)]}'
{
  "log": [
    {
      "commit": "795d580baec0d5386b83a8b557df47c20810e86b",
      "tree": "d0387c37562e9e27a4f43cf7ae425319cbdad359",
      "parents": [
        "449cedf099b23a250e7d61982e35555ccb871182",
        "109f6aef5fc436f355ad027f4d97bd696df2049a"
      ],
      "author": {
        "name": "Linus Torvalds",
        "email": "torvalds@linux-foundation.org",
        "time": "Mon Apr 05 13:21:15 2010 -0700"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@linux-foundation.org",
        "time": "Mon Apr 05 13:21:15 2010 -0700"
      },
      "message": "Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable\n\n* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:\n  Btrfs: add check for changed leaves in setup_leaf_for_split\n  Btrfs: create snapshot references in same commit as snapshot\n  Btrfs: fix small race with delalloc flushing waitqueue\u0027s\n  Btrfs: use add_to_page_cache_lru, use __page_cache_alloc\n  Btrfs: fix chunk allocate size calculation\n  Btrfs: kill max_extent mount option\n  Btrfs: fail to mount if we have problems reading the block groups\n  Btrfs: check btrfs_get_extent return for IS_ERR()\n  Btrfs: handle kmalloc() failure in inode lookup ioctl\n  Btrfs: dereferencing freed memory\n  Btrfs: Simplify num_stripes\u0027s calculation logical for __btrfs_alloc_chunk()\n  Btrfs: Add error handle for btrfs_search_slot() in btrfs_read_chunk_tree()\n  Btrfs: Remove unnecessary finish_wait() in wait_current_trans()\n  Btrfs: add NULL check for do_walk_down()\n  Btrfs: remove duplicate include in ioctl.c\n\nFix trivial conflict in fs/btrfs/compression.c due to slab.h include\ncleanups.\n"
    },
    {
      "commit": "28ecb60906e86e74e9ad4ac7e0218d8631e73a94",
      "tree": "7214fa7bfb39f789aa4a78e174e39f61ef101b95",
      "parents": [
        "0cad8a1130f77c7c445e3298c0e3593b3c0ef439"
      ],
      "author": {
        "name": "Nick Piggin",
        "email": "npiggin@suse.de",
        "time": "Wed Mar 17 13:31:04 2010 +0000"
      },
      "committer": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Mon Apr 05 14:41:51 2010 -0400"
      },
      "message": "Btrfs: use add_to_page_cache_lru, use __page_cache_alloc\n\nPagecache pages should be allocated with __page_cache_alloc, so they\nobey pagecache memory policies.\n\nadd_to_page_cache_lru is exported, so it should be used. Benefits over\nusing a private pagevec: neater code, 128 bytes fewer stack used, percpu\nlru ordering is preserved, and finally don\u0027t need to flush pagevec\nbefore returning so batching may be shared with other LRU insertions.\n\nSigned-off-by: Nick Piggin \u003cnpiggin@suse.de\u003e:\nSigned-off-by: Chris Mason \u003cchris.mason@oracle.com\u003e\n"
    },
    {
      "commit": "5a0e3ad6af8660be21ca98a971cd00f331318c05",
      "tree": "5bfb7be11a03176a87296a43ac6647975c00a1d1",
      "parents": [
        "ed391f4ebf8f701d3566423ce8f17e614cde9806"
      ],
      "author": {
        "name": "Tejun Heo",
        "email": "tj@kernel.org",
        "time": "Wed Mar 24 17:04:11 2010 +0900"
      },
      "committer": {
        "name": "Tejun Heo",
        "email": "tj@kernel.org",
        "time": "Tue Mar 30 22:02:32 2010 +0900"
      },
      "message": "include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h\n\npercpu.h is included by sched.h and module.h and thus ends up being\nincluded when building most .c files.  percpu.h includes slab.h which\nin turn includes gfp.h making everything defined by the two files\nuniversally available and complicating inclusion dependencies.\n\npercpu.h -\u003e slab.h dependency is about to be removed.  Prepare for\nthis change by updating users of gfp and slab facilities include those\nheaders directly instead of assuming availability.  As this conversion\nneeds to touch large number of source files, the following script is\nused as the basis of conversion.\n\n  http://userweb.kernel.org/~tj/misc/slabh-sweep.py\n\nThe script does the followings.\n\n* Scan files for gfp and slab usages and update includes such that\n  only the necessary includes are there.  ie. if only gfp is used,\n  gfp.h, if slab is used, slab.h.\n\n* When the script inserts a new include, it looks at the include\n  blocks and try to put the new include such that its order conforms\n  to its surrounding.  It\u0027s put in the include block which contains\n  core kernel includes, in the same order that the rest are ordered -\n  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there\n  doesn\u0027t seem to be any matching order.\n\n* If the script can\u0027t find a place to put a new include (mostly\n  because the file doesn\u0027t have fitting include block), it prints out\n  an error message indicating which .h file needs to be added to the\n  file.\n\nThe conversion was done in the following steps.\n\n1. The initial automatic conversion of all .c files updated slightly\n   over 4000 files, deleting around 700 includes and adding ~480 gfp.h\n   and ~3000 slab.h inclusions.  The script emitted errors for ~400\n   files.\n\n2. Each error was manually checked.  Some didn\u0027t need the inclusion,\n   some needed manual addition while adding it to implementation .h or\n   embedding .c file was more appropriate for others.  This step added\n   inclusions to around 150 files.\n\n3. The script was run again and the output was compared to the edits\n   from #2 to make sure no file was left behind.\n\n4. Several build tests were done and a couple of problems were fixed.\n   e.g. lib/decompress_*.c used malloc/free() wrappers around slab\n   APIs requiring slab.h to be added manually.\n\n5. The script was run on all .h files but without automatically\n   editing them as sprinkling gfp.h and slab.h inclusions around .h\n   files could easily lead to inclusion dependency hell.  Most gfp.h\n   inclusion directives were ignored as stuff from gfp.h was usually\n   wildly available and often used in preprocessor macros.  Each\n   slab.h inclusion directive was examined and added manually as\n   necessary.\n\n6. percpu.h was updated not to include slab.h.\n\n7. Build test were done on the following configurations and failures\n   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my\n   distributed build env didn\u0027t work with gcov compiles) and a few\n   more options had to be turned off depending on archs to make things\n   build (like ipr on powerpc/64 which failed due to missing writeq).\n\n   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.\n   * powerpc and powerpc64 SMP allmodconfig\n   * sparc and sparc64 SMP allmodconfig\n   * ia64 SMP allmodconfig\n   * s390 SMP allmodconfig\n   * alpha SMP allmodconfig\n   * um on x86_64 SMP allmodconfig\n\n8. percpu.h modifications were reverted so that it could be applied as\n   a separate patch and serve as bisection point.\n\nGiven the fact that I had only a couple of failures from tests on step\n6, I\u0027m fairly confident about the coverage of this conversion patch.\nIf there is a breakage, it\u0027s likely to be something in one of the arch\nheaders which should be easily discoverable easily on most builds of\nthe specific arch.\n\nSigned-off-by: Tejun Heo \u003ctj@kernel.org\u003e\nGuess-its-ok-by: Christoph Lameter \u003ccl@linux-foundation.org\u003e\nCc: Ingo Molnar \u003cmingo@redhat.com\u003e\nCc: Lee Schermerhorn \u003cLee.Schermerhorn@hp.com\u003e\n"
    },
    {
      "commit": "ef5780c018ed169a77b623f87c4ba52faa8ad0fe",
      "tree": "4c93fbaa09ed4b2f4b9713ae462646d149be8550",
      "parents": [
        "5ff7ba3a797a8ffd5299b8477df2dca3c3ebd34e"
      ],
      "author": {
        "name": "Nick Piggin",
        "email": "npiggin@suse.de",
        "time": "Mon Mar 15 11:05:29 2010 -0400"
      },
      "committer": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Mon Mar 15 11:05:57 2010 -0400"
      },
      "message": "Btrfs: fix gfp flags masking in the compression code\n\nGFP_FS must be masked out, NOFS can\u0027t be or\u0027d in.\n\nSigned-off-by: Chris Mason \u003cchris.mason@oracle.com\u003e\n"
    },
    {
      "commit": "83ebade34bc1a90d0c3f77b87b940f336d075fda",
      "tree": "99b6366c52e6bec88119ae995399c985fc61e900",
      "parents": [
        "74fca6a42863ffacaf7ba6f1936a9f228950f657",
        "93c82d575055f1bd0277acae6f966bebafd80dd5"
      ],
      "author": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Fri Sep 11 19:07:25 2009 -0400"
      },
      "committer": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Fri Sep 11 19:07:25 2009 -0400"
      },
      "message": "Merge branch \u0027master\u0027 of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable\n"
    },
    {
      "commit": "890871be854b5f5e43e7ba2475f706209906cc24",
      "tree": "9d087adf7a28bb910992d07d93ea2a992e394110",
      "parents": [
        "57fd5a5ff8b48b99e90b22fc143082aba755c6c0"
      ],
      "author": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Wed Sep 02 16:24:52 2009 -0400"
      },
      "committer": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Fri Sep 11 13:31:05 2009 -0400"
      },
      "message": "Btrfs: switch extent_map to a rw lock\n\nThere are two main users of the extent_map tree.  The\nfirst is regular file inodes, where it is evenly spread\nbetween readers and writers.\n\nThe second is the chunk allocation tree, which maps blocks from\nlogical addresses to phyiscal ones, and it is 99.99% reads.\n\nThe mapping tree is a point of lock contention during heavy IO\nworkloads, so this commit switches things to a rw lock.\n\nSigned-off-by: Chris Mason \u003cchris.mason@oracle.com\u003e\n"
    },
    {
      "commit": "405f55712dfe464b3240d7816cc4fe4174831be2",
      "tree": "96c425ea7fa8b31058b8f83a433c5e5265c8ebc7",
      "parents": [
        "f9fabcb58a6d26d6efde842d1703ac7cfa9427b6"
      ],
      "author": {
        "name": "Alexey Dobriyan",
        "email": "adobriyan@gmail.com",
        "time": "Sat Jul 11 22:08:37 2009 +0400"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@linux-foundation.org",
        "time": "Sun Jul 12 12:22:34 2009 -0700"
      },
      "message": "headers: smp_lock.h redux\n\n* Remove smp_lock.h from files which don\u0027t need it (including some headers!)\n* Add smp_lock.h to files which do need it\n* Make smp_lock.h include conditional in hardirq.h\n  It\u0027s needed only for one kernel_locked() usage which is under CONFIG_PREEMPT\n\n  This will make hardirq.h inclusion cheaper for every PREEMPT\u003dn config\n  (which includes allmodconfig/allyesconfig, BTW)\n\nSigned-off-by: Alexey Dobriyan \u003cadobriyan@gmail.com\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@linux-foundation.org\u003e\n"
    },
    {
      "commit": "6cbff00f4632c8060b06bfc9585805217f11e12e",
      "tree": "1886c4c855662172b84be2bfbd2aa5ac6a5c429d",
      "parents": [
        "c289811cc096c57ff35550ee8132793a4f9b5b59"
      ],
      "author": {
        "name": "Christoph Hellwig",
        "email": "hch@lst.de",
        "time": "Fri Apr 17 10:37:41 2009 +0200"
      },
      "committer": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Wed Jun 10 11:29:52 2009 -0400"
      },
      "message": "Btrfs: implement FS_IOC_GETFLAGS/SETFLAGS/GETVERSION\n\nAdd support for the standard attributes set via chattr and read via\nlsattr.  Currently we store the attributes in the flags value in\nthe btrfs inode, but I wonder whether we should split it into two so\nthat we don\u0027t have to keep converting between the two formats.\n\nRemove the btrfs_clear_flag/btrfs_set_flag/btrfs_test_flag macros\nas they were confusing the existing code and got in the way of the\nnew additions.\n\nAlso add the FS_IOC_GETVERSION ioctl for getting i_generation as it\u0027s\ntrivial.\n\nSigned-off-by: Christoph Hellwig \u003chch@lst.de\u003e\nSigned-off-by: Chris Mason \u003cchris.mason@oracle.com\u003e\n"
    },
    {
      "commit": "7eaebe7d503c3ef240ac7b3efc5433fe647c0298",
      "tree": "6e54b7766559555d3a4e205a0524a4df02f6cf5b",
      "parents": [
        "070604040b86511cc2df0f25f98e26c5529bd928"
      ],
      "author": {
        "name": "Huang Weiyi",
        "email": "weiyi.huang@gmail.com",
        "time": "Wed Jan 21 10:49:16 2009 -0500"
      },
      "committer": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Wed Jan 21 10:49:16 2009 -0500"
      },
      "message": "Btrfs: removed unused #include \u003cversion.h\u003e\u0027s\n\nRemoved unused #include \u003cversion.h\u003e\u0027s in btrfs\n\nSigned-off-by: Huang Weiyi \u003cweiyi.huang@gmail.com\u003e\nSigned-off-by: Chris Mason \u003cchris.mason@oracle.com\u003e\n\n"
    },
    {
      "commit": "d397712bcc6a759a560fd247e6053ecae091f958",
      "tree": "9da8daebb870d8b8b1843507c4621715e23dd31a",
      "parents": [
        "1f3c79a28c8837e8572b98f6d14142d9a6133c56"
      ],
      "author": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Mon Jan 05 21:25:51 2009 -0500"
      },
      "committer": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Mon Jan 05 21:25:51 2009 -0500"
      },
      "message": "Btrfs: Fix checkpatch.pl warnings\n\nThere were many, most are fixed now.  struct-funcs.c generates some warnings\nbut these are bogus.\n\nSigned-off-by: Chris Mason \u003cchris.mason@oracle.com\u003e\n"
    },
    {
      "commit": "17d217fe970d34720f4f1633dca73a6aa2f3d9d1",
      "tree": "4e2e716400cc45a6697475629f4c046b96ff76e7",
      "parents": [
        "e4404d6e8da678d852b7f767f665f8edf76c9e9f"
      ],
      "author": {
        "name": "Yan Zheng",
        "email": "zheng.yan@oracle.com",
        "time": "Fri Dec 12 10:03:38 2008 -0500"
      },
      "committer": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Fri Dec 12 10:03:38 2008 -0500"
      },
      "message": "Btrfs: fix nodatasum handling in balancing code\n\nChecksums on data can be disabled by mount option, so it\u0027s\npossible some data extents don\u0027t have checksums or have\ninvalid checksums. This causes trouble for data relocation.\nThis patch contains following things to make data relocation\nwork.\n\n1) make nodatasum/nodatacow mount option only affects new\nfiles. Checksums and COW on data are only controlled by the\ninode flags.\n\n2) check the existence of checksum in the nodatacow checker.\nIf checksums exist, force COW the data extent. This ensure that\nchecksum for a given block is either valid or does not exist.\n\n3) update data relocation code to properly handle the case\nof checksum missing.\n\nSigned-off-by: Yan Zheng \u003czheng.yan@oracle.com\u003e\n\n"
    },
    {
      "commit": "d20f7043fa65659136c1a7c3c456eeeb5c6f431f",
      "tree": "05d1031cadec6d440a97221e3a32adb504a51699",
      "parents": [
        "c99e905c945c462085c6d64646dc5af0c0a16815"
      ],
      "author": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Mon Dec 08 16:58:54 2008 -0500"
      },
      "committer": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Mon Dec 08 16:58:54 2008 -0500"
      },
      "message": "Btrfs: move data checksumming into a dedicated tree\n\nBtrfs stores checksums for each data block.  Until now, they have\nbeen stored in the subvolume trees, indexed by the inode that is\nreferencing the data block.  This means that when we read the inode,\nwe\u0027ve probably read in at least some checksums as well.\n\nBut, this has a few problems:\n\n* The checksums are indexed by logical offset in the file.  When\ncompression is on, this means we have to do the expensive checksumming\non the uncompressed data.  It would be faster if we could checksum\nthe compressed data instead.\n\n* If we implement encryption, we\u0027ll be checksumming the plain text and\nstoring that on disk.  This is significantly less secure.\n\n* For either compression or encryption, we have to get the plain text\nback before we can verify the checksum as correct.  This makes the raid\nlayer balancing and extent moving much more expensive.\n\n* It makes the front end caching code more complex, as we have touch\nthe subvolume and inodes as we cache extents.\n\n* There is potentitally one copy of the checksum in each subvolume\nreferencing an extent.\n\nThe solution used here is to store the extent checksums in a dedicated\ntree.  This allows us to index the checksums by phyiscal extent\nstart and length.  It means:\n\n* The checksum is against the data stored on disk, after any compression\nor encryption is done.\n\n* The checksum is stored in a central location, and can be verified without\nfollowing back references, or reading inodes.\n\nThis makes compression significantly faster by reducing the amount of\ndata that needs to be checksummed.  It will also allow much faster\nraid management code in general.\n\nThe checksums are indexed by a key with a fixed objectid (a magic value\nin ctree.h) and offset set to the starting byte of the extent.  This\nallows us to copy the checksum items into the fsync log tree directly (or\nany other tree), without having to invent a second format for them.\n\nSigned-off-by: Chris Mason \u003cchris.mason@oracle.com\u003e\n"
    },
    {
      "commit": "4b4e25f2a6ddb070bab7f7dd2bd2926fb8db9e04",
      "tree": "b4417e03a187efd6a88da75a41a94020a2bb76ac",
      "parents": [
        "79683f2d685cfb6ef9c97c5194e3ce3319e80cac"
      ],
      "author": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Thu Nov 20 10:22:27 2008 -0500"
      },
      "committer": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Thu Nov 20 10:22:27 2008 -0500"
      },
      "message": "Btrfs: compat code fixes\n\nThe btrfs git kernel trees is used to build a standalone tree for\ncompiling against older kernels.  This commit makes the standalone tree\nwork with 2.6.27\n\nSigned-off-by: Chris Mason \u003cchris.mason@oracle.com\u003e\n"
    },
    {
      "commit": "15916de835a683bd8133a0d1ac0c982b795ab4ff",
      "tree": "20603c2e0cade00d2e40a3b5390f5def36a02711",
      "parents": [
        "ae20a6afec1cf21919d97303f2d8b737eac5acc7"
      ],
      "author": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Wed Nov 19 21:17:22 2008 -0500"
      },
      "committer": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Wed Nov 19 21:17:22 2008 -0500"
      },
      "message": "Btrfs: Fixes for 2.6.28-rc API changes\n\n* open/close_bdev_excl -\u003e open/close_bdev_exclusive\n* blkdev_issue_discard takes a GFP mask now\n* Fix blkdev_issue_discard usage now that it is enabled\n\nSigned-off-by: Chris Mason \u003cchris.mason@oracle.com\u003e\n"
    },
    {
      "commit": "5b050f04c8ce911c5b6831305a24d70eab95e732",
      "tree": "ebc7be1f9526a75a8d7ac7a7984c20d728ca96d1",
      "parents": [
        "8247b41ac980d125de8aeba6f33f381056ac0ecb"
      ],
      "author": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Tue Nov 11 09:34:41 2008 -0500"
      },
      "committer": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Tue Nov 11 09:34:41 2008 -0500"
      },
      "message": "Btrfs: Fix compile warnings on 32 bit machines\n\nSimple casting here and there to fix things up.\n\nSigned-off-by: Chris Mason \u003cchris.mason@oracle.com\u003e\n\n"
    },
    {
      "commit": "e04ca626baee684bea9d6239e4e1119b696101b2",
      "tree": "f5327eae3e8393f19ef9f40426efb8b3488f36f6",
      "parents": [
        "ff5b7ee33d82414bf4baf299c21fb703bcc89629"
      ],
      "author": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Mon Nov 10 11:44:58 2008 -0500"
      },
      "committer": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Mon Nov 10 11:44:58 2008 -0500"
      },
      "message": "Btrfs: Fix use after free during compressed reads\n\nYan\u0027s fix to use the correct file offset during compressed reads used the\nextent_map struct pointer after it had been freed.  This saves the\nfields we want for later use instead.\n\nSigned-off-by: Chris Mason \u003cchris.mason@oracle.com\u003e\n"
    },
    {
      "commit": "ff5b7ee33d82414bf4baf299c21fb703bcc89629",
      "tree": "926786cf57b375e5ef1f865427c910c3d4bdfc7a",
      "parents": [
        "f2b1c41cf94d7f839fe9ede5f3ead92698a93fb3"
      ],
      "author": {
        "name": "Yan Zheng",
        "email": "zheng.yan@oracle.com",
        "time": "Mon Nov 10 07:34:43 2008 -0500"
      },
      "committer": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Mon Nov 10 07:34:43 2008 -0500"
      },
      "message": "Btrfs: Fix csum error for compressed data\n\nThe decompress code doesn\u0027t take the logical offset in extent\npointer into account. If the logical offset isn\u0027t zero, data\nwill be decompressed into wrong pages.\n\nThe solution used here is to record the starting offset of the extent\nin the file separately from the logical start of the extent_map struct.\nThis allows us to avoid problems inserting overlapping extents.\n\nSigned-off-by: Yan Zheng \u003czheng.yan@oracle.com\u003e\n\n"
    },
    {
      "commit": "af09abfece59aa50bfbf16f6f1f85822554e061f",
      "tree": "ca419511219b433a2bf45626814777df8667a19f",
      "parents": [
        "4366211ccd050e00674b3276b5ed81981b2d7793"
      ],
      "author": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Fri Nov 07 12:35:44 2008 -0500"
      },
      "committer": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Fri Nov 07 12:35:44 2008 -0500"
      },
      "message": "Btrfs: make sure compressed bios don\u0027t complete too soon\n\nWhen writing a compressed extent, a number of bios are created that\npoint to a single struct compressed_bio.  At end_io time an atomic counter in\nthe compressed_bio struct makes sure that all of the bios have finished\nbefore final end_io processing is done.\n\nBut when multiple bios are needed to write a compressed extent, the\ncounter was being incremented after the first bio was sent to submit_bio.\nIt is possible the bio will complete before the counter is incremented,\nmaking the end_io handler free the compressed_bio struct before\nprocessing is finished.\n\nThe fix is to increment the atomic counter before bio submission,\nboth for compressed reads and writes.\n\nSigned-off-by: Chris Mason \u003cchris.mason@oracle.com\u003e\n"
    },
    {
      "commit": "771ed689d2cd53439e28e095bc38fbe40a71429e",
      "tree": "518801f7141928e398d40c2b5955720d4346ce1a",
      "parents": [
        "4a69a41009c4ac691f7d9c289f5f37fabeddce46"
      ],
      "author": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Thu Nov 06 22:02:51 2008 -0500"
      },
      "committer": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Thu Nov 06 22:02:51 2008 -0500"
      },
      "message": "Btrfs: Optimize compressed writeback and reads\n\nWhen reading compressed extents, try to put pages into the page cache\nfor any pages covered by the compressed extent that readpages didn\u0027t already\npreload.\n\nAdd an async work queue to handle transformations at delayed allocation processing\ntime.  Right now this is just compression.  The workflow is:\n\n1) Find offsets in the file marked for delayed allocation\n2) Lock the pages\n3) Lock the state bits\n4) Call the async delalloc code\n\nThe async delalloc code clears the state lock bits and delalloc bits.  It is\nimportant this happens before the range goes into the work queue because\notherwise it might deadlock with other work queue items that try to lock\nthose extent bits.\n\nThe file pages are compressed, and if the compression doesn\u0027t work the\npages are written back directly.\n\nAn ordered work queue is used to make sure the inodes are written in the same\norder that pdflush or writepages sent them down.\n\nThis changes extent_write_cache_pages to let the writepage function\nupdate the wbc nr_written count.\n\nSigned-off-by: Chris Mason \u003cchris.mason@oracle.com\u003e\n\n"
    },
    {
      "commit": "70b99e6959a4c28ae1b314985eca731f3db72f1d",
      "tree": "81578759fe422f7b17a734b8bf16b042aa02a046",
      "parents": [
        "d899e05215178fed903ad0e7fc1cb4d8e0cc0a88"
      ],
      "author": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Fri Oct 31 12:46:39 2008 -0400"
      },
      "committer": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Fri Oct 31 12:46:39 2008 -0400"
      },
      "message": "Btrfs: Compression corner fixes\n\nMake sure we keep page-\u003emapping NULL on the pages we\u0027re getting\nvia alloc_page.  It gets set so a few of the callbacks can do the right\nthing, but in general these pages don\u0027t have a mapping.\n\nDon\u0027t try to truncate compressed inline items in btrfs_drop_extents.\nThe whole compressed item must be preserved.\n\nDon\u0027t try to create multipage inline compressed items.  When we try to\noverwrite just the first page of the file, we would have to read in and recow\nall the pages after it in the same compressed inline items.  For now, only\ncreate single page inline items.\n\nMake sure we lock pages in the correct order during delalloc.  The\nsearch into the state tree for delalloc bytes can return bytes before\nthe page we already have locked.\n\nSigned-off-by: Chris Mason \u003cchris.mason@oracle.com\u003e\n\n"
    },
    {
      "commit": "cfbc246eaae2a1089911016094b74b3055e8a906",
      "tree": "c450f02cd605b38a578778dacd9c8768ce041789",
      "parents": [
        "87ef2bb46bfc4be0b40799e68115cbe28d80a1bd"
      ],
      "author": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Thu Oct 30 13:22:14 2008 -0400"
      },
      "committer": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Thu Oct 30 13:22:14 2008 -0400"
      },
      "message": "Btrfs: walk compressed pages based on the nr_pages count instead of bytes\n\nThe byte walk counting was awkward and error prone.  This uses the\nnumber of pages sent the higher layer to build bios.\n\nSigned-off-by: Chris Mason \u003cchris.mason@oracle.com\u003e\n"
    },
    {
      "commit": "c8b978188c9a0fd3d535c13debd19d522b726f1f",
      "tree": "873628723fb82fe2a7c77adc65fa93eca1d61c0c",
      "parents": [
        "26ce34a9c47334ff7984769e4661b2f1883594ff"
      ],
      "author": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Wed Oct 29 14:49:59 2008 -0400"
      },
      "committer": {
        "name": "Chris Mason",
        "email": "chris.mason@oracle.com",
        "time": "Wed Oct 29 14:49:59 2008 -0400"
      },
      "message": "Btrfs: Add zlib compression support\n\nThis is a large change for adding compression on reading and writing,\nboth for inline and regular extents.  It does some fairly large\nsurgery to the writeback paths.\n\nCompression is off by default and enabled by mount -o compress.  Even\nwhen the -o compress mount option is not used, it is possible to read\ncompressed extents off the disk.\n\nIf compression for a given set of pages fails to make them smaller, the\nfile is flagged to avoid future compression attempts later.\n\n* While finding delalloc extents, the pages are locked before being sent down\nto the delalloc handler.  This allows the delalloc handler to do complex things\nsuch as cleaning the pages, marking them writeback and starting IO on their\nbehalf.\n\n* Inline extents are inserted at delalloc time now.  This allows us to compress\nthe data before inserting the inline extent, and it allows us to insert\nan inline extent that spans multiple pages.\n\n* All of the in-memory extent representations (extent_map.c, ordered-data.c etc)\nare changed to record both an in-memory size and an on disk size, as well\nas a flag for compression.\n\nFrom a disk format point of view, the extent pointers in the file are changed\nto record the on disk size of a given extent and some encoding flags.\nSpace in the disk format is allocated for compression encoding, as well\nas encryption and a generic \u0027other\u0027 field.  Neither the encryption or the\n\u0027other\u0027 field are currently used.\n\nIn order to limit the amount of data read for a single random read in the\nfile, the size of a compressed extent is limited to 128k.  This is a\nsoftware only limit, the disk format supports u64 sized compressed extents.\n\nIn order to limit the ram consumed while processing extents, the uncompressed\nsize of a compressed extent is limited to 256k.  This is a software only limit\nand will be subject to tuning later.\n\nChecksumming is still done on compressed extents, and it is done on the\nuncompressed version of the data.  This way additional encodings can be\nlayered on without having to figure out which encoding to checksum.\n\nCompression happens at delalloc time, which is basically singled threaded because\nit is usually done by a single pdflush thread.  This makes it tricky to\nspread the compression load across all the cpus on the box.  We\u0027ll have to\nlook at parallel pdflush walks of dirty inodes at a later time.\n\nDecompression is hooked into readpages and it does spread across CPUs nicely.\n\nSigned-off-by: Chris Mason \u003cchris.mason@oracle.com\u003e\n"
    }
  ]
}