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path: root/fs/xfs/xfs_alloc.c
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2007-07-14[XFS] Clean up function name handling in tracing codeEric Sandeen
Remove the hardcoded "fnames" for tracing, and just embed them in tracing macros via __FUNCTION__. Kills a lot of #ifdefs too. SGI-PV: 967353 SGI-Modid: xfs-linux-melb:xfs-kern:29099a Signed-off-by: Eric Sandeen <sandeen@sandeen.net> Signed-off-by: David Chinner <dgc@sgi.com> Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-07-14[XFS] Lazy Superblock CountersDavid Chinner
When we have a couple of hundred transactions on the fly at once, they all typically modify the on disk superblock in some way. create/unclink/mkdir/rmdir modify inode counts, allocation/freeing modify free block counts. When these counts are modified in a transaction, they must eventually lock the superblock buffer and apply the mods. The buffer then remains locked until the transaction is committed into the incore log buffer. The result of this is that with enough transactions on the fly the incore superblock buffer becomes a bottleneck. The result of contention on the incore superblock buffer is that transaction rates fall - the more pressure that is put on the superblock buffer, the slower things go. The key to removing the contention is to not require the superblock fields in question to be locked. We do that by not marking the superblock dirty in the transaction. IOWs, we modify the incore superblock but do not modify the cached superblock buffer. In short, we do not log superblock modifications to critical fields in the superblock on every transaction. In fact we only do it just before we write the superblock to disk every sync period or just before unmount. This creates an interesting problem - if we don't log or write out the fields in every transaction, then how do the values get recovered after a crash? the answer is simple - we keep enough duplicate, logged information in other structures that we can reconstruct the correct count after log recovery has been performed. It is the AGF and AGI structures that contain the duplicate information; after recovery, we walk every AGI and AGF and sum their individual counters to get the correct value, and we do a transaction into the log to correct them. An optimisation of this is that if we have a clean unmount record, we know the value in the superblock is correct, so we can avoid the summation walk under normal conditions and so mount/recovery times do not change under normal operation. One wrinkle that was discovered during development was that the blocks used in the freespace btrees are never accounted for in the AGF counters. This was once a valid optimisation to make; when the filesystem is full, the free space btrees are empty and consume no space. Hence when it matters, the "accounting" is correct. But that means the when we do the AGF summations, we would not have a correct count and xfs_check would complain. Hence a new counter was added to track the number of blocks used by the free space btrees. This is an *on-disk format change*. As a result of this, lazy superblock counters are a mkfs option and at the moment on linux there is no way to convert an old filesystem. This is possible - xfs_db can be used to twiddle the right bits and then xfs_repair will do the format conversion for you. Similarly, you can convert backwards as well. At some point we'll add functionality to xfs_admin to do the bit twiddling easily.... SGI-PV: 964999 SGI-Modid: xfs-linux-melb:xfs-kern:28652a Signed-off-by: David Chinner <dgc@sgi.com> Signed-off-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-05-08[XFS] reducing the number of random number functions.Joe Perches
Patch provided by Joe Perches SGI-PV: 961696 SGI-Modid: xfs-linux-melb:xfs-kern:28209a Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Lachlan McIlroy <lachlan@sgi.com> Signed-off-by: Tim Shimmin <tes@sgi.com>
2006-09-28[XFS] Minor code rearranging and cleanup to prevent some coverity falseNathan Scott
positives. SGI-PV: 955502 SGI-Modid: xfs-linux-melb:xfs-kern:26805a Signed-off-by: Nathan Scott <nathans@sgi.com> Signed-off-by: Tim Shimmin <tes@sgi.com>
2006-09-28[XFS] endianess annotation for xfs_agfl_t. Trivial, xfs_agfl_t is alwaysChristoph Hellwig
used for ondisk values. SGI-PV: 954580 SGI-Modid: xfs-linux-melb:xfs-kern:26553a Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Nathan Scott <nathans@sgi.com> Signed-off-by: Tim Shimmin <tes@sgi.com>
2006-08-10[XFS] Fix xfs_free_extent related NULL pointer dereference.Nathan Scott
We recently fixed an out-of-space deadlock in XFS, and part of that fix involved the addition of the XFS_ALLOC_FLAG_FREEING flag to some of the space allocator calls to indicate they're freeing space, not allocating it. There was a missed xfs_alloc_fix_freelist condition test that did not correctly test "flags". The same test would also test an uninitialised structure field (args->userdata) and depending on its value either would or would not return early with a critical buffer pointer set to NULL. This fixes that up, adds asserts to several places to catch future botches of this nature, and skips sections of xfs_alloc_fix_freelist that are irrelevent for the space-freeing case. SGI-PV: 955303 SGI-Modid: xfs-linux-melb:xfs-kern:26743a Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-06-20[XFS] Remove version 1 directory code. Never functioned on Linux, justNathan Scott
pure bloat. SGI-PV: 952969 SGI-Modid: xfs-linux-melb:xfs-kern:26251a Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-06-09[XFS] In actual allocation of file system blocks and freeing extents, theYingping Lu
transaction within each such operation may involve multiple locking of AGF buffer. While the freeing extent function has sorted the extents based on AGF number before entering into transaction, however, when the file system space is very limited, the allocation of space would try every AGF to get space allocated, this could potentially cause out-of-order locking, thus deadlock could happen. This fix mitigates the scarce space for allocation by setting aside a few blocks without reservation, and avoid deadlock by maintaining ascending order of AGF locking. SGI-PV: 947395 SGI-Modid: xfs-linux-melb:xfs-kern:210801a Signed-off-by: Yingping Lu <yingping@sgi.com> Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-05-08[XFS] Fix a possible metadata buffer (AGFL) refcount leak when fixing anNathan Scott
AG freelist. SGI-PV: 952681 SGI-Modid: xfs-linux-melb:xfs-kern:25902a Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-03-29[XFS] We really suck at spulling. Thanks to Chris Pascoe for fixing allNathan Scott
these typos. SGI-PV: 904196 SGI-Modid: xfs-linux-melb:xfs-kern:25539a Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-11-02[XFS] Endianess annotations for various allocator data structuresChristoph Hellwig
SGI-PV: 943272 SGI-Modid: xfs-linux:xfs-kern:201006a Signed-off-by: Christoph Hellwig <hch@sgi.com> Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-11-02[XFS] Update license/copyright notices to match the prefered SGINathan Scott
boilerplate. SGI-PV: 913862 SGI-Modid: xfs-linux:xfs-kern:23903a Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-11-02[XFS] Remove xfs_macros.c, xfs_macros.h, rework headers a whole lot.Nathan Scott
SGI-PV: 943122 SGI-Modid: xfs-linux:xfs-kern:23901a Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-06-21[XFS] mark various symbols static Patch from Adrian BunkChristoph Hellwig
SGI-PV: 936255 SGI-Modid: xfs-linux:xfs-kern:192760a Signed-off-by: Christoph Hellwig <hch@sgi.com> Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!