glusterfs.git/api/src/glfs-resolve.c, branch v3.6.9

api: versioned symbols in libgfapi.so for compatibility

2015-03-04T07:32:16+00:00

Use versioned symbols to keep libgfapi at libgfapi.so.0.0.0

Revisited to address broken build on Mac OS X

See http://review.gluster.org/9055

Change-Id: I0f26668898749f57b61490b18f1f04c42996225d
BUG: 1165129
Signed-off-by: Kaleb S. KEITHLEY 
Reviewed-on: http://review.gluster.org/9145
Reviewed-by: Shyamsundar Ranganathan 
Tested-by: Gluster Build System 
Reviewed-by: Ravishankar N 
Reviewed-by: Raghavendra Bhat

gfapi: new inode created in glfs_resolve_component even if inode is in inode table

2015-01-08T09:40:33+00:00

        Backport of http://review.gluster.org/#/c/9253/

problem: USS allows split-brain file to be accessed while main volume
         gives I/O error.

cause:
        AFR detects split-brain on lookup. It stores this information in
        inode context. open and readv fop checks this flag from inode context.
        open and readv fop fails if split-brain flag is set for the file.

        USS uses gfapi to access snapshot volume. During open call
        gfapi internally calls glfs_resolve_component. glfs_resolve_component
        generates a new inode even if inode is present for the file.
        Because of which afr_lookup acts on a new inode which does not
        contain the split-brain flag.

Change-Id: I56233e1436036783eaf6012034842e52122e981e
Signed-off-by: Rajesh Joseph 
Signed-off-by: Raghavendra Talur 
Reviewed-on: http://review.gluster.org/9415
Tested-by: Gluster Build System 
Reviewed-by: Raghavendra Bhat

gfapi: Change lookup logic for "/.." and "/." .

2015-01-08T09:40:12+00:00

        Backport of http://review.gluster.org/#/c/8455

We should handle /.. and /. in unique way,
otherwise we may end up setting glusterfs xattrs
on parent of the brick dir.

Change-Id: Id317cd625436734f496852b8513f3e9dc1c4fa4e
BUG: 1179658
Signed-off-by: Raghavendra Talur 
Reviewed-on: http://review.gluster.org/9403
Tested-by: Gluster Build System 
Reviewed-by: soumya k 
Reviewed-by: Poornima G 
Reviewed-by: Raghavendra Bhat

api: versioned symbols in libgfapi.so for compatibility

2014-11-07T10:17:56+00:00

Use versioned symbols to keep libgfapi at libgfapi.so.0.0.0

Some nits uncovered:

+ there are a couple functions declared that do not have an
  associated definition, e.g. glfs_truncate(), glfs_caller_specific_init()

+ there are seven private/internal functions used by heal/src/glfsheal
  and the gfapi master xlator (glfs-master.c): glfs_loc_touchup(),
  glfs_active_subvol(), and glfs_subvol_done(), glfs_init_done(),
  glfs_resolve_at(), glfs_free_from_ctx(), and glfs_new_from_ctx();
  which are not declared in glfs.h;

+ for this initial pass at versioned symbols, we use the earliest version
  of all public symbols, i.e. those for which there are declarations in
  glfs.h or glfs-handles.h.
  Further investigation as we do backports to 3.6, 3.4, and 3.4
  will be required to determine if older implementations need to
  be preserved (forward ported) and their associated alias(es) and
  symbol version(s) defined.

FWIW, we should consider linking all of our libraries with a map, it'll
result in a cleaner ABI. Perhaps something for an intern to do or a
Google Summer of Code project.

Change-Id: Ie3323e62bb125a3b26214153278b4e998804de0e
BUG: 1160710
Signed-off-by: Kaleb S. KEITHLEY 
Reviewed-on: http://review.gluster.org/9055
Tested-by: Gluster Build System 
Reviewed-by: Niels de Vos 
Tested-by: Niels de Vos 
Reviewed-by: Vijay Bellur

libgfapi: Fixed an issue with healing files during glfs_resolve

2014-07-16T11:48:20+00:00

          While resolving any path during the first lookup, libgfapi
          should generate and send gfid as well along with the new inode
          created to the syncop_lookup(..) so that POSIX translator
          can heal the files with missing gfid using the new gfid passed.

          This wasn't happening correctly in the current "glfs_resolve_component(..)"
          implementation. Fixed the same.

          Also have added the changes from http://review.gluster.org/5337 in
          libgfapi, which is a fix to unlink the inode on revalidate if entry not found.

          In addition to the above, have cleaned up a redundant gfapi log mesage.

Change-Id: I0757dda782d16ba6bdbe7ebdbde9c43381229b0a
BUG: 1116854
Signed-off-by: Soumya Koduri 
Reviewed-on: http://review.gluster.org/7976
Tested-by: Gluster Build System 
Reviewed-by: Poornima G 
Reviewed-by: Raghavendra G 
Reviewed-by: Vijay Bellur

libgfapi: succeed lookup of "/.."

2014-07-10T04:14:54+00:00

For the root dir, ".." should resolve to itself.

i.e. when
        glfs_h_lookupat (fs, NULL, "/..", &stat)
(or)
        glfs_h_lookupat (fs, root, "..", &stat)

is performed, stat must contain root dir's information.

Change-Id: I1c92091cdc4ff00e6b17e5fa349009c6dfc441c1
BUG: 1114814
Signed-off-by: Ravishankar N 
Reviewed-on: http://review.gluster.org/8207
Tested-by: Gluster Build System 
Reviewed-by: Niels de Vos 
Reviewed-by: Poornima G 
Reviewed-by: Prashanth Pai 
Reviewed-by: Raghavendra Talur

libgfapi: In glfs_resolve_at(), do not override the previous return value.

2014-02-20T01:09:30+00:00

Overriding ret to contain glfs_loc_touchup()s' return value implies that
if glfs_loc_touchup() is successful, glfs_resolve_at() is also successful
which is not necessarily true. This was causing glfs_resolve_at() to
succeed even if it couldn't resolve, thus create and other fops would
fail. Hence overriding ret only if glfs_loc_touchup() fails.

Change-Id: I0804afbd120b3798abe07e870bfc40bf162bc289
BUG: 1066837
Signed-off-by: Poornima G 
Reviewed-on: http://review.gluster.org/7125
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

libgfapi: Don't ignore return value of glfs_loc_touchup()

2014-02-08T19:21:52+00:00

BUG: 789278
CID: 1124353

Change-Id: I7d2958cbc98faf45d723f17868c515762c50c618
Signed-off-by: Jose A. Rivera 
Reviewed-on: http://review.gluster.org/6931
Reviewed-by: Shyamsundar Ranganathan 
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

syncop: Change return value of syncop

2014-01-20T07:05:15+00:00

Problem:
We found a day-1 bug when syncop_xxx() infra is used inside a synctask with
compilation optimization (CFLAGS -O2).

Detailed explanation of the Root cause:
We found the bug in 'gf_defrag_migrate_data' in rebalance operation:

Lets look at interesting parts of the function:

int
gf_defrag_migrate_data (xlator_t *this, gf_defrag_info_t *defrag, loc_t *loc,
                        dict_t *migrate_data)
{
.....
code section - [ Loop ]
        while ((ret = syncop_readdirp (this, fd, 131072, offset, NULL,
                                       &entries)) != 0) {
.....
code section - [ ERRNO-1 ] (errno of readdirp is stored in readdir_operrno by a
thread)
                /* Need to keep track of ENOENT errno, that means, there is no
                   need to send more readdirp() */
                readdir_operrno = errno;
.....
code section - [ SYNCOP-1 ] (syncop_getxattr is called by a thread)
                        ret = syncop_getxattr (this, &entry_loc, &dict,
                                               GF_XATTR_LINKINFO_KEY);
code section - [ ERRNO-2]   (checking for failures of syncop_getxattr(). This
may not always be executed in same thread which executed [SYNCOP-1])
                        if (ret < 0) {
                                if (errno != ENODATA) {
                                        loglevel = GF_LOG_ERROR;
                                        defrag->total_failures += 1;
.....
}

the function above could be executed by thread(t1) till [SYNCOP-1] and code
from [ERRNO-2] can be executed by a different thread(t2) because of the way
syncop-infra schedules the tasks.

when the code is compiled with -O2 optimization this is the assembly code that
is generated:
 [ERRNO-1]
1165                        readdir_operrno = errno; <<---- errno gets expanded
as *(__errno_location())
   0x00007fd149d48b60 <+496>:        callq  0x7fd149d410c0 
   0x00007fd149d48b72 <+514>:        mov    %rax,0x50(%rsp) <<------ Address
returned by __errno_location() is stored in a special location in stack for
later use.
   0x00007fd149d48b77 <+519>:        mov    (%rax),%eax
   0x00007fd149d48b79 <+521>:        mov    %eax,0x78(%rsp)
....
 [ERRNO-2]
1281                                        if (errno != ENODATA) {
   0x00007fd149d492ae <+2366>:        mov    0x50(%rsp),%rax <<-----  Because
it already stored the address returned by __errno_location(), it just
dereferences the address to get the errno value. BUT THIS CODE NEED NOT BE
EXECUTED BY SAME THREAD!!!
   0x00007fd149d492b3 <+2371>:        mov    $0x9,%ebp
   0x00007fd149d492b8 <+2376>:        mov    (%rax),%edi
   0x00007fd149d492ba <+2378>:        cmp    $0x3d,%edi

The problem is that __errno_location() value of t1 and t2 are different. So
[ERRNO-2] ends up reading errno of t1 instead of errno of t2 even though t2 is
executing [ERRNO-2] code section.

When code is compiled without any optimization for [ERRNO-2]:
1281                                        if (errno != ENODATA) {
   0x00007fd58e7a326f <+2237>:        callq  0x7fd58e797300
<<--- As it is calling __errno_location() again it gets the
location from t2 so it works as intended.
   0x00007fd58e7a3274 <+2242>:        mov    (%rax),%eax
   0x00007fd58e7a3276 <+2244>:        cmp    $0x3d,%eax
   0x00007fd58e7a3279 <+2247>:        je     0x7fd58e7a32a1


Fix:
Make syncop_xxx() return (-errno) value as the return value in
case of errors and all the functions which make syncop_xxx() will need to use
(-ret) to figure out the reason for failure in case of syncop_xxx() failures.

Change-Id: I314d20dabe55d3e62ff66f3b4adb1cac2eaebb57
BUG: 1040356
Signed-off-by: Pranith Kumar K 
Reviewed-on: http://review.gluster.org/6475
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

gfapi: remove unnecessary call to glfs_resolve_base()

2013-11-08T07:55:59+00:00

Calling glfs_resolve_base() on the root inode for every resolver
invocation is unnecessary and wasteful.

Here are the results from running a test program which performs
path based operations (creates and deletes 1000 files):

Without patch:
[root@blackbox ~]# sync
[root@blackbox ~]# time ./a.out 1

real    0m4.314s
user    0m1.923s
sys     0m1.144s
[root@blackbox ~]# sync
[root@blackbox ~]# time ./a.out 1

real    0m4.383s
user    0m1.940s
sys     0m1.177s
[root@blackbox ~]# sync
[root@blackbox ~]# time ./a.out 1

real    0m4.339s
user    0m1.863s
sys     0m1.129s

With patch:

[root@blackbox ~]# sync
[root@blackbox ~]# time ./a.out 1

real    0m3.005s
user    0m1.162s
sys     0m0.816s
[root@blackbox ~]# sync
[root@blackbox ~]# time ./a.out 1

real    0m3.188s
user    0m1.222s
sys     0m0.867s
[root@blackbox ~]# sync
[root@blackbox ~]# time ./a.out 1

real    0m2.999s
user    0m1.131s
sys     0m0.832s

Change-Id: Id160a24f44b4dccfcfce99a6f69ddb8938523cd5
BUG: 953694
Signed-off-by: Anand Avati 
Reviewed-on: http://review.gluster.org/6131
Tested-by: Gluster Build System 
Reviewed-by: Raghavendra Talur 
Reviewed-by: Raghavendra Bhat 
Reviewed-by: Vijay Bellur