We still have life time issues with the sysfs command filter kobject,
so disable it for 2.6.27 release. We can revisit this and make it work
properly for 2.6.28, for 2.6.27 release it's too risky.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
For IBM z series certain LUNs can no longer be accessed.
This is because kernel version 2.6.19 a check was introduced not to
create a generic SCSI device for devices that return PQ=1 and
PDT=0x1f. For WLUNs (see SAM-3, p. 41ff) generic SCSI devices should
be created unconditionally without looking at the PQ bit, so add a
check for WLUNs in with this test.
Acked-by: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Change scsi_check_sense HARDWARE_ERROR check to return ADD_TO_MLQUEUE
if device->retry_hwerror is set to allow retries to occur without
restriction of blk_noretry_request check.
Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Change scsi_dh check_sense functions to return ADD_TO_MLQUEUE
to allow retries to occur without restriction of blk_noretry_request
check.
Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Acked-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: "Martin K. Petersen" <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This patch remove blk_register_filter and blk_unregister_filter in
gendisk, and adds them to sd.c, sr.c. and ide-cd.c
The commit abf5439370 moved cmdfilter
from gendisk to request_queue. It turned out that in some subsystems
multiple gendisks share a single request_queue. So we get:
Using physmap partition information
Creating 3 MTD partitions on "physmap-flash":
0x00000000-0x01c00000 : "User FS"
0x01c00000-0x01c40000 : "booter"
kobject (8511c410): tried to init an initialized object, something is seriously wrong.
Call Trace:
[<8036644c>] dump_stack+0x8/0x34
[<8021f050>] kobject_init+0x50/0xcc
[<8021fa18>] kobject_init_and_add+0x24/0x58
[<8021d20c>] blk_register_filter+0x4c/0x64
[<8021c194>] add_disk+0x78/0xe0
[<8027d14c>] add_mtd_blktrans_dev+0x254/0x278
[<8027c8f0>] blktrans_notify_add+0x40/0x78
[<80279c00>] add_mtd_device+0xd0/0x150
[<8027b090>] add_mtd_partitions+0x568/0x5d8
[<80285458>] physmap_flash_probe+0x2ac/0x334
[<802644f8>] driver_probe_device+0x12c/0x244
[<8026465c>] __driver_attach+0x4c/0x84
[<80263c64>] bus_for_each_dev+0x58/0xac
[<802633ec>] bus_add_driver+0xc4/0x24c
[<802648e0>] driver_register+0xcc/0x184
[<80100460>] _stext+0x60/0x1bc
In the long term, we need to fix such subsystems but we need a quick
fix now. This patch add the command filter support to only sd and sr
though it might be useful for other SG_IO users (such as cciss).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reported-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
sg allowed any command for TYPE_SCANNER. The cmd_filter patchset
doesn't. We can't change sg's permission since it might break the
existing software.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
cmd_filter works only for the block layer SG_IO with SCSI block
devices. It breaks scsi/sg.c, bsg, and the block layer SG_IO with SCSI
character devices (such as st). We hit a kernel crash with them.
The problem is that cmd_filter code accesses to gendisk (having struct
blk_scsi_cmd_filter) via inode->i_bdev->bd_disk. It works for only
SCSI block device files. With character device files, inode->i_bdev
leads you to struct cdev. inode->i_bdev->bd_disk->blk_scsi_cmd_filter
isn't safe.
SCSI ULDs don't expose gendisk; they keep it private. bsg needs to be
independent on any protocols. We shouldn't change ULDs to expose their
gendisk.
This patch moves struct blk_scsi_cmd_filter from gendisk to
request_queue, a common object, which eveyone can access to.
The user interface doesn't change; users can change the filters via
/sys/block/. gendisk has a pointer to request_queue so the cmd_filter
code accesses to struct blk_scsi_cmd_filter.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch lets the files using linux/version.h match the files that
#include it.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6: (22 commits)
[SCSI] ibmvfc: Driver version 1.0.2
[SCSI] ibmvfc: Add details to async event log
[SCSI] ibmvfc: Sanitize response lengths
[SCSI] ibmvfc: Fix for lost async events
[SCSI] ibmvfc: Fixup host state during reinit
[SCSI] ibmvfc: Fix another hang on module removal
[SCSI] ibmvscsi: Fixup desired DMA value for shared memory partitions
[SCSI] megaraid_sas: remove sysfs dbg_lvl world writeable permissions
[SCSI] qla2xxx: Update version number to 8.02.01-k7.
[SCSI] qla2xxx: Explicitly tear-down vports during PCI remove_one().
[SCSI] qla2xxx: Reference proper ha during SBR handling.
[SCSI] qla2xxx: Set npiv_supported flag for FCoE HBAs.
[SCSI] qla2xxx: Don't leak SG-DMA mappings while aborting commands.
[SCSI] qla2xxx: Correct vport-state management issues during ISP-ABORT.
[SCSI] qla2xxx: Correct synchronization of software/firmware fcport states.
[SCSI] scsi_dh: Initialize lun_state in check_ownership()
[SCSI] scsi_dh: Do not use scsilun in rdac hardware handler
[SCSI] megaraid_sas: version and Documentation Update
[SCSI] megaraid_sas: add new controllers (0x78 0x79)
[SCSI] megaraid_sas: add the shutdown DCMD cmd to driver shutdown routine
...
Bump driver version to 1.0.2.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
When logging async events, also print the payload in addition to the
event received.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Sanitize the response lengths in order to prevent possible oopses
in the command response path.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
If the client virtual fibre channel adapter is already logged into the
server and does an NPIV Login again, the async queue, which is used for
reporting Link Up/Link Down type of events, does not get reset on the
server side. Fix up the client driver so that we also do not reset it.
This fixes a problem of lost async events following relogins.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
If an ELS is received while the virtual fibre channel adapter is going
through its discovery, a flag is set which causes discovery to get
re-driven. However, the hosts's state does not get set back to
IBMVFC_INITIALIZING and scsi_block_requests does not get called again,
which can result in queuecommand ops getting sent during
discovery. This should not occur and may cause problems. One example
is that we may no longer be logged into the target we send the command
to, resulting in a failure which should not have occurred.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This fixes a hang on module removal. The module removal code was setting
the hosts's state to IBMVFC_HOST_OFFLINE before tearing down the kernel
thread, but, due to a bug in ibmvfc_wait_while_resetting, was not waiting
for the kernel thread's offlining work to be done prior to destroying
the kernel thread, which left the scsi host in a blocked state which we
never got out of.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
When running ibmvscsi in a shared memory partition, it must provide
a default value for the amount of DMA resources it will need in order to
perform reasonably well. This was being calculated in sectors rather than
bytes, as it should. This patch fixes this.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
/sys/bus/pci/drivers/megaraid_sas/dbg_lvl defaults to being
world-writable, which seems bad (letting any user affect kernel driver
behavior and logging level).
This turns off group and user write permissions, so that on typical
production systems only root can write to it.
[jejb: fix up rejections]
Signed-off-by: Joseph Malicki <jmalicki@metacarta.com>
Acked-by: "Yang, Bo" <Bo.Yang@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
During internal testing, we've seen issues (hangs) with the
'deferred' vport tear-down-processing typically accompanied with
the fc_remove_host() call. This is due to the current
implementation's back-end vport handling being performed by the
physical-HA's DPC thread where premature shutdown could lead to
latent vport requests without a processor.
This should also address a problem reported by Gal Rosen
(http://marc.info/?l=linux-scsi&m=121731664417358&w=2) where the
driver would attempt to awaken a previously torn-down DPC thread
from interrupt context by implicitly calling wake_up_process()
rather than the driver's qla2xxx_wake_dpc() helper. Rather, than
reshuffle the remove_one() device-removal code, during unload,
depend on the driver's timer to wake-up the DPC process, by
limiting wake-ups based on an 'unloading' flag.
Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The executing-HA of an SRB can be referenced from the sp->fcport.
Use this correct value while processing status-continuation data
and abort processing.
Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Original code inadvertently cleared an SRB's 'flags' while
aborting; causing a follow-on scsi_dma_unmap() to be potentially
missed.
Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
* Use correct 'ha' to mark a device lost from ISR.
I/Os will always be returned on the physical-HA.
qla2x00_mark_device_lost() should be called with the HA bound
to the fcport.
* Mark *all* devices lost during ISP-ABORT (bighammer).
These fixes correct issues discovered locally where during
link-perturbation and heavy vport-I/O fcport/rport states would
stray and an rport's scsi-target lost (timed-out).
Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Greg Wettstein (greg@enjellic.com) noted:
http://article.gmane.org/gmane.linux.scsi/43409
on a reboot of a previously recognized SCST target, the initiator
driver would be unable to re-recognize the device as a target.
It turns out that prior to the SCST software reloading and
returning it's "target-capable" abilities in the PRLI payload,
the HBA would be re-initialized as an initiator-only type port.
Since initiators typically classify themselves as an FCP-2
capable device, both software and firmware do not perform an
explicit logout during port-loss. Unfortunately, as can be seen
by the failure case, when the port (now target-capable) returns,
firmware performs an ADISC without a follow-on PRLI, leaving
stale 'initiator-only' data in the firmware's port database.
Correct the discrepancy by performing the explicit logout during
the transport's request to terminate-rport-io, thus synchronizing
port states and ensuring a follow-on PRLI is performed.
Reported-by: Greg Wettstein <greg@enjellic.com>
Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
lun_state need to be initialized inside check_ownership().
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
RDAC storage controller doesn't seem to use the scsilun format. It uses
only the last byte for LUN.
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Bo Yang <bo.yang@lsi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Add the new controllers (0x78 0x79) support to the driver. Those
controllers are LSI's next generation (gen2) SAS controllers.
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: parenthesise a macro]
Signed-off-by: Bo Yang <bo.yang@lsi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Add the shutdown DCMD cmd to driver shutdown routine to make megaraid sas
FW shutdown proper.
Signed-off-by: Bo Yang <bo.yang@lsi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
MegaRAID SAS Driver get unexpected Interrupt. Add the dummy readl to
force PCI flush will fix this issue.
Signed-off-by: Bo Yang <bo.yang@lsi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This patch makes several needlessly global struct scsi_dh_devlist's
static.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove includes of asm/hardware.h in addition to asm/arch/hardware.h.
Then, since asm/hardware.h only exists to include asm/arch/hardware.h,
update everything to directly include asm/arch/hardware.h and remove
asm/hardware.h.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This re-introduces commit 2b14290078,
which was reverted due to the regression it caused by commit
fca082c9f1.
That regression was not root-caused by the original commit, it was just
uncovered by it, and the real fix was done by Alan Stern in commit
580da34847 ("Fix USB storage hang on
command abort").
We can thus re-introduce the change that was confirmed by Alan Jenkins
to be still required by his odd card reader.
Cc: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On Monday 28 July 2008, Benjamin Herrenschmidt wrote:
[...]
> Vector: 300 (Data Access) at [c58b7b80]
> pc: c014f264: elv_may_queue+0x10/0x44
> lr: c0152750: get_request+0x2c/0x2c0
> sp: c58b7c30
> msr: 1032
> dar: c
> dsisr: 40000000
> current = 0xc58aaae0
> pid = 854, comm = media-bay
> enter ? for help
> mon> t
> [c58b7c40] c0152750 get_request+0x2c/0x2c0
> [c58b7c70] c0152a08 get_request_wait+0x24/0xec
> [c58b7cc0] c0225674 ide_cd_queue_pc+0x58/0x1a0
> [c58b7d40] c022672c ide_cdrom_packet+0x9c/0xdc
> [c58b7d70] c0261810 cdrom_get_disc_info+0x60/0xd0
> [c58b7dc0] c026208c cdrom_mrw_exit+0x1c/0x11c
> [c58b7e30] c0260f7c unregister_cdrom+0x84/0xe8
> [c58b7e50] c022395c ide_cd_release+0x80/0x84
> [c58b7e70] c0163650 kref_put+0x54/0x6c
> [c58b7e80] c0223884 ide_cd_put+0x40/0x5c
> [c58b7ea0] c0211100 generic_ide_remove+0x28/0x3c
> [c58b7eb0] c01e9d34 __device_release_driver+0x78/0xb4
> [c58b7ec0] c01e9e44 device_release_driver+0x28/0x44
> [c58b7ee0] c01e8f7c bus_remove_device+0xac/0xd8
> [c58b7f00] c01e7424 device_del+0x104/0x198
> [c58b7f20] c01e74d0 device_unregister+0x18/0x30
> [c58b7f40] c02121c4 __ide_port_unregister_devices+0x6c/0x88
> [c58b7f60] c0212398 ide_port_unregister_devices+0x38/0x80
> [c58b7f80] c0208ca4 media_bay_step+0x1cc/0x5c0
> [c58b7fb0] c0209124 media_bay_task+0x8c/0xcc
> [c58b7fd0] c00485c0 kthread+0x48/0x84
> [c58b7ff0] c0011b20 kernel_thread+0x44/0x60
The guilty commit turned out to be 08da591e14
("ide: add ide_device_{get,put}() helpers"). ide_device_put() is called
before kref_put() in ide_cd_put() so IDE device is already gone by the time
ide_cd_release() is reached.
Fix it by calling ide_device_get() before kref_get() and ide_device_put()
after kref_put() in all affected device drivers.
v2:
Brown paper bag time. In v1 cd->drive was referenced after dropping last
reference on cd object (which could result in OOPS in ide_device_put() as
reported/debugged by Mariusz Kozlowski). Fix it by caching cd->drive in
the local variable (fix other device drivers too).
Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reported-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Borislav Petkov <petkovbb@gmail.com>
Tested-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Converting page lock to new locking bitops requires a change of page flag
operation naming, so we might as well convert it to something nicer
(!TestSetPageLocked_Lock => trylock_page, SetPageLocked => set_page_locked).
This also facilitates lockdeping of page lock.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 2b14290078, since it
seems to break some other USB storage devices (at least a JMicron USB to
ATA bridge). As such, while it apparently fixes some cardreaders, it
would need to be made conditional on the exact reader it fixes in order
to avoid causing regressions.
Cc: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The class_device->device conversion is causing an oops in revalidate
because it's assuming that the device_for_each_child iterator will only
return struct scsi_device children. The conversion made all former
class_devices children of the device as well, so this assumption is
broken. Fix it.
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
There are a few kerneloops.org reports like this one:
http://www.kerneloops.org/search.php?search=ses_match_to_enclosure
That seem to imply we're running off the end of the VPD inquiry data
(although at 512 bytes, it should be long enough for just about
anything). we should be using correctly sized buffers anyway, so put
those in and hope this oops goes away.
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Add PCI device ID for new adapter models.
Signed-off-by: HighPoint Linux Team <linux@highpoint-tech.com>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
drivers/scsi/qla2xxx/qla_attr.c: In function 'qla24xx_vport_delete':
drivers/scsi/qla2xxx/qla_attr.c:1184: error: implicit declaration of function 'msleep'
make[3]: *** [drivers/scsi/qla2xxx/qla_attr.o] Error 1
make[3]: *** Waiting for unfinished jobs....
Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (59 commits)
[SCSI] replace __FUNCTION__ with __func__
[SCSI] extend the last_sector_bug flag to cover more sectors
[SCSI] qla2xxx: Update version number to 8.02.01-k6.
[SCSI] qla2xxx: Additional NPIV corrections.
[SCSI] qla2xxx: suppress uninitialized-var warning
[SCSI] qla2xxx: use memory_read_from_buffer()
[SCSI] qla2xxx: Issue proper ISP callbacks during stop-firmware.
[SCSI] ch: fix ch_remove oops
[SCSI] 3w-9xxx: add MSI support and misc fixes
[SCSI] scsi_lib: use blk_rq_tagged in scsi_request_fn
[SCSI] ibmvfc: Update driver version to 1.0.1
[SCSI] ibmvfc: Add ADISC support
[SCSI] ibmvfc: Miscellaneous fixes
[SCSI] ibmvfc: Fix hang on module removal
[SCSI] ibmvfc: Target refcounting fixes
[SCSI] ibmvfc: Reduce unnecessary log noise
[SCSI] sym53c8xx: free luntbl in sym_hcb_free
[SCSI] scsi_scan.c: Release mutex in error handling code
[SCSI] scsi_eh_prep_cmnd should save scmd->underflow
[SCSI] sd: Support for SCSI disk (SBC) Data Integrity Field
...
[jejb: fixed up a ton of missed conversions.
All of you are on notice this has happened, driver trees will now
need to be rebased]
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: SCSI List <linux-scsi@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The last_sector_bug flag was added to work around a bug in certain usb
cardreaders, where they would crash if a multiple sector read included the
last sector. The original implementation avoids this by e.g. splitting an 8
sector read which includes the last sector into a 7 sector read, and a single
sector read for the last sector. The flag is enabled for all USB devices.
This revealed a second bug in other usb cardreaders, which crash when they
get a multiple sector read which stops 1 sector short of the last sector.
Affected hardware includes the Kingston "MobileLite" external USB cardreader
and the internal USB cardreader on the Asus EeePC.
Extend the last_sector_bug workaround to ensure that any access which touches
the last 8 hardware sectors of the device is a single sector long. Requests
are shrunk as necessary to meet this constraint.
This gives us a safety margin against potential unknown or future bugs
affecting multi-sector access to the end of the device. The two known bugs
only affect the last 2 sectors. However, they suggest that these devices
are prone to fencepost errors and that multi-sector access to the end of the
device is not well tested. Popular OS's use multi-sector accesses, but they
rarely read the last few sectors. Linux (with udev & vol_id) automatically
reads sectors from the end of the device on insertion. It is assumed that
single sector accesses are more thoroughly tested during development.
Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Tested-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Linus Torvalds