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2011-04-18GFS2: filesystem hang caused by incorrect lock orderBob Peterson
This patch fixes a deadlock in GFS2 where two processes are trying to reclaim an unlinked dinode: One holds the inode glock and calls gfs2_lookup_by_inum trying to look up the inode, which it can't, due to I_FREEING. The other has set I_FREEING from vfs and is at the beginning of gfs2_delete_inode waiting for the glock, which is held by the first. The solution is to add a new non_block parameter to the gfs2_iget function that causes it to return -ENOENT if the inode is being freed. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-02-24GFS2: deallocation performance patchBob Peterson
This patch is a performance improvement to GFS2's dealloc code. Rather than update the quota file and statfs file for every single block that's stripped off in unlink function do_strip, this patch keeps track and updates them once for every layer that's stripped. This is done entirely inside the existing transaction, so there should be no risk of corruption. The other functions that deallocate blocks will be unaffected because they are using wrapper functions that do the same thing that they do today. I tested this code on my roth cluster by creating 200 files in a directory, each of which is 100MB, then on four nodes, I simultaneously deleted the files, thus competing for GFS2 resources (but different files). The commands I used were: [root@roth-01]# time for i in `seq 1 4 200` ; do rm /mnt/gfs2/bigdir/gfs2.$i; done [root@roth-02]# time for i in `seq 2 4 200` ; do rm /mnt/gfs2/bigdir/gfs2.$i; done [root@roth-03]# time for i in `seq 3 4 200` ; do rm /mnt/gfs2/bigdir/gfs2.$i; done [root@roth-05]# time for i in `seq 4 4 200` ; do rm /mnt/gfs2/bigdir/gfs2.$i; done The performance increase was significant: roth-01 roth-02 roth-03 roth-05 --------- --------- --------- --------- old: real 0m34.027 0m25.021s 0m23.906s 0m35.646s new: real 0m22.379s 0m24.362s 0m24.133s 0m18.562s Total time spent deleting: old: 118.6s new: 89.4 For this particular case, this showed a 25% performance increase for GFS2 unlinks. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-12-07GFS2: fsck.gfs2 reported statfs error after gfs2_growBob Peterson
When you do gfs2_grow it failed to take the very last rgrp into account when adding up the new free space due to an off-by-one error. It was not reading the last rgrp from the rindex because of a check for "<=" that should have been "<". Therefore, fsck.gfs2 was finding (and fixing) an error with the system statfs file. Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2010-11-30GFS2: fix recursive locking during rindex truncatesBenjamin Marzinski
When you truncate the rindex file, you need to avoid calling gfs2_rindex_hold, since you already hold it. However, if you haven't already read in the resource groups, you need to do that. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30GFS2: reread rindex when necessary to grow rindexBenjamin Marzinski
When GFS2 grew the filesystem, it was never rereading the rindex file during the grow. This is necessary for large grows when the filesystem is almost full, and GFS2 needs to use some of the space allocated earlier in the grow to complete it. Now, if GFS2 fails to reserve the necessary space and the rindex file is not uptodate, it rereads it. Also, the only difference between gfs2_ri_update() and gfs2_ri_update_special() was that gfs2_ri_update_special() didn't clear out the existing resource groups, since you knew that it was only called when there were no resource groups. Attempting to clear out the resource groups when there are none takes almost no time, and rarely happens, so I simply removed gfs2_ri_update_special(). Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-15GFS2: Fix inode deallocation raceSteven Whitehouse
This area of the code has always been a bit delicate due to the subtleties of lock ordering. The problem is that for "normal" alloc/dealloc, we always grab the inode locks first and the rgrp lock later. In order to ensure no races in looking up the unlinked, but still allocated inodes, we need to hold the rgrp lock when we do the lookup, which means that we can't take the inode glock. The solution is to borrow the technique already used by NFS to solve what is essentially the same problem (given an inode number, look up the inode carefully, checking that it really is in the expected state). We cannot do that directly from the allocation code (lock ordering again) so we give the job to the pre-existing delete workqueue and carry on with the allocation as normal. If we find there is no space, we do a journal flush (required anyway if space from a deallocation is to be released) which should block against the pending deallocations, so we should always get the space back. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-10-22Merge branch 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block: (46 commits) xen-blkfront: disable barrier/flush write support Added blk-lib.c and blk-barrier.c was renamed to blk-flush.c block: remove BLKDEV_IFL_WAIT aic7xxx_old: removed unused 'req' variable block: remove the BH_Eopnotsupp flag block: remove the BLKDEV_IFL_BARRIER flag block: remove the WRITE_BARRIER flag swap: do not send discards as barriers fat: do not send discards as barriers ext4: do not send discards as barriers jbd2: replace barriers with explicit flush / FUA usage jbd2: Modify ASYNC_COMMIT code to not rely on queue draining on barrier jbd: replace barriers with explicit flush / FUA usage nilfs2: replace barriers with explicit flush / FUA usage reiserfs: replace barriers with explicit flush / FUA usage gfs2: replace barriers with explicit flush / FUA usage btrfs: replace barriers with explicit flush / FUA usage xfs: replace barriers with explicit flush / FUA usage block: pass gfp_mask and flags to sb_issue_discard dm: convey that all flushes are processed as empty ...
2010-09-30GFS2 fatal: filesystem consistency error on renameBob Peterson
This patch fixes a GFS2 problem whereby the first rename after a mount can result in a file system consistency error being flagged improperly and cause the file system to withdraw. The problem is that the rename code tries to run the rgrp list with function gfs2_blk2rgrpd before the rgrp list is guaranteed to be read in from disk. The patch makes the rename function hold the rindex glock (as the gfs2_unlink code does today) which reads in the rgrp list if need be. There were a total of three places in the rename code that improperly referenced the rgrp list without the rindex glock and this patch fixes all three. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-09-20GFS2: fallocate supportBenjamin Marzinski
This patch adds support for fallocate to gfs2. Since the gfs2 does not support uninitialized data blocks, it must write out zeros to all the blocks. However, since it does not need to lock any pages to read from, gfs2 can write out the zero blocks much more efficiently. On a moderately full filesystem, fallocate works around 5 times faster on average. The fallocate call also allows gfs2 to add blocks to the file without changing the filesize, which will make it possible for gfs2 to preallocate space for the rindex file, so that gfs2 can grow a completely full filesystem. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-09-20GFS2: Add a bug trap in allocation codeSteven Whitehouse
This adds a check to ensure that if we reach the block allocator that we don't try and proceed if there is no alloc structure hanging off the inode. This should only happen if there is a bug in GFS2. The error return code is distinctive in order that it will be easily spotted. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-09-20GFS2: Remove i_disksizeSteven Whitehouse
With the update of the truncate code, ip->i_disksize and inode->i_size are merely copies of each other. This means we can remove ip->i_disksize and use inode->i_size exclusively reducing the size of a GFS2 inode by 8 bytes. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-09-16block: remove BLKDEV_IFL_WAITChristoph Hellwig
All the blkdev_issue_* helpers can only sanely be used for synchronous caller. To issue cache flushes or barriers asynchronously the caller needs to set up a bio by itself with a completion callback to move the asynchronous state machine ahead. So drop the BLKDEV_IFL_WAIT flag that is always specified when calling blkdev_issue_* and also remove the now unused flags argument to blkdev_issue_flush and blkdev_issue_zeroout. For blkdev_issue_discard we need to keep it for the secure discard flag, which gains a more descriptive name and loses the bitops vs flag confusion. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10gfs2: replace barriers with explicit flush / FUA usageChristoph Hellwig
Switch to the WRITE_FLUSH_FUA flag for log writes, remove the EOPNOTSUPP detection for barriers and stop setting the barrier flag for discards. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Steven Whitehouse <swhiteho@redhat.com> Acked-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-05-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-fixesLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-fixes: GFS2: Fix permissions checking for setflags ioctl() GFS2: Don't "get" xattrs for ACLs when ACLs are turned off GFS2: Rework reclaiming unlinked dinodes
2010-05-21Merge branch 'master' into for-2.6.35Jens Axboe
Conflicts: fs/ext3/fsync.c Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21GFS2: Rework reclaiming unlinked dinodesBob Peterson
The previous patch I wrote for reclaiming unlinked dinodes had some shortcomings and did not prevent all hangs. This version is much cleaner and more logical, and has passed very difficult testing. Sorry for the churn. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-05-12GFS2: stuck in inode wait, no glocks stuckBob Peterson
This patch changes the lock ordering when gfs2 reclaims unlinked dinodes, thereby avoiding a livelock. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-04-28blkdev: generalize flags for blkdev_issue_fn functionsDmitry Monakhov
The patch just convert all blkdev_issue_xxx function to common set of flags. Wait/allocation semantics preserved. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-14GFS2: glock livelockBob Peterson
This patch fixes a couple gfs2 problems with the reclaiming of unlinked dinodes. First, there were a couple of livelocks where everything would come to a halt waiting for a glock that was seemingly held by a process that no longer existed. In fact, the process did exist, it just had the wrong pid number in the holder information. Second, there was a lock ordering problem between inode locking and glock locking. Third, glock/inode contention could sometimes cause inodes to be improperly marked invalid by iget_failed. Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2010-02-01GFS2: Use GFP_NOFS for alloc structureSteven Whitehouse
This is called under a glock, so its a good plan to use GFP_NOFS Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-02-01GFS2: Fix previous patchSteven Whitehouse
The do_div() call needs to remain. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-02-01GFS2: Don't withdraw on partial rindex entriesBenjamin Marzinski
ince gfs2 writes the rindex file a block at a time, and releases the exclusive lock after each block, it is possible that another process will grab the lock in the middle of the write. Since rindex entries are not an even divisor of blocks, that other process may see partial entries. On grows, this is fine. The process can simply ignore the the partial entires. Previously, the code withdrew when it saw partial entries. Now it simply ignores them. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-12-03GFS2: Locking order fix in gfs2_check_blk_stateSteven Whitehouse
In some cases we already have the rindex lock when we enter this function. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-09-21trivial: fix typo "to to" in multiple filesAnand Gadiyar
Signed-off-by: Anand Gadiyar <gadiyar@ti.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-09-14Merge branch 'for-2.6.32' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-2.6.32' of git://git.kernel.dk/linux-2.6-block: (29 commits) block: use blkdev_issue_discard in blk_ioctl_discard Make DISCARD_BARRIER and DISCARD_NOBARRIER writes instead of reads block: don't assume device has a request list backing in nr_requests store block: Optimal I/O limit wrapper cfq: choose a new next_req when a request is dispatched Seperate read and write statistics of in_flight requests aoe: end barrier bios with EOPNOTSUPP block: trace bio queueing trial only when it occurs block: enable rq CPU completion affinity by default cfq: fix the log message after dispatched a request block: use printk_once cciss: memory leak in cciss_init_one() splice: update mtime and atime on files block: make blk_iopoll_prep_sched() follow normal 0/1 return convention cfq-iosched: get rid of must_alloc flag block: use interrupts disabled version of raise_softirq_irqoff() block: fix comment in blk-iopoll.c block: adjust default budget for blk-iopoll block: fix long lines in block/blk-iopoll.c block: add blk-iopoll, a NAPI like approach for block devices ...
2009-09-14GFS2: Whitespace fixesSteven Whitehouse
Reported-by: Daniel Walker <dwalker@fifo99.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-09-14block: use blkdev_issue_discard in blk_ioctl_discardChristoph Hellwig
blk_ioctl_discard duplicates large amounts of code from blkdev_issue_discard, the only difference between the two is that blkdev_issue_discard needs to send a barrier discard request and blk_ioctl_discard a non-barrier one, and blk_ioctl_discard needs to wait on the request. To facilitates this add a flags argument to blkdev_issue_discard to control both aspects of the behaviour. This will be very useful later on for using the waiting funcitonality for other callers. Based on an earlier patch from Matthew Wilcox <matthew@wil.cx>. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-08GFS2: Be extra careful about deallocating inodesSteven Whitehouse
There is a potential race in the inode deallocation code if two nodes try to deallocate the same inode at the same time. Most of the issue is solved by the iopen locking. There is still a small window which is not covered by the iopen lock. This patches fixes that and also makes the deallocation code more robust in the face of any errors in the rgrp bitmaps, or erroneous iopen callbacks from other nodes. This does introduce one extra disk read, but that is generally not an issue since its the same block that must be written to later in the deallocation process. The total disk accesses therefore stay the same, Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-08-27GFS2: Remove no_formal_ino generating codeSteven Whitehouse
The inum structure used throughout GFS2 has two fields. One no_addr is the disk block number of the inode in question and is used everywhere as the inode number. The other, no_formal_ino, is used only as the generation number for NFS. Historically the no_formal_ino field was set using a complicated system of one global and one per-node file containing inode numbers in order to ensure that each no_formal_ino was unique. Also this code made no provision for what would happen when eventually the (64 bit) numbers ran out. Now I know that is pretty unlikely to happen given the large space of numbers, but it is possible nevertheless. The only guarantee required for no_formal_ino is that, for any single inode, the same number doesn't get reused too quickly. We already have a generation number which is kept in the inode and initialised from a counter in the resource group (almost no overhead, since we have to touch the resource group anyway in order to allocate an inode in the first place). Aside from ensuring that we never use the value 0 in the no_formal_ino field, we can use that counter directly. As a result of that change, we lose about 200 lines of code and also gain about 10 creates/sec on the postmark benchmark (on my test machine). Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-08-17GFS2: Replace assertion with proper error handlingSteven Whitehouse
One fewer assert, one more place we can recover gracefully if there is an error. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-08-17GFS2: Improve error handling in inode allocationSteven Whitehouse
A little while back, block allocation was given some improved error handling which meant that -EIO was returned in the case of there being a problem in the resource group data. In addition a message is printed explaning what went wrong and how to fix it. This extends that error handling so that it also covers inode allocation too. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-07-30GFS2: Fix incorrent statfs consistency checkBenjamin Marzinski
Since both linked and unlinked inodes are counted by rgd->rd_dinodes, It makes no sense to count them with the used data blocks (first check that I changed), it makes sense to count them with the linked inodes (second check), and it makes no sense to care if there are more unlinked inodes than linked ones. This fixes these errors. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-07-30GFS2: Don't try and dealloc own inodeSteven Whitehouse
When searching for unlinked, but still allocated inodes during block allocation, avoid the block relating to the inode that is doing the allocation. This fixes a hang caused when an unlinked, but still open, inode tries to allocate some more blocks and lands up finding itself during the search for deallocatable inodes. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-06-12GFS2: Add tracepointsSteven Whitehouse
This patch adds the ability to trace various aspects of the GFS2 filesystem. The trace points are divided into three groups, glocks, logging and bmap. These points have been chosen because they allow inspection of the major internal functions of GFS2 and they are also generic enough that they are unlikely to need any major changes as the filesystem evolves. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-06-11Merge branch 'for-2.6.31' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block: (153 commits) block: add request clone interface (v2) floppy: fix hibernation ramdisk: remove long-deprecated "ramdisk=" boot-time parameter fs/bio.c: add missing __user annotation block: prevent possible io_context->refcount overflow Add serial number support for virtio_blk, V4a block: Add missing bounce_pfn stacking and fix comments Revert "block: Fix bounce limit setting in DM" cciss: decode unit attention in SCSI error handling code cciss: Remove no longer needed sendcmd reject processing code cciss: change SCSI error handling routines to work with interrupts enabled. cciss: separate error processing and command retrying code in sendcmd_withirq_core() cciss: factor out fix target status processing code from sendcmd functions cciss: simplify interface of sendcmd() and sendcmd_withirq() cciss: factor out core of sendcmd_withirq() for use by SCSI error handling code cciss: Use schedule_timeout_uninterruptible in SCSI error handling code block: needs to set the residual length of a bidi request Revert "block: implement blkdev_readpages" block: Fix bounce limit setting in DM Removed reference to non-existing file Documentation/PCI/PCI-DMA-mapping.txt ... Manually fix conflicts with tracing updates in: block/blk-sysfs.c drivers/ide/ide-atapi.c drivers/ide/ide-cd.c drivers/ide/ide-floppy.c drivers/ide/ide-tape.c include/trace/events/block.h kernel/trace/blktrace.c
2009-05-22block: Do away with the notion of hardsect_sizeMartin K. Petersen
Until now we have had a 1:1 mapping between storage device physical block size and the logical block sized used when addressing the device. With SATA 4KB drives coming out that will no longer be the case. The sector size will be 4KB but the logical block size will remain 512-bytes. Hence we need to distinguish between the physical block size and the logical ditto. This patch renames hardsect_size to logical_block_size. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-22GFS2: Clean up some file namesSteven Whitehouse
This patch renames the ops_*.c files which have no counterpart without the ops_ prefix in order to shorten the name and make it more readable. In addition, ops_address.h (which was very small) is moved into inode.h and inode.h is cleaned up by adding extern where required. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-21GFS2: Be more aggressive in reclaiming unlinked inodesSteven Whitehouse
This patch increases the frequency with which gfs2 looks for unlinked, but still allocated inodes. Its the equivalent operation to ext3's orphan list, but done with bitmaps in the resource groups. This also fixes a bug where a field in the rgrp was too small. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-21GFS2: Add a rgrp bitmap full flagSteven Whitehouse
During block allocation, it is useful to know if sections of disk are full on a finer grained basis than a single resource group. This can make a performance difference when resource groups have larger numbers of bitmap blocks, since we no longer have to search them all block by block in each individual bitmap. The full flag is set on a per-bitmap basis when it has been searched and found to have no free space. It is then skipped in subsequent searches until the flag is reset. The resetting occurs if we have to drop the glock on the resource group for any reason, or if we deallocate some blocks within that resource group and thus free up some space. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-20GFS2: Improve resource group error handlingSteven Whitehouse
This patch improves the error handling in the case where we discover that the summary information in the resource group doesn't match the bitmap information while in the process of allocating blocks. Originally this resulted in a kernel bug, but this patch changes that so that we return -EIO and print some messages explaining what went wrong, and how to fix it. We also remember locally not to try and allocate from the same rgrp again, so that a subsequent allocation in a different rgrp should succeed. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-04-23GFS2: Ensure that the inode goal block settings are updatedSteven Whitehouse
GFS2 has a goal block associated with each inode indicating the search start position for future block allocations (in fact there are two, but thats for backward compatibility with GFS1 as they are set to identical locations in GFS2). In some circumstances, depending on the ordering of updates to the inode it was possible for the goal block settings to not be updated on disk. This patch ensures that the goal block will always get updated, thus reducing the potential for searching the same (already allocated) blocks again when looking for free space during block allocation. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-04-23GFS2: Fix bug in block allocationSteven Whitehouse
The new bitfit algorithm was counting from the wrong end of 64 bit words in the bitfield. This fixes it by using __ffs64 instead of fls64 Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24GFS2: fix sparse warning: Should it be static?Hannes Eder
Impact: Make symbol static. Fix this sparse warning: fs/gfs2/rgrp.c:188:5: warning: symbol 'gfs2_bitfit' was not declared. Should it be static? Signed-off-by: Hannes Eder <hannes@hanneseder.net> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24GFS2: fix sparse warnings: constant is so big it is ...Hannes Eder
Fix this sparse warnings: fs/gfs2/rgrp.c:156:23: warning: constant 0xffffffffffffffff is so big it is unsigned long long fs/gfs2/rgrp.c:157:23: warning: constant 0xaaaaaaaaaaaaaaaa is so big it is unsigned long long fs/gfs2/rgrp.c:158:23: warning: constant 0x5555555555555555 is so big it is long long fs/gfs2/rgrp.c:194:20: warning: constant 0x5555555555555555 is so big it is long long fs/gfs2/rgrp.c:204:44: warning: constant 0x5555555555555555 is so big it is long long Signed-off-by: Hannes Eder <hannes@hanneseder.net> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24GFS2: Fix alignment issue and tidy gfs2_bitfitSteven Whitehouse
An alignment issue with the existing bitfit algorithm was reported on IA64. This patch attempts to fix that, and also to tidy up the code a bit. There is now more documentation about how this works and it has survived a number of different tests. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24GFS2: Add a "demote a glock" interface to sysfsSteven Whitehouse
This adds a sysfs file called demote_rq to GFS2's per filesystem directory. Its possible to use this file to demote arbitrary glocks in exactly the same way as if a request had come in from a remote node. This is intended for testing issues relating to caching of data under glocks. Despite that, the interface is generic enough to send requests to any type of glock, but be careful as its not always safe to send an arbitrary message to an arbitrary glock. For that reason and to prevent DoS, this interface is restricted to root only. The messages look like this: <type>:<glocknumber> <mode> Example: echo -n "2:13324 EX" >/sys/fs/gfs2/unity:myfs/demote_rq Which means "please demote inode glock (type 2) number 13324 so that I can get an EX (exclusive) lock". The lock modes are those which would normally be sent by a remote node in its callback so if you want to unlock a glock, you use EX, to demote to shared, use SH or PR (depending on whether you like GFS2 or DLM lock modes better!). If the glock doesn't exist, you'll get -ENOENT returned. If the arguments don't make sense, you'll get -EINVAL returned. The plan is that this interface will be used in combination with the blktrace patch which I recently posted for comments although it is, of course, still useful in its own right. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24GFS2: Support generation of discard requestsSteven Whitehouse
This patch allows GFS2 to generate discard requests for blocks which are no longer useful to the filesystem (i.e. those which have been freed as the result of an unlink operation). The requests are generated at the time which those blocks become available for reuse in the filesystem. In order to use this new feature, you have to specify the "discard" mount option. The code coalesces adjacent blocks into a single extent when generating the discard requests, thus generating the minimum number. If an error occurs when the request has been sent to the block device, then it will print a message and turn off the requests for that filesystem. If the problem is temporary, then you can use remount to turn the option back on again. There is also a nodiscard mount option so that you can use remount to turn discard requests off, if required. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24GFS2: Merge lock_dlm module into GFS2Steven Whitehouse
This is the big patch that I've been working on for some time now. There are many reasons for wanting to make this change such as: o Reducing overhead by eliminating duplicated fields between structures o Simplifcation of the code (reduces the code size by a fair bit) o The locking interface is now the DLM interface itself as proposed some time ago. o Fewer lookups of glocks when processing replies from the DLM o Fewer memory allocations/deallocations for each glock o Scope to do further optimisations in the future (but this patch is more than big enough for now!) Please note that (a) this patch relates to the lock_dlm module and not the DLM itself, that is still a separate module; and (b) that we retain the ability to build GFS2 as a standalone single node filesystem with out requiring the DLM. This patch needs a lot of testing, hence my keeping it I restarted my -git tree after the last merge window. That way, this has the maximum exposure before its merged. This is (modulo a few minor bug fixes) the same patch that I've been posting on and off the the last three months and its passed a number of different tests so far. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-01-05GFS2: Banish struct gfs2_rgrpd_hostSteven Whitehouse
This patch moves the final field so that we can get rid of struct gfs2_rgrpd_host, as promised some time ago. Also by rearranging the fields slightly, we are able to reduce the size of the gfs2_rgrpd structure at the same time. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-01-05GFS2: Move rg_free from gfs2_rgrpd_host to gfs2_rgrpdSteven Whitehouse
The second of three fields which need to move, in order to remove the struct gfs2_rgrpd_host. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>