5a0e3ad6af
percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
524 lines
13 KiB
C
524 lines
13 KiB
C
/* FS-Cache worker operation management routines
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*
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* Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* See Documentation/filesystems/caching/operations.txt
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*/
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#define FSCACHE_DEBUG_LEVEL OPERATION
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#include <linux/module.h>
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#include <linux/seq_file.h>
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#include <linux/slab.h>
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#include "internal.h"
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atomic_t fscache_op_debug_id;
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EXPORT_SYMBOL(fscache_op_debug_id);
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/**
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* fscache_enqueue_operation - Enqueue an operation for processing
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* @op: The operation to enqueue
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*
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* Enqueue an operation for processing by the FS-Cache thread pool.
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*
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* This will get its own ref on the object.
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*/
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void fscache_enqueue_operation(struct fscache_operation *op)
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{
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_enter("{OBJ%x OP%x,%u}",
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op->object->debug_id, op->debug_id, atomic_read(&op->usage));
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fscache_set_op_state(op, "EnQ");
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ASSERT(list_empty(&op->pend_link));
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ASSERT(op->processor != NULL);
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ASSERTCMP(op->object->state, >=, FSCACHE_OBJECT_AVAILABLE);
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ASSERTCMP(atomic_read(&op->usage), >, 0);
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fscache_stat(&fscache_n_op_enqueue);
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switch (op->flags & FSCACHE_OP_TYPE) {
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case FSCACHE_OP_FAST:
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_debug("queue fast");
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atomic_inc(&op->usage);
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if (!schedule_work(&op->fast_work))
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fscache_put_operation(op);
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break;
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case FSCACHE_OP_SLOW:
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_debug("queue slow");
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slow_work_enqueue(&op->slow_work);
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break;
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case FSCACHE_OP_MYTHREAD:
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_debug("queue for caller's attention");
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break;
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default:
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printk(KERN_ERR "FS-Cache: Unexpected op type %lx",
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op->flags);
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BUG();
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break;
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}
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}
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EXPORT_SYMBOL(fscache_enqueue_operation);
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/*
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* start an op running
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*/
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static void fscache_run_op(struct fscache_object *object,
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struct fscache_operation *op)
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{
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fscache_set_op_state(op, "Run");
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object->n_in_progress++;
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if (test_and_clear_bit(FSCACHE_OP_WAITING, &op->flags))
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wake_up_bit(&op->flags, FSCACHE_OP_WAITING);
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if (op->processor)
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fscache_enqueue_operation(op);
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fscache_stat(&fscache_n_op_run);
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}
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/*
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* submit an exclusive operation for an object
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* - other ops are excluded from running simultaneously with this one
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* - this gets any extra refs it needs on an op
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*/
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int fscache_submit_exclusive_op(struct fscache_object *object,
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struct fscache_operation *op)
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{
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int ret;
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_enter("{OBJ%x OP%x},", object->debug_id, op->debug_id);
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fscache_set_op_state(op, "SubmitX");
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spin_lock(&object->lock);
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ASSERTCMP(object->n_ops, >=, object->n_in_progress);
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ASSERTCMP(object->n_ops, >=, object->n_exclusive);
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ASSERT(list_empty(&op->pend_link));
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ret = -ENOBUFS;
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if (fscache_object_is_active(object)) {
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op->object = object;
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object->n_ops++;
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object->n_exclusive++; /* reads and writes must wait */
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if (object->n_ops > 0) {
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atomic_inc(&op->usage);
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list_add_tail(&op->pend_link, &object->pending_ops);
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fscache_stat(&fscache_n_op_pend);
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} else if (!list_empty(&object->pending_ops)) {
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atomic_inc(&op->usage);
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list_add_tail(&op->pend_link, &object->pending_ops);
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fscache_stat(&fscache_n_op_pend);
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fscache_start_operations(object);
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} else {
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ASSERTCMP(object->n_in_progress, ==, 0);
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fscache_run_op(object, op);
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}
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/* need to issue a new write op after this */
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clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
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ret = 0;
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} else if (object->state == FSCACHE_OBJECT_CREATING) {
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op->object = object;
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object->n_ops++;
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object->n_exclusive++; /* reads and writes must wait */
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atomic_inc(&op->usage);
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list_add_tail(&op->pend_link, &object->pending_ops);
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fscache_stat(&fscache_n_op_pend);
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ret = 0;
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} else {
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/* not allowed to submit ops in any other state */
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BUG();
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}
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spin_unlock(&object->lock);
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return ret;
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}
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/*
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* report an unexpected submission
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*/
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static void fscache_report_unexpected_submission(struct fscache_object *object,
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struct fscache_operation *op,
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unsigned long ostate)
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{
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static bool once_only;
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struct fscache_operation *p;
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unsigned n;
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if (once_only)
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return;
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once_only = true;
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kdebug("unexpected submission OP%x [OBJ%x %s]",
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op->debug_id, object->debug_id,
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fscache_object_states[object->state]);
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kdebug("objstate=%s [%s]",
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fscache_object_states[object->state],
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fscache_object_states[ostate]);
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kdebug("objflags=%lx", object->flags);
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kdebug("objevent=%lx [%lx]", object->events, object->event_mask);
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kdebug("ops=%u inp=%u exc=%u",
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object->n_ops, object->n_in_progress, object->n_exclusive);
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if (!list_empty(&object->pending_ops)) {
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n = 0;
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list_for_each_entry(p, &object->pending_ops, pend_link) {
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ASSERTCMP(p->object, ==, object);
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kdebug("%p %p", op->processor, op->release);
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n++;
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}
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kdebug("n=%u", n);
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}
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dump_stack();
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}
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/*
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* submit an operation for an object
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* - objects may be submitted only in the following states:
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* - during object creation (write ops may be submitted)
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* - whilst the object is active
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* - after an I/O error incurred in one of the two above states (op rejected)
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* - this gets any extra refs it needs on an op
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*/
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int fscache_submit_op(struct fscache_object *object,
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struct fscache_operation *op)
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{
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unsigned long ostate;
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int ret;
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_enter("{OBJ%x OP%x},{%u}",
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object->debug_id, op->debug_id, atomic_read(&op->usage));
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ASSERTCMP(atomic_read(&op->usage), >, 0);
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fscache_set_op_state(op, "Submit");
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spin_lock(&object->lock);
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ASSERTCMP(object->n_ops, >=, object->n_in_progress);
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ASSERTCMP(object->n_ops, >=, object->n_exclusive);
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ASSERT(list_empty(&op->pend_link));
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ostate = object->state;
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smp_rmb();
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if (fscache_object_is_active(object)) {
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op->object = object;
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object->n_ops++;
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if (object->n_exclusive > 0) {
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atomic_inc(&op->usage);
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list_add_tail(&op->pend_link, &object->pending_ops);
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fscache_stat(&fscache_n_op_pend);
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} else if (!list_empty(&object->pending_ops)) {
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atomic_inc(&op->usage);
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list_add_tail(&op->pend_link, &object->pending_ops);
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fscache_stat(&fscache_n_op_pend);
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fscache_start_operations(object);
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} else {
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ASSERTCMP(object->n_exclusive, ==, 0);
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fscache_run_op(object, op);
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}
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ret = 0;
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} else if (object->state == FSCACHE_OBJECT_CREATING) {
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op->object = object;
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object->n_ops++;
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atomic_inc(&op->usage);
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list_add_tail(&op->pend_link, &object->pending_ops);
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fscache_stat(&fscache_n_op_pend);
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ret = 0;
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} else if (object->state == FSCACHE_OBJECT_DYING ||
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object->state == FSCACHE_OBJECT_LC_DYING ||
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object->state == FSCACHE_OBJECT_WITHDRAWING) {
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fscache_stat(&fscache_n_op_rejected);
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ret = -ENOBUFS;
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} else if (!test_bit(FSCACHE_IOERROR, &object->cache->flags)) {
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fscache_report_unexpected_submission(object, op, ostate);
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ASSERT(!fscache_object_is_active(object));
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ret = -ENOBUFS;
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} else {
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ret = -ENOBUFS;
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}
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spin_unlock(&object->lock);
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return ret;
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}
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/*
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* queue an object for withdrawal on error, aborting all following asynchronous
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* operations
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*/
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void fscache_abort_object(struct fscache_object *object)
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{
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_enter("{OBJ%x}", object->debug_id);
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fscache_raise_event(object, FSCACHE_OBJECT_EV_ERROR);
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}
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/*
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* jump start the operation processing on an object
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* - caller must hold object->lock
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*/
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void fscache_start_operations(struct fscache_object *object)
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{
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struct fscache_operation *op;
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bool stop = false;
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while (!list_empty(&object->pending_ops) && !stop) {
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op = list_entry(object->pending_ops.next,
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struct fscache_operation, pend_link);
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if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags)) {
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if (object->n_in_progress > 0)
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break;
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stop = true;
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}
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list_del_init(&op->pend_link);
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fscache_run_op(object, op);
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/* the pending queue was holding a ref on the object */
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fscache_put_operation(op);
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}
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ASSERTCMP(object->n_in_progress, <=, object->n_ops);
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_debug("woke %d ops on OBJ%x",
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object->n_in_progress, object->debug_id);
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}
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/*
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* cancel an operation that's pending on an object
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*/
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int fscache_cancel_op(struct fscache_operation *op)
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{
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struct fscache_object *object = op->object;
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int ret;
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_enter("OBJ%x OP%x}", op->object->debug_id, op->debug_id);
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spin_lock(&object->lock);
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ret = -EBUSY;
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if (!list_empty(&op->pend_link)) {
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fscache_stat(&fscache_n_op_cancelled);
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list_del_init(&op->pend_link);
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object->n_ops--;
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if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags))
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object->n_exclusive--;
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if (test_and_clear_bit(FSCACHE_OP_WAITING, &op->flags))
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wake_up_bit(&op->flags, FSCACHE_OP_WAITING);
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fscache_put_operation(op);
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ret = 0;
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}
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spin_unlock(&object->lock);
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_leave(" = %d", ret);
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return ret;
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}
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/*
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* release an operation
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* - queues pending ops if this is the last in-progress op
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*/
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void fscache_put_operation(struct fscache_operation *op)
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{
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struct fscache_object *object;
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struct fscache_cache *cache;
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_enter("{OBJ%x OP%x,%d}",
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op->object->debug_id, op->debug_id, atomic_read(&op->usage));
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ASSERTCMP(atomic_read(&op->usage), >, 0);
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if (!atomic_dec_and_test(&op->usage))
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return;
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fscache_set_op_state(op, "Put");
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_debug("PUT OP");
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if (test_and_set_bit(FSCACHE_OP_DEAD, &op->flags))
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BUG();
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fscache_stat(&fscache_n_op_release);
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if (op->release) {
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op->release(op);
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op->release = NULL;
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}
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object = op->object;
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if (test_bit(FSCACHE_OP_DEC_READ_CNT, &op->flags))
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atomic_dec(&object->n_reads);
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/* now... we may get called with the object spinlock held, so we
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* complete the cleanup here only if we can immediately acquire the
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* lock, and defer it otherwise */
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if (!spin_trylock(&object->lock)) {
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_debug("defer put");
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fscache_stat(&fscache_n_op_deferred_release);
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cache = object->cache;
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spin_lock(&cache->op_gc_list_lock);
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list_add_tail(&op->pend_link, &cache->op_gc_list);
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spin_unlock(&cache->op_gc_list_lock);
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schedule_work(&cache->op_gc);
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_leave(" [defer]");
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return;
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}
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if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags)) {
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ASSERTCMP(object->n_exclusive, >, 0);
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object->n_exclusive--;
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}
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ASSERTCMP(object->n_in_progress, >, 0);
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object->n_in_progress--;
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if (object->n_in_progress == 0)
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fscache_start_operations(object);
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ASSERTCMP(object->n_ops, >, 0);
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object->n_ops--;
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if (object->n_ops == 0)
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fscache_raise_event(object, FSCACHE_OBJECT_EV_CLEARED);
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spin_unlock(&object->lock);
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kfree(op);
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_leave(" [done]");
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}
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EXPORT_SYMBOL(fscache_put_operation);
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/*
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* garbage collect operations that have had their release deferred
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*/
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void fscache_operation_gc(struct work_struct *work)
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{
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struct fscache_operation *op;
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struct fscache_object *object;
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struct fscache_cache *cache =
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container_of(work, struct fscache_cache, op_gc);
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int count = 0;
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_enter("");
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do {
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spin_lock(&cache->op_gc_list_lock);
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if (list_empty(&cache->op_gc_list)) {
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spin_unlock(&cache->op_gc_list_lock);
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break;
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}
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op = list_entry(cache->op_gc_list.next,
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struct fscache_operation, pend_link);
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list_del(&op->pend_link);
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spin_unlock(&cache->op_gc_list_lock);
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object = op->object;
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_debug("GC DEFERRED REL OBJ%x OP%x",
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object->debug_id, op->debug_id);
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fscache_stat(&fscache_n_op_gc);
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ASSERTCMP(atomic_read(&op->usage), ==, 0);
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spin_lock(&object->lock);
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if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags)) {
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ASSERTCMP(object->n_exclusive, >, 0);
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object->n_exclusive--;
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}
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ASSERTCMP(object->n_in_progress, >, 0);
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object->n_in_progress--;
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if (object->n_in_progress == 0)
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fscache_start_operations(object);
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ASSERTCMP(object->n_ops, >, 0);
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object->n_ops--;
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if (object->n_ops == 0)
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fscache_raise_event(object, FSCACHE_OBJECT_EV_CLEARED);
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spin_unlock(&object->lock);
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} while (count++ < 20);
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if (!list_empty(&cache->op_gc_list))
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schedule_work(&cache->op_gc);
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_leave("");
|
|
}
|
|
|
|
/*
|
|
* allow the slow work item processor to get a ref on an operation
|
|
*/
|
|
static int fscache_op_get_ref(struct slow_work *work)
|
|
{
|
|
struct fscache_operation *op =
|
|
container_of(work, struct fscache_operation, slow_work);
|
|
|
|
atomic_inc(&op->usage);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* allow the slow work item processor to discard a ref on an operation
|
|
*/
|
|
static void fscache_op_put_ref(struct slow_work *work)
|
|
{
|
|
struct fscache_operation *op =
|
|
container_of(work, struct fscache_operation, slow_work);
|
|
|
|
fscache_put_operation(op);
|
|
}
|
|
|
|
/*
|
|
* execute an operation using the slow thread pool to provide processing context
|
|
* - the caller holds a ref to this object, so we don't need to hold one
|
|
*/
|
|
static void fscache_op_execute(struct slow_work *work)
|
|
{
|
|
struct fscache_operation *op =
|
|
container_of(work, struct fscache_operation, slow_work);
|
|
unsigned long start;
|
|
|
|
_enter("{OBJ%x OP%x,%d}",
|
|
op->object->debug_id, op->debug_id, atomic_read(&op->usage));
|
|
|
|
ASSERT(op->processor != NULL);
|
|
start = jiffies;
|
|
op->processor(op);
|
|
fscache_hist(fscache_ops_histogram, start);
|
|
|
|
_leave("");
|
|
}
|
|
|
|
/*
|
|
* describe an operation for slow-work debugging
|
|
*/
|
|
#ifdef CONFIG_SLOW_WORK_DEBUG
|
|
static void fscache_op_desc(struct slow_work *work, struct seq_file *m)
|
|
{
|
|
struct fscache_operation *op =
|
|
container_of(work, struct fscache_operation, slow_work);
|
|
|
|
seq_printf(m, "FSC: OBJ%x OP%x: %s/%s fl=%lx",
|
|
op->object->debug_id, op->debug_id,
|
|
op->name, op->state, op->flags);
|
|
}
|
|
#endif
|
|
|
|
const struct slow_work_ops fscache_op_slow_work_ops = {
|
|
.owner = THIS_MODULE,
|
|
.get_ref = fscache_op_get_ref,
|
|
.put_ref = fscache_op_put_ref,
|
|
.execute = fscache_op_execute,
|
|
#ifdef CONFIG_SLOW_WORK_DEBUG
|
|
.desc = fscache_op_desc,
|
|
#endif
|
|
};
|