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* Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmwLinus Torvalds2012-05-2121-493/+466
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull GFS2 changes from Steven Whitehouse. * git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw: (24 commits) GFS2: Fix quota adjustment return code GFS2: Add rgrp information to block_alloc trace point GFS2: Eliminate unused "new" parameter to gfs2_meta_indirect_buffer GFS2: Update glock doc to add new stats info GFS2: Update main gfs2 doc GFS2: Remove redundant metadata block type check GFS2: Fix sgid propagation when using ACLs GFS2: eliminate log elements and simplify GFS2: Eliminate vestigial sd_log_le_rg GFS2: Eliminate needless parameter from function gfs2_setbit GFS2: Log code fixes GFS2: Remove unused argument from gfs2_internal_read GFS2: Remove bd_list_tr GFS2: Remove duplicate log code GFS2: Clean up log write code path GFS2: Use variable rather than qa to determine if unstuff necessary GFS2: Change variable blk to biblk GFS2: Fix function parameter comments in rgrp.c GFS2: Eliminate offset parameter to gfs2_setbit GFS2: Use slab for block reservation memory ...
| * GFS2: Fix quota adjustment return codeBob Peterson2012-05-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | This patch changes function gfs2_adjust_quota so that it properly returns a good (zero) return code on the normal path through the code. Without this, mounting GFS2 with -o quota=account periodically gave this error message: GFS2: fsid=cluster:fs: gfs2_quotad: sync error -5 Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Add rgrp information to block_alloc trace pointBob Peterson2012-05-112-9/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a second attempt at a patch that adds rgrp information to the block allocation trace point for GFS2. As suggested, the patch was modified to list the rgrp information _after_ the fields that exist today. Again, the reason for this patch is to allow us to trace and debug problems with the block reservations patch, which is still in the works. We can debug problems with reservations if we can see what block allocations result from the block reservations. It may also be handy in figuring out if there are problems in rgrp free space accounting. In other words, we can use it to track the rgrp and its free space along side the allocations that are taking place. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Eliminate unused "new" parameter to gfs2_meta_indirect_bufferBob Peterson2012-05-113-19/+10
| | | | | | | | | | | | | | | | | | | | It turns out that the "new" parameter to function gfs2_meta_indirect_buffer was always being passed in as zero. Therefore, this patch eliminates it and simplifies the function. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Remove redundant metadata block type checkBob Peterson2012-05-081-5/+0
| | | | | | | | | | | | | | | | This patch removes a redundant metadata block check. See description below. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Fix sgid propagation when using ACLsSteven Whitehouse2012-05-041-9/+3
| | | | | | | | | | | | | | | | | | | | | | This cleans up the mode setting code when creating inodes. The SGID bit was being reset by setattr_copy() when the user creating a subdirectory was not in the owning group. When ACLs are in use this SGID bit should have been propagated if the ACL allows creation of a subdirectory. GFS2's behaviour now matches that of the other ACL supporting filesystems in this regard. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: eliminate log elements and simplifyBob Peterson2012-05-027-55/+48
| | | | | | | | | | | | | | | | | | | | | | This patch eliminates the gfs2_log_element data structure and rolls its two components into the gfs2_bufdata. This makes the code easier to understand and makes it easier to migrate to a rbtree to keep the list sorted. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Eliminate vestigial sd_log_le_rgBob Peterson2012-04-302-2/+0
| | | | | | | | | | | | | | | | | | This patch eliminates gfs2 superblock variable sd_log_le_rg which is no longer used. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Eliminate needless parameter from function gfs2_setbitBob Peterson2012-04-271-12/+9
| | | | | | | | | | | | | | | | | | This patch eliminates parameter "buf1" from function gfs2_setbit. This is possible because it was always passed in as bi->bi_bh->b_data. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Log code fixesSteven Whitehouse2012-04-242-5/+1
| | | | | | | | | | | | | | | | This patch removes a log lock from around atomic operation where it is not needed, removes an unused variable, and also changes a void pointer used incorrectly to a struct page pointer. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Remove unused argument from gfs2_internal_readAndrew Price2012-04-244-18/+9
| | | | | | | | | | | | | | | | | | | | gfs2_internal_read accepts an unused ra_state argument, left over from when we did readahead on the rindex. Since there are currently no plans to add back this readahead, this patch removes the ra_state parameter and updates the functions which call gfs2_internal_read accordingly. Signed-off-by: Andrew Price <anprice@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Remove bd_list_trSteven Whitehouse2012-04-247-56/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is another clean up in the logging code. This per-transaction list was largely unused. Its main function was to ensure that the number of buffers in a transaction was correct, however that counter was only used to check the number of buffers in the bd_list_tr, plus an assert at the end of each transaction. With the assert now changed to use the calculated buffer counts, we can remove both bd_list_tr and its associated counter. This should make the code easier to understand as well as shrinking a couple of structures. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Remove duplicate log codeSteven Whitehouse2012-04-241-116/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | The main part of this patch merges the two functions used to write metadata and data buffers to the log. Most of the code is common between the two functions, so this provides a nice clean up, and makes the code more readable. The gfs2_get_log_desc() function is also extended to take two more arguments, and thus avoid having to set the length and data1 fields of this strucuture as a separate operation. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Clean up log write code pathSteven Whitehouse2012-04-248-172/+264
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Prior to this patch, we have two ways of sending i/o to the log. One of those is used when we need to allocate both the data to be written itself and also a buffer head to submit it. This is done via sb_getblk and friends. This is used mostly for writing log headers. The other method is used when writing blocks which have some in-place counterpart. This is the case for all the metadata blocks which are journalled, and when journaled data is in use, for unescaped journalled data blocks. This patch replaces both of those two methods, and about half a dozen separate i/o submission points with a single i/o submission function. We also go direct to bio rather than using buffer heads, since this allows us to build i/o requests of the maximum size for the block device in question. It also reduces the memory required for flushing the log, which can be very useful in low memory situations. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Use variable rather than qa to determine if unstuff necessaryBob Peterson2012-04-241-2/+4
| | | | | | | | | | | | | | | | | | | | | | In the future, the qadata structure will be eliminated and merged back in with the block reservation structure, after we extend the lifespan of that. This patch is a step forward in eliminating the qadata structure. It adds a variable to the do_grow function to determine when unstuffing is necessary, and has been done. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Change variable blk to biblkBob Peterson2012-04-241-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | In the resource group code, we have no less than three different kinds of block references: block relative to the file system (u64), block relative to the rgrp (u32), and block relative to the bitmap. This is a small step to making the code more readable; it renames variable blk to biblk to solidify in my mind that it's relative to the bitmap and nothing else. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Fix function parameter comments in rgrp.cBob Peterson2012-04-241-12/+16
| | | | | | | | | | | | | | | | | | | | This patch just fixes a bunch of function parameter comments. Slowly, over the years, the comments have gotten out of date (mostly my fault, as I haven't been good at keeping them up to date). This patch rectifies some of that. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Eliminate offset parameter to gfs2_setbitBob Peterson2012-04-241-11/+12
| | | | | | | | | | | | | | This patch eliminates a redundant parameter. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Use slab for block reservation memoryBob Peterson2012-04-244-8/+23
| | | | | | | | | | | | | | This patch changes block reservations so it uses slab storage. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: make function gfs2_page_add_databufs staticBob Peterson2012-04-242-4/+2
| | | | | | | | | | | | | | This patch makes function gfs2_page_add_databufs static. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Rename function gfs2_close to gfs2_releaseBob Peterson2012-04-241-6/+6
| | | | | | | | | | | | | | This patch renames function gfs2_close to gfs2_release. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Make gfs2_log_fake_buf() write the buffer tooSteven Whitehouse2012-04-241-14/+11
| | | | | | | | | | | | | | | | | | Since we always write the buffer directly after this function returns, we might as well merge it into here. This is a clean up in preparation for some further updates to the log code which are coming soon. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Drop "pull" argument from log_write_header()Steven Whitehouse2012-04-241-9/+4
| | | | | | | | | | | | | | | | | | The "pull" argument to log_write_header() is only used for debug purposes and it is not really needed any more. There are other tests for this particular problem, so I think we can dispose of it in order to simplify the code. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* | vfs: make it possible to access the dentry hash/len as one 64-bit entryLinus Torvalds2012-05-101-1/+1
|/ | | | | | | | | | | | | | | This allows comparing hash and len in one operation on 64-bit architectures. Right now only __d_lookup_rcu() takes advantage of this, since that is the case we care most about. The use of anonymous struct/unions hides the alternate 64-bit approach from most users, the exception being a few cases where we initialize a 'struct qstr' with a static initializer. This makes the problematic cases use a new QSTR_INIT() helper function for that (but initializing just the name pointer with a "{ .name = xyzzy }" initializer remains valid, as does just copying another qstr structure). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* GFS2: Instruct DLM to avoid queue convert slowdownBob Peterson2012-04-241-3/+7
| | | | | | | | | | | | | | | | | | This patch instructs DLM to prevent an "in place" conversion, where the lock just stays on the granted queue, and instead forces the conversion to the back of the convert queue. This is done on upward conversions only. This is useful in cases where, for example, a lock is frequently needed in PR on one node, but another node needs it temporarily in EX to update it. This may happen, for example, when the rindex is being updated by gfs2_grow. The gfs2_grow needs to have the lock in EX, but the other nodes need to re-read it to retrieve the updates. The glock is already granted in PR on the non-growing nodes, so this prevents them from continually re-granting the lock in PR, and forces the EX from gfs2_grow to go through. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-fixesLinus Torvalds2012-04-117-13/+41
|\ | | | | | | | | | | | | | | | | | | Pull GFS2 fixes from Steven Whitehouse * git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-fixes: GFS2: Allow caching of rindex glock GFS2: Make sure rindex is uptodate before starting transactions GFS2: use depends instead of select in kconfig GFS2: put glock reference in error patch of read_rindex_entry
| * GFS2: Allow caching of rindex glockBob Peterson2012-04-101-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch allows caching of the rindex glock. We were previously setting the GL_NOCACHE bit when the glock was released. That forced the rindex inode to be invalidated, which caused us to re-read rindex at the next access. However, it caused the glock to be unnecessarily bounced around the cluster. This patch allows the glock to remain cached, but it still causes the rindex to be re-read once it has been written to by gfs2_grow. Ben and I have tested single-node gfs2_grow cases and I've tested clustered gfs2_grow cases on my four-node cluster. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Make sure rindex is uptodate before starting transactionsBob Peterson2012-04-055-6/+36
| | | | | | | | | | | | | | | | | | This patch removes the call from gfs2_blk2rgrd to function gfs2_rindex_update and replaces it with individual calls. The former way turned out to be too problematic. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: use depends instead of select in kconfigBenjamin Poirier2012-03-261-5/+2
| | | | | | | | | | | | | | | | | | | | | | | | Avoids having to duplicate the dependencies of what is 'select'ed (and on down...) Those dependencies are currently incomplete, leading to broken builds with GFS2_FS_LOCKING_DLM=y and IP_SCTP=n. Signed-off-by: Benjamin Poirier <bpoirier@suse.de> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: put glock reference in error patch of read_rindex_entryBob Peterson2012-03-261-0/+1
| | | | | | | | | | | | | | | | | | | | This patch fixes the error path of function read_rindex_entry so that it correctly gives up its glock reference in cases where there is a race to re-read the rindex after gfs2_grow. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* | get rid of pointless includes of ext2_fs.hAl Viro2012-03-311-1/+0
|/ | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmwLinus Torvalds2012-03-2119-245/+804
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull gfs2 changes from Steven Whitehouse. * git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw: GFS2: Change truncate page allocation to be GFP_NOFS GFS2: call gfs2_write_alloc_required for each chunk GFS2: Clean up log flush header writing GFS2: Remove a __GFP_NOFAIL allocation GFS2: Flush pending glock work when evicting an inode GFS2: make sure rgrps are up to date in func gfs2_blk2rgrpd GFS2: Eliminate sd_rindex_mutex GFS2: Unlock rindex mutex on glock error GFS2: Make bd_cmp() static GFS2: Sort the ordered write list GFS2: FITRIM ioctl support GFS2: Move two functions from log.c to lops.c GFS2: glock statistics gathering
| * GFS2: Change truncate page allocation to be GFP_NOFSBob Peterson2012-03-202-3/+3
| | | | | | | | | | | | | | | | | | This patch changes the page allocation in gfs2_block_truncate_page and two others to GFP_NOFS to avoid deadlock in low-memory conditions. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: call gfs2_write_alloc_required for each chunkBenjamin Marzinski2012-03-091-5/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | gfs2_fallocate was calling gfs2_write_alloc_required() once at the start of the function. This caused problems since gfs2_write_alloc_required used a long unsigned int for the len, but gfs2_fallocate could allocate a much larger amount. This patch will move the call into the loop where the chunks are actually allocated and zeroed out. This will keep the allocation size under the limit, and also allow gfs2_fallocate to quickly skip over sections of the file that are already completely allocated. fallcate_chunk was also not correctly setting the file size. It was using the len veriable to find the last block written to, but by the time it was setting the size, the len variable had already been decremented to 0. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Clean up log flush header writingSteven Whitehouse2012-03-091-65/+66
| | | | | | | | | | | | | | | | | | | | | | | | We already send both a pre and post flush to the block device when writing a journal header. There is no need to wait for the previous I/O specifically when we do this, unless we've turned "barriers" off. As a side effect, this also cleans up the code path for flushing the journal and makes it more readable. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Remove a __GFP_NOFAIL allocationSteven Whitehouse2012-03-084-2/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to ensure that we've got enough buffer heads for flushing the journal, the orignal code used __GFP_NOFAIL when performing this allocation. Here we dispense with that in favour of using a mempool. This should improve efficiency in low memory conditions since flushing the journal is a good way to get memory back, we don't want to be spinning, waiting on memory allocations. The buffers which are allocated via this mempool are fairly short lived, so that we'll recycle them pretty quickly. Although there are other memory allocations which occur during the journal flush process, this is the one which can potentially require the most memory, so the most important one to fix. The amount of memory reserved is a fixed amount, and we should not need to scale it when there are a greater number of filesystems in use. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Flush pending glock work when evicting an inodeSteven Whitehouse2012-03-071-0/+1
| | | | | | | | | | | | | | This ensures that we will not try to access the inode thats being flushed via the glock after it has been freed. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: make sure rgrps are up to date in func gfs2_blk2rgrpdBob Peterson2012-03-051-10/+4
| | | | | | | | | | | | | | | | | | | | | | This patch adds a call to gfs2_rindex_update from function gfs2_blk2rgrpd and removes calls to it that are made redundant by it. The problem is that a gfs2_grow can add rgrps to the rindex, then put those rgrps into use, thus rendering the rindex we read in at mount time incomplete. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Eliminate sd_rindex_mutexBob Peterson2012-03-053-14/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Over time, we've slowly eliminated the use of sd_rindex_mutex. Up to this point, it was only used in two places: function gfs2_ri_total (which totals the file system size by reading and parsing the rindex file) and function gfs2_rindex_update which updates the rgrps in memory. Both of these functions have the rindex glock to protect them, so the rindex is unnecessary. Since gfs2_grow writes to the rindex via the meta_fs, the mutex is in the wrong order according to the normal rules. This patch eliminates the mutex entirely to avoid the problem. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Unlock rindex mutex on glock errorBob Peterson2012-03-011-1/+2
| | | | | | | | | | | | | | | | | | This patch fixes an error path in function gfs2_rindex_update that leaves the rindex mutex held. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Make bd_cmp() staticSteven Whitehouse2012-02-281-1/+1
| | | | | | | | | | | | Add missing static to bd_cmp() Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Sort the ordered write listBob Peterson2012-02-281-0/+16
| | | | | | | | | | | | | | | | | | | | | | This patch sorts the ordered write list for GFS2 writes. This increases the throughput for simultaneous writes. For example, if you have ten processes, all doing: dd if=/dev/zero of=/mnt/gfs2/fileX on different files, the throughput will be much better. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: FITRIM ioctl supportSteven Whitehouse2012-02-287-36/+152
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The FITRIM ioctl provides an alternative way to send discard requests to the underlying device. Using the discard mount option results in every freed block generating a discard request to the block device. This can be slow, since many block devices can only process discard requests of larger sizes, and also such operations can be time consuming. Rather than using the discard mount option, FITRIM allows a sweep of the filesystem on an occasional basis, and also to optionally avoid sending down discard requests for smaller regions. In GFS2 FITRIM will work at resource group granularity. There is a flag for each resource group which keeps track of which resource groups have been trimmed. This flag is reset whenever a deallocation occurs in the resource group, and set whenever a successful FITRIM of that resource group has taken place. This helps to reduce repeated discard requests for the same block ranges, again improving performance. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Move two functions from log.c to lops.cSteven Whitehouse2012-02-283-101/+97
| | | | | | | | | | | | | | | | gfs2_log_get_buf() and gfs2_log_fake_buf() are both used only in lops.c, so move them next to their callers and they can then become static. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: glock statistics gatheringSteven Whitehouse2012-02-285-19/+431
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The stats are divided into two sets: those relating to the super block and those relating to an individual glock. The super block stats are done on a per cpu basis in order to try and reduce the overhead of gathering them. They are also further divided by glock type. In the case of both the super block and glock statistics, the same information is gathered in each case. The super block statistics are used to provide default values for most of the glock statistics, so that newly created glocks should have, as far as possible, a sensible starting point. The statistics are divided into three pairs of mean and variance, plus two counters. The mean/variance pairs are smoothed exponential estimates and the algorithm used is one which will be very familiar to those used to calculation of round trip times in network code. The three pairs of mean/variance measure the following things: 1. DLM lock time (non-blocking requests) 2. DLM lock time (blocking requests) 3. Inter-request time (again to the DLM) A non-blocking request is one which will complete right away, whatever the state of the DLM lock in question. That currently means any requests when (a) the current state of the lock is exclusive (b) the requested state is either null or unlocked or (c) the "try lock" flag is set. A blocking request covers all the other lock requests. There are two counters. The first is there primarily to show how many lock requests have been made, and thus how much data has gone into the mean/variance calculations. The other counter is counting queueing of holders at the top layer of the glock code. Hopefully that number will be a lot larger than the number of dlm lock requests issued. So why gather these statistics? There are several reasons we'd like to get a better idea of these timings: 1. To be able to better set the glock "min hold time" 2. To spot performance issues more easily 3. To improve the algorithm for selecting resource groups for allocation (to base it on lock wait time, rather than blindly using a "try lock") Due to the smoothing action of the updates, a step change in some input quantity being sampled will only fully be taken into account after 8 samples (or 4 for the variance) and this needs to be carefully considered when interpreting the results. Knowing both the time it takes a lock request to complete and the average time between lock requests for a glock means we can compute the total percentage of the time for which the node is able to use a glock vs. time that the rest of the cluster has its share. That will be very useful when setting the lock min hold time. The other point to remember is that all times are in nanoseconds. Great care has been taken to ensure that we measure exactly the quantities that we want, as accurately as possible. There are always inaccuracies in any measuring system, but I hope this is as accurate as we can reasonably make it. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* | Merge branch 'for-linus' of ↵Linus Torvalds2012-03-211-2/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs pile 1 from Al Viro: "This is _not_ all; in particular, Miklos' and Jan's stuff is not there yet." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (64 commits) ext4: initialization of ext4_li_mtx needs to be done earlier debugfs-related mode_t whack-a-mole hfsplus: add an ioctl to bless files hfsplus: change finder_info to u32 hfsplus: initialise userflags qnx4: new helper - try_extent() qnx4: get rid of qnx4_bread/qnx4_getblk take removal of PF_FORKNOEXEC to flush_old_exec() trim includes in inode.c um: uml_dup_mmap() relies on ->mmap_sem being held, but activate_mm() doesn't hold it um: embed ->stub_pages[] into mmu_context gadgetfs: list_for_each_safe() misuse ocfs2: fix leaks on failure exits in module_init ecryptfs: make register_filesystem() the last potential failure exit ntfs: forgets to unregister sysctls on register_filesystem() failure logfs: missing cleanup on register_filesystem() failure jfs: mising cleanup on register_filesystem() failure make configfs_pin_fs() return root dentry on success configfs: configfs_create_dir() has parent dentry in dentry->d_parent configfs: sanitize configfs_create() ...
| * | switch open-coded instances of d_make_root() to new helperAl Viro2012-03-201-2/+1
| |/ | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | gfs2: remove the second argument of k[un]map_atomic()Cong Wang2012-03-203-12/+12
|/ | | | Signed-off-by: Cong Wang <amwang@redhat.com>
* GFS2: Read resource groups on mountSteven Whitehouse2012-02-284-20/+17
| | | | | | | | | | | | | This makes mount take slightly longer, but at the same time, the first write to the filesystem will be faster too. It also means that if there is a problem in the resource index, then we can refuse to mount rather than having to try and report that when the first write occurs. In addition, to avoid recursive locking, we hvae to take account of instances when the rindex glock may already be held when we are trying to update the rbtree of resource groups. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Ensure rindex is uptodate for fallocateBob Peterson2012-02-281-0/+5
| | | | | | | | | | | | | This patch fixes a problem whereby gfs2_grow was failing and causing GFS2 to assert. The problem was that when GFS2's fallocate operation tried to acquire an "allocation" it made sure the rindex was up to date, and if not, it called gfs2_rindex_update. However, if the file being fallocated was the rindex itself, it was already locked at that point. By calling gfs2_rindex_update at an earlier point in time, we bring rindex up to date and thereby avoid trying to lock it when the "allocation" is acquired. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
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