_requests

2014-08-22T22:04:43Z

This handles the 'nonblock=false' case in nfs_lock_and_join_requests. If the group is already locked and blocking is allowed, drop the inode lock and wait for the group lock to be cleared before trying it all again. This should fix warnings found in peterz's tree (sched/wait branch), where might_sleep() checks are added to wait.[ch]. Reported-by: Fengguang Wu Signed-off-by: Weston Andros Adamson Reviewed-by: Peng Tao Signed-off-by: Trond Myklebust

nfs: fix comment and add warn_on for PG_INODE_REF

2014-08-03T21:05:25Z

Fix the comment in nfs_page.h for PG_INODE_REF to reflect that it's no longer set only on head requests. Also add a WARN_ON_ONCE in nfs_inode_remove_request as PG_INODE_REF should always be set. Suggested-by: Peng Tao Signed-off-by: Weston Andros Adamson Signed-off-by: Trond Myklebust

nfs: check wait_on_bit_lock err in page_group_lock

2014-08-03T21:05:24Z

Return errors from wait_on_bit_lock from nfs_page_group_lock. Add a bool argument @wait to nfs_page_group_lock. If true, loop over wait_on_bit_lock until it returns cleanly. If false, return the error from wait_on_bit_lock. Signed-off-by: Weston Andros Adamson Signed-off-by: Trond Myklebust

pnfs: clean up *_resend_to_mds

2014-06-24T22:47:01Z

Clean up pnfs_read_done_resend_to_mds and pnfs_write_done_resend_to_mds: - instead of passing all arguments from a nfs_pgio_header, just pass the header - share the common code Reviewed-by: Christoph Hellwig Signed-off-by: Weston Andros Adamson Signed-off-by: Trond Myklebust

nfs: merge nfs_pgio_data into _header

2014-06-24T22:47:00Z

struct nfs_pgio_data only exists as a member of nfs_pgio_header, but is passed around everywhere, because there used to be multiple _data structs per _header. Many of these functions then use the _data to find a pointer to the _header. This patch cleans this up by merging the nfs_pgio_data structure into nfs_pgio_header and passing nfs_pgio_header around instead. Reviewed-by: Christoph Hellwig Signed-off-by: Weston Andros Adamson Signed-off-by: Trond Myklebust

nfs: move nfs_pgio_data and remove nfs_rw_header

2014-06-24T22:46:59Z

nfs_rw_header was used to allocate an nfs_pgio_header along with an nfs_pgio_data, because a _header would need at least one _data. Now there is only ever one nfs_pgio_data for each nfs_pgio_header -- move it to nfs_pgio_header and get rid of nfs_rw_header. Reviewed-by: Christoph Hellwig Signed-off-by: Weston Andros Adamson Signed-off-by: Trond Myklebust

nfs: page group syncing in write path

2014-05-29T15:11:45Z

Operations that modify state for a whole page must be syncronized across all requests within a page group. In the write path, this is calling end_page_writeback and removing the head request from an inode. Both of these operations should not be called until all requests in a page group have reached the point where they would call them. This patch should have no effect yet since all page groups currently have one request, but will come into play when pg_test functions are modified to split pages into sub-page regions. Signed-off-by: Weston Andros Adamson Signed-off-by: Trond Myklebust

nfs: page group syncing in read path

2014-05-29T15:11:45Z

Operations that modify state for a whole page must be syncronized across all requests within a page group. In the read path, this is calling unlock_page and SetPageUptodate. Both of these functions should not be called until all requests in a page group have reached the point where they would call them. This patch should have no effect yet since all page groups currently have one request, but will come into play when pg_test functions are modified to split pages into sub-page regions. Signed-off-by: Weston Andros Adamson Signed-off-by: Trond Myklebust

nfs: add support for multiple nfs reqs per page

2014-05-29T15:11:44Z

Add "page groups" - a circular list of nfs requests (struct nfs_page) that all reference the same page. This gives nfs read and write paths the ability to account for sub-page regions independently. This somewhat follows the design of struct buffer_head's sub-page accounting. Only "head" requests are ever added/removed from the inode list in the buffered write path. "head" and "sub" requests are treated the same through the read path and the rest of the write/commit path. Requests are given an extra reference across the life of the list. Page groups are never rejoined after being split. If the read/write request fails and the client falls back to another path (ie revert to MDS in PNFS case), the already split requests are pushed through the recoalescing code again, which may split them further and then coalesce them into properly sized requests on the wire. Fragmentation shouldn't be a problem with the current design, because we flush all requests in page group when a non-contiguous request is added, so the only time resplitting should occur is on a resend of a read or write. This patch lays the groundwork for sub-page splitting, but does not actually do any splitting. For now all page groups have one request as pg_test functions don't yet split pages. There are several related patches that are needed support multiple requests per page group. Signed-off-by: Weston Andros Adamson Signed-off-by: Trond Myklebust

nfs: modify pg_test interface to return size_t

2014-05-29T15:11:43Z

This is a step toward allowing pg_test to inform the the coalescing code to reduce the size of requests so they may fit in whatever scheme the pg_test callback wants to define. For now, just return the size of the request if there is space, or 0 if there is not. This shouldn't change any behavior as it acts the same as when the pg_test functions returned bool. Signed-off-by: Weston Andros Adamson Signed-off-by: Trond Myklebust