kernel/git/stable/linux.git/fs/nfs/blocklayout/extents.c, branch master

pnfs/blocklayout: rewrite extent tracking

2014-09-10T19:47:03+00:00

Currently the block layout driver tracks extents in three separate data structures: - the two list of pnfs_block_extent structures returned by the server - the list of sectors that were in invalid state but have been written to - a list of pnfs_block_short_extent structures for LAYOUTCOMMIT All of these share the property that they are not only highly inefficient data structures, but also that operations on them are even more inefficient than nessecary. In addition there are various implementation defects like: - using an int to track sectors, causing corruption for large offsets - incorrect normalization of page or block granularity ranges - insufficient error handling - incorrect synchronization as extents can be modified while they are in use This patch replace all three data with a single unified rbtree structure tracking all extents, as well as their in-memory state, although we still need to instance for read-only and read-write extent due to the arcane client side COW feature in the block layouts spec. To fix the problem of extent possibly being modified while in use we make sure to return a copy of the extent for use in the write path - the extent can only be invalidated by a layout recall or return which has to wait until the I/O operations finished due to refcounts on the layout segment. The new extent tree work similar to the schemes used by block based filesystems like XFS or ext4. Signed-off-by: Christoph Hellwig Signed-off-by: Trond Myklebust

nfs: fix do_div() warning by instead using sector_div()

2013-12-04T17:57:37+00:00

When compiling a 32bit kernel with CONFIG_LBDAF=n the compiler complains like shown below. Fix this warning by instead using sector_div() which is provided by the kernel.h header file. fs/nfs/blocklayout/extents.c: In function ‘normalize’: include/asm-generic/div64.h:43:28: warning: comparison of distinct pointer types lacks a cast [enabled by default] fs/nfs/blocklayout/extents.c:47:13: note: in expansion of macro ‘do_div’ nfs/blocklayout/extents.c:47:2: warning: right shift count >= width of type [enabled by default] fs/nfs/blocklayout/extents.c:47:2: warning: passing argument 1 of ‘__div64_32’ from incompatible pointer type [enabled by default] include/asm-generic/div64.h:35:17: note: expected ‘uint64_t *’ but argument is of type ‘sector_t *’ extern uint32_t __div64_32(uint64_t *dividend, uint32_t divisor); Signed-off-by: Helge Deller Signed-off-by: Trond Myklebust

pnfsblock: use list_move_tail instead of list_del/list_add_tail

2012-10-01T22:39:05+00:00

Using list_move_tail() instead of list_del() + list_add_tail(). spatch with a semantic match is used to found this problem. (http://coccinelle.lip6.fr/) Signed-off-by: Wei Yongjun Signed-off-by: Trond Myklebust

NFS: Use kcalloc() when allocating arrays

2012-02-01T00:28:22+00:00

Signed-off-by: Trond Myklebust

pnfsblock: alloc short extent before submit bio

2012-01-12T21:52:10+00:00

As discussed earlier, it is better for block client to allocate memory for tracking extents state before submitting bio. So the patch does it by allocating a short_extent for every INVALID extent touched by write pagelist and for every zeroing page we created, saving them in layout header. Then in end_io we can just use them to create commit list items and avoid memory allocation there. Signed-off-by: Peng Tao Signed-off-by: Benny Halevy Signed-off-by: Trond Myklebust

pnfsblock: cleanup bl_mark_sectors_init

2012-01-12T21:52:09+00:00

It does not need to manipulate on partial initialized blocks. Writeback code takes care of it. Signed-off-by: Peng Tao Signed-off-by: Benny Halevy Signed-off-by: Trond Myklebust

pnfsblock: clean up _add_entry

2012-01-12T21:38:55+00:00

It is wrong to kmalloc in _add_entry() as it is inside spinlock. memory should be already allocated _add_entry() is called. Signed-off-by: Peng Tao Signed-off-by: Benny Halevy Signed-off-by: Trond Myklebust

pnfsblock: acquire im_lock in _preload_range

2012-01-12T21:38:49+00:00

When calling _add_entry, we should take the im_lock to protect agains other modifiers. Cc: #3.1+ Signed-off-by: Peng Tao Signed-off-by: Benny Halevy Signed-off-by: Trond Myklebust

pnfsblock: note written INVAL areas for layoutcommit

2011-07-31T16:18:17+00:00

Signed-off-by: Peng Tao Signed-off-by: Fred Isaman Signed-off-by: Benny Halevy Signed-off-by: Benny Halevy Signed-off-by: Jim Rees Signed-off-by: Trond Myklebust

pnfsblock: cleanup_layoutcommit

2011-07-31T16:18:17+00:00

In blocklayout driver. There are two things happening while layoutcommit/cleanup. 1. the modified extents are encoded. 2. On cleanup the extents are put back on the layout rw extents list, for reads. In the new system where actual xdr encoding is done in encode_layoutcommit() directly into xdr buffer, these are the new commit stages: 1. On setup_layoutcommit, the range is adjusted as before and a structure is allocated for communication with bl_encode_layoutcommit && bl_cleanup_layoutcommit (Generic layer provides a void-star to hang it on) 2. bl_encode_layoutcommit is called to do the actual encoding directly into xdr. The commit-extent-list is not freed and is stored on above structure. FIXME: The code is not yet converted to the new XDR cleanup 3. On cleanup the commit-extent-list is put back by a call to set_to_rw() as before, but with no need for XDR decoding of the list as before. And the commit-extent-list is freed. Finally allocated structure is freed. [rm inode and pnfs_layout_hdr args from cleanup_layoutcommit()] Signed-off-by: Jim Rees [pnfsblock: introduce bl_committing list] Signed-off-by: Peng Tao [pnfsblock: SQUASHME: adjust to API change] Signed-off-by: Fred Isaman [blocklayout: encode_layoutcommit implementation] Signed-off-by: Boaz Harrosh [pnfsblock: fix bug setting up layoutcommit.] Signed-off-by: Tao Guo [pnfsblock: cleanup_layoutcommit wants a status parameter] Signed-off-by: Boaz Harrosh Signed-off-by: Benny Halevy Signed-off-by: Benny Halevy Signed-off-by: Jim Rees Signed-off-by: Trond Myklebust