)]}'
{
  "log": [
    {
      "commit": "52bd75fdb135d6133d878ae60c6e7e3f4ebc1cfc",
      "tree": "4fad4fa37ce533c520a4575e5b7df90e19c6a666",
      "parents": [
        "4fbf4291aa15926cd4fdca0ffe9122e89d0459db"
      ],
      "author": {
        "name": "David Howells",
        "email": "dhowells@redhat.com",
        "time": "Thu Nov 19 18:11:08 2009 +0000"
      },
      "committer": {
        "name": "David Howells",
        "email": "dhowells@redhat.com",
        "time": "Thu Nov 19 18:11:08 2009 +0000"
      },
      "message": "FS-Cache: Add counters for entry/exit to/from cache operation functions\n\nCount entries to and exits from cache operation table functions.  Maintain\nthese as a single counter that\u0027s added to or removed from as appropriate.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\n"
    },
    {
      "commit": "4fbf4291aa15926cd4fdca0ffe9122e89d0459db",
      "tree": "ec2195c39ef8117acea598af4a5c20c77f67aa0b",
      "parents": [
        "440f0affe247e9990c8f8778f1861da4fd7d5e50"
      ],
      "author": {
        "name": "David Howells",
        "email": "dhowells@redhat.com",
        "time": "Thu Nov 19 18:11:04 2009 +0000"
      },
      "committer": {
        "name": "David Howells",
        "email": "dhowells@redhat.com",
        "time": "Thu Nov 19 18:11:04 2009 +0000"
      },
      "message": "FS-Cache: Allow the current state of all objects to be dumped\n\nAllow the current state of all fscache objects to be dumped by doing:\n\n\tcat /proc/fs/fscache/objects\n\nBy default, all objects and all fields will be shown.  This can be restricted\nby adding a suitable key to one of the caller\u0027s keyrings (such as the session\nkeyring):\n\n\tkeyctl add user fscache:objlist \"\u003crestrictions\u003e\" @s\n\nThe \u003crestrictions\u003e are:\n\n\tK\tShow hexdump of object key (don\u0027t show if not given)\n\tA\tShow hexdump of object aux data (don\u0027t show if not given)\n\nAnd paired restrictions:\n\n\tC\tShow objects that have a cookie\n\tc\tShow objects that don\u0027t have a cookie\n\tB\tShow objects that are busy\n\tb\tShow objects that aren\u0027t busy\n\tW\tShow objects that have pending writes\n\tw\tShow objects that don\u0027t have pending writes\n\tR\tShow objects that have outstanding reads\n\tr\tShow objects that don\u0027t have outstanding reads\n\tS\tShow objects that have slow work queued\n\ts\tShow objects that don\u0027t have slow work queued\n\nIf neither side of a restriction pair is given, then both are implied.  For\nexample:\n\n\tkeyctl add user fscache:objlist KB @s\n\nshows objects that are busy, and lists their object keys, but does not dump\ntheir auxiliary data.  It also implies \"CcWwRrSs\", but as \u0027B\u0027 is given, \u0027b\u0027 is\nnot implied.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\n"
    },
    {
      "commit": "952efe7b7840e1c726ae88222245e4efe6bd88f3",
      "tree": "fed43da6709707d0eb51b8695b6b382a221e99bd",
      "parents": [
        "ccc4fc3d11e91477036d1f82bfa2d442f6ce77f0"
      ],
      "author": {
        "name": "David Howells",
        "email": "dhowells@redhat.com",
        "time": "Fri Apr 03 16:42:39 2009 +0100"
      },
      "committer": {
        "name": "David Howells",
        "email": "dhowells@redhat.com",
        "time": "Fri Apr 03 16:42:39 2009 +0100"
      },
      "message": "FS-Cache: Add and document asynchronous operation handling\n\nAdd and document asynchronous operation handling for use by FS-Cache\u0027s data\nstorage and retrieval routines.\n\nThe following documentation is added to:\n\n\tDocumentation/filesystems/caching/operations.txt\n\n\t\t       \u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\n\t\t       ASYNCHRONOUS OPERATIONS HANDLING\n\t\t       \u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\n\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\nOVERVIEW\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\n\nFS-Cache has an asynchronous operations handling facility that it uses for its\ndata storage and retrieval routines.  Its operations are represented by\nfscache_operation structs, though these are usually embedded into some other\nstructure.\n\nThis facility is available to and expected to be be used by the cache backends,\nand FS-Cache will create operations and pass them off to the appropriate cache\nbackend for completion.\n\nTo make use of this facility, \u003clinux/fscache-cache.h\u003e should be #included.\n\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\nOPERATION RECORD INITIALISATION\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\n\nAn operation is recorded in an fscache_operation struct:\n\n\tstruct fscache_operation {\n\t\tunion {\n\t\t\tstruct work_struct fast_work;\n\t\t\tstruct slow_work slow_work;\n\t\t};\n\t\tunsigned long\t\tflags;\n\t\tfscache_operation_processor_t processor;\n\t\t...\n\t};\n\nSomeone wanting to issue an operation should allocate something with this\nstruct embedded in it.  They should initialise it by calling:\n\n\tvoid fscache_operation_init(struct fscache_operation *op,\n\t\t\t\t    fscache_operation_release_t release);\n\nwith the operation to be initialised and the release function to use.\n\nThe op-\u003eflags parameter should be set to indicate the CPU time provision and\nthe exclusivity (see the Parameters section).\n\nThe op-\u003efast_work, op-\u003eslow_work and op-\u003eprocessor flags should be set as\nappropriate for the CPU time provision (see the Parameters section).\n\nFSCACHE_OP_WAITING may be set in op-\u003eflags prior to each submission of the\noperation and waited for afterwards.\n\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\nPARAMETERS\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\n\nThere are a number of parameters that can be set in the operation record\u0027s flag\nparameter.  There are three options for the provision of CPU time in these\noperations:\n\n (1) The operation may be done synchronously (FSCACHE_OP_MYTHREAD).  A thread\n     may decide it wants to handle an operation itself without deferring it to\n     another thread.\n\n     This is, for example, used in read operations for calling readpages() on\n     the backing filesystem in CacheFiles.  Although readpages() does an\n     asynchronous data fetch, the determination of whether pages exist is done\n     synchronously - and the netfs does not proceed until this has been\n     determined.\n\n     If this option is to be used, FSCACHE_OP_WAITING must be set in op-\u003eflags\n     before submitting the operation, and the operating thread must wait for it\n     to be cleared before proceeding:\n\n\t\twait_on_bit(\u0026op-\u003eflags, FSCACHE_OP_WAITING,\n\t\t\t    fscache_wait_bit, TASK_UNINTERRUPTIBLE);\n\n (2) The operation may be fast asynchronous (FSCACHE_OP_FAST), in which case it\n     will be given to keventd to process.  Such an operation is not permitted\n     to sleep on I/O.\n\n     This is, for example, used by CacheFiles to copy data from a backing fs\n     page to a netfs page after the backing fs has read the page in.\n\n     If this option is used, op-\u003efast_work and op-\u003eprocessor must be\n     initialised before submitting the operation:\n\n\t\tINIT_WORK(\u0026op-\u003efast_work, do_some_work);\n\n (3) The operation may be slow asynchronous (FSCACHE_OP_SLOW), in which case it\n     will be given to the slow work facility to process.  Such an operation is\n     permitted to sleep on I/O.\n\n     This is, for example, used by FS-Cache to handle background writes of\n     pages that have just been fetched from a remote server.\n\n     If this option is used, op-\u003eslow_work and op-\u003eprocessor must be\n     initialised before submitting the operation:\n\n\t\tfscache_operation_init_slow(op, processor)\n\nFurthermore, operations may be one of two types:\n\n (1) Exclusive (FSCACHE_OP_EXCLUSIVE).  Operations of this type may not run in\n     conjunction with any other operation on the object being operated upon.\n\n     An example of this is the attribute change operation, in which the file\n     being written to may need truncation.\n\n (2) Shareable.  Operations of this type may be running simultaneously.  It\u0027s\n     up to the operation implementation to prevent interference between other\n     operations running at the same time.\n\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\nPROCEDURE\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\n\nOperations are used through the following procedure:\n\n (1) The submitting thread must allocate the operation and initialise it\n     itself.  Normally this would be part of a more specific structure with the\n     generic op embedded within.\n\n (2) The submitting thread must then submit the operation for processing using\n     one of the following two functions:\n\n\tint fscache_submit_op(struct fscache_object *object,\n\t\t\t      struct fscache_operation *op);\n\n\tint fscache_submit_exclusive_op(struct fscache_object *object,\n\t\t\t\t\tstruct fscache_operation *op);\n\n     The first function should be used to submit non-exclusive ops and the\n     second to submit exclusive ones.  The caller must still set the\n     FSCACHE_OP_EXCLUSIVE flag.\n\n     If successful, both functions will assign the operation to the specified\n     object and return 0.  -ENOBUFS will be returned if the object specified is\n     permanently unavailable.\n\n     The operation manager will defer operations on an object that is still\n     undergoing lookup or creation.  The operation will also be deferred if an\n     operation of conflicting exclusivity is in progress on the object.\n\n     If the operation is asynchronous, the manager will retain a reference to\n     it, so the caller should put their reference to it by passing it to:\n\n\tvoid fscache_put_operation(struct fscache_operation *op);\n\n (3) If the submitting thread wants to do the work itself, and has marked the\n     operation with FSCACHE_OP_MYTHREAD, then it should monitor\n     FSCACHE_OP_WAITING as described above and check the state of the object if\n     necessary (the object might have died whilst the thread was waiting).\n\n     When it has finished doing its processing, it should call\n     fscache_put_operation() on it.\n\n (4) The operation holds an effective lock upon the object, preventing other\n     exclusive ops conflicting until it is released.  The operation can be\n     enqueued for further immediate asynchronous processing by adjusting the\n     CPU time provisioning option if necessary, eg:\n\n\top-\u003eflags \u0026\u003d ~FSCACHE_OP_TYPE;\n\top-\u003eflags |\u003d ~FSCACHE_OP_FAST;\n\n     and calling:\n\n\tvoid fscache_enqueue_operation(struct fscache_operation *op)\n\n     This can be used to allow other things to have use of the worker thread\n     pools.\n\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\nASYNCHRONOUS CALLBACK\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\n\nWhen used in asynchronous mode, the worker thread pool will invoke the\nprocessor method with a pointer to the operation.  This should then get at the\ncontainer struct by using container_of():\n\n\tstatic void fscache_write_op(struct fscache_operation *_op)\n\t{\n\t\tstruct fscache_storage *op \u003d\n\t\t\tcontainer_of(_op, struct fscache_storage, op);\n\t...\n\t}\n\nThe caller holds a reference on the operation, and will invoke\nfscache_put_operation() when the processor function returns.  The processor\nfunction is at liberty to call fscache_enqueue_operation() or to take extra\nreferences.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\nAcked-by: Steve Dickson \u003csteved@redhat.com\u003e\nAcked-by: Trond Myklebust \u003cTrond.Myklebust@netapp.com\u003e\nAcked-by: Al Viro \u003cviro@zeniv.linux.org.uk\u003e\nTested-by: Daire Byrne \u003cDaire.Byrne@framestore.com\u003e\n"
    },
    {
      "commit": "4c515dd47ab41be3f89e757d441661795470b376",
      "tree": "22b1959663cf77ecd60125ef112b87f1ee4fa6ef",
      "parents": [
        "0e04d4cefcf4d8fbbdb2c50e93ad541582933fd2"
      ],
      "author": {
        "name": "David Howells",
        "email": "dhowells@redhat.com",
        "time": "Fri Apr 03 16:42:37 2009 +0100"
      },
      "committer": {
        "name": "David Howells",
        "email": "dhowells@redhat.com",
        "time": "Fri Apr 03 16:42:37 2009 +0100"
      },
      "message": "FS-Cache: Add cache management\n\nImplement the entry points by which a cache backend may initialise, add,\ndeclare an error upon and withdraw a cache.\n\nFurther, an object is created in sysfs under which each cache added will get\nan object created:\n\n\t/sys/fs/fscache/\u003ccachetag\u003e/\n\nAll of this is described in Documentation/filesystems/caching/backend-api.txt\nadded by a previous patch.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\nAcked-by: Steve Dickson \u003csteved@redhat.com\u003e\nAcked-by: Trond Myklebust \u003cTrond.Myklebust@netapp.com\u003e\nAcked-by: Al Viro \u003cviro@zeniv.linux.org.uk\u003e\nTested-by: Daire Byrne \u003cDaire.Byrne@framestore.com\u003e\n"
    },
    {
      "commit": "0e04d4cefcf4d8fbbdb2c50e93ad541582933fd2",
      "tree": "97c4cda6a2c246660e6a5c718a9272375cdb259c",
      "parents": [
        "a6891645cf2ddd4778096848a864580e7258faba"
      ],
      "author": {
        "name": "David Howells",
        "email": "dhowells@redhat.com",
        "time": "Fri Apr 03 16:42:37 2009 +0100"
      },
      "committer": {
        "name": "David Howells",
        "email": "dhowells@redhat.com",
        "time": "Fri Apr 03 16:42:37 2009 +0100"
      },
      "message": "FS-Cache: Add cache tag handling\n\nImplement two features of FS-Cache:\n\n (1) The ability to request and release cache tags - names by which a cache may\n     be known to a netfs, and thus selected for use.\n\n (2) An internal function by which a cache is selected by consulting the netfs,\n     if the netfs wishes to be consulted.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\nAcked-by: Steve Dickson \u003csteved@redhat.com\u003e\nAcked-by: Trond Myklebust \u003cTrond.Myklebust@netapp.com\u003e\nAcked-by: Al Viro \u003cviro@zeniv.linux.org.uk\u003e\nTested-by: Daire Byrne \u003cDaire.Byrne@framestore.com\u003e\n"
    }
  ]
}