glusterfs.git/xlators/protocol/server/src/server-resolve.c, branch v3.5.0

core: fix errno for non-existent GFID

2013-11-26T18:29:23+00:00

When clients refer to a GFID which does not exist, the errno to
be returned in ESTALE (and not ENOENT). Even though ENOENT might
look "proper" most of the time, as the application eventually expects
ENOENT even if a parent directory does not exist, not returning
ESTALE results in resolvers (FUSE and GFAPI) to not retry resolution
in uncached mode. This can result in spurious ENOENTs during
concurrent path modification operations.

Change-Id: I7a06ea6d6a191739f2e9c6e333a1969615e05936
BUG: 1032894
Signed-off-by: Anand Avati 
Reviewed-on: http://review.gluster.org/6318
Tested-by: Gluster Build System 
Reviewed-by: Amar Tumballi 
Reviewed-by: Brian Foster 
Reviewed-by: Vijay Bellur

client_t: phase 2, refactor server_ctx and locks_ctx out

2013-10-31T16:32:50+00:00

remove server_ctx and locks_ctx from client_ctx directly and store as
into discrete entities in the scratch_ctx

hooking up dump will be in phase 3

BUG: 849630
Change-Id: I94cea328326db236cdfdf306cb381e4d58f58d4c
Signed-off-by: Kaleb S. KEITHLEY 
Reviewed-on: http://review.gluster.org/5678
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

libglusterfs/client_t client_t implementation, phase 1

2013-07-30T05:22:21+00:00

Implementation of client_t

The feature page for client_t is at
http://www.gluster.org/community/documentation/index.php/Planning34/client_t

In addition to adding libglusterfs/client_t.[ch] it also extracts/moves
the locktable functionality from xlators/protocol/server to libglusterfs,
where it is used; thus it may now be shared by other xlators too.

This patch is large as it is. Hooking up the state dump is left to do
in phase 2 of this patch set.

(N.B. this change/patch-set supercedes previous change 3689, which was
corrupted during a rebase. That change will be abandoned.)

BUG: 849630
Change-Id: I1433743190630a6d8119a72b81439c0c4c990340
Signed-off-by: Kaleb S. KEITHLEY 
Reviewed-on: http://review.gluster.org/3957
Tested-by: Gluster Build System 
Reviewed-by: Amar Tumballi

license: xlators/protocol/server dual license GPLv2 and LGPLv3+

2013-04-12T17:06:05+00:00

BUG: 951549
Change-Id: I3de5bd86d4238a60a0a85ba2e15d9c131969b210
Signed-off-by: Kaleb S. KEITHLEY 
Reviewed-on: http://review.gluster.org/4816
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

protocol/client: Periodically attempt reopens

2013-02-03T19:33:31+00:00

If the brick is taken down and the hard disk is replaced
and the brick is brought back up, the re-opens of the open-fds
will fail because the file is not present on the brick.
Re-opens are not attempted even if the files are re-created by
self-heal until the brick is brought down after the files are
re-created and brought back up. This is a problem with a VM-store
in a replica-setup.  Until the fd is re-opened the writes will
never happen on the brick where the hard-disk is replaced.
To handle this situation gracefully, client xlator is enhanced
to perform finodelk, fxattrop, writev, readv using anonymous fds
if the file is yet to be re-opened. If the fop succeeds then client
xlator attempts re-open.

Change-Id: I1cc6d1bbf8227cd996868ab2ed0a57fb05e00017
BUG: 821056
Signed-off-by: Pranith Kumar K 
Reviewed-on: http://review.gluster.org/4358
Tested-by: Gluster Build System 
Reviewed-by: Jeff Darcy

protocol/server: do not wind opendir call if fd creation fails

2012-06-01T20:09:08+00:00

If resolve fails in some fd based operation, then do not use fd to get
gfid (fd might be NULL). Use the gfid present in resolve structure.

Change-Id: I1058274a2f9b4e58a76e4e6019e7c5ce1906d365
BUG: 827376
Signed-off-by: Raghavendra Bhat 
Reviewed-on: http://review.gluster.com/3504
Tested-by: Gluster Build System 
Reviewed-by: Brian Foster 
Reviewed-by: Jeff Darcy 
Reviewed-by: Anand Avati

Resolve: Assign correct path while resolving

2012-05-08T20:39:01+00:00

Change-Id: Ia17ff38a60225dd2e9115aaa298bed42f9e43f56
BUG: 812277
Signed-off-by: Pranith Kumar K 
Reviewed-on: http://review.gluster.com/3248
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

core: adding extra data for fops

2012-03-22T23:40:27+00:00

with this change, the xlator APIs will have a dictionary as extra
argument, which is passed between all the layers. This can be
utilized for overloading in some of the operations.

Change-Id: I58a8186b3ef647650280e63f3e5e9b9de7827b40
Signed-off-by: Amar Tumballi 
BUG: 782265
Reviewed-on: http://review.gluster.com/2960
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

core: GFID filehandle based backend and anonymous FDs

2012-01-20T13:03:42+00:00

1. What
--------
This change introduces an infrastructure change in the filesystem
which lets filesystem operation address objects (inodes) just by its
GFID. Thus far GFID has been a unique identifier of a user-visible
inode. But in terms of addressability the only mechanism thus far has
been the backend filesystem path, which could be derived from the
GFID only if it was cached in the inode table along with the entire set
of dentry ancestry leading up to the root.

This change essentially decouples addressability from the namespace. It
is no more necessary to be aware of the parent directory to address a
file or directory.

2. Why
-------
The biggest use case for such a feature is NFS for generating
persistent filehandles. So far the technique for generating filehandles
in NFS has been to encode path components so that the appropriate
inode_t can be repopulated into the inode table by means of a recursive
lookup of each component top-down.

Another use case is the ability to perform more intelligent self-healing
and rebalancing of inodes with hardlinks and also to detect renames.

A derived feature from GFID filehandles is anonymous FDs. An anonymous FD
is an internal USABLE "fd_t" which does not map to a user opened file
descriptor or to an internal ->open()'d fd. The ability to address a file
by the GFID eliminates the need to have a persistent ->open()'d fd for the
purpose of avoiding the namespace. This improves NFS read/write performance
significantly eliminating open/close calls and also fixes some of today's
limitations (like keeping an FD open longer than necessary resulting
in disk space leakage)

3. How
-------

At each storage/posix translator level, every file is hardlinked inside
a hidden .glusterfs directory (under the top level export) with the name
as the ascii-encoded standard UUID format string. For reasons of performance
and scalability there is a two-tier classification of those hardlinks
under directories with the initial parts of the UUID string as the directory
names.

For directories (which cannot be hardlinked), the approach is to use a symlink
which dereferences the parent GFID path along with basename of the directory.
The parent GFID dereference will in turn be a dereference of the grandparent
with the parent's basename, and so on recursively up to the root export.

4. Development
---------------

4a. To leverage the ability to address an inode by its GFID, the technique is
to perform a "nameless lookup". This means, to populate a loc_t structure as:

loc_t {
   pargfid: NULL
   parent: NULL
   name: NULL
   path: NULL
   gfid: GFID to be looked up [out parameter]
   inode: inode_new () result [in parameter]
}

and performing such lookup will return in its callback an inode_t
populated with the right contexts and a struct iatt which can be
used to perform an inode_link () on the inode (without a parent and
basename). The inode will now be hashed and linked in the inode table
and findable via inode_find().

A fundamental change moving forward is that the primary fields in a
loc_t structure are now going to be (pargfid, name) and (gfid) depending
on the kind of FOP. So far path had been the primary field for operations.
The remaining fields only serve as hints/helpers.

4b. If read/write is to be performed on an inode_t, the approach so far
has been to: fd_create(), STACK_WIND(open, fd), fd_bind (in callback) and
then perform STACK_WIND(read, fd) etc. With anonymous fds now you can do
fd_anonymous (inode), STACK_WIND (read, fd). This results in great boost
in performance in the inbuilt NFS server.

5. Misc
-------
The inode_ctx_put[2] has been renamed to inode_ctx_set[2] to be consistent
with the rest of the codebase.

Change-Id: Ie4629edf6bd32a595f4d7f01e90c0a01f16fb12f
BUG: 781318
Reviewed-on: http://review.gluster.com/669
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

core: remove 'ino' variable from 'inode_t' structure

2011-11-16T11:44:32+00:00

Change-Id: I0f078d1753db65d2f2e0380d1b0450c114cf40dd
BUG: 3518
Reviewed-on: http://review.gluster.com/522
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur