Commit Graph

164 Commits

Author SHA1 Message Date
Bryan Schumaker
ff9099f266 NFS: Create a try_mount rpc op
I'm already looking up the nfs subversion in nfs_fs_mount(), so I have
easy access to rpc_ops that used to be difficult to reach.  This allows
me to set up a different mount path for NFS v2/3 and NFS v4.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-30 19:04:53 -04:00
Bryan Schumaker
ab7017a3a0 NFS: Add version registering framework
This patch adds in the code to track multiple versions of the NFS
protocol.  I created default structures for v2, v3 and v4 so that each
version can continue to work while I convert them into kernel modules.
I also removed the const parameter from the rpc_version array so that I
can change it at runtime.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-30 19:04:17 -04:00
Bryan Schumaker
fbdefd6442 NFS: Split out the NFS v4 filesystem types
This allows me to move the v4 mounting and unmounting functions out of
the generic client and into a file that is only compiled when CONFIG_NFS_V4
is enabled.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-17 13:33:55 -04:00
Bryan Schumaker
fcf10398f6 NFS: Split out NFS v4 server creating code
These functions are specific to NFS v4 and can be moved to nfs4client.c
to keep them out of the generic client.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-17 13:33:53 -04:00
Bryan Schumaker
428360d77c NFS: Initialize the NFS v4 client from init_nfs_v4()
And split these functions out of the generic client into a v4 specific
file.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-17 13:33:52 -04:00
Bryan Schumaker
ce4ef7c0a8 NFS: Split out NFS v4 file operations
This patch moves the NFS v4 file functions into a new file that is only
compiled when CONFIG_NFS_V4 is enabled.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-17 13:33:50 -04:00
Bryan Schumaker
597d92891b NFS: Split out NFS v2 inode operations
This patch moves the NFS v2 file and directory inode functions into
files that are only compiled whet CONFIG_NFS_V2 is enabled.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-17 13:32:55 -04:00
Bryan Schumaker
57208fa7e5 NFS: Create an write_pageio_init() function
pNFS needs to select a write function based on the layout driver
currently in use, so I let each NFS version decide how to best handle
initializing writes.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-06-29 11:46:46 -04:00
Bryan Schumaker
1abb50886a NFS: Create an read_pageio_init() function
pNFS needs to select a read function based on the layout driver
currently in use, so I let each NFS version decide how to best handle
initializing reads.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-06-29 11:46:46 -04:00
Bryan Schumaker
6663ee7f81 NFS: Create an alloc_client rpc_op
This gives NFS v4 a way to set up callbacks and sessions without v2 or
v3 having to do them as well.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-06-29 11:46:46 -04:00
Bryan Schumaker
cdb7ecedec NFS: Create a free_client rpc_op
NFS v4 needs a way to shut down callbacks and sessions, but v2 and v3
don't.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-06-29 11:46:45 -04:00
Trond Myklebust
1d59d61f60 NFS: Ensure that setattr and getattr wait for O_DIRECT write completion
Use the same mechanism as the block devices are using, but move the
helper functions from fs/direct-io.c into fs/inode.c to remove the
dependency on CONFIG_BLOCK.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-31 11:41:36 -07:00
Trond Myklebust
4697bd5e94 NFSv4: Fix a race in the net namespace mount notification
Since the struct nfs_client gets added to the global nfs_client_list
before it is initialised, it is possible that rpc_pipefs_event can
end up trying to create idmapper entries on such a thing.

The solution is to have the mount notification wait for the
initialisation of each nfs_client to complete, and then to
skip any entries for which the it failed.

Reported-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
2012-05-23 15:21:13 -04:00
Trond Myklebust
7b38c3682c NFSv4.1: Fix session initialisation races
Session initialisation is not complete until the lease manager
has run. We need to ensure that both nfs4_init_session and
nfs4_init_ds_session do so, and that they check for any resulting
errors in clp->cl_cons_state.

Only after this is done, can nfs4_ds_connect check the contents
of clp->cl_exchange_flags.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Andy Adamson <andros@netapp.com>
2012-05-23 15:20:57 -04:00
Chuck Lever
4bf590e08f NFS: Add nfs_client behavior flags
"noresvport" and "discrtry" can be passed to nfs_create_rpc_client()
by setting flags in the passed-in nfs_client.  This change makes it
easy to add new flags.

Note that these settings are now "sticky" over the lifetime of a
struct nfs_client, and may even be copied when an nfs_client is
cloned.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-05-22 16:45:47 -04:00
Chuck Lever
8cab4c390b NFS: Refactor nfs_get_client(): initialize nfs_client
Clean up: Continue to rationalize the locking in nfs_get_client() by
moving the logic that handles the case where a matching server IP
address is not found.

When we support server trunking detection, client initialization may
return a different nfs_client struct than was passed to it.  Change
the synopsis of the init_client methods to return an nfs_client.

The client initialization logic in nfs_get_client() is not much more
than a wrapper around ->init_client.  It's simpler to keep the little
bits of error handling in the version-specific init_client methods.

No behavior change is expected.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-05-22 16:45:47 -04:00
Andy Adamson
a033a09189 NFSv4.1 remove nfs4_reset_write and nfs4_reset_read
Replaced by filelayout_reset_write and filelayout_reset_read

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-05-19 17:54:59 -04:00
Andy Adamson
98fc685ae2 NFSv4.1 data server timeo and retrans module parameters
Set the recovery parameters for data servers.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-05-19 17:54:20 -04:00
Andy Adamson
9f0ec176b3 NFSv4.1 set RPC_TASK_SOFTCONN for filelayout DS RPC calls
RPC_TASK_SOFTCONN returns connection errors to the caller which allows the pNFS
file layout to quickly try the MDS or perhaps another DS.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-05-19 17:54:19 -04:00
Bryan Schumaker
5e7e5a0da2 NFS: Create an NFS v3 stat_to_errno()
In theory, NFS v3 can have different error versions than NFS v2. v4 is
already using its own nfs4_stat_to_errno() to map error codes, so
rather than create something in the generic client for v2 and v3 to
share I instead give v3 its own function.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-05-14 17:42:21 -07:00
Bryan Schumaker
b72e4f42a3 NFS: Create a single function for text mount data
The v2/3 and v4 cases were very similar, with just a few parameters
changed.  This makes it easy to share code.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-05-14 17:30:30 -07:00
Trond Myklebust
3a1556e866 NFSv2/v3: Simulate the change attribute
Use the ctime to simulate a change attribute for NFSv2 and NFSv3.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-05-01 15:42:43 -04:00
Bryan Schumaker
281cad46b3 NFS: Create a submount rpc_op
This simplifies the code for v2 and v3 and gives v4 a chance to decide
on referrals without needing to modify the generic client.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27 14:10:39 -04:00
Bryan Schumaker
2671bfc3be NFS: Remove secinfo knowledge out of the generic client
And also remove the unneeded rpc_op.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27 14:10:39 -04:00
Fred Isaman
1763da1234 NFS: rewrite directio write to use async coalesce code
This also has the advantage that it allows directio to use pnfs.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27 14:10:39 -04:00
Fred Isaman
f453a54a01 NFS: create nfs_commit_completion_ops
Factors out the code that needs to change when directio
starts using these code paths.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27 14:10:38 -04:00
Fred Isaman
ea2cf2282b NFS: create struct nfs_commit_info
It is COMMIT that is handled the most differently between
the paged and direct paths.  Create a structure that encapsulates
everything either path needs to know about the commit state.

We could use void to hide some of the layout driver stuff, but
Trond suggests pulling it out to ensure type checking, given the
huge changes being made, and the fact that it doesn't interfere
with other drivers.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27 14:10:38 -04:00
Fred Isaman
584aa810b6 NFS: rewrite directio read to use async coalesce code
This also has the advantage that it allows directio to use pnfs.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27 14:10:38 -04:00
Fred Isaman
061ae2edb7 NFS: create completion structure to pass into page_init functions
Factors out the code that will need to change when directio
starts using these code paths.  This will allow directio to use
the generic pagein and flush routines

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27 14:10:38 -04:00
Fred Isaman
6c75dc0d49 NFS: merge _full and _partial write rpc_ops
Decouple nfs_pgio_header and nfs_write_data, and have (possibly
multiple) nfs_write_datas each take a refcount on nfs_pgio_header.

For the moment keeps nfs_write_header as a way to preallocate a single
nfs_write_data with the nfs_pgio_header.  The code doesn't need this,
and would be prettier without, but given the amount of churn I am
already introducing I didn't want to play with tuning new mempools.

This also fixes bug in pnfs_ld_handle_write_error.  In the case of
desc->pg_bsize < PAGE_CACHE_SIZE, the pages list was empty, causing
replay attempt to do nothing.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27 14:10:37 -04:00
Fred Isaman
4db6e0b74c NFS: merge _full and _partial read rpc_ops
Decouple nfs_pgio_header and nfs_read_data, and have (possibly
multiple) nfs_read_datas each take a refcount on nfs_pgio_header.

For the moment keeps nfs_read_header as a way to preallocate a single
nfs_read_data with the nfs_pgio_header.  The code doesn't need this,
and would be prettier without, but given the amount of churn I am
already introducing I didn't want to play with tuning new mempools.

This also fixes bug in pnfs_ld_handle_read_error.  In the case of
desc->pg_bsize < PAGE_CACHE_SIZE, the pages list was empty, causing
replay attempt to do nothing.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27 14:10:37 -04:00
Fred Isaman
30dd374f6f NFS: create struct nfs_page_array
Both nfs_read_data and nfs_write_data devote several fields which
can be combined into a single shared struct.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27 14:10:37 -04:00
Fred Isaman
cd841605f7 NFS: create common nfs_pgio_header for both read and write
In order to avoid duplicating all the data in nfs_read_data whenever we
split it up into multiple RPC calls (either due to a short read result
or due to rsize < PAGE_SIZE), we split out the bits that are the same
per RPC call into a separate "header" structure.

The goal this patch moves towards is to have a single header
refcounted by several rpc_data structures.  Thus, want to always refer
from rpc_data to the header, and not the other way.  This patch comes
close to that ideal, but the directio code currently needs some
special casing, isolated in the nfs_direct_[read_write]hdr_release()
functions.  This will be dealt with in a future patch.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27 14:10:37 -04:00
Fred Isaman
c5996c4efb NFS: reverse arg order in nfs_initiate_[read|write]
Make it consistent with nfs_initiate_commit.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27 14:10:37 -04:00
Fred Isaman
0b7c01533a NFS: add a struct nfs_commit_data to replace nfs_write_data in commits
Commits don't need the vectors of pages, etc. that writes do. Split out
a separate structure for the commit operation.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27 14:10:37 -04:00
Bryan Schumaker
7e6eb683d2 NFS: Honor the authflavor set in the clone mount data
The authflavor is set in an nfs_clone_mount structure and passed to the
xdev_mount() functions where it was promptly ignored.  Instead, use it
to initialize an rpc_clnt for the cloned server.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27 14:10:03 -04:00
Bryan Schumaker
f05d147f7e NFS: Fix following referral mount points with different security
I create a new proc_lookup_mountpoint() to use when submounting an NFS
v4 share.  This function returns an rpc_clnt to use for performing an
fs_locations() call on a referral's mountpoint.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27 14:10:02 -04:00
Bryan Schumaker
72de53ec4b NFS: Do secinfo as part of lookup
Whenever lookup sees wrongsec do a secinfo and retry the lookup to find
attributes of the file or directory, such as "is this a referral
mountpoint?".  This also allows me to remove handling -NFS4ERR_WRONSEC
as part of getattr xdr decoding.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27 14:10:02 -04:00
Trond Myklebust
8dd3775889 NFSv4.1: Clean ups and bugfixes for the pNFS read/writeback/commit code
Move more pnfs-isms out of the generic commit code.

Bugfixes:

- filelayout_scan_commit_lists doesn't need to get/put the lseg.
  In fact since it is run under the inode->i_lock, the lseg_put()
  can deadlock.

- Ensure that we distinguish between what needs to be done for
  commit-to-data server and what needs to be done for commit-to-MDS
  using the new flag PG_COMMIT_TO_DS. Otherwise we may end up calling
  put_lseg() on a bucket for a struct nfs_page that got written
  through the MDS.

- Fix a case where we were using list_del() on an nfs_page->wb_list
  instead of list_del_init().

- filelayout_initiate_commit needs to call filelayout_commit_release
  on error instead of the mds_ops->rpc_release(). Otherwise it won't
  clear the commit lock.

Cleanups:

- Let the files layout manage the commit lists for the pNFS case.
  Don't expose stuff like pnfs_choose_commit_list, and the fact
  that the commit buckets hold references to the layout segment
  in common code.

- Cast out the put_lseg() calls for the struct nfs_read/write_data->lseg
  into the pNFS layer from whence they came.

- Let the pNFS layer manage the NFS_INO_PNFS_COMMIT bit.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Fred Isaman <iisaman@netapp.com>
2012-03-17 11:09:33 -04:00
Fred Isaman
d6d6dc7cdf NFS: remove nfs_inode radix tree
The radix tree is only being used to compile lists of reqs needing commit.
It is simpler to just put the reqs directly into a list.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-03-10 17:14:10 -05:00
Stanislav Kinsbursky
c7add9a972 NFS: search for client session id in proper network namespace
Network namespace is taken from request transport and passed as a part of
cb_process_state structure.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-02-06 18:48:04 -05:00
Stanislav Kinsbursky
dc03085834 NFS: make nfs_client_lock per net ns
This patch makes nfs_clients_lock allocated per network namespace. All items it
protects are already network namespace aware.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-02-06 18:48:03 -05:00
Stanislav Kinsbursky
28cd1b3f26 NFS: make cb_ident_idr per net ns
This patch makes ID's infrastructure network namespace aware. This was done
mainly because of nfs_client_lock, which is desired to be per network
namespace, but protects NFS clients ID's.

NOTE: NFS client's net pointer have to be set prior to ID initialization,
proper assignment was moved.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-02-06 18:48:03 -05:00
Stanislav Kinsbursky
6b13168b36 NFS: make nfs_client_list per net ns
This patch splits global list of NFS clients into per-net-ns array of lists.
This looks more strict and clearer.
BTW, this patch also makes "/proc/fs/nfsfs/servers" entry content depends on
/proc mount owner pid namespace. See below for details.

NOTE: few words about how was /proc/fs/nfsfs/ entries content show per network
namespace done. This is a little bit tricky and not the best is could be. But
it's cheap (proper fix for /proc conteinerization is a hard nut to crack).
The idea is simple: take proper network namespace from pid namespace
child reaper nsproxy of /proc/ mount creator.
This actually means, that if there are 2 containers with different net
namespace sharing pid namespace, then read of /proc/fs/nfsfs/ entries will
always return content, taken from net namespace of pid namespace creator task
(and thus second namespace set wil be unvisible).

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-02-06 18:48:02 -05:00
Trond Myklebust
a613fa168a SUNRPC: constify the rpc_program
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-01-31 19:28:20 -05:00
Stanislav Kinsbursky
babea479b7 NFS: remove unused nfs4_find_client_no_ident function
Looks like this function survived after some cleanup patch without a reason.
Now it's not called or referenced and I believe, that it can be simply removed.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-01-31 19:28:19 -05:00
Stanislav Kinsbursky
eee17325f1 NFS: idmap PipeFS notifier introduced
v2:
1) Added "nfs_idmap_init" and "nfs_idmap_quit" definitions for kernels built
without CONFIG_NFS_V4 option set.

This patch subscribes NFS clients to RPC pipefs notifications. Idmap notifier
is registering on NFS module load. This notifier callback is responsible for
creation/destruction of PipeFS idmap pipe dentry for NFS4 clients.

Since ipdmap pipe is created in rpc client pipefs directory, we have make sure,
that this directory has been created already. IOW RPC client notifier callback
has been called already. To achive this, PipeFS notifier priorities has been
introduced (RPC clients notifier priority is greater than NFS idmap one).
But this approach gives another problem: unlink for RPC client directory will
be called before NFS idmap pipe unlink on UMOUNT event and will fail, because
directory is not empty.
The solution, introduced in this patch, is to try to remove client directory
once again after idmap pipe was unlinked. This looks like ugly hack, so
probably it should be replaced in some more elegant way.

Note that no locking required in notifier callback because PipeFS superblock
pointer is passed as an argument from it's creation or destruction routine and
thus we can be sure about it's validity.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-01-31 18:20:27 -05:00
Stanislav Kinsbursky
6d59b8d599 NFS: pass NFS client owner network namespace to RPC client creation routine
This patch replaces static "init_net" with nfs_client->net pointer in RPC
client creation calls.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-01-31 18:20:27 -05:00
Stanislav Kinsbursky
e50a7a1a42 NFS: make NFS client allocated per network namespace context
This patch adds new net variable to nfs_client structure. This variable is set
on NFS client creation and cheched during matching NFS client search.
Initially current->nsproxy->net_ns is used as network namespace owner for new
NFS client to create. This network namespace pointer is set during mount
options parsing and thus can be passed from user-spave utils in future if will
be necessary.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-01-31 18:20:26 -05:00
Mel Gorman
a6bc32b899 mm: compaction: introduce sync-light migration for use by compaction
This patch adds a lightweight sync migrate operation MIGRATE_SYNC_LIGHT
mode that avoids writing back pages to backing storage.  Async compaction
maps to MIGRATE_ASYNC while sync compaction maps to MIGRATE_SYNC_LIGHT.
For other migrate_pages users such as memory hotplug, MIGRATE_SYNC is
used.

This avoids sync compaction stalling for an excessive length of time,
particularly when copying files to a USB stick where there might be a
large number of dirty pages backed by a filesystem that does not support
->writepages.

[aarcange@redhat.com: This patch is heavily based on Andrea's work]
[akpm@linux-foundation.org: fix fs/nfs/write.c build]
[akpm@linux-foundation.org: fix fs/btrfs/disk-io.c build]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andy Isaacson <adi@hexapodia.org>
Cc: Nai Xia <nai.xia@gmail.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12 20:13:09 -08:00