This patch includes the following CID from Coverity Scan:

  * 1425196
  * 1425197
  * 1425198
  * 1425199
  * 1525200

Change-Id: Iddcfea449d3dd56d4dfcc39f4c3c608518e611e4
Signed-off-by: Xavi Hernandez <xhernandez@redhat.com>
Updates: #1060

The general idea of the changes is to prevent resetting event generation
to zero in the inode ctx, since event gen is something that should
follow 'causal order'.

Change #1:
For a read txn, in inode refresh cbk, if event_generation is
found zero, we are failing the read fop. This is not needed
because change in event gen is only a marker for the next inode refresh to
happen and should not be taken into account by the current read txn.

Change #2:
The event gen being zero above can happen if there is a racing lookup,
which resets even get (in afr_lookup_done) if there are non zero afr
xattrs. The resetting is done only to trigger an inode refresh and a
possible client side heal on the next lookup. That can be acheived by
setting the need_refresh flag in the inode ctx. So replaced all
occurences of resetting even gen to zero with a call to
afr_inode_need_refresh_set().

Change #3:
In both lookup and discover path, we are doing an inode refresh which is
not required since all 3 essentially do the same thing- update the inode
ctx with the good/bad copies from the brick replies. Inode refresh also
triggers background heals, but I think it is okay to do it when we call
refresh during the read and write txns and not in the lookup path.

The .ts which relied on inode refresh in lookup path to trigger heals are
now changed to do read txn so that inode refresh and the heal happens.

Change-Id: Iebf39a9be6ffd7ffd6e4046c96b0fa78ade6c5ec
Fixes: #1179
Signed-off-by: Ravishankar N <ravishankar@redhat.com>
Reported-by: Erik Jacobson <erik.jacobson at hpe.com>
(cherry picked from commit f0fcd909ad4535b60c9208d4804ebe6afe421a09)

mdc_inode_xatt_set() blindly cleared current cache when dict was not
NULL, even if there was no xattr requested.

This patch fixes this by only calling mdc_inode_xatt_set() when we have
explicitly requested something to cache.

Change-Id: Idc91a4693f1ff39f7059acde26682ccc361b947d
Fixes: #1140
Signed-off-by: Xavi Hernandez <xhernandez@redhat.com>

Problem:

FUSE uses failures of communicating with /dev/fuse with various
errnos to indicate in-kernel conditions to userspace. Some of these
shouldn't be handled as an application error. Also the standard
POSIX errno description should not be shown as they are misleading
in this context.

Solution:

When writing to the fuse device, the caller of the respective
convenience routine can mask those errnos which don't qualify to
be an error for the application in that context, so then those
shall be reported at DEBUG level.

The possible non-standard errnos are reported with their
POSIX name instead of their description to avoid confusion.
(Eg. for ENOENT we don't log "no such file or directory",
we log indeed literal "ENOENT".)

Change-Id: I510158843e4b1d482bdc496c2e97b1860dc1ba93
>updates: bz#1193929
updates: #1000
Signed-off-by: Csaba Henk <csaba@redhat.com>
(cherry picked from commit 1166df1920dd9b2bd5fce53ab49d27117db40238)

Problem: Sometime brick is going down to health check thread is
         failed without logging error codes return by aio system calls.
         As per aio_error man page it returns a positive error number
         if the asynchronous I/O operation failed.

Solution: log aio_error return codes in error message

> Change-Id: I2496b1bc16e602b0fd3ad53e211de11ec8c641ef
> (Cherry picked from commit 032862fa3944fc7152140aaa13cdc474ae594a51)
> (Reviwed on upstream link https://review.gluster.org/#/c/glusterfs/+/23284/
> Signed-off-by: Mohit Agrawal <moagrawal@redhat.com>

Change-Id: I2496b1bc16e602b0fd3ad53e211de11ec8c641ef
Fixes: #1168
Signed-off-by: Mohit Agrawal <moagrawal@redhat.com>

Problem:
tests/bugs/protocol/bug-1433815-auth-allow.t fails
sometimes because of stale mount. This stale mount
comes into picture when parent process dies without
waiting for the child process which mounts fuse fs
to die

Fix:
Wait for mounting child process to die before dying.

Fixes: #1152
Change-Id: I8baee8720e88614fdb762ea822d5877973eef8dc
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>

Problem:
frame is accessed after stack-wind. This can lead to crash
if the cbk frees the frame.

Fix:
Use new frame for the wind instead.

Fixes: #832
Change-Id: I64754609f1114b0bbd4d1336fa81a56f2cca6e03
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>

There was a bug in write-behind that allowed a previous completed write
to overwrite the overlapping region of data from a future write.

Suppose we want to send three writes (W1, W2 and W3). W1 and W2 are
sequential, and W3 writes at the same offset of W2:

    W2.offset = W3.offset = W1.offset + W1.size

Both W1 and W2 are sent in parallel. W3 is only sent after W2 completes.
So W3 should *always* overwrite the overlapping part of W2.

Suppose write-behind processes the requests from 2 concurrent threads:

    Thread 1                    Thread 2

    <received W1>
                                <received W2>
    wb_enqueue_tempted(W1)
    /* W1 is assigned gen X */
                                wb_enqueue_tempted(W2)
                                /* W2 is assigned gen X */

                                wb_process_queue()
                                  __wb_preprocess_winds()
                                    /* W1 and W2 are sequential and all
                                     * other requisites are met to merge
                                     * both requests. */
                                    __wb_collapse_small_writes(W1, W2)
                                    __wb_fulfill_request(W2)

                                  __wb_pick_unwinds() -> W2
                                  /* In this case, since the request is
                                   * already fulfilled, wb_inode->gen
                                   * is not updated. */

                                wb_do_unwinds()
                                  STACK_UNWIND(W2)

                                /* The application has received the
                                 * result of W2, so it can send W3. */
                                <received W3>

                                wb_enqueue_tempted(W3)
                                /* W3 is assigned gen X */

                                wb_process_queue()
                                  /* Here we have W1 (which contains
                                   * the conflicting W2) and W3 with
                                   * same gen, so they are interpreted
                                   * as concurrent writes that do not
                                   * conflict. */
                                  __wb_pick_winds() -> W3

                                wb_do_winds()
                                  STACK_WIND(W3)

    wb_process_queue()
      /* Eventually W1 will be
       * ready to be sent */
      __wb_pick_winds() -> W1
      __wb_pick_unwinds() -> W1
        /* Here wb_inode->gen is
         * incremented. */

    wb_do_unwinds()
      STACK_UNWIND(W1)

    wb_do_winds()
      STACK_WIND(W1)

So, as we can see, W3 is sent before W1, which shouldn't happen.

The problem is that wb_inode->gen is only incremented for requests that
have not been fulfilled but, after a merge, the request is marked as
fulfilled even though it has not been sent to the brick. This allows
that future requests are assigned to the same generation, which could
be internally reordered.

Solution:

Increment wb_inode->gen before any unwind, even if it's for a fulfilled
request.

Special thanks to Stefan Ring for writing a reproducer that has been
crucial to identify the issue.

Change-Id: Id4ab0f294a09aca9a863ecaeef8856474662ab45
Signed-off-by: Xavi Hernandez <xhernandez@redhat.com>
Fixes: #884

In case where uid is not set to be 0, there are possible errors
from acl xlator. So, set `uid = 0;` with pid indicating this is
set from UTIME activity.

The message "E [MSGID: 148002] [utime.c:146:gf_utime_set_mdata_setxattr_cbk] 0-dev_SNIP_data-utime: dict set of key for set-ctime-mdata failed [Permission denied]" repeated 2 times between [2019-12-19 21:27:55.042634] and [2019-12-19 21:27:55.047887]

Change-Id: Ieadf329835a40a13ac0bf908dac776e66954466c
Updates: #832
Signed-off-by: Amar Tumballi <amar@kadalu.io>
(cherry picked from commit eb916c057036db8289b41265797e5dce066d1512)

A crash is seen during a reattempt to clean up shards in background
upon remount. And this happens even on remount (which means a remount
is no workaround for the crash).

In such a situation, the in-memory base inode object will not be
existent (new process, non-existent base shard).
So local->resolver_base_inode will be NULL.

In the event of an error (in this case, of space running out), the
process would crash at the time of logging the error in the following line -

        gf_msg(this->name, GF_LOG_ERROR, local->op_errno, SHARD_MSG_FOP_FAILED,
               "failed to delete shards of %s",
               uuid_utoa(local->resolver_base_inode->gfid));

Fixed that by using local->base_gfid as the source of gfid when
local->resolver_base_inode is NULL.

Change-Id: I0b49f2b58becd0d8874b3d4b14ff8d92a89d02d5
Fixes: #1127
Signed-off-by: Krutika Dhananjay <kdhananj@redhat.com>
(cherry picked from commit cc43ac8651de9aa508b01cb259b43c02d89b2afc)