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path: root/fs/gfs2/rgrp.c
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2012-09-24GFS2: Fix infinite loop in rbm_findBob Peterson
This patch fixes an infinite loop in gfs2_rbm_find that was introduced by the previous patch. The problem occurred when the length was less than 3 but the rbm block was byte-aligned, causing it to improperly return a extent length of zero, which caused it to spin. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Tested-by: Bob Peterson <rpeterso@redhat.com> Tested-by: Barry Marson <bmarson@redhat.com>
2012-09-24GFS2: Consolidate free block searching functionsSteven Whitehouse
With the recently added block reservation code, an additional function was added to search for free blocks. This had a restriction of only being able to search for aligned extents of free blocks. As a result the allocation patterns when reserving blocks were suboptimal when the existing allocation of blocks for an inode was not aligned to the same boundary. This patch resolves that problem by adding the ability for gfs2_rbm_find to search for extents of a particular minimum size. We can then use gfs2_rbm_find for both looking for reservations, and also looking for free blocks on an individual basis when we actually come to do the allocation later on. As a result we only need a single set of code to deal with both situations. The function gfs2_rbm_from_block() is moved up rgrp.c so that it occurs before all of its callers. Many thanks are due to Bob for helping track down the final issue in this patch. That fix to the rb_tree traversal and to not share block reservations from a dirctory to its children is included here. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2012-09-24GFS2: Stop block extents at the end of bitmapsBob Peterson
This patch stops multiple block allocations if a nonzero return code is received from gfs2_rbm_from_block. Without this patch, if enough pressure is put on the file system, you get a kernel warning quickly followed by: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffffa04f47e8>] gfs2_alloc_blocks+0x2c8/0x880 [gfs2] With this patch, things run normally. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-09-24GFS2: Fix unclaimed_blocks() wrapping bug and clean upSteven Whitehouse
When rgd->rd_free_clone is less than rgd->rd_reserved, the unclaimed_blocks() calculation would wrap and produce incorrect results. This patch checks for this condition when this function is called from gfs2_mblk_search() In addition, the use of this particular function in other places in the code has been dropped by means of a general clean up of gfs2_inplace_reserve(). This function is now much easier to follow. Also the setting of the rgd->rd_last_alloc field is corrected. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-09-24GFS2: Improve block reservation tracingSteven Whitehouse
This patch improves the tracing of block reservations by removing some corner cases and also providing more useful detail in the traces. A new field is added to the reservation structure to contain the inode number. This is used since in certain contexts it is not possible to access the inode itself to obtain this information. As a result we can then display the inode number for all tracepoints and also in case we dump the resource group. The "del" tracepoint operation has been removed. This could be called with the reservation rgrp set to NULL. That resulted in not printing the device number, and thus making the information largely useless anyway. Also, the conditional on the rgrp being NULL can then be removed from the tracepoint. After this change, all the block reservation tracepoint calls will be called with the rgrp information. The existing ins,clm and tdel calls to the block reservation tracepoint are sufficient to track the entire life of the block reservation. In gfs2_block_alloc() the error detection is updated to print out the inode number of the problematic inode. This can then be compared against the information in the glock dump,tracepoints, etc. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-09-24GFS2: Fall back to ignoring reservations, if there are no other blocks leftSteven Whitehouse
When we get to the stage of allocating blocks, we know that the resource group in question must contain enough free blocks, otherwise gfs2_inplace_reserve() would have failed. So if we are left with only free blocks which are reserved, then we must use those. This can happen if another node has sneeked in and use some blocks reserved on this node, for example. Generally this will happen very rarely and only when the resouce group is nearly full. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-09-24GFS2: Use rbm for gfs2_setbit()Steven Whitehouse
Use the rbm structure for gfs2_setbit() in order to simplify the arguments to the function. We have to add a bool to control whether the clone bitmap should be updated (if it exists) but otherwise it is a more or less direct substitution. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-09-24GFS2: Use rbm for gfs2_testbit()Steven Whitehouse
Change the arguments to gfs2_testbit() so that it now just takes an rbm specifying the position of the two bit entry to return. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-09-24GFS2: Eliminate unnecessary check for state > 3 in bitfitBob Peterson
Function gfs2_bitfit was checking for state > 3, but that's impossible since it is only called from rgblk_search, which receives only GFS2_BLKST_ constants. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-09-24GFS2: rbm code cleanupBob Peterson
This patch fixes a few small rbm related things. First, it fixes a corner case where the rbm needs to switch bitmaps and wasn't adjusting its buffer pointer. Second, there's a white space issue fixed. Third, the logic in function gfs2_rbm_from_block was optimized a bit. Lastly, a check for goal block overflows was added to function gfs2_alloc_blocks. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-09-24GFS2: Fix case where reservation finished at end of rgrpSteven Whitehouse
One corner case which the original patch failed to take into account was when there is a reservation which ended such that the following block was one beyond the end of the rgrp in question. This extra test fixes that case. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Reported-by: Bob Peterson <rpeterso@redhat.com> Tested-by: Bob Peterson <rpeterso@redhat.com>
2012-09-24GFS2: Use RB_CLEAR_NODE() rather than rb_init_node()Michel Lespinasse
gfs2 calls RB_EMPTY_NODE() to check if nodes are not on an rbtree. The corresponding initialization function is RB_CLEAR_NODE(). rb_init_node() was never clearly defined and is going away. Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-09-24GFS2: Update rgblk_free() to use rbmSteven Whitehouse
Replace open coded version with a call to gfs2_rbm_from_block() Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-09-24GFS2: Update gfs2_get_block_type() to use rbmSteven Whitehouse
Use the new gfs2_rbm_from_block() function to replace an open coded version of the same code. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-09-24GFS2: Replace rgblk_search with gfs2_rbm_findSteven Whitehouse
This is part of a series of patches which are introducing the gfs2_rbm structure throughout the block allocation code. The main aim of this part is to create a search function which can deal directly with struct gfs2_rbm. In this case it specifies the initial position at which to start the search and also the point at which the search terminates. The net result of this is to clean up the search code and make it rather more readable, and the various possible exceptions which may occur during the search are partitioned into their own functions. There are some bug fixes too. We should not be checking the reservations while allocating extents - the time for that is when we are searching for where to put the extent, not when we've already made that decision. Also, rgblk_search had two uses, and in only one of those cases did it make sense to check for reservations. This is fixed in the new gfs2_rbm_find function, which has a cleaner interface. The reservation checking has been improved by always checking for contiguous reservations, and returning the first free block after all contiguous reservations. This is done under the spin lock to ensure consistancy of the tree. The allocation of extents is now in all cases done by the existing allocation code, and if there is an active reservation, that is updated after the fact. Again this is done under the spin lock, since it entails changing the lookup key for the reservation in question. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-09-24GFS2: Add structure to contain rgrp, bitmap, offset tupleSteven Whitehouse
This patch introduces a new structure, gfs2_rbm, which is a tuple of a resource group, a bitmap within the resource group and an offset within that bitmap. This is designed to make manipulating these sets of variables easier. There is also a new helper function which converts this representation back to a disk block address. In addition, the rbtree nodes which are used for the reservations were not being correctly initialised, which is now fixed. Also, the tracing was not passing through the inode where it should have been. That is mostly fixed aside from one corner case. This needs to be revisited since there can also be a NULL rgrp in some cases which results in the device being incorrect in the trace. This is intended to be the first step towards cleaning up some of the allocation code, and some further bug fixes. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-09-24GFS2: Remove rs_requested field from reservationsSteven Whitehouse
The rs_requested field is left over from the original allocation code, however this should have been a parameter passed to the various functions from gfs2_inplace_reserve() and not a member of the reservation structure as the value is not required after the initial allocation. This also helps simplify the code since we no longer need to set the rs_requested to zero. Also the gfs2_inplace_release() function can also be simplified since the reservation structure will always be defined when it is called, and the only remaining task is to unlock the rgrp if required. It can also now be called unconditionally too, resulting in a further simplification. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-09-13GFS2: Take account of blockages when using reserved blocksSteven Whitehouse
The claim_reserved_blks() function was not taking account of the possibility of "blockages" while performing allocation. This can be caused by another node allocating something in the same extent which has been reserved locally. This patch tests for this condition and then skips the remainder of the reservation in this case. This is a relatively rare event, so that it should not affect the general performance improvement which the block reservations provide. The claim_reserved_blks() function also appears not to be able to deal with reservations which cross bitmap boundaries, but that can be dealt with in a future patch since we don't generate boundary crossing reservations currently. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Reported-by: David Teigland <teigland@redhat.com> Cc: Bob Peterson <rpeterso@redhat.com>
2012-07-19GFS2: Reduce file fragmentationBob Peterson
This patch reduces GFS2 file fragmentation by pre-reserving blocks. The resulting improved on disk layout greatly speeds up operations in cases which would have resulted in interlaced allocation of blocks previously. A typical example of this is 10 parallel dd processes, each writing to a file in a common dirctory. The implementation uses an rbtree of reservations attached to each resource group (and each inode). Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-07-18GFS2: kernel panic with small gfs2 filesystems - 1 RGAbhijith Das
In the unlikely setup where there's only one resource group in the gfs2 filesystem, gfs2_rgrpd_get_next() returns a NULL rgd that is not dealt with properly, causing a kernel NULL ptr dereference. This patch fixes this issue. Signed-off-by: Abhi Das <adas@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-06-14GFS2: Combine functions get_local_rgrp and gfs2_inplace_reserveBob Peterson
This function combines rgrp functions get_local_rgrp and gfs2_inplace_reserve so that the double retry loop is gone. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-06-08GFS2: Use lvbs for storing rgrp information with mount optionBenjamin Marzinski
Instead of reading in the resource groups when gfs2 is checking for free space to allocate from, gfs2 can store the necessary infromation in the resource group's lvb. Also, instead of searching for unlinked inodes in every resource group that's checked for free space, gfs2 can store the number of unlinked but inodes in the lvb, and only check for unlinked inodes if it will find some. The first time a resource group is locked, the lvb must initialized. Since this involves counting the unlinked inodes in the resource group, this takes a little extra time. But after that, if the resource group is locked with GL_SKIP, the buffer head won't be read in unless it's actually needed. Enabling the resource groups lvbs is done via the rgrplvb mount option. If this option isn't set, the lvbs will still be set and updated, but they won't be verfied or used by the filesystem. To safely turn on this option, all of the nodes mounting the filesystem must be running code with this patch, and the filesystem must have been completely unmounted since they were updated. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-06-06GFS2: Fold quota data into the reservations structBob Peterson
This patch moves the ancillary quota data structures into the block reservations structure. This saves GFS2 some time and effort in allocating and deallocating the qadata structure. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-06-06GFS2: Extend the life of the reservationsBob Peterson
This patch lengthens the lifespan of the reservations structure for inodes. Before, they were allocated and deallocated for every write operation. With this patch, they are allocated when the first write occurs, and deallocated when the last process closes the file. It's more efficient to do it this way because it saves GFS2 a lot of unnecessary allocates and frees. It also gives us more flexibility for the future: (1) we can now fold the qadata structure back into the structure and save those alloc/frees, (2) we can use this for multi-block reservations. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-05-11GFS2: Add rgrp information to block_alloc trace pointBob Peterson
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>
2012-04-27GFS2: Eliminate needless parameter from function gfs2_setbitBob Peterson
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>
2012-04-24GFS2: Remove unused argument from gfs2_internal_readAndrew Price
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>
2012-04-24GFS2: Change variable blk to biblkBob Peterson
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>
2012-04-24GFS2: Fix function parameter comments in rgrp.cBob Peterson
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>
2012-04-24GFS2: Eliminate offset parameter to gfs2_setbitBob Peterson
This patch eliminates a redundant parameter. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-04-24GFS2: Use slab for block reservation memoryBob Peterson
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>
2012-04-05GFS2: Make sure rindex is uptodate before starting transactionsBob Peterson
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>
2012-03-26GFS2: put glock reference in error patch of read_rindex_entryBob Peterson
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>
2012-03-05GFS2: make sure rgrps are up to date in func gfs2_blk2rgrpdBob Peterson
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>
2012-03-05GFS2: Eliminate sd_rindex_mutexBob Peterson
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>
2012-03-01GFS2: Unlock rindex mutex on glock errorBob Peterson
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>
2012-02-28GFS2: FITRIM ioctl supportSteven Whitehouse
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>
2012-02-28GFS2: Read resource groups on mountSteven Whitehouse
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>
2012-01-11GFS2: Fix a use-after-free that coverity spottedBob Peterson
In function gfs2_inplace_release it was trying to unlock a gfs2_holder structure associated with a reservation, after said reservation was freed. The problem is that the statements have the wrong order. This patch corrects the order so that the reservation is freed after the gfs2_holder is unlocked. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-11-22GFS2: Fix multi-block allocationSteven Whitehouse
Clean up gfs2_alloc_blocks so that it takes the full extent length rather than just the number of non-inode blocks as an argument. That will only make a difference in the inode allocation case for now. Also, this fixes the extent length handling around gfs2_alloc_extent() so that multi block allocations will work again. The rd_last_alloc block is set to the final block in the allocated extent (as per the update to i_goal, but referenced to a different start point). This also removes the dinode argument to rgblk_search() which is no longer used. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-11-22GFS2: decouple quota allocations from block allocationsBob Peterson
This patch separates the code pertaining to allocations into two parts: quota-related information and block reservations. This patch also moves all the block reservation structure allocations to function gfs2_inplace_reserve to simplify the code, and moves the frees to function gfs2_inplace_release. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-11-21GFS2: split function rgblk_searchBob Peterson
This patch splits function rgblk_search into a function that finds blocks to allocate (rgblk_search) and a function that assigns those blocks (gfs2_alloc_extent). Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@rehat.com>
2011-11-21GFS2: Fix up "off by one" in the previous patchSteven Whitehouse
The trace point should take extlen and not *ndata as the extent length. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-11-21GFS2: move toward a generic multi-block allocatorBob Peterson
This patch is a revision of the one I previously posted. I tried to integrate all the suggestions Steve gave. The purpose of the patch is to change function gfs2_alloc_block (allocate either a dinode block or an extent of data blocks) to a more generic gfs2_alloc_blocks function that can allocate both a dinode _and_ an extent of data blocks in the same call. This will ultimately help us create a multi-block reservation scheme to reduce file fragmentation. This patch moves more toward a generic multi-block allocator that takes a pointer to the number of data blocks to allocate, plus whether or not to allocate a dinode. In theory, it could be called to allocate (1) a single dinode block, (2) a group of one or more data blocks, or (3) a dinode plus several data blocks. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-11-18GFS2: remove vestigial al_allocedBob Peterson
This patch removes the vestigial variable al_alloced from the gfs2_alloc structure. This is another baby step toward multi-block reservations. My next planned step is to decouple the quota variables from the gfs2_alloc structure so we can use a different method for allocations. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-11-15GFS2: combine gfs2_alloc_block and gfs2_alloc_diBob Peterson
GFS2 functions gfs2_alloc_block and gfs2_alloc_di do basically the same things, with a few exceptions. This patch combines the two functions into a slightly more generic gfs2_alloc_block. Having one centralized block allocation function will reduce code redundancy and make it easier to implement multi-block reservations to reduce file fragmentation in the future. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-11-15GFS2: Add non-try locks back to get_local_rgrpBob Peterson
This upstream patch had what I believe is an unintended consequence: http://git.kernel.org/?p=linux/kernel/git/steve/gfs2-3.0-nmw.git;a=commitdiff;h=beca42486749c1538a5ed58fe9dcc9f26d428c93 The patch changed function get_local_rgrp such that it ONLY used TRY locks for RGRP searches. Prior to that patch, the code used TRY locks during the first loop, and if that was unsuccessful, it used normal blocking locks on subsequent searches. This patch changes it back to the old way. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-10-21GFS2: Remove two unused variablesSteven Whitehouse
The two variables being initialised in gfs2_inplace_reserve to track the file & line number of the caller are never used, so we might as well remove them. If something does go wrong, then a stack trace is probably more useful anyway. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-10-21GFS2: Fix off-by-one in gfs2_blk2rgrpdSteven Whitehouse
Bob reported: I found an off-by-one problem with how I coded this section: It should be: + else if (blk >= cur->rd_data0 + cur->rd_data) In fact, cur->rd_data0 + cur->rd_data is the start of the next rgrp (the next ri_addr), so without the "=" check it can land on the wrong rgrp. In all normal cases, this won't be a problem: you're searching for a block _within_ the rgrp, which will pass the test properly. Where it gets into trouble is if you search the rgrps for the block exactly equal to ri_addr. I don't think anything in the kernel does this, but I found a place in gfs2-utils gfs2_edit where it does. So I definitely need to fix it in libgfs2. I'd like to suggest we fix it in the kernel as well for the sake of keeping the functions similar. So this patch fixes the above mentioned off by one error as well as removing the unused parent pointer. Reported-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-10-21GFS2: Correctly set goal block after allocationSteven Whitehouse
The new goal block should be set to the end of the newly allocated extent, not the start of it. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>