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path: root/drivers/block/xen-blkback
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2011-08-23Merge branch 'stable/for-jens' of ↵Jens Axboe
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-linus
2011-08-22xen-blkback: fixed indentation and commentsJoe Jin
This patch fixes belows: 1. Fix code style issue. 2. Fix incorrect functions name in comments. Signed-off-by: Joe Jin <joe.jin@oracle.com> Cc: Jens Axboe <jaxboe@fusionio.com> Cc: Ian Campbell <Ian.Campbell@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-08-22xen-blkback: Don't disconnect backend until state switched to XenbusStateClosed.Joe Jin
When do block-attach/block-detach test with below steps, umount hangs in the guest. Furthermore shutdown ends up being stuck when umounting file-systems. 1. start guest. 2. attach new block device by xm block-attach in Dom0. 3. mount new disk in guest. 4. execute xm block-detach to detach the block device in dom0 until timeout 5. Any request to the disk will hung. Root cause: This issue is caused when setting backend device's state to 'XenbusStateClosing', which sends to the frontend the XenbusStateClosing notification. When frontend receives the notification it tries to release the disk in blkfront_closing(), but at that moment the disk is still in use by guest, so frontend refuses to close. Specifically it sets the disk state to XenbusStateClosing and sends the notification to backend - when backend receives the event, it disconnects the vbd from real device, and sets the vbd device state to XenbusStateClosing. The backend disconnects the real device/file, and any IO requests to the disk in guest will end up in ether, leaving disk DEAD and set to XenbusStateClosing. When the guest wants to disconnect the disk, umount will hang on blkif_release()->xlvbd_release_gendisk() as it is unable to send any IO to the disk, which prevents clean system shutdown. Solution: Don't disconnect backend until frontend state switched to XenbusStateClosed. Signed-off-by: Joe Jin <joe.jin@oracle.com> Cc: Daniel Stodden <daniel.stodden@citrix.com> Cc: Jens Axboe <jaxboe@fusionio.com> Cc: Annie Li <annie.li@oracle.com> Cc: Ian Campbell <Ian.Campbell@eu.citrix.com> [v1: Modified description a bit] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-07-25Merge branch 'for-3.1/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds
* 'for-3.1/drivers' of git://git.kernel.dk/linux-block: cciss: do not attempt to read from a write-only register xen/blkback: Add module alias for autoloading xen/blkback: Don't let in-flight requests defer pending ones. bsg: fix address space warning from sparse bsg: remove unnecessary conditional expressions bsg: fix bsg_poll() to return POLLOUT properly
2011-06-30xen/blkback: Add module alias for autoloadingBastian Blank
Add xen-backend:vbd module alias to the xen-blkback module. This allows automatic loading of the module. Signed-off-by: Bastian Blank <waldi@debian.org> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-06-30xen/blkback: Don't let in-flight requests defer pending ones.Daniel Stodden
Running RING_FINAL_CHECK_FOR_REQUESTS from make_response is a bad idea. It means that in-flight I/O is essentially blocking continued batches. This essentially kills throughput on frontends which unplug (or even just notify) early and rightfully assume addtional requests will be picked up on time, not synchronously. Signed-off-by: Daniel Stodden <daniel.stodden@citrix.com> [v1: Rebased and fixed compile problems] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-06-30xen: Add __attribute__((format(printf... where appropriateJoe Perches
Use the compiler to verify printf formats and arguments. Fix fallout. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-06-01xen/blkback: potential null dereference in error handlingDan Carpenter
blkbk->pending_pages can be NULL here so I added a check for it. Signed-off-by: Dan Carpenter <error27@gmail.com> [v1: Redid the loop a bit] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-06-01xen/blkback: don't call vbd_size() if bd_disk is NULLLaszlo Ersek
...because vbd_size() dereferences bd_disk if bd_part is NULL. Signed-off-by: Laszlo Ersek<lersek@redhat.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-18xen/blkback: don't fail empty barrier requestsJan Beulich
The sector number on empty barrier requests may (will?) be -1, which, given that it's being treated as unsigned 64-bit quantity, will almost always exceed the actual (virtual) disk's size. Inspired by Konrad's "When writting barriers set the sector number to zero...". While at it also add overflow checking to the math in vbd_translate(). Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-13xen/blkback: fix xenbus_transaction_start() hang caused by double ↵Laszlo Ersek
xenbus_transaction_end() vbd_resize() up_read()'s xs_state.suspend_mutex twice in a row via double xenbus_transaction_end() calls. The next down_read() in xenbus_transaction_start() (at eg. the next resize attempt) hangs. Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=618317 Acked-by: Jan Beulich <jbeulich@novell.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12xen/blkback: Align the tabs on the structure.Konrad Rzeszutek Wilk
The recent changes caused this field of the structure to be offset a bit. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12xen/blkback: if log_stats is enabled print out the data.Konrad Rzeszutek Wilk
And not depend on the driver being built with -DDEBUG flag. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12xen/blkback: Add the prefix XEN in the common.h.Konrad Rzeszutek Wilk
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12xen/blkback: Prefix 'vbd' with 'xen' in structs and functions.Konrad Rzeszutek Wilk
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12xen/blkback: Change structure name blkif_st to xen_blkif.Konrad Rzeszutek Wilk
No need for that '_st' and xen_blkif is more apt. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12xen/blkback: Remove the unused typedefs.Konrad Rzeszutek Wilk
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12xen/blkback: Move include/xen/blkif.h into drivers/block/xen-blkback/common.hKonrad Rzeszutek Wilk
Not point of the blkif.h file. It is not used by the frontend. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12xen/blkback: Fixing some more of the cleanpatch.pl warnings.Konrad Rzeszutek Wilk
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12xen/blkback: Checkpatch.pl recommend against multiple assigments.Konrad Rzeszutek Wilk
CHECK: multiple assignments should be avoided Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12xen/blkback: Fix spelling mistakes.Konrad Rzeszutek Wilk
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12xen/blkback: Move blkif_get_x86_[32|64]_req to common.h in block/xen-blkback ↵Konrad Rzeszutek Wilk
dir. From the blkif.h header, which was exposed to the frontend. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12xen/blkback: Removing the debug_lvl option.Konrad Rzeszutek Wilk
It is not really used for anything. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12xen/blkback: Use the DRV_PFX in the pr_.. macros.Konrad Rzeszutek Wilk
To make it easier to read. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12xen/blkback: Make the DPRINTK uniform.Konrad Rzeszutek Wilk
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12xen/blkback: Change printk/DPRINTK to pr_.. type variant.Konrad Rzeszutek Wilk
And also make them uniform and prefix the message with 'xen-blkback'. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-11xen/blkback: Fixed up comments and converted spaces to tabs.Konrad Rzeszutek Wilk
Suggested-by: Ian Campbell <Ian.Campbell@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-05xen/blkback: Fix up some of the comments.Konrad Rzeszutek Wilk
They had the wrong data or were in the wrong spot. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-05xen/blkback: Squash the checking for operation into dispatch_rw_block_ioKonrad Rzeszutek Wilk
We do a check for the operations right before calling dispatch_rw_block_io. And then we do the same check in dispatch_rw_block_io. This patch squashes those checks into the 'dispatch_rw_block_io' function. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-05xen/blkback: Add support for BLKIF_OP_FLUSH_DISKCACHE and drop ↵Konrad Rzeszutek Wilk
BLKIF_OP_WRITE_BARRIER. We drop the support for 'feature-barrier' and add in the support for the 'feature-flush-cache' if the real backend storage supports flushing. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-04-27Revert "xen/blkback: Move the plugging/unplugging to a higher level."Konrad Rzeszutek Wilk
This reverts commit 97961ef46b9b5a6a7c918a38b898a7b3e49869f4 b/c we lose about 15% performance if we do the unplugging and the end of the reading the ring buffer.
2011-04-26xen/blkback: Stick REQ_SYNC on WRITEs to deal with CFQ I/O scheduler.Konrad Rzeszutek Wilk
If one runs a simple fio request with random read/write with a 20%/80% ratio, the numbers are incredibly bad when using the CFQ scheduler. IOmeter | | | | 64K, randrw | NOOP | CFQ | deadline | randrwmix=80 | | | | --------------+-------+------+----------+ blkback |103/27 |32/10 | 102/27 | --------------+-------+------+----------+ QEMU qdisk |103/27 |102/27| 102/27 | The problem as explained by Vivek Goyal was: ".. that difference is that sync vs async requests. In the case of a kernel thread submitting IO, [..] all the WRITES might be being considered as async and will go in a different queue. If you mix those with some READS, they are always sync and will go in differnet queue. In presence of sync queue, CFQ will idle and choke up WRITES in an attempt to improve latencies of READs. In case of AIO [note: this is what QEMU qdisk is doing] , [..] it is direct IO and both READS and WRITES will be considered SYNC and will go in a single queue and no choking of WRITES will take place." The solution is quite simple, tack on REQ_SYNC (which is what the WRITE_ODIRECT macro points to) and the numbers go back up. Suggested-by: Vivek Goyal <vgoyal@redhat.com Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-04-26xen/blkback: Move the plugging/unplugging to a higher level.Konrad Rzeszutek Wilk
We used to the plug/unplug on the submit_bio. But that means if within a stream of WRITE, WRITE, WRITE,...,WRITE we have one READ, it could stall the pipeline (as the 'submio_bio' could trigger the unplug_fnc to be called and stall/sync when doing the READ). Instead we want to move the unplugging when the whole (or as a much as possible) ring buffer has been processed. This also eliminates us doing plug/unplug for each request. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-04-20xen/blkback: Prefix exposed functions with xen_Konrad Rzeszutek Wilk
And also shorten the name if it has blkback to blkbk. This results in the symbol table (if compiled in the kernel) to be much shorter, prettier, and also easier to search for. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-04-20xen-blkback: Inline some of the functions that were moved from vbd/interface.cKonrad Rzeszutek Wilk
Shuffling code around. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-04-20xen-blkback: Remove from the copyright notice the address.Konrad Rzeszutek Wilk
There is no need for it, as the address is updated constatly in the root of the Linux kernel. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-04-20xen/blkback: Squash vbd.c,interface.c in blkback.c and xenbus.c respectivly.Konrad Rzeszutek Wilk
Daniel Stodden suggested to eliminate vbd.c and interface.c, inlining the critical bits where they belong, respectively. Leaving only blkback.c for the data- and xenbus.c for the control path. Suggested-by: Daniel Stodden <daniel.stodden@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-04-18xen/blkback: Move it from drivers/xen to drivers/blockKonrad Rzeszutek Wilk
.. and modify the Makefile and Kconfig files appropriately. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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