glusterfs.git/xlators/cluster/ec/src/ec-locks.c, branch v3.7.0beta2

ec: Fix failures with missing files

2015-05-10T00:30:19+00:00

      Backport of http://review.gluster.com/9407

When a file does not exist on a brick but it does on others, there
could be problems trying to access it because there was some loc_t
structures with null 'pargfid' but 'name' was set. This forced
inode resolution based on /name instead of  which
would be the correct one. To solve this problem, 'name' is always
set to NULL when 'pargfid' is not present.

Another problem was caused by an incorrect management of errors
while doing incremental locking. The only allowed error during an
incremental locking was ENOTCONN, but missing files on a brick can
be returned as ESTALE. This caused an EIO on the operation.

This patch doesn't care of errors during an incremental locking. At
the end of the operation it will check if there are enough successfully
locked bricks to continue or not.

BUG: 1220011
Change-Id: I4a1e6235d80e20ef7ef12daba0807b859ee5c435
Signed-off-by: Xavier Hernandez 
Reviewed-on: http://review.gluster.org/10701
Reviewed-by: Pranith Kumar Karampuri 
Tested-by: Gluster Build System

ec: Fix return errors when not enough bricks

2014-12-05T11:39:07+00:00

Changes introduced by this patch:

* Fix an incorrect error propagation when the state of the life
  cycle of a fop returns an error.

* Fix incorrect unlocking of failed locks.

* Return ENOTCONN if there aren't enough bricks online.

* In readdir(p) check that the fd has been successfully open by
  a previous opendir.

Change-Id: Ib44f25a1297849ebcbab839332f3b6359f275ebe
BUG: 1162805
Signed-off-by: Xavier Hernandez 
Reviewed-on: http://review.gluster.org/9098
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

ec: Change license

2014-12-03T18:45:26+00:00

Change-Id: Iae90ade2421898417b53dec0417a610cf306c44b
BUG: 1168167
Signed-off-by: Xavier Hernandez 
Reviewed-on: http://review.gluster.org/9201
Reviewed-by: Kaleb KEITHLEY 
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

ec: Fix self-heal issues

2014-10-21T18:38:45+00:00

Problem: Doing an 'ls' of a directory that has been modified while one
         of the bricks was down, sometimes returns the old directory
         contents.

Cause: Directories are not marked when they are modified as files are.
       The ec xlator balances requests amongst available and healthy
       bricks. Since there is no way to detect that a directory is
       out of date in one of the bricks, it is used from time to time
       to return the directory contents.

Solution: Basically the solution consists in use versioning information
          also for directories, however some additional changes have
          been necessary.

Changes:

 * Use directory versioning:

     This required to lock full directory instead of a single entry for
     all requests that add or remove entries from it. This is needed to
     allow atomic version update. This affects the following fops:

         create, mkdir, mknod, link, symlink, rename, unlink, rmdir

     Another side effect is that opendir requires to do a previous
     lookup to get versioning information and discard out of date
     bricks for subsequent readdir(p) calls.

 * Restrict directory self-heal:

     Till now, when one discrepancy was found in lookup, a self-heal
     was automatically started. This caused the versioning information
     of a bad directory to be healed instantly, making the original
     problem to reapear again.

     To solve this, when a missing directory is detected in one or more
     bricks on lookup or opendir fops, only a partial self-heal is
     performed on it. A partial self-heal basically creates the
     directory but does not restore any additional information.

     This avoids that an 'ls' could repair the directory and cause the
     problem to happen again. With this change, output of 'ls' is
     always consistent. However, since the directory has been created
     in the brick, this allows any other operation on it (create new
     files, for example) to succeed on all bricks and not add additional
     work to the self-heal process.

     To force a self-heal of a directory, any other operation must be
     done on it. For example a getxattr.

     With these changes, the correct healing procedure that would avoid
     inconsistent directory browsing consists on a post-order traversal
     of directoriesi being healed. This way, the directory contents will
     be healed before healing the directory itslef.

 * Additional changes to fix self-heal errors

     - Don't use fop->fd to decide between fd/loc.

         open, opendir and create have an fd, but the correct data is in
         loc.

     - Fix incorrect management of bad bricks per inode/fd.

     - Fix incorrect selection of fop's target bricks when there are bad
       bricks involved.

     - Improved ec_loc_parent() to always return a parent loc as
       complete as possible.

Change-Id: Iaf3df174d7857da57d4a87b4a8740a7048b366ad
BUG: 1149726
Signed-off-by: Xavier Hernandez 
Reviewed-on: http://review.gluster.org/8916
Reviewed-by: Dan Lambright 
Tested-by: Gluster Build System

ec: Fix invalid inode lock in ftruncate

2014-09-19T10:05:25+00:00

The fops 'truncate' and 'ftruncate' share some code and inodelk()
was always made against the inode inside the loc_t structure
instead of that of fd_t. Since ftruncate has the loc initialized
to NULL, this fop was executed without any lock, allowing some
concurrent modifications in the file size.

Also changed the way in which 'fop' and 'ffop' are differentiated
in shared code. Now it uses 'id' field instead of checking if 'fd'
is NULL.

Change-Id: Ibd18accf2652193b395a841b9029729e5f4867c6
BUG: 1140396
Signed-off-by: Xavier Hernandez 
Reviewed-on: http://review.gluster.org/8695
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

ec: Fixed coveriry scan issues

2014-07-22T01:39:46+00:00

CID list:

  1226163 Logically dead code
  1226166 Missing break in switch
  1226167 Missing break in switch
  1226168 Missing break in switch
  1226169 Missing break in switch
  1226170 Missing break in switch
  1226171 Missing break in switch
  1226172 Missing break in switch
  1226173 Missing break in switch
  1226174 Missing break in switch
  1226175 Missing break in switch
  1226176 Missing break in switch
  1226177 Missing break in switch
  1226178 Data race condition
  1226179 Data race condition
  1226180 Data race condition
  1226181 Thread deadlock
  1226182 Uninitialized pointer read
  1226183 Uninitialized pointer read
  1226184 Read from pointer after free

Change-Id: I4d33aa42289371927175c43bb29e018df64fb943
BUG: 789278
Signed-off-by: Xavier Hernandez 
Reviewed-on: http://review.gluster.org/8317
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

cluster/ec: Added erasure code translator

2014-07-11T17:33:40+00:00

Change-Id: I293917501d5c2ca4cdc6303df30cf0b568cea361
BUG: 1118629
Signed-off-by: Xavier Hernandez 
Reviewed-on: http://review.gluster.org/7749
Reviewed-by: Krishnan Parthasarathi 
Reviewed-by: Jeff Darcy 
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur