)]}' { "log": [ { "commit": "12fdff3fc2483f906ae6404a6e8dcf2550310b6f", "tree": "a79fb1365fce7c7529655a8802d6d6bf8509b374", "parents": [ "1490cf5f0cb07dd49cdab4bceb769d7f711d7ca6" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Aug 12 16:54:57 2010 +0100" }, "committer": { "name": "Linus Torvalds", "email": "torvalds@linux-foundation.org", "time": "Thu Aug 12 09:51:35 2010 -0700" }, "message": "Add a dummy printk function for the maintenance of unused printks\n\nAdd a dummy printk function for the maintenance of unused printks through gcc\nformat checking, and also so that side-effect checking is maintained too.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@linux-foundation.org\u003e\n" }, { "commit": "40f2b6ffe525e975203c1621d4d4abaa7689b674", "tree": "bb6052496a824e0ee3d1725465871819caf704cb", "parents": [ "181a51f6e040d0ac006d6adaf4a031ffa440f41c" ], "author": { "name": "Tejun Heo", "email": "tj@kernel.org", "time": "Sat Jul 24 11:10:09 2010 +0200" }, "committer": { "name": "Tejun Heo", "email": "tj@kernel.org", "time": "Sat Jul 24 11:10:09 2010 +0200" }, "message": "fscache: fix build on !CONFIG_SYSCTL\n\nCommit 8b8edefa (fscache: convert object to use workqueue instead of\nslow-work) made fscache_exit() call unregister_sysctl_table()\nunconditionally breaking build when sysctl is disabled. Fix it by\nputting it inside CONFIG_SYSCTL.\n\nSigned-off-by: Tejun Heo \u003ctj@kernel.org\u003e\nReported-by: Randy Dunlap \u003crandy.dunlap@oracle.com\u003e\nCc: David Howells \u003cdhowells@redhat.com\u003e\n" }, { "commit": "d098adfb7d281258173a43151483e52e21761021", "tree": "29a28d972770cdcd6b316d4ab43a5829f4fbe795", "parents": [ "8af7c12436803291c90295259db23d371a7ad9cc" ], "author": { "name": "Tejun Heo", "email": "tj@kernel.org", "time": "Tue Jul 20 22:09:01 2010 +0200" }, "committer": { "name": "Tejun Heo", "email": "tj@kernel.org", "time": "Thu Jul 22 22:58:58 2010 +0200" }, "message": "fscache: drop references to slow-work\n\nfscache no longer uses slow-work. Drop references to it.\n\nSigned-off-by: Tejun Heo \u003ctj@kernel.org\u003e\nAcked-by: David Howells \u003cdhowells@redhat.com\u003e\n" }, { "commit": "8af7c12436803291c90295259db23d371a7ad9cc", "tree": "5e75360876ac5783a3e64bd35a1715847d90e9ce", "parents": [ "8b8edefa2fffbff97f9eec8b70e78ae23abad1a0" ], "author": { "name": "Tejun Heo", "email": "tj@kernel.org", "time": "Tue Jul 20 22:09:01 2010 +0200" }, "committer": { "name": "Tejun Heo", "email": "tj@kernel.org", "time": "Thu Jul 22 22:58:47 2010 +0200" }, "message": "fscache: convert operation to use workqueue instead of slow-work\n\nMake fscache operation to use only workqueue instead of combination of\nworkqueue and slow-work. FSCACHE_OP_SLOW is dropped and\nFSCACHE_OP_FAST is renamed to FSCACHE_OP_ASYNC and uses newly added\nfscache_op_wq workqueue to execute op-\u003eprocessor().\nfscache_operation_init_slow() is dropped and fscache_operation_init()\nnow takes @processor argument directly.\n\n* Unbound workqueue is used.\n\n* fscache_retrieval_work() is no longer necessary as OP_ASYNC now does\n the equivalent thing.\n\n* sysctl fscache.operation_max_active added to control concurrency.\n The default value is nr_cpus clamped between 2 and\n WQ_UNBOUND_MAX_ACTIVE.\n\n* debugfs support is dropped for now. Tracing API based debug\n facility is planned to be added.\n\nSigned-off-by: Tejun Heo \u003ctj@kernel.org\u003e\nAcked-by: David Howells \u003cdhowells@redhat.com\u003e\n" }, { "commit": "8b8edefa2fffbff97f9eec8b70e78ae23abad1a0", "tree": "7f0efac8adb9c9ed7be8af63e51510954f1c51dc", "parents": [ "e120153ddf8620fd0a194d301e9c5a8b28483bb5" ], "author": { "name": "Tejun Heo", "email": "tj@kernel.org", "time": "Tue Jul 20 22:09:01 2010 +0200" }, "committer": { "name": "Tejun Heo", "email": "tj@kernel.org", "time": "Thu Jul 22 22:58:34 2010 +0200" }, "message": "fscache: convert object to use workqueue instead of slow-work\n\nMake fscache object state transition callbacks use workqueue instead\nof slow-work. New dedicated unbound CPU workqueue fscache_object_wq\nis created. get/put callbacks are renamed and modified to take\n@object and called directly from the enqueue wrapper and the work\nfunction. While at it, make all open coded instances of get/put to\nuse fscache_get/put_object().\n\n* Unbound workqueue is used.\n\n* work_busy() output is printed instead of slow-work flags in object\n debugging outputs. They mean basically the same thing bit-for-bit.\n\n* sysctl fscache.object_max_active added to control concurrency. The\n default value is nr_cpus clamped between 4 and\n WQ_UNBOUND_MAX_ACTIVE.\n\n* slow_work_sleep_till_thread_needed() is replaced with fscache\n private implementation fscache_object_sleep_till_congested() which\n waits on fscache_object_wq congestion.\n\n* debugfs support is dropped for now. Tracing API based debug\n facility is planned to be added.\n\nSigned-off-by: Tejun Heo \u003ctj@kernel.org\u003e\nAcked-by: David Howells \u003cdhowells@redhat.com\u003e\n" }, { "commit": "08a66859e69264f3223560d06b88e80c1a6a6387", "tree": "509c8808edb8e2d66aaa5d6fefccc1c862a1dca0", "parents": [ "0a6531ebea13b164825ba28e77dcbed3e9386884" ], "author": { "name": "Dan Carpenter", "email": "error27@gmail.com", "time": "Tue Jun 01 20:58:22 2010 +0100" }, "committer": { "name": "Linus Torvalds", "email": "torvalds@linux-foundation.org", "time": "Tue Jun 01 13:32:11 2010 -0700" }, "message": "FS-Cache: Remove unneeded null checks\n\nfscache_write_op() makes unnecessary checks of the page variable to see if it\nis NULL. It can\u0027t be NULL at those points as the kernel would already have\ncrashed a little higher up where we examined page-\u003eindex.\n\nFurthermore, unless radix_tree_gang_lookup_tag() can return 1 but no page, a\nNULL pointer crash should not be encountered there as we can only get there if\nr_t_g_l_t() returned 1.\n\nSigned-off-by: Dan Carpenter \u003cerror27@gmail.com\u003e\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@linux-foundation.org\u003e\n" }, { "commit": "cc68e3be7412baaa1ea2a2df9e88770f1753da78", "tree": "a92e184579a6810d6178aa305a3b7ba0694487bd", "parents": [ "3c7b204547bc3d342a4e31196fe14803581d279f" ], "author": { "name": "Andrew Morton", "email": "akpm@linux-foundation.org", "time": "Tue May 25 23:43:02 2010 -0700" }, "committer": { "name": "Linus Torvalds", "email": "torvalds@linux-foundation.org", "time": "Wed May 26 08:19:23 2010 -0700" }, "message": "fs/fscache/object-list.c: fix warning on 32-bit\n\nfs/fscache/object-list.c: In function \u0027fscache_objlist_lookup\u0027:\nfs/fscache/object-list.c:105: warning: cast to pointer from integer of different size\n\nAcked-by: David Howells \u003cdhowells@redhat.com\u003e\nSigned-off-by: Andrew Morton \u003cakpm@linux-foundation.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@linux-foundation.org\u003e\n" }, { "commit": "cc4fc29e59c386919a7674e203be7822dc968dc0", "tree": "b20f18950bc9e7c2a79a6694bae221dd48b9fdf7", "parents": [ "08dc179b9b00cfbed006ae6f5d0e471ef79dc69c" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Tue Apr 06 14:35:09 2010 -0700" }, "committer": { "name": "Linus Torvalds", "email": "torvalds@linux-foundation.org", "time": "Wed Apr 07 08:38:05 2010 -0700" }, "message": "fs-cache: order the debugfs stats correctly\n\nOrder the debugfs statistics correctly. The values displayed through a\nseq_printf() statement should be in the same order as the names in the\nformat string.\n\nIn the \u0027Lookups\u0027 line, objects created (\u0027crt\u003d\u0027) and lookups timed out\n(\u0027tmo\u003d\u0027) have their values transposed.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\nSigned-off-by: Andrew Morton \u003cakpm@linux-foundation.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@linux-foundation.org\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": "a53f4f9efaeb1d87cfae066346979d4d70e1abe9", "tree": "d774e3c010b96bc71226d5aedd1df04462629db5", "parents": [ "88be12c440cfa2fa3f5be83507360aac9ea1c54e" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Mon Mar 29 13:08:52 2010 +0100" }, "committer": { "name": "Linus Torvalds", "email": "torvalds@linux-foundation.org", "time": "Mon Mar 29 09:14:47 2010 -0700" }, "message": "SLOW_WORK: CONFIG_SLOW_WORK_PROC should be CONFIG_SLOW_WORK_DEBUG\n\nCONFIG_SLOW_WORK_PROC was changed to CONFIG_SLOW_WORK_DEBUG, but not in all\ninstances. Change the remaining instances. This makes the debugfs file\ndisplay the time mark and the owner\u0027s description again.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@linux-foundation.org\u003e\n" }, { "commit": "1147d0f915e3b4c5c4fa279dae2c40016b8f441d", "tree": "384638a14a7ce81d422790bbe1314d97c047e90d", "parents": [ "34c1c460f82c809f20a2d378373d6aeb58c7808a" ], "author": { "name": "Dan Carpenter", "email": "error27@gmail.com", "time": "Tue Mar 23 14:48:37 2010 +0000" }, "committer": { "name": "Linus Torvalds", "email": "torvalds@linux-foundation.org", "time": "Wed Mar 24 16:49:21 2010 -0700" }, "message": "fscache: add missing unlock\n\nSparse complained about this missing spin_unlock()\n\nSigned-off-by: Dan Carpenter \u003cerror27@gmail.com\u003e\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@linux-foundation.org\u003e\n" }, { "commit": "d4014030d2b2508aaf54093a5885f1c8a2275dd7", "tree": "1954a7500d9ab035671503fdc39f4609fa240c53", "parents": [ "25cf84cf377c0aae5dbcf937ea89bc7893db5176" ], "author": { "name": "Christian Kujau", "email": "lists@nerdbynature.de", "time": "Mon Mar 08 15:03:09 2010 +0000" }, "committer": { "name": "Linus Torvalds", "email": "torvalds@linux-foundation.org", "time": "Mon Mar 08 07:32:34 2010 -0800" }, "message": "FS-Cache: Remove the EXPERIMENTAL flag\n\nRemove the EXPERIMENTAL flag from FS-Cache so that Ubuntu can make use of the\nfacility.\n\nSigned-off-by: Christian Kujau \u003clists@nerdbynature.de\u003e\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@linux-foundation.org\u003e\n" }, { "commit": "ea58ceb543b45d45b257a86eaf9d60c94e8adcf2", "tree": "d2c44790f9a79e4d1eab26ff02b6880ab7966120", "parents": [ "06a7f711246b081afc21fff859f1003f1f2a0fbc" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Tue Dec 15 16:47:46 2009 -0800" }, "committer": { "name": "Linus Torvalds", "email": "torvalds@linux-foundation.org", "time": "Wed Dec 16 07:20:13 2009 -0800" }, "message": "FS-Cache: Avoid maybe-used-uninitialised warning on variable\n\nAndrew Morton\u0027s compiler sees the following warning in FS-Cache:\n\nfs/fscache/object-list.c: In function \u0027fscache_objlist_lookup\u0027:\nfs/fscache/object-list.c:94: warning: \u0027obj\u0027 may be used uninitialized in this function\n\nwhich my compiler doesn\u0027t. This is a false positive as obj can only be\nused in the comparison against minobj if minobj has been set to something\nother than NULL, but for that to happen, obj has to be first set to\nsomething.\n\nDeal with this by preclearing obj too.\n\nReported-by: Andrew Morton \u003cakpm@linux-foundation.org\u003e\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\nSigned-off-by: Andrew Morton \u003cakpm@linux-foundation.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@linux-foundation.org\u003e\n" }, { "commit": "4fa9f4ede88b4e2ff135b6e5717499d734508c62", "tree": "4a640f94091141d7115a7ef1000f97fd28f05e7a", "parents": [ "1c2ea8a2c0b71cc5e07f518370d458d692c9b21a" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Fri Nov 20 21:50:44 2009 +0000" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Fri Nov 20 21:50:44 2009 +0000" }, "message": "FS-Cache: Provide nop fscache_stat_d() if CONFIG_FSCACHE_STATS\u003dn\n\nProvide nop fscache_stat_d() macro if CONFIG_FSCACHE_STATS\u003dn lest errors like\nthe following occur:\n\n\tfs/fscache/cache.c: In function \u0027fscache_withdraw_cache\u0027:\n\tfs/fscache/cache.c:386: error: implicit declaration of function \u0027fscache_stat_d\u0027\n\tfs/fscache/cache.c:386: error: \u0027fscache_n_cop_sync_cache\u0027 undeclared (first use in this function)\n\tfs/fscache/cache.c:386: error: (Each undeclared identifier is reported only once\n\tfs/fscache/cache.c:386: error: for each function it appears in.)\n\tfs/fscache/cache.c:392: error: \u0027fscache_n_cop_dissociate_pages\u0027 undeclared (first use in this function)\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\n" }, { "commit": "fee096deb4f33897937b974cb2c5168bab7935be", "tree": "c86e5ed5b3435ff0f0266f343b19f8cc7be63340", "parents": [ "d0e27b7808dc667f3015be0b6888f6d680e222c8" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:12:05 2009 +0000" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:12:05 2009 +0000" }, "message": "CacheFiles: Catch an overly long wait for an old active object\n\nCatch an overly long wait for an old, dying active object when we want to\nreplace it with a new one. The probability is that all the slow-work threads\nare hogged, and the delete can\u0027t get a look in.\n\nWhat we do instead is:\n\n (1) if there\u0027s nothing in the slow work queue, we sleep until either the dying\n object has finished dying or there is something in the slow work queue\n behind which we can queue our object.\n\n (2) if there is something in the slow work queue, we return ETIMEDOUT to\n fscache_lookup_object(), which then puts us back on the slow work queue,\n presumably behind the deletion that we\u0027re blocked by. We are then\n deferred for a while until we work our way back through the queue -\n without blocking a slow-work thread unnecessarily.\n\nA backtrace similar to the following may appear in the log without this patch:\n\n\tINFO: task kslowd004:5711 blocked for more than 120 seconds.\n\t\"echo 0 \u003e /proc/sys/kernel/hung_task_timeout_secs\" disables this message.\n\tkslowd004 D 0000000000000000 0 5711 2 0x00000080\n\t ffff88000340bb80 0000000000000046 ffff88002550d000 0000000000000000\n\t ffff88002550d000 0000000000000007 ffff88000340bfd8 ffff88002550d2a8\n\t 000000000000ddf0 00000000000118c0 00000000000118c0 ffff88002550d2a8\n\tCall Trace:\n\t [\u003cffffffff81058e21\u003e] ? trace_hardirqs_on+0xd/0xf\n\t [\u003cffffffffa011c4d8\u003e] ? cachefiles_wait_bit+0x0/0xd [cachefiles]\n\t [\u003cffffffffa011c4e1\u003e] cachefiles_wait_bit+0x9/0xd [cachefiles]\n\t [\u003cffffffff81353153\u003e] __wait_on_bit+0x43/0x76\n\t [\u003cffffffff8111ae39\u003e] ? ext3_xattr_get+0x1ec/0x270\n\t [\u003cffffffff813531ef\u003e] out_of_line_wait_on_bit+0x69/0x74\n\t [\u003cffffffffa011c4d8\u003e] ? cachefiles_wait_bit+0x0/0xd [cachefiles]\n\t [\u003cffffffff8104c125\u003e] ? wake_bit_function+0x0/0x2e\n\t [\u003cffffffffa011bc79\u003e] cachefiles_mark_object_active+0x203/0x23b [cachefiles]\n\t [\u003cffffffffa011c209\u003e] cachefiles_walk_to_object+0x558/0x827 [cachefiles]\n\t [\u003cffffffffa011a429\u003e] cachefiles_lookup_object+0xac/0x12a [cachefiles]\n\t [\u003cffffffffa00aa1e9\u003e] fscache_lookup_object+0x1c7/0x214 [fscache]\n\t [\u003cffffffffa00aafc5\u003e] fscache_object_state_machine+0xa5/0x52d [fscache]\n\t [\u003cffffffffa00ab4ac\u003e] fscache_object_slow_work_execute+0x5f/0xa0 [fscache]\n\t [\u003cffffffff81082093\u003e] slow_work_execute+0x18f/0x2d1\n\t [\u003cffffffff8108239a\u003e] slow_work_thread+0x1c5/0x308\n\t [\u003cffffffff8104c0f1\u003e] ? autoremove_wake_function+0x0/0x34\n\t [\u003cffffffff810821d5\u003e] ? slow_work_thread+0x0/0x308\n\t [\u003cffffffff8104be91\u003e] kthread+0x7a/0x82\n\t [\u003cffffffff8100beda\u003e] child_rip+0xa/0x20\n\t [\u003cffffffff8100b87c\u003e] ? restore_args+0x0/0x30\n\t [\u003cffffffff8104be17\u003e] ? kthread+0x0/0x82\n\t [\u003cffffffff8100bed0\u003e] ? child_rip+0x0/0x20\n\t1 lock held by kslowd004/5711:\n\t #0: (\u0026sb-\u003es_type-\u003ei_mutex_key#7/1){+.+.+.}, at: [\u003cffffffffa011be64\u003e] cachefiles_walk_to_object+0x1b3/0x827 [cachefiles]\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\n" }, { "commit": "868411be3f445a83fafbd734f3e426400138add5", "tree": "5eb855730adfa903abae29a9a20a78f1cfe597af", "parents": [ "60d543ca724be155c2b6166e36a00c80b21bd810" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:48 2009 +0000" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:48 2009 +0000" }, "message": "FS-Cache: Actually requeue an object when requested\n\nFS-Cache objects have an FSCACHE_OBJECT_EV_REQUEUE event that can theoretically\nbe raised to ask the state machine to requeue the object for further processing\nbefore the work function returns to the slow-work facility.\n\nHowever, fscache_object_work_execute() was clearing that bit before checking\nthe event mask to see whether the object has any pending events that require it\nto be requeued immediately.\n\nInstead, the bit should be cleared after the check and enqueue.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\n" }, { "commit": "60d543ca724be155c2b6166e36a00c80b21bd810", "tree": "90ec6edd77ddb7666dbf7069aa2e001f155cea49", "parents": [ "d461d26dde901b0523c46b0317e7fccf574a3933" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:45 2009 +0000" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:45 2009 +0000" }, "message": "FS-Cache: Start processing an object\u0027s operations on that object\u0027s death\n\nStart processing an object\u0027s operations when that object moves into the DYING\nstate as the object cannot be destroyed until all its outstanding operations\nhave completed.\n\nFurthermore, make sure that read and allocation operations handle being woken\nup on a dead object. Such events are recorded in the Allocs.abt and\nRetrvls.abt statistics as viewable through /proc/fs/fscache/stats.\n\nThe code for waiting for object activation for the read and allocation\noperations is also extracted into its own function as it is much the same in\nall cases, differing only in the stats incremented.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\n" }, { "commit": "d461d26dde901b0523c46b0317e7fccf574a3933", "tree": "abaac0f4259ec9458fa40be85ed7a3d4f8982cc5", "parents": [ "2175bb06dc6cf2af9c098a1770561f9e63edae4e" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:41 2009 +0000" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:41 2009 +0000" }, "message": "FS-Cache: Make sure FSCACHE_COOKIE_LOOKING_UP cleared on lookup failure\n\nWe must make sure that FSCACHE_COOKIE_LOOKING_UP is cleared on lookup failure\n(if an object reaches the LC_DYING state), and we should clear it before\nclearing FSCACHE_COOKIE_CREATING.\n\nIf this doesn\u0027t happen then fscache_wait_for_deferred_lookup() may hold\nallocation and retrieval operations indefinitely until they\u0027re interrupted by\nsignals - which in turn pins the dying object until they go away.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\n" }, { "commit": "2175bb06dc6cf2af9c098a1770561f9e63edae4e", "tree": "579c8d4b3f4f92efee919953dab2c78cea8c21ea", "parents": [ "201a15428bd54f83eccec8b7c64a04b8f9431204" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:38 2009 +0000" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:38 2009 +0000" }, "message": "FS-Cache: Add a retirement stat counter\n\nAdd a stat counter to count retirement events rather than ordinary release\nevents (the retire argument to fscache_relinquish_cookie()).\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\n" }, { "commit": "201a15428bd54f83eccec8b7c64a04b8f9431204", "tree": "326fcce64ce96657253fd141a3f4a767ac95418a", "parents": [ "e3d4d28b1c8cc7c26536a50b43d86ccd39878550" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:35 2009 +0000" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:35 2009 +0000" }, "message": "FS-Cache: Handle pages pending storage that get evicted under OOM conditions\n\nHandle netfs pages that the vmscan algorithm wants to evict from the pagecache\nunder OOM conditions, but that are waiting for write to the cache. Under these\nconditions, vmscan calls the releasepage() function of the netfs, asking if a\npage can be discarded.\n\nThe problem is typified by the following trace of a stuck process:\n\n\tkslowd005 D 0000000000000000 0 4253 2 0x00000080\n\t ffff88001b14f370 0000000000000046 ffff880020d0d000 0000000000000007\n\t 0000000000000006 0000000000000001 ffff88001b14ffd8 ffff880020d0d2a8\n\t 000000000000ddf0 00000000000118c0 00000000000118c0 ffff880020d0d2a8\n\tCall Trace:\n\t [\u003cffffffffa00782d8\u003e] __fscache_wait_on_page_write+0x8b/0xa7 [fscache]\n\t [\u003cffffffff8104c0f1\u003e] ? autoremove_wake_function+0x0/0x34\n\t [\u003cffffffffa0078240\u003e] ? __fscache_check_page_write+0x63/0x70 [fscache]\n\t [\u003cffffffffa00b671d\u003e] nfs_fscache_release_page+0x4e/0xc4 [nfs]\n\t [\u003cffffffffa00927f0\u003e] nfs_release_page+0x3c/0x41 [nfs]\n\t [\u003cffffffff810885d3\u003e] try_to_release_page+0x32/0x3b\n\t [\u003cffffffff81093203\u003e] shrink_page_list+0x316/0x4ac\n\t [\u003cffffffff8109372b\u003e] shrink_inactive_list+0x392/0x67c\n\t [\u003cffffffff813532fa\u003e] ? __mutex_unlock_slowpath+0x100/0x10b\n\t [\u003cffffffff81058df0\u003e] ? trace_hardirqs_on_caller+0x10c/0x130\n\t [\u003cffffffff8135330e\u003e] ? mutex_unlock+0x9/0xb\n\t [\u003cffffffff81093aa2\u003e] shrink_list+0x8d/0x8f\n\t [\u003cffffffff81093d1c\u003e] shrink_zone+0x278/0x33c\n\t [\u003cffffffff81052d6c\u003e] ? ktime_get_ts+0xad/0xba\n\t [\u003cffffffff81094b13\u003e] try_to_free_pages+0x22e/0x392\n\t [\u003cffffffff81091e24\u003e] ? isolate_pages_global+0x0/0x212\n\t [\u003cffffffff8108e743\u003e] __alloc_pages_nodemask+0x3dc/0x5cf\n\t [\u003cffffffff81089529\u003e] grab_cache_page_write_begin+0x65/0xaa\n\t [\u003cffffffff8110f8c0\u003e] ext3_write_begin+0x78/0x1eb\n\t [\u003cffffffff81089ec5\u003e] generic_file_buffered_write+0x109/0x28c\n\t [\u003cffffffff8103cb69\u003e] ? current_fs_time+0x22/0x29\n\t [\u003cffffffff8108a509\u003e] __generic_file_aio_write+0x350/0x385\n\t [\u003cffffffff8108a588\u003e] ? generic_file_aio_write+0x4a/0xae\n\t [\u003cffffffff8108a59e\u003e] generic_file_aio_write+0x60/0xae\n\t [\u003cffffffff810b2e82\u003e] do_sync_write+0xe3/0x120\n\t [\u003cffffffff8104c0f1\u003e] ? autoremove_wake_function+0x0/0x34\n\t [\u003cffffffff810b18e1\u003e] ? __dentry_open+0x1a5/0x2b8\n\t [\u003cffffffff810b1a76\u003e] ? dentry_open+0x82/0x89\n\t [\u003cffffffffa00e693c\u003e] cachefiles_write_page+0x298/0x335 [cachefiles]\n\t [\u003cffffffffa0077147\u003e] fscache_write_op+0x178/0x2c2 [fscache]\n\t [\u003cffffffffa0075656\u003e] fscache_op_execute+0x7a/0xd1 [fscache]\n\t [\u003cffffffff81082093\u003e] slow_work_execute+0x18f/0x2d1\n\t [\u003cffffffff8108239a\u003e] slow_work_thread+0x1c5/0x308\n\t [\u003cffffffff8104c0f1\u003e] ? autoremove_wake_function+0x0/0x34\n\t [\u003cffffffff810821d5\u003e] ? slow_work_thread+0x0/0x308\n\t [\u003cffffffff8104be91\u003e] kthread+0x7a/0x82\n\t [\u003cffffffff8100beda\u003e] child_rip+0xa/0x20\n\t [\u003cffffffff8100b87c\u003e] ? restore_args+0x0/0x30\n\t [\u003cffffffff8102ef83\u003e] ? tg_shares_up+0x171/0x227\n\t [\u003cffffffff8104be17\u003e] ? kthread+0x0/0x82\n\t [\u003cffffffff8100bed0\u003e] ? child_rip+0x0/0x20\n\nIn the above backtrace, the following is happening:\n\n (1) A page storage operation is being executed by a slow-work thread\n (fscache_write_op()).\n\n (2) FS-Cache farms the operation out to the cache to perform\n (cachefiles_write_page()).\n\n (3) CacheFiles is then calling Ext3 to perform the actual write, using Ext3\u0027s\n standard write (do_sync_write()) under KERNEL_DS directly from the netfs\n page.\n\n (4) However, for Ext3 to perform the write, it must allocate some memory, in\n particular, it must allocate at least one page cache page into which it\n can copy the data from the netfs page.\n\n (5) Under OOM conditions, the memory allocator can\u0027t immediately come up with\n a page, so it uses vmscan to find something to discard\n (try_to_free_pages()).\n\n (6) vmscan finds a clean netfs page it might be able to discard (possibly the\n one it\u0027s trying to write out).\n\n (7) The netfs is called to throw the page away (nfs_release_page()) - but it\u0027s\n called with __GFP_WAIT, so the netfs decides to wait for the store to\n complete (__fscache_wait_on_page_write()).\n\n (8) This blocks a slow-work processing thread - possibly against itself.\n\nThe system ends up stuck because it can\u0027t write out any netfs pages to the\ncache without allocating more memory.\n\nTo avoid this, we make FS-Cache cancel some writes that aren\u0027t in the middle of\nactually being performed. This means that some data won\u0027t make it into the\ncache this time. To support this, a new FS-Cache function is added\nfscache_maybe_release_page() that replaces what the netfs releasepage()\nfunctions used to do with respect to the cache.\n\nThe decisions fscache_maybe_release_page() makes are counted and displayed\nthrough /proc/fs/fscache/stats on a line labelled \"VmScan\". There are four\ncounters provided: \"nos\u003dN\" - pages that weren\u0027t pending storage; \"gon\u003dN\" -\npages that were pending storage when we first looked, but weren\u0027t by the time\nwe got the object lock; \"bsy\u003dN\" - pages that we ignored as they were actively\nbeing written when we looked; and \"can\u003dN\" - pages that we cancelled the storage\nof.\n\nWhat I\u0027d really like to do is alter the behaviour of the cancellation\nheuristics, depending on how necessary it is to expel pages. If there are\nplenty of other pages that aren\u0027t waiting to be written to the cache that\ncould be ejected first, then it would be nice to hold up on immediate\ncancellation of cache writes - but I don\u0027t see a way of doing that.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\n" }, { "commit": "e3d4d28b1c8cc7c26536a50b43d86ccd39878550", "tree": "23f6dacd5ffdf6c6d01c411517855a41405381b9", "parents": [ "285e728b0ac55b53a673114096168d6f74930167" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:32 2009 +0000" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:32 2009 +0000" }, "message": "FS-Cache: Handle read request vs lookup, creation or other cache failure\n\nFS-Cache doesn\u0027t correctly handle the netfs requesting a read from the cache\non an object that failed or was withdrawn by the cache. A trace similar to\nthe following might be seen:\n\n\tCacheFiles: Lookup failed error -105\n\t[exe ] unexpected submission OP165afe [OBJ6cac OBJECT_LC_DYING]\n\t[exe ] objstate\u003dOBJECT_LC_DYING [OBJECT_LC_DYING]\n\t[exe ] objflags\u003d0\n\t[exe ] objevent\u003d9 [fffffffffffffffb]\n\t[exe ] ops\u003d0 inp\u003d0 exc\u003d0\n\tPid: 6970, comm: exe Not tainted 2.6.32-rc6-cachefs #50\n\tCall Trace:\n\t [\u003cffffffffa0076477\u003e] fscache_submit_op+0x3ff/0x45a [fscache]\n\t [\u003cffffffffa0077997\u003e] __fscache_read_or_alloc_pages+0x187/0x3c4 [fscache]\n\t [\u003cffffffffa00b6480\u003e] ? nfs_readpage_from_fscache_complete+0x0/0x66 [nfs]\n\t [\u003cffffffffa00b6388\u003e] __nfs_readpages_from_fscache+0x7e/0x176 [nfs]\n\t [\u003cffffffff8108e483\u003e] ? __alloc_pages_nodemask+0x11c/0x5cf\n\t [\u003cffffffffa009d796\u003e] nfs_readpages+0x114/0x1d7 [nfs]\n\t [\u003cffffffff81090314\u003e] __do_page_cache_readahead+0x15f/0x1ec\n\t [\u003cffffffff81090228\u003e] ? __do_page_cache_readahead+0x73/0x1ec\n\t [\u003cffffffff810903bd\u003e] ra_submit+0x1c/0x20\n\t [\u003cffffffff810906bb\u003e] ondemand_readahead+0x227/0x23a\n\t [\u003cffffffff81090762\u003e] page_cache_sync_readahead+0x17/0x19\n\t [\u003cffffffff8108a99e\u003e] generic_file_aio_read+0x236/0x5a0\n\t [\u003cffffffffa00937bd\u003e] nfs_file_read+0xe4/0xf3 [nfs]\n\t [\u003cffffffff810b2fa2\u003e] do_sync_read+0xe3/0x120\n\t [\u003cffffffff81354cc3\u003e] ? _spin_unlock_irq+0x2b/0x31\n\t [\u003cffffffff8104c0f1\u003e] ? autoremove_wake_function+0x0/0x34\n\t [\u003cffffffff811848e5\u003e] ? selinux_file_permission+0x5d/0x10f\n\t [\u003cffffffff81352bdb\u003e] ? thread_return+0x3e/0x101\n\t [\u003cffffffff8117d7b0\u003e] ? security_file_permission+0x11/0x13\n\t [\u003cffffffff810b3b06\u003e] vfs_read+0xaa/0x16f\n\t [\u003cffffffff81058df0\u003e] ? trace_hardirqs_on_caller+0x10c/0x130\n\t [\u003cffffffff810b3c84\u003e] sys_read+0x45/0x6c\n\t [\u003cffffffff8100ae2b\u003e] system_call_fastpath+0x16/0x1b\n\nThe object state might also be OBJECT_DYING or OBJECT_WITHDRAWING.\n\nThis should be handled by simply rejecting the new operation with ENOBUFS.\nThere\u0027s no need to log an error for it. Events of this type now appear in the\nstats file under Ops:rej.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\n" }, { "commit": "285e728b0ac55b53a673114096168d6f74930167", "tree": "725dbd61cc9a3fecd593163d9b2cb0a061315cbf", "parents": [ "1bccf513ac49d44604ba1cddcc29f5886e70f1b6" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:29 2009 +0000" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:29 2009 +0000" }, "message": "FS-Cache: Don\u0027t delete pending pages from the page-store tracking tree\n\nDon\u0027t delete pending pages from the page-store tracking tree, but rather send\nthem for another write as they\u0027ve presumably been updated.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\n" }, { "commit": "1bccf513ac49d44604ba1cddcc29f5886e70f1b6", "tree": "096ba75a3d02018c5f6e1857aaf1d41471733850", "parents": [ "6897e3df8fc37bd4a58bbcdef8306da7fc175584" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:25 2009 +0000" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:25 2009 +0000" }, "message": "FS-Cache: Fix lock misorder in fscache_write_op()\n\nFS-Cache has two structs internally for keeping track of the internal state of\na cached file: the fscache_cookie struct, which represents the netfs\u0027s state,\nand fscache_object struct, which represents the cache\u0027s state. Each has a\npointer that points to the other (when both are in existence), and each has a\nspinlock for pointer maintenance.\n\nSince netfs operations approach these structures from the cookie side, they get\nthe cookie lock first, then the object lock. Cache operations, on the other\nhand, approach from the object side, and get the object lock first. It is not\nthen permitted for a cache operation to get the cookie lock whilst it is\nholding the object lock lest deadlock occur; instead, it must do one of two\nthings:\n\n (1) increment the cookie usage counter, drop the object lock and then get both\n locks in order, or\n\n (2) simply hold the object lock as certain parts of the cookie may not be\n altered whilst the object lock is held.\n\nIt is also not permitted to follow either pointer without holding the lock at\nthe end you start with. To break the pointers between the cookie and the\nobject, both locks must be held.\n\nfscache_write_op(), however, violates the locking rules: It attempts to get the\ncookie lock without (a) checking that the cookie pointer is a valid pointer,\nand (b) holding the object lock to protect the cookie pointer whilst it follows\nit. This is so that it can access the pending page store tree without\ninterference from __fscache_write_page().\n\nThis is fixed by splitting the cookie lock, such that the page store tracking\ntree is protected by its own lock, and checking that the cookie pointer is\nnon-NULL before we attempt to follow it whilst holding the object lock.\n\nThe new lock is subordinate to both the cookie lock and the object lock, and so\nshould be taken after those.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\n" }, { "commit": "6897e3df8fc37bd4a58bbcdef8306da7fc175584", "tree": "e826cd96f0395775d4fea113dc283ae0282f0384", "parents": [ "5753c441889253e4323eee85f791a1d64cf08196" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:22 2009 +0000" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:22 2009 +0000" }, "message": "FS-Cache: The object-available state can\u0027t rely on the cookie to be available\n\nThe object-available state in the object processing state machine (as\nprocessed by fscache_object_available()) can\u0027t rely on the cookie to be\navailable because the FSCACHE_COOKIE_CREATING bit may have been cleared by\nfscache_obtained_object() prior to the object being put into the\nFSCACHE_OBJECT_AVAILABLE state.\n\nClearing the FSCACHE_COOKIE_CREATING bit on a cookie permits\n__fscache_relinquish_cookie() to proceed and detach the cookie from the\nobject.\n\nTo deal with this, we don\u0027t dereference object-\u003ecookie in\nfscache_object_available() if the object has already been detached.\n\nIn addition, a couple of assertions are added into fscache_drop_object() to\nmake sure the object is unbound from the cookie before it gets there.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\n" }, { "commit": "5753c441889253e4323eee85f791a1d64cf08196", "tree": "55a0de053d0593d96e99710f978277df668412d1", "parents": [ "b34df792b4e9e311db47fad27949095d0629c197" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:19 2009 +0000" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:19 2009 +0000" }, "message": "FS-Cache: Permit cache retrieval ops to be interrupted in the initial wait phase\n\nPermit the operations to retrieve data from the cache or to allocate space in\nthe cache for future writes to be interrupted whilst they\u0027re waiting for\npermission for the operation to proceed. Typically this wait occurs whilst the\ncache object is being looked up on disk in the background.\n\nIf an interruption occurs, and the operation has not yet been given the\ngo-ahead to run, the operation is dequeued and cancelled, and control returns\nto the read operation of the netfs routine with none of the requested pages\nhaving been read or in any way marked as known by the cache.\n\nThis means that the initial wait is done interruptibly rather than\nuninterruptibly.\n\nIn addition, extra stats values are made available to show the number of ops\ncancelled and the number of cache space allocations interrupted.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\n" }, { "commit": "b34df792b4e9e311db47fad27949095d0629c197", "tree": "c0d513580d5d714066666993224970916e1f9358", "parents": [ "7e311a207d596b9273d811149d6e3e14f05ac4c0" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:14 2009 +0000" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:14 2009 +0000" }, "message": "FS-Cache: Use radix tree preload correctly in tracking of pages to be stored\n\n__fscache_write_page() attempts to load the radix tree preallocation pool for\nthe CPU it is on before calling radix_tree_insert(), as the insertion must be\ndone inside a pair of spinlocks.\n\nUse of the preallocation pool, however, is contingent on the radix tree being\ninitialised without __GFP_WAIT specified. __fscache_acquire_cookie() was\npassing GFP_NOFS to INIT_RADIX_TREE() - but that includes __GFP_WAIT.\n\nThe solution is to AND out __GFP_WAIT.\n\nAdditionally, the banner comment to radix_tree_preload() is altered to make\nnote of this prerequisite. Possibly there should be a WARN_ON() too.\n\nWithout this fix, I have seen the following recursive deadlock caused by\nradix_tree_insert() attempting to allocate memory inside the spinlocked\nregion, which resulted in FS-Cache being called back into to release memory -\nwhich required the spinlock already held.\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\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\n[ INFO: possible recursive locking detected ]\n2.6.32-rc6-cachefs #24\n---------------------------------------------\nnfsiod/7916 is trying to acquire lock:\n (\u0026cookie-\u003elock){+.+.-.}, at: [\u003cffffffffa0076872\u003e] __fscache_uncache_page+0xdb/0x160 [fscache]\n\nbut task is already holding lock:\n (\u0026cookie-\u003elock){+.+.-.}, at: [\u003cffffffffa0076acc\u003e] __fscache_write_page+0x15c/0x3f3 [fscache]\n\nother info that might help us debug this:\n5 locks held by nfsiod/7916:\n #0: (nfsiod){+.+.+.}, at: [\u003cffffffff81048290\u003e] worker_thread+0x19a/0x2e2\n #1: (\u0026task-\u003eu.tk_work#2){+.+.+.}, at: [\u003cffffffff81048290\u003e] worker_thread+0x19a/0x2e2\n #2: (\u0026cookie-\u003elock){+.+.-.}, at: [\u003cffffffffa0076acc\u003e] __fscache_write_page+0x15c/0x3f3 [fscache]\n #3: (\u0026object-\u003elock#2){+.+.-.}, at: [\u003cffffffffa0076b07\u003e] __fscache_write_page+0x197/0x3f3 [fscache]\n #4: (\u0026cookie-\u003estores_lock){+.+...}, at: [\u003cffffffffa0076b0f\u003e] __fscache_write_page+0x19f/0x3f3 [fscache]\n\nstack backtrace:\nPid: 7916, comm: nfsiod Not tainted 2.6.32-rc6-cachefs #24\nCall Trace:\n [\u003cffffffff8105ac7f\u003e] __lock_acquire+0x1649/0x16e3\n [\u003cffffffff81059ded\u003e] ? __lock_acquire+0x7b7/0x16e3\n [\u003cffffffff8100e27d\u003e] ? dump_trace+0x248/0x257\n [\u003cffffffff8105ad70\u003e] lock_acquire+0x57/0x6d\n [\u003cffffffffa0076872\u003e] ? __fscache_uncache_page+0xdb/0x160 [fscache]\n [\u003cffffffff8135467c\u003e] _spin_lock+0x2c/0x3b\n [\u003cffffffffa0076872\u003e] ? __fscache_uncache_page+0xdb/0x160 [fscache]\n [\u003cffffffffa0076872\u003e] __fscache_uncache_page+0xdb/0x160 [fscache]\n [\u003cffffffffa0077eb7\u003e] ? __fscache_check_page_write+0x0/0x71 [fscache]\n [\u003cffffffffa00b4755\u003e] nfs_fscache_release_page+0x86/0xc4 [nfs]\n [\u003cffffffffa00907f0\u003e] nfs_release_page+0x3c/0x41 [nfs]\n [\u003cffffffff81087ffb\u003e] try_to_release_page+0x32/0x3b\n [\u003cffffffff81092c2b\u003e] shrink_page_list+0x316/0x4ac\n [\u003cffffffff81058a9b\u003e] ? mark_held_locks+0x52/0x70\n [\u003cffffffff8135451b\u003e] ? _spin_unlock_irq+0x2b/0x31\n [\u003cffffffff81093153\u003e] shrink_inactive_list+0x392/0x67c\n [\u003cffffffff81058a9b\u003e] ? mark_held_locks+0x52/0x70\n [\u003cffffffff810934ca\u003e] shrink_list+0x8d/0x8f\n [\u003cffffffff81093744\u003e] shrink_zone+0x278/0x33c\n [\u003cffffffff81052c70\u003e] ? ktime_get_ts+0xad/0xba\n [\u003cffffffff8109453b\u003e] try_to_free_pages+0x22e/0x392\n [\u003cffffffff8109184c\u003e] ? isolate_pages_global+0x0/0x212\n [\u003cffffffff8108e16b\u003e] __alloc_pages_nodemask+0x3dc/0x5cf\n [\u003cffffffff810ae24a\u003e] cache_alloc_refill+0x34d/0x6c1\n [\u003cffffffff811bcf74\u003e] ? radix_tree_node_alloc+0x52/0x5c\n [\u003cffffffff810ae929\u003e] kmem_cache_alloc+0xb2/0x118\n [\u003cffffffff811bcf74\u003e] radix_tree_node_alloc+0x52/0x5c\n [\u003cffffffff811bcfd5\u003e] radix_tree_insert+0x57/0x19c\n [\u003cffffffffa0076b53\u003e] __fscache_write_page+0x1e3/0x3f3 [fscache]\n [\u003cffffffffa00b4248\u003e] __nfs_readpage_to_fscache+0x58/0x11e [nfs]\n [\u003cffffffffa009bb77\u003e] nfs_readpage_release+0x34/0x9b [nfs]\n [\u003cffffffffa009c0d9\u003e] nfs_readpage_release_full+0x32/0x4b [nfs]\n [\u003cffffffffa0006cff\u003e] rpc_release_calldata+0x12/0x14 [sunrpc]\n [\u003cffffffffa0006e2d\u003e] rpc_free_task+0x59/0x61 [sunrpc]\n [\u003cffffffffa0006f03\u003e] rpc_async_release+0x10/0x12 [sunrpc]\n [\u003cffffffff810482e5\u003e] worker_thread+0x1ef/0x2e2\n [\u003cffffffff81048290\u003e] ? worker_thread+0x19a/0x2e2\n [\u003cffffffff81352433\u003e] ? thread_return+0x3e/0x101\n [\u003cffffffffa0006ef3\u003e] ? rpc_async_release+0x0/0x12 [sunrpc]\n [\u003cffffffff8104bff5\u003e] ? autoremove_wake_function+0x0/0x34\n [\u003cffffffff81058d25\u003e] ? trace_hardirqs_on+0xd/0xf\n [\u003cffffffff810480f6\u003e] ? worker_thread+0x0/0x2e2\n [\u003cffffffff8104bd21\u003e] kthread+0x7a/0x82\n [\u003cffffffff8100beda\u003e] child_rip+0xa/0x20\n [\u003cffffffff8100b87c\u003e] ? restore_args+0x0/0x30\n [\u003cffffffff8104c2b9\u003e] ? add_wait_queue+0x15/0x44\n [\u003cffffffff8104bca7\u003e] ? kthread+0x0/0x82\n [\u003cffffffff8100bed0\u003e] ? child_rip+0x0/0x20\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\n" }, { "commit": "7e311a207d596b9273d811149d6e3e14f05ac4c0", "tree": "96c766e56e73df02a430bc0df72066413838fed0", "parents": [ "52bd75fdb135d6133d878ae60c6e7e3f4ebc1cfc" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:11 2009 +0000" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:11 2009 +0000" }, "message": "FS-Cache: Clear netfs pointers in cookie after detaching object, not before\n\nClear the pointers from the fscache_cookie struct to netfs private data after\nclearing the pointer to the cookie from the fscache_object struct and\nreleasing the object lock, rather than before.\n\nThis allows the netfs private data pointers to be relied on simply by holding\nthe object lock, rather than having to hold the cookie lock. This is makes\nthings simpler as the cookie lock has to be taken before the object lock, but\nsometimes the object pointer is all that the code has.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\n" }, { "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": "440f0affe247e9990c8f8778f1861da4fd7d5e50", "tree": "0012732ac8af0245005403d9a3b0a2b1209edf32", "parents": [ "3bde31a4ac225cb5805be02eff6eaaf7e0766ccd" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:01 2009 +0000" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:11:01 2009 +0000" }, "message": "FS-Cache: Annotate slow-work runqueue proc lines for FS-Cache work items\n\nAnnotate slow-work runqueue proc lines for FS-Cache work items. Objects\ninclude the object ID and the state. Operations include the object ID, the\noperation ID and the operation type and state.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\n" }, { "commit": "3d7a641e544e428191667e8b1f83f96fa46dbd65", "tree": "172aa672eca96b94f5531885b82abb82b43c7d8a", "parents": [ "66b00a7c93ec782d118d2c03bd599cfd041e80a1" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:10:23 2009 +0000" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Thu Nov 19 18:10:23 2009 +0000" }, "message": "SLOW_WORK: Wait for outstanding work items belonging to a module to clear\n\nWait for outstanding slow work items belonging to a module to clear when\nunregistering that module as a user of the facility. This prevents the put_ref\ncode of a work item from being taken away before it returns.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\n" }, { "commit": "348ca1029e8bae6e0c49097ad25439b17c5326f4", "tree": "136f281f3c3b9b963d005369238b335029ff4475", "parents": [ "54726f14b53cae061c504ac572320a16a5616de5" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Wed May 27 15:46:50 2009 +0100" }, "committer": { "name": "Linus Torvalds", "email": "torvalds@linux-foundation.org", "time": "Wed May 27 10:20:13 2009 -0700" }, "message": "FS-Cache: Fixup renamed filenames in comments in internal.h\n\nFix up renamed filenames in comments in fs/fscache/internal.h.\n\nOriginally, the files were all called fsc-xxx.c, but they got renamed to\njust xxx.c.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@linux-foundation.org\u003e\n" }, { "commit": "b510882281d56873e1194021643b7c325336f84f", "tree": "86cd206b0d2b55dc355833ca238d46488161b64c", "parents": [ "952efe7b7840e1c726ae88222245e4efe6bd88f3" ], "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: Implement data I/O part of netfs API\n\nImplement the data I/O part of the FS-Cache netfs API. The documentation and\nAPI header file were added in a previous patch.\n\nThis patch implements the following functions for the netfs to call:\n\n (*) fscache_attr_changed().\n\n Indicate that the object has changed its attributes. The only attribute\n currently recorded is the file size. Only pages within the set file size\n will be stored in the cache.\n\n This operation is submitted for asynchronous processing, and will return\n immediately. It will return -ENOMEM if an out of memory error is\n encountered, -ENOBUFS if the object is not actually cached, or 0 if the\n operation is successfully queued.\n\n (*) fscache_read_or_alloc_page().\n (*) fscache_read_or_alloc_pages().\n\n Request data be fetched from the disk, and allocate internal metadata to\n track the netfs pages and reserve disk space for unknown pages.\n\n These operations perform semi-asynchronous data reads. Upon returning\n they will indicate which pages they think can be retrieved from disk, and\n will have set in progress attempts to retrieve those pages.\n\n These will return, in order of preference, -ENOMEM on memory allocation\n error, -ERESTARTSYS if a signal interrupted proceedings, -ENODATA if one\n or more requested pages are not yet cached, -ENOBUFS if the object is not\n actually cached or if there isn\u0027t space for future pages to be cached on\n this object, or 0 if successful.\n\n In the case of the multipage function, the pages for which reads are set\n in progress will be removed from the list and the page count decreased\n appropriately.\n\n If any read operations should fail, the completion function will be given\n an error, and will also be passed contextual information to allow the\n netfs to fall back to querying the server for the absent pages.\n\n For each successful read, the page completion function will also be\n called.\n\n Any pages subsequently tracked by the cache will have PG_fscache set upon\n them on return. fscache_uncache_page() must be called for such pages.\n\n If supplied by the netfs, the mark_pages_cached() cookie op will be\n invoked for any pages now tracked.\n\n (*) fscache_alloc_page().\n\n Allocate internal metadata to track a netfs page and reserve disk space.\n\n This will return -ENOMEM on memory allocation error, -ERESTARTSYS on\n signal, -ENOBUFS if the object isn\u0027t cached, or there isn\u0027t enough space\n in the cache, or 0 if successful.\n\n Any pages subsequently tracked by the cache will have PG_fscache set upon\n them on return. fscache_uncache_page() must be called for such pages.\n\n If supplied by the netfs, the mark_pages_cached() cookie op will be\n invoked for any pages now tracked.\n\n (*) fscache_write_page().\n\n Request data be stored to disk. This may only be called on pages that\n have been read or alloc\u0027d by the above three functions and have not yet\n been uncached.\n\n This will return -ENOMEM on memory allocation error, -ERESTARTSYS on\n signal, -ENOBUFS if the object isn\u0027t cached, or there isn\u0027t immediately\n enough space in the cache, or 0 if successful.\n\n On a successful return, this operation will have queued the page for\n asynchronous writing to the cache. The page will be returned with\n PG_fscache_write set until the write completes one way or another. The\n caller will not be notified if the write fails due to an I/O error. If\n that happens, the object will become available and all pending writes will\n be aborted.\n\n Note that the cache may batch up page writes, and so it may take a while\n to get around to writing them out.\n\n The caller must assume that until PG_fscache_write is cleared the page is\n use by the cache. Any changes made to the page may be reflected on disk.\n The page may even be under DMA.\n\n (*) fscache_uncache_page().\n\n Indicate that the cache should stop tracking a page previously read or\n alloc\u0027d from the cache. If the page was alloc\u0027d only, but unwritten, it\n will not appear on disk.\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": "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": "ccc4fc3d11e91477036d1f82bfa2d442f6ce77f0", "tree": "c3ead4b385f9efce6e2688832dfb76391e18345d", "parents": [ "36c9559022850f919269564a74bf17fdabf4bb30" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Fri Apr 03 16:42:38 2009 +0100" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Fri Apr 03 16:42:38 2009 +0100" }, "message": "FS-Cache: Implement the cookie management part of the netfs API\n\nImplement the cookie management part of the FS-Cache netfs client API. The\ndocumentation and API header file were added in a previous patch.\n\nThis patch implements the following three functions:\n\n (1) fscache_acquire_cookie().\n\n Acquire a cookie to represent an object to the netfs. If the object in\n question is a non-index object, then that object and its parent indices\n will be created on disk at this point if they don\u0027t already exist. Index\n creation is deferred because an index may reside in multiple caches.\n\n (2) fscache_relinquish_cookie().\n\n Retire or release a cookie previously acquired. At this point, the\n object on disk may be destroyed.\n\n (3) fscache_update_cookie().\n\n Update the in-cache representation of a cookie. This is used to update\n the auxiliary data for coherency management purposes.\n\nWith this patch it is possible to have a netfs instruct a cache backend to\nlook up, validate and create metadata on disk and to destroy it again.\nThe ability to actually store and retrieve data in the objects so created is\nadded in later patches.\n\nNote that these functions will never return an error. _All_ errors are\nhandled internally to FS-Cache.\n\nThe worst that can happen is that fscache_acquire_cookie() may return a NULL\npointer - which is considered a negative cookie pointer and can be passed back\nto any function that takes a cookie without harm. A negative cookie pointer\nmerely suppresses caching at that level.\n\nThe stub in linux/fscache.h will detect inline the negative cookie pointer and\nabort the operation as fast as possible. This means that the compiler doesn\u0027t\nhave to set up for a call in that case.\n\nSee the documentation in Documentation/filesystems/caching/netfs-api.txt for\nmore information.\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": "36c9559022850f919269564a74bf17fdabf4bb30", "tree": "f163afcf8f8a9eb1a5d63fd6198fcb3e29564493", "parents": [ "2868cbea72dc89ae0eb17693596b1dedaafff1c5" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Fri Apr 03 16:42:38 2009 +0100" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Fri Apr 03 16:42:38 2009 +0100" }, "message": "FS-Cache: Object management state machine\n\nImplement the cache object management state machine.\n\nThe following documentation is added to illuminate the working of this state\nmachine. It will also be added as:\n\n\tDocumentation/filesystems/caching/object.txt\n\n\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\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\n\t IN-KERNEL CACHE OBJECT REPRESENTATION AND MANAGEMENT\n\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\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\u003d\u003d\u003d\u003d\u003d\u003d\nREPRESENTATION\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\n\nFS-Cache maintains an in-kernel representation of each object that a netfs is\ncurrently interested in. Such objects are represented by the fscache_cookie\nstruct and are referred to as cookies.\n\nFS-Cache also maintains a separate in-kernel representation of the objects that\na cache backend is currently actively caching. Such objects are represented by\nthe fscache_object struct. The cache backends allocate these upon request, and\nare expected to embed them in their own representations. These are referred to\nas objects.\n\nThere is a 1:N relationship between cookies and objects. A cookie may be\nrepresented by multiple objects - an index may exist in more than one cache -\nor even by no objects (it may not be cached).\n\nFurthermore, both cookies and objects are hierarchical. The two hierarchies\ncorrespond, but the cookies tree is a superset of the union of the object trees\nof multiple caches:\n\n\t NETFS INDEX TREE : CACHE 1 : CACHE 2\n\t : :\n\t : +-----------+ :\n\t +-----------\u003e| IObject | :\n\t +-----------+ | : +-----------+ :\n\t | ICookie |-------+ : | :\n\t +-----------+ | : | : +-----------+\n\t | +------------------------------\u003e| IObject |\n\t | : | : +-----------+\n\t | : V : |\n\t | : +-----------+ : |\n\t V +-----------\u003e| IObject | : |\n\t +-----------+ | : +-----------+ : |\n\t | ICookie |-------+ : | : V\n\t +-----------+ | : | : +-----------+\n\t | +------------------------------\u003e| IObject |\n\t +-----+-----+ : | : +-----------+\n\t | | : | : |\n\t V | : V : |\n\t+-----------+ | : +-----------+ : |\n\t| ICookie |-------------------------\u003e| IObject | : |\n\t+-----------+ | : +-----------+ : |\n\t | V : | : V\n\t | +-----------+ : | : +-----------+\n\t | | ICookie |--------------------------------\u003e| IObject |\n\t | +-----------+ : | : +-----------+\n\t V | : V : |\n\t+-----------+ | : +-----------+ : |\n\t| DCookie |-------------------------\u003e| DObject | : |\n\t+-----------+ | : +-----------+ : |\n\t | : : |\n\t +-------+-------+ : : |\n\t | | : : |\n\t V V : : V\n\t +-----------+ +-----------+ : : +-----------+\n\t | DCookie | | DCookie |------------------------\u003e| DObject |\n\t +-----------+ +-----------+ : : +-----------+\n\t : :\n\nIn the above illustration, ICookie and IObject represent indices and DCookie\nand DObject represent data storage objects. Indices may have representation in\nmultiple caches, but currently, non-index objects may not. Objects of any type\nmay also be entirely unrepresented.\n\nAs far as the netfs API goes, the netfs is only actually permitted to see\npointers to the cookies. The cookies themselves and any objects attached to\nthose cookies are hidden from it.\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\nOBJECT MANAGEMENT STATE MACHINE\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\nWithin FS-Cache, each active object is managed by its own individual state\nmachine. The state for an object is kept in the fscache_object struct, in\nobject-\u003estate. A cookie may point to a set of objects that are in different\nstates.\n\nEach state has an action associated with it that is invoked when the machine\nwakes up in that state. There are four logical sets of states:\n\n (1) Preparation: states that wait for the parent objects to become ready. The\n representations are hierarchical, and it is expected that an object must\n be created or accessed with respect to its parent object.\n\n (2) Initialisation: states that perform lookups in the cache and validate\n what\u0027s found and that create on disk any missing metadata.\n\n (3) Normal running: states that allow netfs operations on objects to proceed\n and that update the state of objects.\n\n (4) Termination: states that detach objects from their netfs cookies, that\n delete objects from disk, that handle disk and system errors and that free\n up in-memory resources.\n\nIn most cases, transitioning between states is in response to signalled events.\nWhen a state has finished processing, it will usually set the mask of events in\nwhich it is interested (object-\u003eevent_mask) and relinquish the worker thread.\nThen when an event is raised (by calling fscache_raise_event()), if the event\nis not masked, the object will be queued for processing (by calling\nfscache_enqueue_object()).\n\nPROVISION OF CPU TIME\n---------------------\n\nThe work to be done by the various states is given CPU time by the threads of\nthe slow work facility (see Documentation/slow-work.txt). This is used in\npreference to the workqueue facility because:\n\n (1) Threads may be completely occupied for very long periods of time by a\n particular work item. These state actions may be doing sequences of\n synchronous, journalled disk accesses (lookup, mkdir, create, setxattr,\n getxattr, truncate, unlink, rmdir, rename).\n\n (2) Threads may do little actual work, but may rather spend a lot of time\n sleeping on I/O. This means that single-threaded and 1-per-CPU-threaded\n workqueues don\u0027t necessarily have the right numbers of threads.\n\nLOCKING SIMPLIFICATION\n----------------------\n\nBecause only one worker thread may be operating on any particular object\u0027s\nstate machine at once, this simplifies the locking, particularly with respect\nto disconnecting the netfs\u0027s representation of a cache object (fscache_cookie)\nfrom the cache backend\u0027s representation (fscache_object) - which may be\nrequested from either end.\n\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\nTHE SET OF STATES\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\n\nThe object state machine has a set of states that it can be in. There are\npreparation states in which the object sets itself up and waits for its parent\nobject to transit to a state that allows access to its children:\n\n (1) State FSCACHE_OBJECT_INIT.\n\n Initialise the object and wait for the parent object to become active. In\n the cache, it is expected that it will not be possible to look an object\n up from the parent object, until that parent object itself has been looked\n up.\n\nThere are initialisation states in which the object sets itself up and accesses\ndisk for the object metadata:\n\n (2) State FSCACHE_OBJECT_LOOKING_UP.\n\n Look up the object on disk, using the parent as a starting point.\n FS-Cache expects the cache backend to probe the cache to see whether this\n object is represented there, and if it is, to see if it\u0027s valid (coherency\n management).\n\n The cache should call fscache_object_lookup_negative() to indicate lookup\n failure for whatever reason, and should call fscache_obtained_object() to\n indicate success.\n\n At the completion of lookup, FS-Cache will let the netfs go ahead with\n read operations, no matter whether the file is yet cached. If not yet\n cached, read operations will be immediately rejected with ENODATA until\n the first known page is uncached - as to that point there can be no data\n to be read out of the cache for that file that isn\u0027t currently also held\n in the pagecache.\n\n (3) State FSCACHE_OBJECT_CREATING.\n\n Create an object on disk, using the parent as a starting point. This\n happens if the lookup failed to find the object, or if the object\u0027s\n coherency data indicated what\u0027s on disk is out of date. In this state,\n FS-Cache expects the cache to create\n\n The cache should call fscache_obtained_object() if creation completes\n successfully, fscache_object_lookup_negative() otherwise.\n\n At the completion of creation, FS-Cache will start processing write\n operations the netfs has queued for an object. If creation failed, the\n write ops will be transparently discarded, and nothing recorded in the\n cache.\n\nThere are some normal running states in which the object spends its time\nservicing netfs requests:\n\n (4) State FSCACHE_OBJECT_AVAILABLE.\n\n A transient state in which pending operations are started, child objects\n are permitted to advance from FSCACHE_OBJECT_INIT state, and temporary\n lookup data is freed.\n\n (5) State FSCACHE_OBJECT_ACTIVE.\n\n The normal running state. In this state, requests the netfs makes will be\n passed on to the cache.\n\n (6) State FSCACHE_OBJECT_UPDATING.\n\n The state machine comes here to update the object in the cache from the\n netfs\u0027s records. This involves updating the auxiliary data that is used\n to maintain coherency.\n\nAnd there are terminal states in which an object cleans itself up, deallocates\nmemory and potentially deletes stuff from disk:\n\n (7) State FSCACHE_OBJECT_LC_DYING.\n\n The object comes here if it is dying because of a lookup or creation\n error. This would be due to a disk error or system error of some sort.\n Temporary data is cleaned up, and the parent is released.\n\n (8) State FSCACHE_OBJECT_DYING.\n\n The object comes here if it is dying due to an error, because its parent\n cookie has been relinquished by the netfs or because the cache is being\n withdrawn.\n\n Any child objects waiting on this one are given CPU time so that they too\n can destroy themselves. This object waits for all its children to go away\n before advancing to the next state.\n\n (9) State FSCACHE_OBJECT_ABORT_INIT.\n\n The object comes to this state if it was waiting on its parent in\n FSCACHE_OBJECT_INIT, but its parent died. The object will destroy itself\n so that the parent may proceed from the FSCACHE_OBJECT_DYING state.\n\n(10) State FSCACHE_OBJECT_RELEASING.\n(11) State FSCACHE_OBJECT_RECYCLING.\n\n The object comes to one of these two states when dying once it is rid of\n all its children, if it is dying because the netfs relinquished its\n cookie. In the first state, the cached data is expected to persist, and\n in the second it will be deleted.\n\n(12) State FSCACHE_OBJECT_WITHDRAWING.\n\n The object transits to this state if the cache decides it wants to\n withdraw the object from service, perhaps to make space, but also due to\n error or just because the whole cache is being withdrawn.\n\n(13) State FSCACHE_OBJECT_DEAD.\n\n The object transits to this state when the in-memory object record is\n ready to be deleted. The object processor shouldn\u0027t ever see an object in\n this state.\n\nTHE SET OF EVENTS\n-----------------\n\nThere are a number of events that can be raised to an object state machine:\n\n (*) FSCACHE_OBJECT_EV_UPDATE\n\n The netfs requested that an object be updated. The state machine will ask\n the cache backend to update the object, and the cache backend will ask the\n netfs for details of the change through its cookie definition ops.\n\n (*) FSCACHE_OBJECT_EV_CLEARED\n\n This is signalled in two circumstances:\n\n (a) when an object\u0027s last child object is dropped and\n\n (b) when the last operation outstanding on an object is completed.\n\n This is used to proceed from the dying state.\n\n (*) FSCACHE_OBJECT_EV_ERROR\n\n This is signalled when an I/O error occurs during the processing of some\n object.\n\n (*) FSCACHE_OBJECT_EV_RELEASE\n (*) FSCACHE_OBJECT_EV_RETIRE\n\n These are signalled when the netfs relinquishes a cookie it was using.\n The event selected depends on whether the netfs asks for the backing\n object to be retired (deleted) or retained.\n\n (*) FSCACHE_OBJECT_EV_WITHDRAW\n\n This is signalled when the cache backend wants to withdraw an object.\n This means that the object will have to be detached from the netfs\u0027s\n cookie.\n\nBecause the withdrawing releasing/retiring events are all handled by the object\nstate machine, it doesn\u0027t matter if there\u0027s a collision with both ends trying\nto sever the connection at the same time. The state machine can just pick\nwhich one it wants to honour, and that effects the other.\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": "2868cbea72dc89ae0eb17693596b1dedaafff1c5", "tree": "277e2cbdafabe6ca74458445838a07b571a94996", "parents": [ "726dd7ff10c217dd74329c94643dc8ebea27334b" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Fri Apr 03 16:42:38 2009 +0100" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Fri Apr 03 16:42:38 2009 +0100" }, "message": "FS-Cache: Bit waiting helpers\n\nAdd helpers for use with wait_on_bit().\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": "726dd7ff10c217dd74329c94643dc8ebea27334b", "tree": "9bd5b011f945fca4f1b057f7e7750414b1fd9fbd", "parents": [ "955d00917f0c094e0f2fb88df967e980ab66b8ca" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Fri Apr 03 16:42:38 2009 +0100" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Fri Apr 03 16:42:38 2009 +0100" }, "message": "FS-Cache: Add netfs registration\n\nAdd functions to register and unregister a network filesystem or other client\nof the FS-Cache service. This allocates and releases the cookie representing\nthe top-level index for a netfs, and makes it available to the netfs.\n\nIf the FS-Cache facility is disabled, then the calls are optimised away at\ncompile time.\n\nNote that whilst this patch may appear to work with FS-Cache enabled and a\nnetfs attempting to use it, it will leak the cookie it allocates for the netfs\nas fscache_relinquish_cookie() is implemented in a later patch. This will\ncause the slab code to emit a warning when the module is removed.\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": "955d00917f0c094e0f2fb88df967e980ab66b8ca", "tree": "c6109684239fd45462e494fb4f26aa8e2e651922", "parents": [ "4c515dd47ab41be3f89e757d441661795470b376" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Fri Apr 03 16:42:38 2009 +0100" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Fri Apr 03 16:42:38 2009 +0100" }, "message": "FS-Cache: Provide a slab for cookie allocation\n\nProvide a slab from which can be allocated the FS-Cache cookies that will be\npresented to the netfs.\n\nAlso provide a slab constructor and a function to recursively discard a cookie\nand its ancestor chain.\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" }, { "commit": "a6891645cf2ddd4778096848a864580e7258faba", "tree": "e0095e8b87e199e7310508fc3687660746860600", "parents": [ "7394daa8c61dfda4baa687f133748fa0b599b017" ], "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: Root index definition\n\nAdd a description of the root index of the cache for later patches to make use\nof.\n\nThe root index is owned by FS-Cache itself. When a netfs requests caching\nfacilities, FS-Cache will, if one doesn\u0027t already exist, create an entry in\nthe root index with the key being the name of the netfs (\"AFS\" for example),\nand the auxiliary data holding the index structure version supplied by the\nnetfs:\n\n\t\t\t\t FSDEF\n\t\t\t\t |\n\t\t\t\t +-----------+\n\t\t\t\t | |\n\t\t\t\tNFS AFS\n\t\t\t [v\u003d1] [v\u003d1]\n\nIf an entry with the appropriate name does already exist, the version is\ncompared. If the version is different, the entire subtree from that entry\nwill be discarded and a new entry created.\n\nThe new entry will be an index, and a cookie referring to it will be passed to\nthe netfs. This is then the root handle by which the netfs accesses the\ncache. It can create whatever objects it likes in that index, including\nfurther indices.\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": "7394daa8c61dfda4baa687f133748fa0b599b017", "tree": "32d2c55ed60596918ec62ce6ecca186337bf4660", "parents": [ "06b3db1b9bccdc8c2c743122a89745279e5ecc46" ], "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 use of /proc and presentation of statistics\n\nMake FS-Cache create its /proc interface and present various statistical\ninformation through it. Also provide the functions for updating this\ninformation.\n\nThese features are enabled by:\n\n\tCONFIG_FSCACHE_PROC\n\tCONFIG_FSCACHE_STATS\n\tCONFIG_FSCACHE_HISTOGRAM\n\nThe /proc directory for FS-Cache is also exported so that caching modules can\nadd their own statistics there too.\n\nThe FS-Cache module is loadable at this point, and the statistics files can be\nexamined by userspace:\n\n\tcat /proc/fs/fscache/stats\n\tcat /proc/fs/fscache/histogram\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": "06b3db1b9bccdc8c2c743122a89745279e5ecc46", "tree": "b60850bd899c1a87b5b372cfbf1e72cf380c862a", "parents": [ "0dfc41d1efcc4180abfd32f68f0ade540e636ff6" ], "author": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Fri Apr 03 16:42:36 2009 +0100" }, "committer": { "name": "David Howells", "email": "dhowells@redhat.com", "time": "Fri Apr 03 16:42:36 2009 +0100" }, "message": "FS-Cache: Add main configuration option, module entry points and debugging\n\nAdd the main configuration option, allowing FS-Cache to be selected; the\nmodule entry and exit functions and the debugging stuff used by these patches.\n\nThe two configuration options added are:\n\n\tCONFIG_FSCACHE\n\tCONFIG_FSCACHE_DEBUG\n\nThe first enables the facility, and the second makes the debugging statements\nenableable through the \"debug\" module parameter. The value of this parameter\nis a bitmask as described in:\n\n\tDocumentation/filesystems/caching/fscache.txt\n\nThe module can be loaded at this point, but all it will do at this point in\nthe patch series is to start up the slow work facility and shut it down again.\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" } ] }