drbd: Defer new writes when detecting conflicting writes
Before submitting a new local write request, wait for any conflicting
local or remote requests to complete.
We could assume that the new request occurred first and that the
conflicting requests overwrote it (and therefore discard the new
reques), but we know for sure that the new request occurred after the
conflicting requests and so this behavior would we weird. We would also
end up with the wrong result if the new request is not fully contained
within the conflicting requests.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
drbd: _req_conflicts(): Get rid of the epoch_entries tree
Instead of keeping a separate tree for local and remote write requests
for finding requests and for conflict detection, use the same tree for
both purposes. Introduce a flag to allow distinguishing the two
possible types of entries in this tree.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
The open_cnt check is an open-coded D_ASSERT() check.
In case the data.work queue is not empty, it does not really help to
know which drbd_work elements remained on that list: they will be freed
immediately afterwards, anyway.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
drbd: Replace the ERR_IF macro with an assert-like macro
Remove the file name and line number from the syslog messages generated:
we have no duplicate function names, and no function contains the same
assertion more than once.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
We do not do collision detection for read requests, but we still need to
look up the request objects when we receive a package over the network.
Using the same data structure for read and write requests results in
simpler code once the tl_hash and app_reads_hash tables are removed.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Unify the ar_id_to_req() and ack_id_to_req() functions: make both fail
if the consistency check fails. Move the request lookup code now
duplicated in both functions into its own function.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Move _ar_id_to_req() to drbd_receiver.c and mark it non-inline. Remove
the leading underscores from _ar_id_to_req() and _ack_id_to_req(). Mark
ar_hash_slot() inline.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Kay Sievers [Tue, 23 Aug 2011 18:12:04 +0000 (20:12 +0200)]
loop: always allow userspace partitions and optionally support automatic scanning
Automatic partition scanning can be requested individually per loop
device during its setup by setting LO_FLAGS_PARTSCAN. By default, no
partition tables are scanned.
Userspace can now always add and remove partitions from all loop
devices, regardless if the in-kernel partition scanner is enabled or
not.
The needed partition minor numbers are allocated from the extended
minors space, the main loop device numbers will continue to match the
loop minors, regardless of the number of partitions used.
Tejun Heo [Tue, 23 Aug 2011 18:01:04 +0000 (20:01 +0200)]
block: add GENHD_FL_NO_PART_SCAN
There are cases where suppressing partition scan is useful - e.g. for
lo devices and pseudo SATA devices which advertise to be a disk but
get upset on partition scan (some port multiplier control devices show
such behavior).
This patch adds GENHD_FL_NO_PART_SCAN which suppresses partition scan
regardless of the number of possible partitions. disk_partitionable()
is renamed to disk_part_scan_enabled() as suppressing partition scan
doesn't imply the device can't be partitioned using
BLKPG_ADD/DEL_PARTITION calls from userland. show_partition() now
directly tests disk_max_parts() to maintain backward-compatibility.
-v2: Updated to make it clear that only partition scan is suppressed
not partitioning itself as suggested by Kay Sievers.
Lukas Czerner [Fri, 19 Aug 2011 12:50:46 +0000 (14:50 +0200)]
loop: add discard support for loop devices
This commit adds discard support for loop devices. Discard is usually
supported by SSD and thinly provisioned devices as a method for
reclaiming unused space. This is no different than trying to reclaim
back space which is not used by the file system on the image, but it
still occupies space on the host file system.
We can do the reclamation on file system which does support hole
punching. So when discard request gets to the loop driver we can
translate that to punch a hole to the underlying file, hence reclaim
the free space.
This is very useful for trimming down the size of the image to only what
is really used by the file system on that image. Fstrim may be used for
that purpose.
It has been tested on ext4, xfs and btrfs with the image file systems
ext4, ext3, xfs and btrfs. ext4, or ext6 image on ext4 file system has
some problems but it seems that ext4 punch hole implementation is
somewhat flawed and it is unrelated to this commit.
Also this is a very good method of validating file systems punch hole
implementation.
Note that when encryption is used, discard support is disabled, because
using it might leak some information useful for possible attacker.
Joe Handzik [Mon, 8 Aug 2011 09:40:17 +0000 (11:40 +0200)]
cciss: add transport mode attribute to sys
Signed-off-by: Joseph Handzik <joseph.t.handzik@beardog.cce.hp.com> Acked-by: Stephen M. Cameron <scameron@beardog.cce.hp.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Joseph Handzik [Mon, 8 Aug 2011 09:40:15 +0000 (11:40 +0200)]
cciss: Adds simple mode functionality
Signed-off-by: Joseph Handzik <joseph.t.handzik@beardog.cce.hp.com> Acked-by: Stephen M. Cameron <scameron@beardog.cce.hp.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Commit d006199e72a9 ("serial: sh-sci: Regtype probing doesn't need to be
fatal.") made sci_init_single() return when sci_probe_regmap() succeeds,
although it should return when sci_probe_regmap() fails. This causes
systems using the serial sh-sci driver to crash during boot.
Fix the problem by using the right return condition.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Sun, 7 Aug 2011 21:07:03 +0000 (14:07 -0700)]
arm: remove "optimized" SHA1 routines
Since commit 1eb19a12bd22 ("lib/sha1: use the git implementation of
SHA-1"), the ARM SHA1 routines no longer work. The reason? They
depended on the larger 320-byte workspace, and now the sha1 workspace is
just 16 words (64 bytes). So the assembly version would overwrite the
stack randomly.
The optimized asm version is also probably slower than the new improved
C version, so there's no reason to keep it around. At least that was
the case in git, where what appears to be the same assembly language
version was removed two years ago because the optimized C BLK_SHA1 code
was faster.
Reported-and-tested-by: Joachim Eastwood <manabian@gmail.com> Cc: Andreas Schwab <schwab@linux-m68k.org> Cc: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Al Viro [Sun, 7 Aug 2011 17:55:11 +0000 (18:55 +0100)]
fix rcu annotations noise in cred.h
task->cred is declared as __rcu, and access to other tasks' ->cred is,
indeed, protected. Access to current->cred does not need rcu_dereference()
at all, since only the task itself can change its ->cred. sparse, of
course, has no way of knowing that...
Add force-cast in current_cred(), make current_fsuid() et.al. use it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Sun, 7 Aug 2011 16:53:20 +0000 (09:53 -0700)]
vfs: rename 'do_follow_link' to 'should_follow_link'
Al points out that the do_follow_link() helper function really is
misnamed - it's about whether we should try to follow a symlink or not,
not about actually doing the following.
Ari Savolainen [Sat, 6 Aug 2011 16:43:07 +0000 (19:43 +0300)]
Fix POSIX ACL permission check
After commit 3567866bf261: "RCUify freeing acls, let check_acl() go ahead in
RCU mode if acl is cached" posix_acl_permission is being called with an
unsupported flag and the permission check fails. This patch fixes the issue.
Signed-off-by: Ari Savolainen <ari.m.savolainen@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Linus Torvalds [Sun, 7 Aug 2011 05:56:03 +0000 (22:56 -0700)]
Merge branch 'for-linus' of git://git.open-osd.org/linux-open-osd
* 'for-linus' of git://git.open-osd.org/linux-open-osd:
ore: Make ore its own module
exofs: Rename raid engine from exofs/ios.c => ore
exofs: ios: Move to a per inode components & device-table
exofs: Move exofs specific osd operations out of ios.c
exofs: Add offset/length to exofs_get_io_state
exofs: Fix truncate for the raid-groups case
exofs: Small cleanup of exofs_fill_super
exofs: BUG: Avoid sbi realloc
exofs: Remove pnfs-osd private definitions
nfs_xdr: Move nfs4_string definition out of #ifdef CONFIG_NFS_V4
Linus Torvalds [Sun, 7 Aug 2011 05:45:50 +0000 (22:45 -0700)]
vfs: optimize inode cache access patterns
The inode structure layout is largely random, and some of the vfs paths
really do care. The path lookup in particular is already quite D$
intensive, and profiles show that accessing the 'inode->i_op->xyz'
fields is quite costly.
We already optimized the dcache to not unnecessarily load the d_op
structure for members that are often NULL using the DCACHE_OP_xyz bits
in dentry->d_flags, and this does something very similar for the inode
ops that are used during pathname lookup.
It also re-orders the fields so that the fields accessed by 'stat' are
together at the beginning of the inode structure, and roughly in the
order accessed.
The effect of this seems to be in the 1-2% range for an empty kernel
"make -j" run (which is fairly kernel-intensive, mostly in filename
lookup), so it's visible. The numbers are fairly noisy, though, and
likely depend a lot on exact microarchitecture. So there's more tuning
to be done.
Linus Torvalds [Sun, 7 Aug 2011 05:41:50 +0000 (22:41 -0700)]
vfs: renumber DCACHE_xyz flags, remove some stale ones
Gcc tends to generate better code with small integers, including the
DCACHE_xyz flag tests - so move the common ones to be first in the list.
Also just remove the unused DCACHE_INOTIFY_PARENT_WATCHED and
DCACHE_AUTOFS_PENDING values, their users no longer exists in the source
tree.
And add a "unlikely()" to the DCACHE_OP_COMPARE test, since we want the
common case to be a nice straight-line fall-through.