Commit Graph

241 Commits

Author SHA1 Message Date
Linus Torvalds 28890d3598 Merge branch 'nfs-for-3.1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
* 'nfs-for-3.1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (44 commits)
  NFSv4: Don't use the delegation->inode in nfs_mark_return_delegation()
  nfs: don't use d_move in nfs_async_rename_done
  RDMA: Increasing RPCRDMA_MAX_DATA_SEGS
  SUNRPC: Replace xprt->resend and xprt->sending with a priority queue
  SUNRPC: Allow caller of rpc_sleep_on() to select priority levels
  SUNRPC: Support dynamic slot allocation for TCP connections
  SUNRPC: Clean up the slot table allocation
  SUNRPC: Initalise the struct xprt upon allocation
  SUNRPC: Ensure that we grab the XPRT_LOCK before calling xprt_alloc_slot
  pnfs: simplify pnfs files module autoloading
  nfs: document nfsv4 sillyrename issues
  NFS: Convert nfs4_set_ds_client to EXPORT_SYMBOL_GPL
  SUNRPC: Convert the backchannel exports to EXPORT_SYMBOL_GPL
  SUNRPC: sunrpc should not explicitly depend on NFS config options
  NFS: Clean up - simplify the switch to read/write-through-MDS
  NFS: Move the pnfs write code into pnfs.c
  NFS: Move the pnfs read code into pnfs.c
  NFS: Allow the nfs_pageio_descriptor to signal that a re-coalesce is needed
  NFS: Use the nfs_pageio_descriptor->pg_bsize in the read/write request
  NFS: Cache rpc_ops in struct nfs_pageio_descriptor
  ...
2011-07-27 13:23:02 -07:00
Linus Torvalds f01ef569cd Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/writeback
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/writeback: (27 commits)
  mm: properly reflect task dirty limits in dirty_exceeded logic
  writeback: don't busy retry writeback on new/freeing inodes
  writeback: scale IO chunk size up to half device bandwidth
  writeback: trace global_dirty_state
  writeback: introduce max-pause and pass-good dirty limits
  writeback: introduce smoothed global dirty limit
  writeback: consolidate variable names in balance_dirty_pages()
  writeback: show bdi write bandwidth in debugfs
  writeback: bdi write bandwidth estimation
  writeback: account per-bdi accumulated written pages
  writeback: make writeback_control.nr_to_write straight
  writeback: skip tmpfs early in balance_dirty_pages_ratelimited_nr()
  writeback: trace event writeback_queue_io
  writeback: trace event writeback_single_inode
  writeback: remove .nonblocking and .encountered_congestion
  writeback: remove writeback_control.more_io
  writeback: skip balance_dirty_pages() for in-memory fs
  writeback: add bdi_dirty_limit() kernel-doc
  writeback: avoid extra sync work at enqueue time
  writeback: elevate queue_io() into wb_writeback()
  ...

Fix up trivial conflicts in fs/fs-writeback.c and mm/filemap.c
2011-07-26 10:39:54 -07:00
Stephen Rothwell 5f00bcb38e Merge branch 'master' into devel and apply fixup from Stephen Rothwell:
vfs/nfs: fixup for nfs_open_context change

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-07-25 14:53:52 -04:00
Al Viro 3d4ff43d89 nfs_open_context doesn't need struct path either
just dentry, please...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:43:44 -04:00
Trond Myklebust 1f9453578f NFS: Clean up - simplify the switch to read/write-through-MDS
Use nfs_pageio_reset_read_mds and nfs_pageio_reset_write_mds instead of
completely reinitialising the struct nfs_pageio_descriptor.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-07-15 09:12:22 -04:00
Trond Myklebust dce81290ee NFS: Move the pnfs write code into pnfs.c
...and ensure that we recoalese to take into account differences in
differences in block sizes when falling back to write through the MDS.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-07-15 09:12:22 -04:00
Trond Myklebust d097971d8a NFS: Use the nfs_pageio_descriptor->pg_bsize in the read/write request
Instead of looking up the rsize and wsize, the routines that generate the
RPC requests should really be using the pg_bsize, since that is what we
use when deciding whether or not to coalesce write requests...

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-07-15 09:12:20 -04:00
Trond Myklebust 50828d7e67 NFS: Cache rpc_ops in struct nfs_pageio_descriptor
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-07-15 09:12:20 -04:00
Trond Myklebust 275acaafd4 NFS: Clean up: split out the RPC transmission from nfs_pagein_multi/one
...and do the same for nfs_flush_multi/one.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-07-15 09:12:17 -04:00
Peng Tao 3b6091846d NFS: fix return value of nfs_pagein_one/nfs_flush_one
Signed-off-by: Peng Tao <peng_tao@emc.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-07-15 09:11:28 -04:00
Trond Myklebust 6e4efd5685 NFS: Clean up nfs_read_rpcsetup and nfs_write_rpcsetup
Split them up into two parts: one which sets up the struct nfs_read/write_data,
the other which sets up the actual RPC call or pNFS call.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-07-12 13:42:02 -04:00
Trond Myklebust 87ed5eb44a NFS: Don't use DATA_SYNC writes
If we're writing back data, and the FLUSH_STABLE flag is set, then we
always want to use NFS_FILE_SYNC, since we're always in a situation where
we're doing page reclaim, and so we want to free up the page as quickly
as possible.

If we're in the FLUSH_COND_STABLE case, then we either want to use another
unstable write (if we have to do a commit anyway) or again, we want to
use NFS_FILE_SYNC because we know that we have no more pages to write
out.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-07-12 13:42:01 -04:00
Andy Adamson 7c24d9489f NFSv4.1: File layout only supports whole file layouts
Ask for whole file layouts. Until support for layout segments is fully
supported in the file layout code, discard non-whole file layouts.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-07-12 13:40:28 -04:00
Trond Myklebust e885de1a5b NFSv4.1: Fall back to ordinary i/o through the mds if we have no layout segment
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-07-12 13:40:28 -04:00
Trond Myklebust d8007d4dd6 NFSv4.1: Add an initialisation callback for pNFS
Ensure that we always get a layout before setting up the i/o request.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-07-12 13:40:28 -04:00
Trond Myklebust 1751c3638f NFS: Cleanup of the nfs_pageio code in preparation for a pnfs bugfix
We need to ensure that the layouts are set up before we can decide to
coalesce requests. To do so, we want to further split up the struct
nfs_pageio_descriptor operations into an initialisation callback, a
coalescing test callback, and a 'do i/o' callback.

This patch cleans up the existing callback methods before adding the
'initialisation' callback.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-07-12 13:40:28 -04:00
Boaz Harrosh 2bea038c52 pnfs: write: Set mds_offset in the generic layer - it is needed by all LDs
In current pnfs tree, all the layouts set mds_offset in their
.write_pagelist member.
mds_offset is only used by generic layer and should be handled by it.

This patch is for upstream. It is needed in this -rc series to fix a
bug in objects layout_commit.

I'll send patches for objects and blocks to be
squashed into current pnfs tree.

TODO: It looks like the read path needs the same patch.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-06-28 14:12:11 -04:00
Wu Fengguang 846d5a091b writeback: remove .nonblocking and .encountered_congestion
Remove two unused struct writeback_control fields:

	.encountered_congestion	(completely unused)
	.nonblocking		(never set, checked/showed in XFS,NFS/btrfs)

The .for_background check in nfs_write_inode() is also removed btw,
as .for_background implies WB_SYNC_NONE.

Reviewed-by: Jan Kara <jack@suse.cz>
Proposed-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-06-08 08:25:23 +08:00
Benny Halevy dfed206b88 NFSv4.1: unify pnfs_pageio_init functions
Use common code for pnfs_pageio_init_{read,write} and use
a common generic pg_test function.

Note that this function always assumes the the layout driver's
pg_test method is implemented.

[Fix BUG]
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2011-05-29 20:56:43 +03:00
Benny Halevy fb3296eb46 pnfs: Use byte-range for layoutget
Add offset and count parameters to pnfs_update_layout and use them to get
the layout in the pageio path.

Order cache layout segments in the following order:
* offset (ascending)
* length (descending)
* iomode (RW before READ)

Test byte range against the layout segment in use in pnfs_{read,write}_pg_test
so not to coalesce pages not using the same layout segment.

[fix lseg ordering]
[clean up pnfs_find_lseg lseg arg]
[remove unnecessary FIXME]
[fix ordering in pnfs_insert_layout]
[clean up pnfs_insert_layout]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2011-05-29 20:52:32 +03:00
Trond Myklebust a75b9df9d3 NFSv4.1: Ensure that layoutget uses the correct gfp modes
Currently, writebacks may end up recursing back into the filesystem due to
GFP_KERNEL direct reclaims in the pnfs subsystem.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-05-11 22:52:13 -04:00
Trond Myklebust c0d0e96b84 NFS: Get rid of pointless test in nfs_commit_done
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-04-12 19:34:23 -04:00
Trond Myklebust 4b38a6db01 NFS: Eliminate duplicate call to nfs_mark_request_dirty
We only need to call nfs_mark_request_dirty() once in nfs_writepage_setup().

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-04-12 19:34:22 -04:00
Dave Chinner 0d88f6e804 nfs: don't call __mark_inode_dirty while holding i_lock
nfs_scan_commit() is called with the inode->i_lock held, but it then
calls __mark_inode_dirty() while still holding the lock. This causes
a deadlock.

Push the inode->i_lock into nfs_scan_commit() so it can protect only
the parts of the code it needs to and can be dropped before the call
to __mark_inode_dirty() to avoid the deadlock.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Tested-by: Will Simoneau <simoneau@ele.uri.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-12 14:17:24 -07:00
Trond Myklebust 4d65c520fb NFS: Fix a hang in the writeback path
Now that the inode scalability patches have been merged, it is no longer
safe to call igrab() under the inode->i_lock.
Now that we no longer call nfs_clear_request() until the nfs_page is
being freed, we know that we are always holding a reference to the
nfs_open_context, which again holds a reference to the path, and so
the inode cannot be freed until the last nfs_page has been removed
from the radix tree and freed.

We can therefore skip the igrab()/iput() altogether.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-27 17:48:07 +02:00
Andy Adamson ef31153786 NFSv4.1 convert layoutcommit sync to boolean
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-24 15:49:48 -04:00
Andy Adamson 863a3c6c68 NFSv4.1: layoutcommit
The filelayout driver sends LAYOUTCOMMIT only when COMMIT goes to
the data server (as opposed to the MDS) and the data server WRITE
is not NFS_FILE_SYNC.

Only whole file layout support means that there is only one IOMODE_RW layout
segment.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Alexandros Batsakis <batsakis@netapp.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Mingyang Guo <guomingyang@nrchpc.ac.cn>
Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: Zhang Jingwang <zhangjingwang@nrchpc.ac.cn>
Tested-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-23 15:29:04 -04:00
Fred Isaman e0c2b38018 NFSv4.1: filelayout driver specific code for COMMIT
Implement all the hooks created in the previous patches.
This requires exporting quite a few functions and adding a few
structure fields.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-23 15:29:04 -04:00
Fred Isaman 988b6dceb0 NFSv4.1: remove GETATTR from ds commits
Any COMMIT compound directed to a data server needs to have the
GETATTR calls suppressed.  We here, make sure the field we are testing
(data->lseg) is set and refcounted correctly.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-23 15:29:03 -04:00
Fred Isaman a861a1e1c3 NFSv4.1: add generic layer hooks for pnfs COMMIT
We create three major hooks for the pnfs code.

pnfs_mark_request_commit() is called during writeback_done from
nfs_mark_request_commit, which gives the driver an opportunity to
claim it wants control over commiting a particular req.

pnfs_choose_commit_list() is called from nfs_scan_list
to choose which list a given req should be added to, based on
where we intend to send it for COMMIT.  It is up to the driver
to have preallocated list headers for each destination it may need.

pnfs_commit_list() is how the driver actually takes control, it is
used instead of nfs_commit_list().

In order to pass information between the above functions, we create
a union in nfs_page to hold a lseg (which is possible because the req is
not on any list while in transition), and add some flags to indicate
if we need to use the pnfs code.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-23 15:29:03 -04:00
Fred Isaman 5917ce8440 NFSv4.1: pull out code from nfs_commit_release
Create a separate support function for later use by data server
commit code.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-23 15:29:03 -04:00
Fred Isaman 64bfeb49bd NFSv4.1: pull error handling out of nfs_commit_list
Create a separate support function for later use by data server
commit code.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-23 15:29:03 -04:00
Fred Isaman 9ace33cdc6 NFSv4.1: rearrange nfs_commit_rpcsetup
Reorder nfs_commit_rpcsetup, preparing for a pnfs entry point.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-23 15:29:02 -04:00
Fred Isaman 465d52437d NFSv4.1: don't send COMMIT to ds for data sync writes
Based on consensus reached in Feb 2011 interim IETF meeting regarding
use of LAYOUTCOMMIT, it has been decided that a NFS_DATA_SYNC return
from a WRITE to data server should not initiate a COMMIT.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-23 15:29:02 -04:00
Trond Myklebust b8413f98f9 NFS: Fix a hang/infinite loop in nfs_wb_page()
When one of the two waits in nfs_commit_inode() is interrupted, it
returns a non-negative value, which causes nfs_wb_page() to think
that the operation was successful causing it to busy-loop rather
than exiting.
It also causes nfs_file_fsync() to incorrectly report the file as
being successfully committed to disk.

This patch fixes both problems by ensuring that we return an error
if the attempts to wait fail.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org
2011-03-21 21:09:24 -04:00
Trond Myklebust b31268ac79 FS: Use stable writes when not doing a bulk flush
If we're only doing a single write, and there are no other unstable
writes being queued up, we might want to just flip to using a stable
write RPC call.

Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-21 21:08:17 -04:00
Fred Isaman 36fe432d33 NFSv4.1: Clear lseg pointer in ->doio function
Now that we have access to the pointer, clear it immediately after
the put, instead of in caller.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:45 -05:00
Fred Isaman c76069bda0 NFSv4.1: rearrange ->doio args
This will make it possible to clear the lseg pointer in the same
function as it is put, instead of in the caller nfs_pageio_doio().

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:44 -05:00
Fred Isaman a69aef1496 NFSv4.1: pnfs filelayout driver write
Allows the pnfs filelayout driver to write to the data servers.

Note that COMMIT to data servers will be implemented in a future
patch.  To avoid improper behavior, for the moment any WRITE to a data
server that would also require a COMMIT to the data server is sent
NFS_FILE_SYNC.

Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Mingyang Guo <guomingyang@nrchpc.ac.cn>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:44 -05:00
Andy Adamson 0382b74409 NFSv4.1: implement generic pnfs layer write switch
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Mike Sager <sager@netapp.com>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:44 -05:00
Fred Isaman 44b83799a9 NFSv4.1: trigger LAYOUTGET for writes
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:44 -05:00
Fred Isaman 5053aa568d NFSv4.1: Send lseg down into nfs_write_rpcsetup
We grab the lseg sent in from the doio function and attach it to
each struct nfs_write_data created.  This is how the lseg will be
sent to the layout driver.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:44 -05:00
Andy Adamson d138d5d17b NFSv4.1: rearrange nfs_write_rpcsetup
Reorder nfs_write_rpcsetup, preparing for a pnfs entry point.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:43 -05:00
Fred Isaman bae724ef95 NFSv4.1: shift pnfs_update_layout locations
Move the pnfs_update_layout call location to nfs_pageio_do_add_request().
Grab the lseg sent in the doio function to nfs_read_rpcsetup and attach
it to each nfs_read_data so it can be sent to the layout driver.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:42 -05:00
Fred Isaman 94ad1c80e2 NFSv4.1: coelesce across layout stripes
Add a pg_test layout driver hook which is used to avoid coelescing I/O across
layout stripes.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:42 -05:00
Fred Isaman 136028967a NFS: change nfs_writeback_done to return void
The return values are not used by any callers.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:40 -05:00
Jeff Layton d2224e7afb nfs: close NFSv4 COMMIT vs. CLOSE race
I've been adding in more artificial delays in the NFSv4 commit and close
codepaths to uncover races. The kernel I'm testing has the patch to
close the race in __rpc_wait_for_completion_task that's in Trond's
cthon2011 branch. The reproducer I've been using does this in a loop:

	mkdir("DIR");
	fd = open("DIR/FILE", O_WRONLY|O_CREAT|O_EXCL, 0644);
	write(fd, "abcdefg", 7);
	close(fd);
	unlink("DIR/FILE");
	rmdir("DIR");

The above reproducer shouldn't result in any silly-renaming. However,
when I add a "msleep(100)" just after the nfs_commit_clear_lock call in
nfs_commit_release, I can almost always force one to occur. If I can
force it to occur with that, then it can happen without that delay
given the right timing.

nfs_commit_inode waits for the NFS_INO_COMMIT bit to clear when called
with FLUSH_SYNC set. nfs_commit_rpcsetup on the other hand does not wait
for the task to complete before putting its reference to it, so the last
reference get put in rpc_release task and gets queued to a workqueue.

In this situation, the last open context reference may be put by the
COMMIT release instead of the close() syscall. The close() syscall
returns too quickly and the unlink runs while the d_count is still
high since the COMMIT release hasn't put its dentry reference yet.

Fix this by having rpc_commit_rpcsetup wait for the RPC call to complete
before putting the task reference when FLUSH_SYNC is set. With this, the
last reference is put by the process that's initiating the FLUSH_SYNC
commit and the race is closed.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-10 15:04:53 -05:00
Fred Isaman 0da2a4ac33 NFS: fix handling of malloc failure during nfs_flush_multi()
Cleanup of the allocated list entries should not call
put_nfs_open_context() on each entry, as the context will
always be NULL, causing an oops.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-19 15:37:49 -05:00
Trond Myklebust 2df485a774 nfs: remove extraneous and problematic calls to nfs_clear_request
When a nfs_page is freed, nfs_free_request is called which also calls
nfs_clear_request to clean out the lock and open contexts and free the
pagecache page.

However, a couple of places in the nfs code call nfs_clear_request
themselves. What happens here if the refcount on the request is still high?
We'll be releasing contexts and freeing pointers while the request is
possibly still in use.

Remove those bare calls to nfs_clear_context. That should only be done when
the request is being freed.

Note that when doing this, we need to watch out for tests of req->wb_page.
Previously, nfs_set_page_tag_locked() and nfs_clear_page_tag_locked()
would check the value of req->wb_page to figure out if the page is mapped
into the nfsi->nfs_page_tree. We now indicate the page is mapped using
the new bit PG_MAPPED in req->wb_flags .

Reported-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-12-07 23:02:44 -05:00
Wu Fengguang 1b430beee5 writeback: remove nonblocking/encountered_congestion references
This removes more dead code that was somehow missed by commit 0d99519efe
(writeback: remove unused nonblocking and congestion checks).  There are
no behavior change except for the removal of two entries from one of the
ext4 tracing interface.

The nonblocking checks in ->writepages are no longer used because the
flusher now prefer to block on get_request_wait() than to skip inodes on
IO congestion.  The latter will lead to more seeky IO.

The nonblocking checks in ->writepage are no longer used because it's
redundant with the WB_SYNC_NONE check.

We no long set ->nonblocking in VM page out and page migration, because
a) it's effectively redundant with WB_SYNC_NONE in current code
b) it's old semantic of "Don't get stuck on request queues" is mis-behavior:
   that would skip some dirty inodes on congestion and page out others, which
   is unfair in terms of LRU age.

Inspired by Christoph Hellwig. Thanks!

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: David Howells <dhowells@redhat.com>
Cc: Sage Weil <sage@newdream.net>
Cc: Steve French <sfrench@samba.org>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:05 -07:00