glusterfs-afrv1.git/xlators/cluster/dht/src/dht-linkfile.c, branch v3.3.0qa18

distribute rebalance: handle the open file migration

2011-09-13T06:57:38+00:00

Complexity involved: To migrate a file with open fd, we have to
notify the other client process which has the open fd, and make
sure the write()s happening on that fd is properly synced to the
migrated file. Once the migration is complete, the client
process which has open-fd should get notified and it should
start performing all the operations on the new subvolume,
instead of earlier cached volume.

How to solve the notification part:

We can overload the 'postbuf' attribute in the _cbk() function to
understand if a file is 'under-migration' or 'migration-complete'
state. (This will be something similar to deciding whether a file
is DHT-linkfile by its 'mode').

Overall change includes below mentioned major changes:

1. dht_linkfile is decided by only 2 factors (mode(01000),
   xattr(trusted.glusterfs.dht.linkto)), instead of earlier
   3 factors (size==0)

2. in linkfile self-heal part (in 'dht_lookup_everywhere_cbk()'),
   don't delete a linkfile if there is a open-fd on it. It means,
   there may be a migration in progress.

3. if a file's revalidate fails with ENOENT, it may be due to file
   migration, and hence need a lookup_everywhere()

4. There will be 2 phases of file-migration.

-> Phase 1: Migration in progress
   * The source data file will have SGID and STICKY bit set in its mode.
   * The source data file will have a 'linkto' xattr pointing the
     destination.
   * Destination file will have mode set to '01000', and 'linkto' xattr
     set to itself.

-> Phase 2: File migration Complete
   * The source data file will have mode '01000', and will be 'truncated'
     to size 0.
   * The destination file will have inherited mode from the source. (without
     sgid and sticky bit) and its 'linkto' attribute will be removed.

4. Changes in distribute to work smoothly with a file which is in migration /
   got migrated.

The 'fops' are divided into 3 categories, inode-read, inode-write and others.
inode-read fops need to handle only 'phase 2' notification, where as, the
inode-write fops need to handle both 'phase 1' and phase2. The inode-write
operations will be done on source file, and if any of 'file-migration' procedures
are detected in _cbk(), then the operations should be performed on the destination
too.

when a phase-2 is detected, then the inode-ctx itself should be changed to represent
a new layout.

With these changes, the open file migration will work smoothly with multiple clients.

Change-Id: I512408463814e650f34c62ed009bf2101d016fd6
BUG: 3071
Reviewed-on: http://review.gluster.com/209
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

Change Copyright current year

2011-08-10T17:57:19+00:00

Change-Id: I2d10f2be44f518f496427f257988f1858e888084
BUG: 3348
Reviewed-on: http://review.gluster.com/200
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

LICENSE: s/GNU Affero General Public/GNU General Public/

2011-08-06T13:33:52+00:00

Change-Id: I3914467611e573cccee0d22df93920cf1b2eb79f
BUG: 3348
Reviewed-on: http://review.gluster.com/182
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

DHT rename: Recreate linkfile after unlink

2011-08-04T04:57:27+00:00

This is done, so that there is no gfid mismatch. Unlink the older
linkfile if it exists, and recreate it with the correct gfid.

Also removed unused rename related code.

Change-Id: Ice0cdff51db786dafb1a019f7642c7d000e8c5f3
BUG: 2522
Reviewed-on: http://review.gluster.com/142
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

cluster/distribute: send proper 'params' dictionary during linkfile creation

2011-07-12T12:37:17+00:00

when the code path enters the 'subvol_filled()' case, local->params is set,
which contains the 'gfid-req' value, but the linkfile creation was not
checking for its existance.

Signed-off-by: Amar Tumballi 
Signed-off-by: Anand Avati 

BUG: 3159 (mknod (linkfile creation) with no 'gfid-req' key)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=3159

dht: set linkto xattr with linkfile create (mknod)

2011-07-08T09:25:49+00:00

Signed-off-by: Anand Avati 

BUG: 2815 (Server-enforced ACLs)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=2815

dht-rename: Unlink older link files before creating new one

2011-05-31T16:10:43+00:00

If a older link file exists, unlink it and then create the linkfile.
This will prevent mis-match of gfid's.

Signed-off-by: shishir gowda 
Signed-off-by: Anand Avati 

BUG: 2464 ([7b07d444a77526f27f860210930bf1d4c7fbea9b]: rm -rf gives Invalid argumenrt error)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=2464

loc_t: add 'gfid' and 'pargfid' fields

2011-05-03T17:17:04+00:00

these fields are used mainly in case of selfheal path, where
'inode->gfid'||'parent->gfid' is not yet set.

These fields in 'loc' will have lower precedence than 'inode->gfid'
in client protocol.

Signed-off-by: Amar Tumballi 
Signed-off-by: Anand Avati 

BUG: 2346 (Log message enhancements in GlusterFS - phase 1)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=2346

cluster/dht: log enhancements

2011-03-17T18:59:00+00:00

Signed-off-by: Shishir Gowda 
Signed-off-by: Amar Tumballi 
Signed-off-by: Vijay Bellur 

BUG: 2346 (Log message enhancements in GlusterFS - phase 1)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=2346

cluster/dht: whitespace cleanup

2011-03-17T18:58:55+00:00

also fill tabs by spaces (untabify), and indent the code

Signed-off-by: Amar Tumballi 
Signed-off-by: Vijay Bellur 

BUG: 2346 (Log message enhancements in GlusterFS - phase 1)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=2346