)]}'
{
  "log": [
    {
      "commit": "e3c96f53ac132743fda1384910feb863a2eab916",
      "tree": "48b97fdf50897d5ee97409db86bd4e4d7220be03",
      "parents": [
        "904e812931f001b984912b2d2f653ea69520313c"
      ],
      "author": {
        "name": "Alexey Dobriyan",
        "email": "adobriyan@gmail.com",
        "time": "Tue Dec 15 16:46:54 2009 -0800"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@linux-foundation.org",
        "time": "Wed Dec 16 07:20:06 2009 -0800"
      },
      "message": "reiserfs: don\u0027t compile procfs.o at all if no support\n\n* small define cleanup in header\n* fix #ifdeffery in procfs.c via Kconfig\n\nSigned-off-by: Alexey Dobriyan \u003cadobriyan@gmail.com\u003e\nCc: Jeff Mahoney \u003cjeffm@suse.com\u003e\nSigned-off-by: Andrew Morton \u003cakpm@linux-foundation.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@linux-foundation.org\u003e\n"
    },
    {
      "commit": "8ebc423238341b52912c7295b045a32477b33f09",
      "tree": "39677401de0df98c09ca888c87d85033b6fe93c9",
      "parents": [
        "74fca6a42863ffacaf7ba6f1936a9f228950f657"
      ],
      "author": {
        "name": "Frederic Weisbecker",
        "email": "fweisbec@gmail.com",
        "time": "Tue Apr 07 04:19:49 2009 +0200"
      },
      "committer": {
        "name": "Frederic Weisbecker",
        "email": "fweisbec@gmail.com",
        "time": "Mon Sep 14 07:17:59 2009 +0200"
      },
      "message": "reiserfs: kill-the-BKL\n\nThis patch is an attempt to remove the Bkl based locking scheme from\nreiserfs and is intended.\n\nIt is a bit inspired from an old attempt by Peter Zijlstra:\n\n   http://lkml.indiana.edu/hypermail/linux/kernel/0704.2/2174.html\n\nThe bkl is heavily used in this filesystem to prevent from\nconcurrent write accesses on the filesystem.\n\nReiserfs makes a deep use of the specific properties of the Bkl:\n\n- It can be acqquired recursively by a same task\n- It is released on the schedule() calls and reacquired when schedule() returns\n\nThe two properties above are a roadmap for the reiserfs write locking so it\u0027s\nvery hard to simply replace it with a common mutex.\n\n- We need a recursive-able locking unless we want to restructure several blocks\n  of the code.\n- We need to identify the sites where the bkl was implictly relaxed\n  (schedule, wait, sync, etc...) so that we can in turn release and\n  reacquire our new lock explicitly.\n  Such implicit releases of the lock are often required to let other\n  resources producer/consumer do their job or we can suffer unexpected\n  starvations or deadlocks.\n\nSo the new lock that replaces the bkl here is a per superblock mutex with a\nspecific property: it can be acquired recursively by a same task, like the\nbkl.\n\nFor such purpose, we integrate a lock owner and a lock depth field on the\nsuperblock information structure.\n\nThe first axis on this patch is to turn reiserfs_write_(un)lock() function\ninto a wrapper to manage this mutex. Also some explicit calls to\nlock_kernel() have been converted to reiserfs_write_lock() helpers.\n\nThe second axis is to find the important blocking sites (schedule...(),\nwait_on_buffer(), sync_dirty_buffer(), etc...) and then apply an explicit\nrelease of the write lock on these locations before blocking. Then we can\nsafely wait for those who can give us resources or those who need some.\nTypically this is a fight between the current writer, the reiserfs workqueue\n(aka the async commiter) and the pdflush threads.\n\nThe third axis is a consequence of the second. The write lock is usually\non top of a lock dependency chain which can include the journal lock, the\nflush lock or the commit lock. So it\u0027s dangerous to release and trying to\nreacquire the write lock while we still hold other locks.\n\nThis is fine with the bkl:\n\n      T1                       T2\n\nlock_kernel()\n    mutex_lock(A)\n    unlock_kernel()\n    // do something\n                            lock_kernel()\n                                mutex_lock(A) -\u003e already locked by T1\n                                schedule() (and then unlock_kernel())\n    lock_kernel()\n    mutex_unlock(A)\n    ....\n\nThis is not fine with a mutex:\n\n      T1                       T2\n\nmutex_lock(write)\n    mutex_lock(A)\n    mutex_unlock(write)\n    // do something\n                           mutex_lock(write)\n                              mutex_lock(A) -\u003e already locked by T1\n                              schedule()\n\n    mutex_lock(write) -\u003e already locked by T2\n    deadlock\n\nThe solution in this patch is to provide a helper which releases the write\nlock and sleep a bit if we can\u0027t lock a mutex that depend on it. It\u0027s another\nsimulation of the bkl behaviour.\n\nThe last axis is to locate the fs callbacks that are called with the bkl held,\naccording to Documentation/filesystem/Locking.\n\nThose are:\n\n- reiserfs_remount\n- reiserfs_fill_super\n- reiserfs_put_super\n\nReiserfs didn\u0027t need to explicitly lock because of the context of these callbacks.\nBut now we must take care of that with the new locking.\n\nAfter this patch, reiserfs suffers from a slight performance regression (for now).\nOn UP, a high volume write with dd reports an average of 27 MB/s instead\nof 30 MB/s without the patch applied.\n\nSigned-off-by: Frederic Weisbecker \u003cfweisbec@gmail.com\u003e\nReviewed-by: Ingo Molnar \u003cmingo@elte.hu\u003e\nCc: Jeff Mahoney \u003cjeffm@suse.com\u003e\nCc: Peter Zijlstra \u003ca.p.zijlstra@chello.nl\u003e\nCc: Bron Gondwana \u003cbrong@fastmail.fm\u003e\nCc: Andrew Morton \u003cakpm@linux-foundation.org\u003e\nCc: Linus Torvalds \u003ctorvalds@linux-foundation.org\u003e\nCc: Alexander Viro \u003cviro@zeniv.linux.org.uk\u003e\nLKML-Reference: \u003c1239070789-13354-1-git-send-email-fweisbec@gmail.com\u003e\nSigned-off-by: Ingo Molnar \u003cmingo@elte.hu\u003e\n"
    },
    {
      "commit": "a72bdb1cd244725ff47b3a29662e2cb820d8c60f",
      "tree": "68f9022b303ca5183bd64eddbff41f0624e84188",
      "parents": [
        "6dfede696391133eadd7ce90b61c9573ee6e5a90"
      ],
      "author": {
        "name": "Jeff Mahoney",
        "email": "jeffm@suse.com",
        "time": "Mon Mar 30 14:02:33 2009 -0400"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@linux-foundation.org",
        "time": "Mon Mar 30 12:16:37 2009 -0700"
      },
      "message": "reiserfs: Clean up xattrs when REISERFS_FS_XATTR is unset\n\nThe current reiserfs xattr implementation will not clean up old xattr\nfiles if files are deleted when REISERFS_FS_XATTR is unset.  This\nresults in inaccessible lost files, wasting space.\n\nThis patch compiles in basic xattr knowledge, such as how to delete them\nand change ownership for quota tracking.  If the file system has never\nused xattrs, then the operation is quite fast: it returns immediately\nwhen it sees there is no .reiserfs_priv directory.\n\nSigned-off-by: Jeff Mahoney \u003cjeffm@suse.com\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@linux-foundation.org\u003e\n"
    },
    {
      "commit": "42012cc4a2183c555a907eee32d7ce4fc7dc3a6a",
      "tree": "90fbd712085050fac8f06544e3186736539cf2bc",
      "parents": [
        "4d24607bfaab3d02fd0d6e0ffc22f29c2bc8eb30"
      ],
      "author": {
        "name": "Olaf Hering",
        "email": "olh@suse.de",
        "time": "Fri Sep 29 01:59:21 2006 -0700"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@g5.osdl.org",
        "time": "Fri Sep 29 09:18:07 2006 -0700"
      },
      "message": "[PATCH] use gcc -O1 in fs/reiserfs only for ancient gcc versions\n\nOnly compile with -O1 if the (very old) compiler is broken.  We use\nreiserfs alot since SLES9 on ppc64, and it was never seen with gcc33.\nAssume the broken gcc is gcc-3.4 or older.\n\nSigned-off-by: Olaf Hering \u003colh@suse.de\u003e\nSigned-off-by: Andrew Morton \u003cakpm@osdl.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@osdl.org\u003e\n"
    },
    {
      "commit": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
      "tree": "0bba044c4ce775e45a88a51686b5d9f90697ea9d",
      "parents": [],
      "author": {
        "name": "Linus Torvalds",
        "email": "torvalds@ppc970.osdl.org",
        "time": "Sat Apr 16 15:20:36 2005 -0700"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@ppc970.osdl.org",
        "time": "Sat Apr 16 15:20:36 2005 -0700"
      },
      "message": "Linux-2.6.12-rc2\n\nInitial git repository build. I\u0027m not bothering with the full history,\neven though we have it. We can create a separate \"historical\" git\narchive of that later if we want to, and in the meantime it\u0027s about\n3.2GB when imported into git - space that would just make the early\ngit days unnecessarily complicated, when we don\u0027t have a lot of good\ninfrastructure for it.\n\nLet it rip!\n"
    }
  ]
}