linux/fs
Boaz Harrosh 7de6e28417 pnfs-obj: Better IO pattern in case of unaligned offset
Depending on layout and ARCH, ORE has some limits on max IO sizes
which is communicated on (what else) ore_layout->max_io_length,
which is always stripe aligned.
This was considered as the pg_test boundary for splitting and starting
a new IO.

But in the case of a long IO where the start offset is not aligned
what would happen is that both end of IO[N] and start of IO[N+1]
would be unaligned, causing each IO boundary parity unit to be
calculated and written twice.

So what we do in this patch is split the very start of an unaligned
IO, up to a stripe boundary, and then next IO's can continue fully
aligned til the end.

We might be sacrificing the case where the full unaligned IO would
fit within a single max_io_length, but the sacrifice is well worth
the elimination of double calculation and parity units IO.
Actually the sacrificing is marginal and is almost unmeasurable.

TODO:
	If we know the total expected linear segment that will
	be received, at pg_init, we could use that information
	in many places:
	1. blocks-layout get_layout write segment size
	2. Better mds-threshold
	3. In above situation for a better clean split

	I will do this in future submission.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-08-02 17:42:51 -04:00
..
9p VFS: Pass mount flags to sget() 2012-07-14 16:38:34 +04:00
adfs stop passing nameidata to ->lookup() 2012-07-14 16:34:32 +04:00
affs affs: use memweight() 2012-07-30 17:25:16 -07:00
afs VFS: Pass mount flags to sget() 2012-07-14 16:38:34 +04:00
autofs4 switch dentry_open() to struct path, make it grab references itself 2012-07-23 00:01:29 +04:00
befs stop passing nameidata to ->lookup() 2012-07-14 16:34:32 +04:00
bfs don't pass nameidata to ->create() 2012-07-14 16:34:47 +04:00
btrfs btrfs: use printk_get_level and printk_skip_level, add __printf, fix fallout 2012-07-30 17:25:14 -07:00
cachefiles fs: cachefiles: add support for large files in filesystem caching 2012-07-30 17:25:21 -07:00
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2012-07-31 14:35:28 -07:00
cifs cifs: ensure that we always do cifsFileInfo_get under the spinlock 2012-07-25 14:51:30 -05:00
coda don't pass nameidata to ->create() 2012-07-14 16:34:47 +04:00
configfs stop passing nameidata to ->lookup() 2012-07-14 16:34:32 +04:00
cramfs stop passing nameidata to ->lookup() 2012-07-14 16:34:32 +04:00
debugfs Driver core merge for 3.6-rc1 2012-07-26 11:25:33 -07:00
devpts VFS: Pass mount flags to sget() 2012-07-14 16:38:34 +04:00
dlm dlm: fix missing dir remove 2012-07-16 14:24:43 -05:00
ecryptfs switch dentry_open() to struct path, make it grab references itself 2012-07-23 00:01:29 +04:00
efs stop passing nameidata to ->lookup() 2012-07-14 16:34:32 +04:00
exofs Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-07-23 12:27:27 -07:00
exportfs switch dentry_open() to struct path, make it grab references itself 2012-07-23 00:01:29 +04:00
ext2 ext2: use memweight() 2012-07-30 17:25:16 -07:00
ext3 ext3: use memweight() 2012-07-30 17:25:16 -07:00
ext4 ext4: use memweight() 2012-07-30 17:25:16 -07:00
fat fat: refactor shortname parsing 2012-07-30 17:25:20 -07:00
freevxfs stop passing nameidata to ->lookup() 2012-07-14 16:34:32 +04:00
fscache
fuse don't pass nameidata to ->create() 2012-07-14 16:34:47 +04:00
gfs2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw 2012-07-24 17:57:05 -07:00
hfs hfs: get rid of hfs_sync_super 2012-07-22 23:58:09 +04:00
hfsplus hfsplus: use -ENOMEM when kzalloc() fails 2012-07-30 17:25:19 -07:00
hostfs don't pass nameidata to ->create() 2012-07-14 16:34:47 +04:00
hpfs don't pass nameidata to ->create() 2012-07-14 16:34:47 +04:00
hppfs switch dentry_open() to struct path, make it grab references itself 2012-07-23 00:01:29 +04:00
hugetlbfs hugetlb: use mmu_gather instead of a temporary linked list for accumulating pages 2012-07-31 18:42:40 -07:00
isofs Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2012-07-24 17:40:44 -07:00
jbd jbd: Check return value of blkdev_issue_flush() 2012-07-09 23:38:36 +02:00
jbd2 jbd2: remove the second argument of kmap_atomic 2012-07-23 14:11:22 +08:00
jffs2 don't expose I_NEW inodes via dentry->d_inode 2012-07-23 00:00:58 +04:00
jfs don't expose I_NEW inodes via dentry->d_inode 2012-07-23 00:00:58 +04:00
lockd Lockd: move grace period management from lockd() to per-net functions 2012-07-27 16:49:22 -04:00
logfs VFS: Pass mount flags to sget() 2012-07-14 16:38:34 +04:00
minix minixfs: fix block limit check 2012-07-30 17:25:19 -07:00
ncpfs don't pass nameidata to ->create() 2012-07-14 16:34:47 +04:00
nfs pnfs-obj: Better IO pattern in case of unaligned offset 2012-08-02 17:42:51 -04:00
nfs_common
nfsd Merge branch 'nfsd-next' of git://linux-nfs.org/~bfields/linux 2012-07-31 14:42:28 -07:00
nilfs2 nilfs2: add omitted comments for different structures in driver implementation 2012-07-30 17:25:19 -07:00
nls nls: fix (and rename) mac NLS table files and config options 2012-06-01 19:51:22 -07:00
notify switch dentry_open() to struct path, make it grab references itself 2012-07-23 00:01:29 +04:00
ntfs ntfs: remove references to long gone super operations and unimplemented methods 2012-07-30 17:25:11 -07:00
ocfs2 ocfs2: use memweight() 2012-07-30 17:25:16 -07:00
omfs don't pass nameidata to ->create() 2012-07-14 16:34:47 +04:00
openpromfs stop passing nameidata to ->lookup() 2012-07-14 16:34:32 +04:00
proc proc: do not allow negative offsets on /proc/<pid>/environ 2012-07-30 17:25:20 -07:00
pstore pstore/ram: Make tracing log versioned 2012-07-17 16:48:09 -07:00
qnx4 qnx4fs: use memweight() 2012-07-30 17:25:16 -07:00
qnx6 stop passing nameidata to ->lookup() 2012-07-14 16:34:32 +04:00
quota Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2012-07-24 17:40:44 -07:00
ramfs don't pass nameidata to ->create() 2012-07-14 16:34:47 +04:00
reiserfs don't expose I_NEW inodes via dentry->d_inode 2012-07-23 00:00:58 +04:00
romfs stop passing nameidata to ->lookup() 2012-07-14 16:34:32 +04:00
squashfs stop passing nameidata to ->lookup() 2012-07-14 16:34:32 +04:00
sysfs Driver core merge for 3.6-rc1 2012-07-26 11:25:33 -07:00
sysv fs/sysv: stop using write_super and s_dirt 2012-07-22 23:58:12 +04:00
ubifs * Added another debugfs knob for forcing UBIFS R/O mode without flushing caches 2012-07-23 15:50:52 -07:00
udf Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2012-07-24 17:40:44 -07:00
ufs fs/ufs: get rid of write_super 2012-07-22 23:58:16 +04:00
xfs xfs: update for 3.6-rc1 2012-07-30 13:37:53 -07:00
aio.c aio: now fput() is OK from interrupt context; get rid of manual delayed __fput() 2012-07-22 23:57:59 +04:00
anon_inodes.c
attr.c notify_change(): check that i_mutex is held 2012-07-14 16:35:42 +04:00
bad_inode.c don't pass nameidata to ->create() 2012-07-14 16:34:47 +04:00
binfmt_aout.c
binfmt_elf_fdpic.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-05-23 17:42:39 -07:00
binfmt_elf.c binfmt_elf: switch elf_map() to vm_mmap/vm_munmap 2012-05-30 21:04:55 -04:00
binfmt_em86.c
binfmt_flat.c binfmt_flat: use vm_munmap, we are missing ->mmap_sem there 2012-05-30 21:04:56 -04:00
binfmt_misc.c vfs: Rename end_writeback() to clear_inode() 2012-05-06 13:43:41 +08:00
binfmt_script.c
binfmt_som.c
bio-integrity.c
bio.c Merge branch 'for-3.5/core' of git://git.kernel.dk/linux-block 2012-05-30 08:52:42 -07:00
block_dev.c vfs: Create function for iterating over block devices 2012-07-22 23:58:45 +04:00
buffer.c block: fix infinite loop in __getblk_slow 2012-07-13 08:36:35 -07:00
char_dev.c
compat_binfmt_elf.c
compat_ioctl.c
compat.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2012-06-01 11:53:44 -07:00
dcache.c __d_unalias() should refuse to move mountpoints 2012-07-14 16:35:15 +04:00
dcookies.c
direct-io.c fs/direct-io.c: adjust suspicious bit operation 2012-07-14 16:32:46 +04:00
drop_caches.c
eventfd.c eventfd: change int to __u64 in eventfd_signal() 2012-05-31 17:49:32 -07:00
eventpoll.c PM: Rename CAP_EPOLLWAKEUP to CAP_BLOCK_SUSPEND 2012-07-17 21:37:27 +02:00
exec.c coredump: fix wrong comments on core limits of pipe coredump case 2012-07-30 17:25:20 -07:00
fcntl.c c/r: fcntl: add F_GETOWNER_UIDS option 2012-07-30 17:25:21 -07:00
fhandle.c
fifo.c fifo: Do not restart open() if it already found a partner 2012-07-16 08:33:14 -07:00
file_table.c switch fput to task_work_add 2012-07-22 23:57:58 +04:00
file.c
filesystems.c
fs_struct.c get rid of ->mnt_longterm 2012-07-14 16:32:47 +04:00
fs-writeback.c mm: prepare for removal of obsolete /proc/sys/vm/nr_pdflush_threads 2012-07-31 18:42:40 -07:00
generic_acl.c
inode.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2012-07-26 14:48:55 -07:00
internal.h VFS: Split inode_permission() 2012-07-14 16:38:36 +04:00
ioctl.c
ioprio.c Merge branch 'for-3.5/core' of git://git.kernel.dk/linux-block 2012-05-30 08:52:42 -07:00
Kconfig
Kconfig.binfmt C6X: add support to build with BINFMT_ELF_FDPIC 2012-05-15 09:17:34 -04:00
libfs.c VFS: Pass mount flags to sget() 2012-07-14 16:38:34 +04:00
locks.c Merge branch 'nfsd-next' of git://linux-nfs.org/~bfields/linux 2012-07-31 14:42:28 -07:00
Makefile
mbcache.c
mount.h get rid of magic in proc_namespace.c 2012-07-14 16:32:48 +04:00
mpage.c
namei.c tidy up namei.c a bit 2012-07-23 00:00:55 +04:00
namespace.c VFS: Comment mount following code 2012-07-14 16:38:32 +04:00
no-block.c
open.c switch dentry_open() to struct path, make it grab references itself 2012-07-23 00:01:29 +04:00
pipe.c pipe: remove KM_USER0 from comments 2012-07-24 15:27:34 +08:00
pnode.c VFS: Make clone_mnt()/copy_tree()/collect_mounts() return errors 2012-07-14 16:37:27 +04:00
pnode.h
posix_acl.c
proc_namespace.c get rid of magic in proc_namespace.c 2012-07-14 16:32:48 +04:00
read_write.c vfs: allow custom EOF in generic_file_llseek code 2012-07-23 00:00:15 +04:00
read_write.h
readdir.c switch readdir/getdents to fget_light/fput_light 2012-05-29 23:28:29 -04:00
select.c posix_types.h: Cleanup stale __NFDBITS and related definitions 2012-07-26 13:36:43 -07:00
seq_file.c seq_file: Add seq_vprintf function and export it 2012-06-11 13:16:35 +01:00
signalfd.c switch signalfd4() to fget_light/fput_light 2012-05-29 23:28:30 -04:00
splice.c splice: fix racy pipe->buffers uses 2012-06-13 21:16:42 +02:00
stack.c
stat.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-05-23 17:42:39 -07:00
statfs.c switch statfs to fget_light/fput_light 2012-05-29 23:28:31 -04:00
super.c vmscan: remove obsolete shrink_control comment 2012-07-31 18:42:43 -07:00
sync.c vfs: Avoid unnecessary WB_SYNC_NONE writeback during sys_sync and reorder sync passes 2012-07-22 23:59:01 +04:00
timerfd.c
utimes.c switch utimes() to fget_light/fput_light 2012-05-29 23:28:32 -04:00
xattr_acl.c
xattr.c fs/xattr.c:getxattr(): improve handling of allocation failures 2012-07-30 17:25:11 -07:00