glusterfs.git/xlators/cluster/dht/src/dht-inode-write.c, branch v4.0.0alpha

cluster/dht : User xattrs are not healed after brick stop/start

2017-10-04T09:55:35+00:00

Problem: In a distributed volume custom extended attribute value for a directory
         does not display correct value after stop/start or added newly brick.
         If any extended(acl) attribute value is set for a directory after stop/added
         the brick the attribute(user|acl|quota) value is not updated on brick
         after start the brick.

Solution: First store hashed subvol or subvol(has internal xattr) on inode ctx and
          consider it as a MDS subvol.At the time of update custom xattr
          (user,quota,acl, selinux) on directory first check the mds from
          inode ctx, if mds is not present on inode ctx then throw EINVAL error
          to application otherwise set xattr on MDS subvol with internal xattr
          value of -1 and then try to update the attribute on other non MDS
          volumes also.If mds subvol is down in that case throw an
          error "Transport endpoint is not connected". In dht_dir_lookup_cbk|
          dht_revalidate_cbk|dht_discover_complete call dht_call_dir_xattr_heal
          to heal custom extended attribute.
          In case of gnfs server if hashed subvol has not found based on
          loc then wind a call on all subvol to update xattr.

Fix:    1) Save MDS subvol on inode ctx
        2) Check if mds subvol is present on inode ctx
        3) If mds subvol is down then call unwind with error ENOTCONN and if it is up
           then set new xattr "GF_DHT_XATTR_MDS" to -1 and wind a call on other
           subvol.
        4) If setxattr fop is successful on non-mds subvol then increment the value of
           internal xattr to +1
        5) At the time of directory_lookup check the value of new xattr GF_DHT_XATTR_MDS
        6) If value is not 0 in dht_lookup_dir_cbk(other cbk) functions then call heal
           function to heal user xattr
        7) syncop_setxattr on hashed_subvol to reset the value of xattr to 0
           if heal is successful on all subvol.

Test : To reproduce the issue followed below steps
       1) Create a distributed volume and create mount point
       2) Create some directory from mount point mkdir tmp{1..5}
       3) Kill any one brick from the volume
       4) Set extended attribute from mount point on directory
          setfattr -n user.foo -v "abc" ./tmp{1..5}
          It will throw error " Transport End point is not connected "
          for those hashed subvol is down
       5) Start volume with force option to start brick process
       6) Execute getfattr command on mount point for directory
       7) Check extended attribute on brick
          getfattr -n user.foo /tmp{1..5}
          It shows correct value for directories for those
          xattr fop were executed successfully.

Note: The patch will resolve xattr healing problem only for fuse mount
      not for nfs mount.

BUG: 1371806
Signed-off-by: Mohit Agrawal 

Change-Id: I4eb137eace24a8cb796712b742f1d177a65343d5

dht: add FOP check to dht_file_setattr_cbk

2017-09-07T02:17:04+00:00

Problem:
bug-797171.7 loaded error-gen xlator on the brick which sent EBADF for a
non fd-based fop, namely setattr. This caused
dht_check_and_open_fd_on_subvol_task() to crash as local->fd was NULL.

Fix:
Call dht_check_and_open_fd_on_subvol_task() from dht_file_setattr_cbk
only for dht_fsetattr and not dht_setattr or dht_setattr2

Signed-off-by: Ravishankar N 
Change-Id: Iab4999e213bf2065804f3f8237e470ad454e3c99
BUG: 1488399
Reviewed-on: https://review.gluster.org/18208
Smoke: Gluster Build System 
Reviewed-by: Susant Palai 
Reviewed-by: Amar Tumballi 
Reviewed-by: Raghavendra G 
Reviewed-by: N Balachandran 
CentOS-regression: Gluster Build System

cluster/dht: Check for open fd only on EBADF

2017-08-08T10:21:18+00:00

DHT fd based fops used to check if the fd was open
on the cached subvol before winding the call. However,
this introduced a performance regression of about
30% for reads.

This check was introduced to handle cases where files
were migrated while IOs were happening. As this is not
the common case, dht will now check if the fd is
open on the cached subvol only if the call fails
with EBADF.

This will prevent a performance hit where a rebalance
is not running.

Change-Id: I2035a858d63c3fcd22bb634055bbb0ad01686808
BUG: 1476665
Signed-off-by: N Balachandran 
Reviewed-on: https://review.gluster.org/17976
Smoke: Gluster Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Amar Tumballi 
Reviewed-by: Susant Palai 
Reviewed-by: Raghavendra G

Revert "cluster/dht: Check for open fd only on EBADF"

2017-08-04T08:56:21+00:00

This reverts commit 91c9f4a19fde4894576b398252c77f730832a26a.
This patch needs to be reworked.

Change-Id: I4c24f647c2b1abc68fc4e9fe6eb810418e2033aa
BUG: 1476665
Signed-off-by: N Balachandran 
Reviewed-on: https://review.gluster.org/17970
Smoke: Gluster Build System 
CentOS-regression: Gluster Build System

cluster/dht: Check for open fd only on EBADF

2017-07-31T14:00:21+00:00

DHT fd based fops will now check if the fd is
open on the cached subvol only if the call fails
with EBADF.

This will improve performance for scenarios where
a rebalance is not running which would be most of
the time.

Change-Id: Idfaeb8927af769c6110d07a165a0fe2307369239
BUG: 1476665
Signed-off-by: N Balachandran 
Reviewed-on: https://review.gluster.org/17922
Smoke: Gluster Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Raghavendra G

cluster/dht: Check if fd is opened on dst subvol

2017-06-28T11:42:21+00:00

If an fd is opened on a file, the file is migrated
and the cached subvol is updated in the inode_ctx
before an fd based fop is sent, the fop is sent to
the dst subvol on which the fd is not opened.
This causes the FOP to fail with EBADF.

Now, every fd based fop will check to see that the fd
has been opened on the dst subvol before winding it down.

Change-Id: Id92ef5eb7a5b5226688e2d2868b15e383f5f240e
BUG: 1465075
Signed-off-by: N Balachandran 
Reviewed-on: https://review.gluster.org/17630
Smoke: Gluster Build System 
Reviewed-by: Raghavendra G 
Reviewed-by: Susant Palai 
CentOS-regression: Gluster Build System

cluster/dht: Pass the req dict instead of NULL in dht_attr2()

2017-04-24T04:12:57+00:00

This bug was causing VMs to pause during rebalance. When qemu winds
down a STAT, shard fills the trusted.glusterfs.shard.file-size attribute
in the req dict which DHT doesn't wind its STAT fop with upon detecting
the file has undergone migration. As a result shard doesn't find the
value to this key in the unwind path, causing it to fail the STAT
with EINVAL.

Also, the same bug exists in other fops too, which is also fixed in
this patch.

Change-Id: Id7823fd932b4e5a9b8779ebb2b612a399c0ef5f0
BUG: 1440051
Signed-off-by: Krutika Dhananjay 
Reviewed-on: https://review.gluster.org/17085
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Raghavendra G

dht: At places needed use STACK_WIND_COOKIE

2017-01-09T18:37:02+00:00

Issue:
frame has a void * cookie pointer.
In case of STACK_WIND_COOKIE frame->cookie is assigned
to what is sent by the caller.
In case of STACK_WIND frame->cookie is assigned to point
point to the frame itself.

For ease of coding, at many places, the cookie in the cbk
is used to get the pointer to the next xl. This is
inconsistent when STACK_WIND_TAIL comes into picture.

Eg: dht_setxattr () {
    for (i = 0 ; i < conf->subvolume_cnt ; i++) {
       STACK_WIND (..dht_checking_pathinfo_cbk,
                   conf->subvolumes[i] ..);
    }

    dht_checking_pathinfo_cbk (...void *cookie...) {
        prev = cookie;
        ...
        for (i = 0; i < conf->subvolume_cnt; i++) {
            if (conf->subvolumes[i] == prev->this) {
                 ...
            }
        }
    }

    Consider the below graph:
    dht (parent)
    readdir-ahead  => Doesn't define setxattr and uses STACK_WIND_TAIL
    protocol-client

    With this graph, when dht_checking_pathinfo_cbk is called,
    cookie will have frame pointing to protocol-client.
    i.e. prev->this will be protocol-client. But dht was expecting
    it to be readdir-ahead as it has stored in conf->subvolumes[i]

Solution:
    Hence, as a thumb rule, if cbk is using cookie, then we explicitly
    call STACK_WIND_COOKIE.

Change-Id: I83aea1e24c809c5a91a0db7283e908e125471bd4
BUG: 1401812
Signed-off-by: Poornima G 
Reviewed-on: http://review.gluster.org/16039
Reviewed-by: Raghavendra G 
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System

cluster/dht : Ftruncate on migrating file fails with EINVAL

2015-12-22T19:13:00+00:00

What:
If dht_open is called on a migrating file after the inode_ctx is set,
subsequent FOPs on that fd do not open the fd on the dst subvol.
This is seen when the open-ftruncate-close sequence is repeatedly
called on a migrating file.
A second call to the sequence described above causes dht_truncate_cbk
to call dht_truncate2 as the dht_inode_ctx was already set by the first
call. As dht_rebalance_in_progress_check is not called, the fd is not
opened on the dst subvol.
On a distributed-replicate volume, this causes AFR to
open the fd using afr_fix_open, but with the wrong flags, causing
posix_ftruncate to fail with EINVAL.
The fix: We require fd specific information to make a decision while
handling migrating files.
Set the fd_ctx to indicate the fd has been opened on the dst subvol
and check if it has been set while processing Phase1/Phase2 checks
in the FOP callback functions.

Change-Id: I43cdcd8017b4a11e18afdd210469de7cd9a5ef14
BUG: 1284823
Signed-off-by: N Balachandran 
Reviewed-on: http://review.gluster.org/12985
Reviewed-by: Raghavendra G 
Tested-by: Gluster Build System 
Reviewed-by: Dan Lambright 
Tested-by: Dan Lambright

cluster/tier: Handle FOPs on files being migrated

2015-09-23T03:56:40+00:00

Determine which DHT level is responsible for
handling fops on a file undergoing migration based
on the name of the the linkto xattr set on the file
 being migrated and process accordingly.

Change-Id: I82772e39314d4fe7f2ba0dcf22de0c6a374ee139
BUG: 1254428
Signed-off-by: N Balachandran 
Signed-off-by: Nithya Balachandran 
Reviewed-on: http://review.gluster.org/12090
Tested-by: NetBSD Build System 
Tested-by: Gluster Build System 
Reviewed-by: Raghavendra G