When we detach a subrequest from the list, we must also release the
reference it holds to the parent.

Fixes: 5b2b5187 ("NFS: Fix nfs_page_group_destroy() and nfs_lock_and_join_requests() race cases")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

If the FLUSH_SYNC flag is set, nfs_initiate_pgio() will currently
wait for completion, and then return the status of the I/O operation.
What we actually want to report in nfs_pageio_doio() is whether or
not the RPC call was launched successfully, whereas actual I/O
status is intended handled in the reply callbacks.

Since FLUSH_SYNC is never set by any of the callers anyway, let's
just remove that code altogether.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Move from requesting only full file layout segments, to requesting
layout segments that match our I/O size. This means the server is
still free to return a full file layout, but we will no longer
error out if it does not.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Remove the requirement that the server always sends whole file
layouts.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

When starting to read or write with a layout segment, check that the
range matches our request.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Check that the number of mirrors, and the mirror information matches
before deciding to merge layout segments in pNFS/flexfiles.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Fix up pnfs_layout_mark_request_commit() to alway reschedule the write
if the layout segment is invalid. Also minor cleanup.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Move the pNFS commit related operations into a separate structure
that can be carried by the pnfs_ds_commit_info.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Remove the unused bucket array in struct pnfs_ds_commit_info.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Lift filelayout_search_commit_reqs() into the generic pnfs/nfs code,
and add support for commit arrays.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Enable adding and lookup of per-layout segment commits in filelayout
and flexfilelayout.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Ensure that both the file and flexfiles layout types clean up when
freeing the layout segments.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Add support for scanning the full list of per-layout segment commit
arrays to nfs_clear_pnfs_ds_commit_verifiers().
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Instead of trying to save the commit verifiers and checking them against
previous writes, adopt the same strategy as for buffered writes, of
just checking the verifiers at commit time.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Fix the O_DIRECT code to avoid retries if the COMMIT fails with a fatal
error.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Add a pNFS callback to allow the O_DIRECT code to release the DS
commitinfo when freeing the dreq.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Add support for scanning the full list of per-layout segment commit
arrays to pnfs_generic_commit_pagelist().
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Add support for scanning the full list of per-layout segment commit
arrays to pnfs_generic_recover_commit_reqs().
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Add support for scanning the full list of per-layout segment commit
arrays to pnfs_generic_scan_commit_lists()
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

When we have multiple layout segments with different lists of mirrored
data, we need to track the commits on a per layout segment basis.
This patch adds a list to support this tracking in struct
pnfs_ds_commit_info.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Refactor pnfs_generic_commit_pagelist() to simplify the conversion
to layout segment based commit lists.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Just allocate the array at the end of the layout segment structure,
instead of allocating it as a separate array of pointers.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

UDP was originally disabled in 6da1a034 for NFSv4. Later in
b24ee6c6 UDP is by default disabled by NFS_DISABLE_UDP_SUPPORT=y for
all NFS versions. Therefore remove v4 from error message.

Fixes: b24ee6c6 ("NFS: allow deprecation of NFS UDP protocol")
Signed-off-by: NPetr Vorel <pvorel@suse.cz>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

UDP is disabled by default in commit b24ee6c6 ("NFS: allow
deprecation of NFS UDP protocol"), but the default mount options
is still udp, change it to tcp to avoid the "Unsupported transport
protocol udp" error if no protocol is specified when mount nfs.

Fixes: b24ee6c6 ("NFS: allow deprecation of NFS UDP protocol")
Signed-off-by: NLiwei Song <liwei.song@windriver.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

When dreq is allocated by nfs_direct_req_alloc(), dreq->kref is
initialized to 2. Therefore we need to call nfs_direct_req_release()
twice to release the allocated dreq. Usually it is called in
nfs_file_direct_{read, write}() and nfs_direct_complete().

However, current code only calls nfs_direct_req_relese() once if
nfs_get_lock_context() fails in nfs_file_direct_{read, write}().
So, that case would result in memory leak.

Fix this by adding the missing call.
Signed-off-by: NMisono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Fallout from the mount patches.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

This fixes xfstests generic/356 failure on NFSv4.2.
Signed-off-by: NMurphy Zhou <jencce.kernel@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

In function nfs_permission:
1. the rcu_read_lock and rcu_read_unlock around nfs_do_access
is unnecessary because the rcu critical data structure is already
protected in subsidiary function nfs_access_get_cached_rcu. No other
data structure needs rcu_read_lock in nfs_do_access.

2. call nfs_do_access once is enough, because:
2-1. when mask has MAY_NOT_BLOCK bit
The second call to nfs_do_access will not happen.

2-2. when mask has no MAY_NOT_BLOCK bit
The second call to nfs_do_access will happen if res == -ECHILD, which
means the first nfs_do_access goes out after statement if (!may_block).
The second call to nfs_do_access will go through this procedure once
again except continue the work after if (!may_block).
But above work can be performed by only one call to nfs_do_access
without mangling the mask flag.

Tested in x86_64
Signed-off-by: NZhouyi Zhou <zhouzhouyi@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

When we receive a CB_RECALL_ANY that asks us to return flexfiles
layouts, we iterate through all the layouts and look at whether or
not there are active open file descriptors that might need them
for I/O. If there are no such descriptors, we return the layouts.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Convert to use nfs_client_for_each_server() for efficiency.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Convert nfs_delegation_reap_unclaimed() to use nfs_client_for_each_server()
for efficiency.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Convert it to use the nfs_client_for_each_server() helper, and
make it more efficient by skipping delegations for inodes we
know are in the process of being freed. Also improve the efficiency
of the cursor by skipping delegations that are being freed.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Add a helper nfs_client_for_each_server() to iterate through all the
filesystems that are attached to a struct nfs_client, and apply
a function to all the active ones.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Now that we can rely on just the rcu_read_lock(), remove the
clp->cl_lock and clean up.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Make sure to test the stateid for validity so that we catch instances
where the server may have been reusing stateids in
nfs_layout_find_inode_by_stateid().

Fixes: 7b410d9c ("pNFS: Delay getting the layout header in CB_LAYOUTRECALL handlers")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Ensure that if the DS is returning too many DELAY and GRACE errors, we
also report that to the MDS through the layouterror mechanism.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>