aboutsummaryrefslogtreecommitdiff
AgeCommit message (Collapse)Author
2017-09-09NFS: Don't hold the group lock when calling nfs_release_request()Trond Myklebust
That can deadlock if this is the last reference since nfs_page_group_destroy() calls nfs_page_group_sync_on_bit(). Note that even if the page was removed from the subpage list, the req->wb_head could still be pointing to the old head. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-09NFS: Remove pnfs_generic_transfer_commit_list()Trond Myklebust
It's pretty much a duplicate of nfs_scan_commit_list() that also clears the PG_COMMIT_TO_DS flag. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-09NFS: nfs_lock_and_join_requests and nfs_scan_commit_list can deadlockTrond Myklebust
Since the commit list is not ordered, it is possible for nfs_scan_commit_list to hold a request that nfs_lock_and_join_requests() is waiting for, while at the same time trying to grab a request that nfs_lock_and_join_requests already holds. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-08NFS: Fix 2 use after free issues in the I/O codeTrond Myklebust
The writeback code wants to send a commit after processing the pages, which is why we want to delay releasing the struct path until after that's done. Also, the layout code expects that we do not free the inode before we've put the layout segments in pnfs_writehdr_free() and pnfs_readhdr_free() Fixes: 919e3bd9a875 ("NFS: Ensure we commit after writeback is complete") Fixes: 4714fb51fd03 ("nfs: remove pgio_header refcount, related cleanup") Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-07NFS: Sync the correct byte range during synchronous writestarangg@amazon.com
Since commit 18290650b1c8 ("NFS: Move buffered I/O locking into nfs_file_write()") nfs_file_write() has not flushed the correct byte range during synchronous writes. generic_write_sync() expects that iocb->ki_pos points to the right edge of the range rather than the left edge. To replicate the problem, open a file with O_DSYNC, have the client write at increasing offsets, and then print the successful offsets. Block port 2049 partway through that sequence, and observe that the client application indicates successful writes in advance of what the server received. Fixes: 18290650b1c8 ("NFS: Move buffered I/O locking into nfs_file_write()") Signed-off-by: Jacob Strauss <jsstraus@amazon.com> Signed-off-by: Tarang Gupta <tarangg@amazon.com> Tested-by: Tarang Gupta <tarangg@amazon.com> Cc: stable@vger.kernel.org # v4.8+ Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-06lockd: Delete an error message for a failed memory allocation in reclaimer()Markus Elfring
Omit an extra message for a memory allocation failure in this function. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-06NFS: remove jiffies field from access cacheNeilBrown
This field hasn't been used since commit 57b691819ee2 ("NFS: Cache access checks more aggressively"). Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-06NFS: flush data when locking a file to ensure cache coherence for mmap.NeilBrown
When a byte range lock (or flock) is taken out on an NFS file, the validity of the cached data is checked and the inode is marked NFS_INODE_INVALID_DATA. However the cached data isn't flushed from the page cache. This is sufficient for future read() requests or mmap() requests as they call nfs_revalidate_mapping() which performs the flush if necessary. However an existing mapping is not affected. Accessing data through that mapping will continue to return old data even though the inode is marked NFS_INODE_INVALID_DATA. This can easily be confirmed using the 'nfs' tool in git://github.com/okirch/twopence-nfs.git and running nfs coherence FILENAME on one client, and nfs coherence -r FILENAME on another client. It appears that prior to Linux 2.6.0 this worked correctly. However commit: http://git.kernel.org/cgit/linux/kernel/git/history/history.git/commit/?id=ca9268fe3ddd075714005adecd4afbd7f9ab87d0 removed the call to inode_invalidate_pages() from nfs_zap_caches(). I haven't tested this code, but inspection suggests that prior to this commit, file locking would invalidate all inode pages. This patch adds a call to nfs_revalidate_mapping() after a successful SETLK so that invalid data is flushed. With this patch the above test passes. To minimize impact (and possibly avoid a GETATTR call) this only happens if the mapping might be mapped into userspace. Cc: Olaf Kirch <okir@suse.com> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-06SUNRPC: remove some dead code.NeilBrown
RPC_TASK_NO_RETRANS_TIMEOUT is set when cl_noretranstimeo is set, which happens when RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT is set, which happens when NFS_CS_NO_RETRANS_TIMEOUT is set. This flag means "don't resend on a timeout, only resend if the connection gets broken for some reason". cl_discrtry is set when RPC_CLNT_CREATE_DISCRTRY is set, which happens when NFS_CS_DISCRTRY is set. This flag means "always disconnect before resending". NFS_CS_NO_RETRANS_TIMEOUT and NFS_CS_DISCRTRY are both only set in nfs4_init_client(), and it always sets both. So we will never have a situation where only one of the flags is set. So this code, which tests if timeout retransmits are allowed, and disconnection is required, will never run. So it makes sense to remove this code as it cannot be tested and could confuse people reading the code (like me). (alternately we could leave it there with a comment saying it is never actually used). Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-06NFS: don't expect errors from mempool_alloc().NeilBrown
Commit fbe77c30e9ab ("NFS: move rw_mode to nfs_pageio_header") reintroduced some pointless code that commit 518662e0fcb9 ("NFS: fix usage of mempools.") had recently removed. Remove it again. Cc: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-05xprtrdma: Use xprt_pin_rqst in rpcrdma_reply_handlerChuck Lever
Adopt the use of xprt_pin_rqst to eliminate contention between Call-side users of rb_lock and the use of rb_lock in rpcrdma_reply_handler. This replaces the mechanism introduced in 431af645cf66 ("xprtrdma: Fix client lock-up after application signal fires"). Use recv_lock to quickly find the completing rqst, pin it, then drop the lock. At that point invalidation and pull-up of the Reply XDR can be done. Both are often expensive operations. Finally, take recv_lock again to signal completion to the RPC layer. It also protects adjustment of "cwnd". This greatly reduces the amount of time a lock is held by the reply handler. Comparing lock_stat results shows a marked decrease in contention on rb_lock and recv_lock. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> [trond.myklebust@primarydata.com: Remove call to rpcrdma_buffer_put() from the "out_norqst:" path in rpcrdma_reply_handler.] Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-05Merge tag 'nfs-rdma-for-4.14-1' of ↵Trond Myklebust
git://git.linux-nfs.org/projects/anna/linux-nfs into linux-next NFS-over-RDMA client updates for Linux 4.14 Bugfixes and cleanups: - Constify rpc_xprt_ops - Harden RPC call encoding and decoding - Clean up rpc call decoding to use xdr_streams - Remove unused variables from various structures - Refactor code to remove imul instructions - Rearrange rx_stats structure for better cacheline sharing
2017-08-22xprtrdma: Re-arrange struct rx_statsChuck Lever
To reduce false cacheline sharing, separate counters that are likely to be accessed in the Call path from those accessed in the Reply path. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-08-20Merge branch 'bugfixes'Trond Myklebust
2017-08-20NFS: Fix NFSv2 security settingsChuck Lever
For a while now any NFSv2 mount where sec= is specified uses AUTH_NULL. If sec= is not specified, the mount uses AUTH_UNIX. Commit e68fd7c8071d ("mount: use sec= that was specified on the command line") attempted to address a very similar problem with NFSv3, and should have fixed this too, but it has a bug. The MNTv1 MNT procedure does not return a list of security flavors, so our client makes up a list containing just AUTH_NULL. This should enable nfs_verify_authflavors() to assign the sec= specified flavor, but instead, it incorrectly sets it to AUTH_NULL. I expect this would also be a problem for any NFSv3 server whose MNTv3 MNT procedure returned a security flavor list containing only AUTH_NULL. Fixes: e68fd7c8071d ("mount: use sec= that was specified on ... ") BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=310 Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-20NFSv4.1: don't use machine credentials for CLOSE when using 'sec=sys'NeilBrown
An NFSv4.1 client might close a file after the user who opened it has logged off. In this case the user's credentials may no longer be valid, if they are e.g. kerberos credentials that have expired. NFSv4.1 has a mechanism to allow the client to use machine credentials to close a file. However due to a short-coming in the RFC, a CLOSE with those credentials may not be possible if the file in question isn't exported to the same security flavor - the required PUTFH must be rejected when this is the case. Specifically if a server and client support kerberos in general and have used it to form a machine credential, but the file is only exported to "sec=sys", a PUTFH with the machine credentials will fail, so CLOSE is not possible. As RPC_AUTH_UNIX (used by sec=sys) credentials can never expire, there is no value in using the machine credential in place of them. So in that case, just use the users credentials for CLOSE etc, as you would in NFSv4.0 Signed-off-by: Neil Brown <neilb@suse.com> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-20SUNRPC: ECONNREFUSED should cause a rebind.NeilBrown
If you - mount and NFSv3 filesystem - do some file locking which requires the server to make a GRANT call back - unmount - mount again and do the same locking then the second attempt at locking suffers a 30 second delay. Unmounting and remounting causes lockd to stop and restart, which causes it to bind to a new port. The server still thinks the old port is valid and gets ECONNREFUSED when trying to contact it. ECONNREFUSED should be seen as a hard error that is not worth retrying. Rebinding is the only reasonable response. This patch forces a rebind if that makes sense. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-20NFS: Remove unused parameter gfp_flags from nfs_pageio_init()Trond Myklebust
Now that the mirror allocation has been moved, the parameter can go. Also remove the redundant symbol export. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-20NFSv4: Fix up mirror allocationTrond Myklebust
There are a number of callers of nfs_pageio_complete() that want to continue using the nfs_pageio_descriptor without needing to call nfs_pageio_init() again. Examples include nfs_pageio_resend() and nfs_pageio_cond_complete(). The problem is that nfs_pageio_complete() also calls nfs_pageio_cleanup_mirroring(), which frees up the array of mirrors. This can lead to writeback errors, in the next call to nfs_pageio_setup_mirroring(). Fix by simply moving the allocation of the mirrors to nfs_pageio_setup_mirroring(). Link: https://bugzilla.kernel.org/show_bug.cgi?id=196709 Reported-by: JianhongYin <yin-jianhong@163.com> Cc: stable@vger.kernel.org # 4.0+ Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-18Merge branch 'writeback'Trond Myklebust
2017-08-18SUNRPC: Add a separate spinlock to protect the RPC request receive listTrond Myklebust
This further reduces contention with the transport_lock, and allows us to convert to using a non-bh-safe spinlock, since the list is now never accessed from a bh context. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-16SUNRPC: Cleanup xs_tcp_read_common()Trond Myklebust
Simplify the code to avoid a full copy of the struct xdr_skb_reader. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-16SUNRPC: Don't loop forever in xs_tcp_data_receive()Trond Myklebust
Ensure that we don't hog the workqueue thread by requeuing the job every 64 loops. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-16SUNRPC: Don't hold the transport lock when receiving backchannel dataTrond Myklebust
The backchannel request has no associated task, so it is going nowhere until we call xprt_complete_bc_request(). Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-16SUNRPC: Don't hold the transport lock across socket copy operationsTrond Myklebust
Instead add a mechanism to ensure that the request doesn't disappear from underneath us while copying from the socket. We do this by preventing xprt_release() from freeing the XDR buffers until the flag RPC_TASK_MSG_RECV has been cleared from the request. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
2017-08-15xprtrdma: Remove imul instructions from chunk list encodersChuck Lever
Re-arrange the pointer arithmetic in the chunk list encoders to eliminate several more integer multiplication instructions during Transport Header encoding. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-08-15xprtrdma: Remove imul instructions from rpcrdma_convert_iovs()Chuck Lever
Re-arrange the pointer arithmetic in rpcrdma_convert_iovs() to eliminate several integer multiplication instructions during Transport Header encoding. Also, array overflow does not occur outside development environments, so replace overflow checking with one spot check at the end. This reduces the number of conditional branches in the common case. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-08-15NFS: Wait for requests that are locked on the commit listTrond Myklebust
If a request is on the commit list, but is locked, we will currently skip it, which can lead to livelocking when the commit count doesn't reduce to zero. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFSv4/pnfs: Replace pnfs_put_lseg_locked() with pnfs_put_lseg()Trond Myklebust
Now that we no longer hold the inode->i_lock when manipulating the commit lists, it is safe to call pnfs_put_lseg() again. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFS: Switch to using mapping->private_lock for page writeback lookups.Trond Myklebust
Switch from using the inode->i_lock for this to avoid contention with other metadata manipulation. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFS: Use an atomic_long_t to count the number of commitsTrond Myklebust
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFS: Use an atomic_long_t to count the number of requestsTrond Myklebust
Rather than forcing us to take the inode->i_lock just in order to bump the number. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFSv4: Use a mutex to protect the per-inode commit listsTrond Myklebust
The commit lists can get very large, so using the inode->i_lock can end up affecting general metadata performance. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFS: Refactor nfs_page_find_head_request()Trond Myklebust
Split out the 2 cases so that we can treat the locking differently. The issue is that the locking in the pageswapcache cache is highly linked to the commit list locking. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFSv4: Convert nfs_lock_and_join_requests() to use nfs_page_find_head_request()Trond Myklebust
Hide the locking from nfs_lock_and_join_requests() so that we can separate out the requirements for swapcache pages. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFS: Fix up nfs_page_group_covers_page()Trond Myklebust
Fix up the test in nfs_page_group_covers_page(). The simplest implementation is to check that we have a set of intersecting or contiguous subrequests that connect page offset 0 to nfs_page_length(req->wb_page). Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFS: Remove unused parameter from nfs_page_group_lock()Trond Myklebust
nfs_page_group_lock() is now always called with the 'nonblock' parameter set to 'false'. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFS: Remove unuse function nfs_page_group_lock_wait()Trond Myklebust
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFS: Remove nfs_page_group_clear_bits()Trond Myklebust
At this point, we only expect ever to potentially see PG_REMOVE and PG_TEARDOWN being set on the subrequests. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFS: Fix nfs_page_group_destroy() and nfs_lock_and_join_requests() race casesTrond Myklebust
Since nfs_page_group_destroy() does not take any locks on the requests to be freed, we need to ensure that we don't inadvertently free the request in nfs_destroy_unlinked_subrequests() while the last reference is being released elsewhere. Do this by: 1) Taking a reference to the request unless it is already being freed 2) Checking (under the page group lock) if PG_TEARDOWN is already set before freeing an unreferenced request in nfs_destroy_unlinked_subrequests() Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFS: Further optimise nfs_lock_and_join_requests()Trond Myklebust
When locking the entire group in order to remove subrequests, the locks are always taken in order, and with the page group lock being taken after the page head is locked. The intention is that: 1) The lock on the group head guarantees that requests may not be removed from the group (although new entries could be appended if we're not holding the group lock). 2) It is safe to drop and retake the page group lock while iterating through the list, in particular when waiting for a subrequest lock. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFS: Reduce inode->i_lock contention in nfs_lock_and_join_requests()Trond Myklebust
We should no longer need the inode->i_lock, now that we've straightened out the request locking. The locking schema is now: 1) Lock page head request 2) Lock the page group 3) Lock the subrequests one by one Note that there is a subtle race with nfs_inode_remove_request() due to the fact that the latter does not lock the page head, when removing it from the struct page. Only the last subrequest is locked, hence we need to re-check that the PagePrivate(page) is still set after we've locked all the subrequests. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFS: Remove page group limit in nfs_flush_incompatible()Trond Myklebust
nfs_try_to_update_request() should be able to cope now. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFS: Teach nfs_try_to_update_request() to deal with request page_groupsTrond Myklebust
Simplify the code, and avoid some flushes to disk. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFS: Fix the inode request accounting when pages have subrequestsTrond Myklebust
Both nfs_destroy_unlinked_subrequests() and nfs_lock_and_join_requests() manipulate the inode flags adjusting the NFS_I(inode)->nrequests. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFS: Don't unlock writebacks before declaring PG_WB_ENDTrond Myklebust
We don't want nfs_lock_and_join_requests() to start fiddling with the request before the call to nfs_page_group_sync_on_bit(). Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFS: Don't check request offset and size without holding a lockTrond Myklebust
Request offsets and sizes are not guaranteed to be stable unless you are holding the request locked. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFS: Fix an ABBA issue in nfs_lock_and_join_requests()Trond Myklebust
All other callers of nfs_page_group_lock() appear to already hold the page lock on the head page, so doing it in the opposite order here is inefficient, although not deadlock prone since we roll back all locks on contention. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFS: Fix a reference and lock leak in nfs_lock_and_join_requests()Trond Myklebust
Yes, this is a situation that should never happen (hence the WARN_ON) but we should still ensure that we free up the locks and references to the faulty pages. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15NFS: Ensure we always dereference the page head lastTrond Myklebust
This fixes a race with nfs_page_group_sync_on_bit() whereby the call to wake_up_bit() in nfs_page_group_unlock() could occur after the page header had been freed. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>