kernel.git/drivers/scsi/sd.c, branch linux-2.6.36.y

fix medium error problems with some arrays which can cause data corruption

2011-02-17T22:46:54Z

commit a8733c7baf457b071528e385a0b7d4aaec79287c upstream. Our current handling of medium error assumes that data is returned up to the bad sector. This assumption holds good for all disk devices, all DIF arrays and most ordinary arrays. However, an LSI array engine was recently discovered which reports a medium error without returning any data. This means that when we report good data up to the medium error, we've reported junk originally in the buffer as good. Worse, if the read consists of requested data plus a readahead, and the error occurs in readahead, we'll just strip off the readahead and report junk up to userspace as good data with no error. The fix for this is to have the error position computation take into account the amount of data returned by the driver using the scsi residual data. Unfortunately, not every driver fills in this data, but for those who don't, it's set to zero, which means we'll think a full set of data was transferred and the behaviour will be identical to the prior behaviour of the code (believe the buffer up to the error sector). All modern drivers seem to set the residual, so that should fix up the LSI failure/corruption case. Reported-by: Douglas Gilbert Signed-off-by: James Bottomley Signed-off-by: Greg Kroah-Hartman

sd name space exhaustion causes system hang

2010-11-22T19:03:15Z

commit 1a03ae0f556a931aa3747b70e44b78308f5b0590 upstream. Following a site power outage which re-enabled all the ports on my FC switches, my system subsequently booted with far too many luns! I had let it run hoping it would make multi-user. It didn't. :( It hung solid after exhausting the last sd device, sdzzz, and attempting to create sdaaaa and beyond. I was unable to get a dump. Discovered using a 2.6.32.13 based system. correct this by detecting when the last index is utilized and failing the sd probe of the device. Patch applies to scsi-misc-2.6. Signed-off-by: Michael Reed Signed-off-by: James Bottomley Signed-off-by: Greg Kroah-Hartman

[SCSI] sd: fix medium-removal bug

2010-09-07T15:31:54Z

Commit 409f3499a2cfcd1e9c2857c53af7fcce069f027f (scsi/sd: remove big kernel lock) introduced a bug in the sd_release routine. Medium removal should be allowed when the number of open file references drops to 0, not when it becomes non-zero. This patch (as1414) adjusts the test to fix the bug. Signed-off-by: Alan Stern Signed-off-by: James Bottomley

[SCSI] sd, sym53c8xx: Remove warnings after vsprintf %pV introducation.

2010-09-02T20:23:20Z

GCC warns about empty printf format strings, and after the addition of %pV these existing such cases in the scsi driver layer were exposed enough for the compiler to start seeing them. Based almost entirely upon a patch by Joe Perches. [jejb: fix up sym53c8xx msg] Signed-off-by: David S. Miller Signed-off-by: James Bottomley

scsi/sd.c: quiet all sparse noise

2010-08-11T15:59:01Z

In sd_store_cache_type the symbol 'len' is declared twice. Remove the second declaration to quiet the following sparse warning. warning: symbol 'len' shadows an earlier one In sd_probe the variable 'index' is declared as a u32. This variable is used in a call to ida_get_new which is expecting an int *. Make the variable an int to quiet the following sparse warning. warning: incorrect type in argument 2 (different signedness) There are 4 symbols in the file that are not exported and produce the following sparse warnings. warning: symbol 'sd_cdb_cache' was not declared. Should it be static? warning: symbol 'sd_cdb_pool' was not declared. Should it be static? warning: symbol 'sd_read_protection_type' was not declared. Should it be static? warning: symbol 'sd_read_app_tag_own' was not declared. Should it be static? Make them static to quiet the warnings. Signed-off-by: H Hartley Sweeten Cc: James E.J. Bottomley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block

2010-08-10T22:22:42Z

* 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block: (149 commits) block: make sure that REQ_* types are seen even with CONFIG_BLOCK=n xen-blkfront: fix missing out label blkdev: fix blkdev_issue_zeroout return value block: update request stacking methods to support discards block: fix missing export of blk_types.h writeback: fix bad _bh spinlock nesting drbd: revert "delay probes", feature is being re-implemented differently drbd: Initialize all members of sync_conf to their defaults [Bugz 315] drbd: Disable delay probes for the upcomming release writeback: cleanup bdi_register writeback: add new tracepoints writeback: remove unnecessary init_timer call writeback: optimize periodic bdi thread wakeups writeback: prevent unnecessary bdi threads wakeups writeback: move bdi threads exiting logic to the forker thread writeback: restructure bdi forker loop a little writeback: move last_active to bdi writeback: do not remove bdi from bdi_list writeback: simplify bdi code a little writeback: do not lose wake-ups in bdi threads ... Fixed up pretty trivial conflicts in drivers/block/virtio_blk.c and drivers/scsi/scsi_error.c as per Jens.

scsi: use REQ_TYPE_FS for flush request

2010-08-07T16:52:41Z

scsi-ml uses REQ_TYPE_BLOCK_PC for flush requests from file systems. The definition of REQ_TYPE_BLOCK_PC is that we don't retry requests even when we can (e.g. UNIT ATTENTION) and we send the response to the callers (then the callers can decide what they want). We need a workaround such as the commit 77a4229719e511a0d38d9c355317ae1469adeb54 to retry BLOCK_PC flush requests. We will need the similar workaround for discard requests too since SCSI-ml handle them as BLOCK_PC internally. This uses REQ_TYPE_FS for flush requests from file systems instead of REQ_TYPE_BLOCK_PC. scsi-ml retries only REQ_TYPE_FS requests that have data to transfer when we can retry them (e.g. UNIT_ATTENTION). However, we also need to retry REQ_TYPE_FS requests without data because the callers don't. This also changes scsi_check_sense() to retry all the REQ_TYPE_FS requests when appropriate. Thanks to scsi_noretry_cmd(), REQ_TYPE_BLOCK_PC requests don't be retried as before. Note that basically, this reverts the commit 77a4229719e511a0d38d9c355317ae1469adeb54 since now we use REQ_TYPE_FS for flush requests. Signed-off-by: FUJITA Tomonori Signed-off-by: Jens Axboe

scsi: convert discard to REQ_TYPE_FS from REQ_TYPE_BLOCK_PC

2010-08-07T16:52:31Z

Jens, any reason why this isn't included in your for-2.6.36 yet? = From: FUJITA Tomonori Subject: [PATCH resend] scsi: convert discard to REQ_TYPE_FS from REQ_TYPE_BLOCK_PC The block layer (file systems) sends discard requests as REQ_TYPE_FS (the role of REQ_TYPE_FS is that setting up commands and interpreting the results). But SCSI-ml treats discard requests as REQ_TYPE_BLOCK_PC. scsi-ml can handle discard requests as REQ_TYPE_FS easily. scsi_setup_discard_cmnd() sets up struct request and the bio nicely. Only remaining issue is that discard requests can't be completed partially so we need to modify sd_done. This conversion also fixes the problem that discard requests aren't retried when possible (e.g. UNIT ATTENTION). Signed-off-by: FUJITA Tomonori Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

scsi/sd: remove big kernel lock

2010-08-07T16:26:08Z

Every user of the BKL in the sd driver is the result of the pushdown from the block layer into the open/close/ioctl functions. The only place that used to rely on the BKL is the sdkp->openers variable, which gets converted into an atomic_t. Nothing else seems to rely on the BKL, since the functions do not touch global data without holding another lock, and the open/close functions are still protected from concurrent execution using the bdev->bd_mutex. Signed-off-by: Arnd Bergmann Cc: linux-scsi@vger.kernel.org Cc: "James E.J. Bottomley" Acked-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: push down BKL into .open and .release

2010-08-07T16:25:34Z

The open and release block_device_operations are currently called with the BKL held. In order to change that, we must first make sure that all drivers that currently rely on this have no regressions. This blindly pushes the BKL into all .open and .release operations for all block drivers to prepare for the next step. The drivers can subsequently replace the BKL with their own locks or remove it completely when it can be shown that it is not needed. The functions blkdev_get and blkdev_put are the only remaining users of the big kernel lock in the block layer, besides a few uses in the ioctl code, none of which need to serialize with blkdev_{get,put}. Most of these two functions is also under the protection of bdev->bd_mutex, including the actual calls to ->open and ->release, and the common code does not access any global data structures that need the BKL. Signed-off-by: Arnd Bergmann Acked-by: Christoph Hellwig Signed-off-by: Jens Axboe