glusterfs.git/xlators/features/qemu-block/src/qemu-block.c, branch v4.0dev1

qemu-block: deprecated/defunct, remove from tree

2016-03-07T11:34:59+00:00

qemu-block xlator is not used by anyone, or so I'm told.

It's also substantially out of date. There's little reason to keep
it in our sources. (And FedoraProject doesn't like bundled software
either.)

Change-Id: I4aeb2fdfd962ec6d93de6bae126874121272220a
Signed-off-by: Kaleb S KEITHLEY 
Reviewed-on: http://review.gluster.org/13473
Smoke: Gluster Build System 
CentOS-regression: Gluster Build System 
NetBSD-regression: NetBSD Build System 
Reviewed-by: Shyamsundar Ranganathan 
Reviewed-by: Jeff Darcy

features/qemu-block: Add comment about root_inode handling

2015-06-12T08:53:17+00:00

This is handling the comment on 3.7 backport
http://review.gluster.com/11047

Change-Id: I253a8e0bfebde63f25c839efd55ed3cc30e6cd9b
BUG: 1226276
Signed-off-by: Pranith Kumar K 
Reviewed-on: http://review.gluster.org/11076
Tested-by: NetBSD Build System 
Tested-by: Gluster Build System 
Reviewed-by: Poornima G

features/qemu-block: Don't unref root inode

2015-05-30T12:37:18+00:00

Root inode doesn't participate in ref/unref. Don't do it
in fini as by the time fini is called itable would be destroyed.

BUG: 1226276
Change-Id: I704d0a3c0813cb8f6c3f1f7d613c89aca8f4f9ad
Signed-off-by: Pranith Kumar K 
Reviewed-on: http://review.gluster.org/11002
Tested-by: Gluster Build System 
Reviewed-by: Niels de Vos

build: do not #include "config.h" in each file

2015-05-29T12:43:17+00:00

Instead of including config.h in each file, and have the additional
config.h included from the compiler commandline (-include option).

When a .c file tests for a certain #define, and config.h was not
included, incorrect assumtions were made. With this change, it can not
happen again.

BUG: 1222319
Change-Id: I4f9097b8740b81ecfe8b218d52ca50361f74cb64
Signed-off-by: Niels de Vos 
Reviewed-on: http://review.gluster.org/10808
Tested-by: Gluster Build System 
Tested-by: NetBSD Build System
Reviewed-by: Kaleb KEITHLEY 
Reviewed-by: Pranith Kumar Karampuri

Avoid conflict between contrib/uuid and system uuid

2015-04-04T17:48:35+00:00

glusterfs relies on Linux uuid implementation, which
API is incompatible with most other systems's uuid. As
a result, libglusterfs has to embed contrib/uuid,
which is the Linux implementation, on non Linux systems.
This implementation is incompatible with systtem's
built in, but the symbols have the same names.

Usually this is not a problem because when we link
with -lglusterfs, libc's symbols are trumped. However
there is a problem when a program not linked with
-lglusterfs will dlopen() glusterfs component. In
such a case, libc's uuid implementation is already
loaded in the calling program, and it will be used
instead of libglusterfs's implementation, causing
crashes.

A possible workaround is to use pre-load libglusterfs
in the calling program (using LD_PRELOAD on NetBSD for
instance), but such a mechanism is not portable, nor
is it flexible. A much better approach is to rename
libglusterfs's uuid_* functions to gf_uuid_* to avoid
any possible conflict. This is what this change attempts.

BUG: 1206587
Change-Id: I9ccd3e13afed1c7fc18508e92c7beb0f5d49f31a
Signed-off-by: Emmanuel Dreyfus 
Reviewed-on: http://review.gluster.org/10017
Tested-by: Gluster Build System 
Reviewed-by: Niels de Vos

qemu-block: Fixing coverity issue(Unused value)

2015-03-30T12:42:38+00:00

Coverity ID: 1124889 1124889 1124889 1124889 1124889 1124889 1124889
1124889 1124889 1124889 1124889

Change-Id: I82d57022c4a06fb70573b4e9436f934185f8fb84
BUG: 789278
Signed-off-by: Nandaja Varma 
Reviewed-on: http://review.gluster.org/9642
Tested-by: Gluster Build System 
Reviewed-by: Humble Devassy Chirammal 
Reviewed-by: Kaleb KEITHLEY

Do not assume sizeof(size_t)

2014-09-16T11:47:15+00:00

This fixes an assumption that sizeof(size_t) == sizeof(uint64_t), which
is not guaranteed. At least on NetBSD/i386, size_t is 32 bit long.

Caught by tests/basics/file-snapshot.t

BUG: 764655
Change-Id: Ib7620a2ffe8758521886af37bc280101a040d860
Signed-off-by: Emmanuel Dreyfus 
Reviewed-on: http://review.gluster.org/8441
Reviewed-by: Humble Devassy Chirammal 
Tested-by: Gluster Build System 
Reviewed-by: Dan Lambright

features/qemu-block: simplify coroutine model to use single synctask, ucontext

2013-11-11T07:45:46+00:00

The current coroutine model, mapping synctasks 1-1 with qemu internal
Coroutines, has some unresolved raciness issues. This problem usually
manifests as lifecycle mismatches between top-level (gluster created)
synctasks and the subsequently created internal coroutines from that
context. Qemu's internal queueing (and locking) can cause situations
where the top-level synctask is destroyed before the internal scheduler
has released references to memory, leading to use after free crashes
and asserts.

Simplify the coroutine model to use a single synctask as a coroutine
processor and rely on the existing native ucontext coroutine
implementation. The syncenv thread is donated to qemu and ensures a
single top-level coroutine is processed at a time. Qemu now has
complete control over coroutine scheduling.

BUG: 986775
Change-Id: I38223479a608d80353128e390f243933fc946fd6
Signed-off-by: Brian Foster 
Reviewed-on: http://review.gluster.org/6110
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

features/qemu-block: add qemu backing image support (clone)

2013-11-11T07:02:37+00:00

Add basic backing image support to the block-format mechanism. This
is a functionality checkpoint that enables the raw mechanism
required to support client driven "snapshot" and "clone" requests.

This change enhances the block-format setxattr command to support
an additional and optional backing image reference. For example:

setxattr -n trusted.glusterfs.block-format -v "qcow2:10GB:" ./newimage

... where  refers to the backing image for unallocated blocks
in newimage.  can be provided in one of two formats:

- a gfid string in the following format (assuming a valid gfid):



- or a filename that must be resident in the same directory as the
new clone file being formatted. E.g.,

setxattr -n trusted.glusterfs.block-format -v "qcow2:10GB:baseimg" ./newimage

This latter format is more restrictive, simply provided for
convenience or until something more refined is available.

This change makes no assumptions about the backing image file and
affords no additional protection. It is up to the user/client to
recognize the relationship between the files and manage them
appropriately (i.e., no writes to the backing image, etc.).

BUG: 986775
Change-Id: I7aff7bdc59b85a6459001a6bfeae4db6bf74f703
Signed-off-by: Brian Foster 
Reviewed-on: http://review.gluster.org/5967
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

features/qemu-block: invoke bdrv_init() only once

2013-10-10T01:57:18+00:00

bdrv_init() is intended to be invoked only once. If invoked again
after initialization (i.e., due to graph changes), the block driver
registration code can reinsert entries into bdrv_drivers,
effectively corrupting the NULL terminated linked list. This
manifests as an infinite loop for callers attempt to traverse the
list (to locate a driver).

BUG: 986775
Change-Id: I2f95bda3c753dece4648cdad009d0e2a2d16f644
Signed-off-by: Brian Foster 
Reviewed-on: http://review.gluster.org/6021
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati