![Tejun Heo](/assets/img/avatar_default.png)
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>
994 lines
26 KiB
C
994 lines
26 KiB
C
/* Cache page management and data I/O routines
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*
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* Copyright (C) 2004-2008 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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#define FSCACHE_DEBUG_LEVEL PAGE
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#include <linux/module.h>
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#include <linux/fscache-cache.h>
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#include <linux/buffer_head.h>
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#include <linux/pagevec.h>
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#include <linux/slab.h>
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#include "internal.h"
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/*
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* check to see if a page is being written to the cache
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*/
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bool __fscache_check_page_write(struct fscache_cookie *cookie, struct page *page)
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{
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void *val;
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rcu_read_lock();
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val = radix_tree_lookup(&cookie->stores, page->index);
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rcu_read_unlock();
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return val != NULL;
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}
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EXPORT_SYMBOL(__fscache_check_page_write);
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/*
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* wait for a page to finish being written to the cache
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*/
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void __fscache_wait_on_page_write(struct fscache_cookie *cookie, struct page *page)
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{
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wait_queue_head_t *wq = bit_waitqueue(&cookie->flags, 0);
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wait_event(*wq, !__fscache_check_page_write(cookie, page));
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}
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EXPORT_SYMBOL(__fscache_wait_on_page_write);
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/*
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* decide whether a page can be released, possibly by cancelling a store to it
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* - we're allowed to sleep if __GFP_WAIT is flagged
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*/
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bool __fscache_maybe_release_page(struct fscache_cookie *cookie,
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struct page *page,
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gfp_t gfp)
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{
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struct page *xpage;
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void *val;
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_enter("%p,%p,%x", cookie, page, gfp);
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rcu_read_lock();
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val = radix_tree_lookup(&cookie->stores, page->index);
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if (!val) {
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rcu_read_unlock();
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fscache_stat(&fscache_n_store_vmscan_not_storing);
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__fscache_uncache_page(cookie, page);
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return true;
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}
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/* see if the page is actually undergoing storage - if so we can't get
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* rid of it till the cache has finished with it */
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if (radix_tree_tag_get(&cookie->stores, page->index,
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FSCACHE_COOKIE_STORING_TAG)) {
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rcu_read_unlock();
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goto page_busy;
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}
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/* the page is pending storage, so we attempt to cancel the store and
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* discard the store request so that the page can be reclaimed */
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spin_lock(&cookie->stores_lock);
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rcu_read_unlock();
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if (radix_tree_tag_get(&cookie->stores, page->index,
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FSCACHE_COOKIE_STORING_TAG)) {
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/* the page started to undergo storage whilst we were looking,
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* so now we can only wait or return */
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spin_unlock(&cookie->stores_lock);
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goto page_busy;
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}
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xpage = radix_tree_delete(&cookie->stores, page->index);
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spin_unlock(&cookie->stores_lock);
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if (xpage) {
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fscache_stat(&fscache_n_store_vmscan_cancelled);
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fscache_stat(&fscache_n_store_radix_deletes);
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ASSERTCMP(xpage, ==, page);
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} else {
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fscache_stat(&fscache_n_store_vmscan_gone);
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}
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wake_up_bit(&cookie->flags, 0);
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if (xpage)
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page_cache_release(xpage);
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__fscache_uncache_page(cookie, page);
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return true;
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page_busy:
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/* we might want to wait here, but that could deadlock the allocator as
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* the slow-work threads writing to the cache may all end up sleeping
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* on memory allocation */
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fscache_stat(&fscache_n_store_vmscan_busy);
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return false;
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}
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EXPORT_SYMBOL(__fscache_maybe_release_page);
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/*
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* note that a page has finished being written to the cache
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*/
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static void fscache_end_page_write(struct fscache_object *object,
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struct page *page)
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{
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struct fscache_cookie *cookie;
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struct page *xpage = NULL;
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spin_lock(&object->lock);
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cookie = object->cookie;
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if (cookie) {
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/* delete the page from the tree if it is now no longer
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* pending */
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spin_lock(&cookie->stores_lock);
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radix_tree_tag_clear(&cookie->stores, page->index,
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FSCACHE_COOKIE_STORING_TAG);
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if (!radix_tree_tag_get(&cookie->stores, page->index,
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FSCACHE_COOKIE_PENDING_TAG)) {
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fscache_stat(&fscache_n_store_radix_deletes);
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xpage = radix_tree_delete(&cookie->stores, page->index);
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}
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spin_unlock(&cookie->stores_lock);
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wake_up_bit(&cookie->flags, 0);
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}
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spin_unlock(&object->lock);
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if (xpage)
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page_cache_release(xpage);
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}
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/*
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* actually apply the changed attributes to a cache object
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*/
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static void fscache_attr_changed_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}", object->debug_id, op->debug_id);
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fscache_stat(&fscache_n_attr_changed_calls);
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if (fscache_object_is_active(object)) {
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fscache_set_op_state(op, "CallFS");
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fscache_stat(&fscache_n_cop_attr_changed);
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ret = object->cache->ops->attr_changed(object);
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fscache_stat_d(&fscache_n_cop_attr_changed);
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fscache_set_op_state(op, "Done");
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if (ret < 0)
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fscache_abort_object(object);
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}
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_leave("");
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}
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/*
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* notification that the attributes on an object have changed
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*/
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int __fscache_attr_changed(struct fscache_cookie *cookie)
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{
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struct fscache_operation *op;
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struct fscache_object *object;
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_enter("%p", cookie);
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ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);
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fscache_stat(&fscache_n_attr_changed);
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op = kzalloc(sizeof(*op), GFP_KERNEL);
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if (!op) {
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fscache_stat(&fscache_n_attr_changed_nomem);
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_leave(" = -ENOMEM");
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return -ENOMEM;
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}
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fscache_operation_init(op, NULL);
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fscache_operation_init_slow(op, fscache_attr_changed_op);
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op->flags = FSCACHE_OP_SLOW | (1 << FSCACHE_OP_EXCLUSIVE);
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fscache_set_op_name(op, "Attr");
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spin_lock(&cookie->lock);
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if (hlist_empty(&cookie->backing_objects))
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goto nobufs;
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object = hlist_entry(cookie->backing_objects.first,
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struct fscache_object, cookie_link);
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if (fscache_submit_exclusive_op(object, op) < 0)
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goto nobufs;
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spin_unlock(&cookie->lock);
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fscache_stat(&fscache_n_attr_changed_ok);
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fscache_put_operation(op);
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_leave(" = 0");
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return 0;
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nobufs:
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spin_unlock(&cookie->lock);
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kfree(op);
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fscache_stat(&fscache_n_attr_changed_nobufs);
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_leave(" = %d", -ENOBUFS);
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return -ENOBUFS;
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}
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EXPORT_SYMBOL(__fscache_attr_changed);
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/*
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* handle secondary execution given to a retrieval op on behalf of the
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* cache
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*/
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static void fscache_retrieval_work(struct work_struct *work)
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{
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struct fscache_retrieval *op =
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container_of(work, struct fscache_retrieval, op.fast_work);
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unsigned long start;
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_enter("{OP%x}", op->op.debug_id);
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start = jiffies;
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op->op.processor(&op->op);
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fscache_hist(fscache_ops_histogram, start);
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fscache_put_operation(&op->op);
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}
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/*
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* release a retrieval op reference
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*/
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static void fscache_release_retrieval_op(struct fscache_operation *_op)
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{
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struct fscache_retrieval *op =
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container_of(_op, struct fscache_retrieval, op);
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_enter("{OP%x}", op->op.debug_id);
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fscache_hist(fscache_retrieval_histogram, op->start_time);
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if (op->context)
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fscache_put_context(op->op.object->cookie, op->context);
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_leave("");
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}
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/*
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* allocate a retrieval op
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*/
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static struct fscache_retrieval *fscache_alloc_retrieval(
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struct address_space *mapping,
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fscache_rw_complete_t end_io_func,
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void *context)
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{
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struct fscache_retrieval *op;
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/* allocate a retrieval operation and attempt to submit it */
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op = kzalloc(sizeof(*op), GFP_NOIO);
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if (!op) {
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fscache_stat(&fscache_n_retrievals_nomem);
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return NULL;
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}
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fscache_operation_init(&op->op, fscache_release_retrieval_op);
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op->op.flags = FSCACHE_OP_MYTHREAD | (1 << FSCACHE_OP_WAITING);
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op->mapping = mapping;
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op->end_io_func = end_io_func;
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op->context = context;
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op->start_time = jiffies;
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INIT_WORK(&op->op.fast_work, fscache_retrieval_work);
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INIT_LIST_HEAD(&op->to_do);
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fscache_set_op_name(&op->op, "Retr");
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return op;
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}
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/*
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* wait for a deferred lookup to complete
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*/
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static int fscache_wait_for_deferred_lookup(struct fscache_cookie *cookie)
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{
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unsigned long jif;
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_enter("");
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if (!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags)) {
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_leave(" = 0 [imm]");
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return 0;
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}
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fscache_stat(&fscache_n_retrievals_wait);
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jif = jiffies;
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if (wait_on_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP,
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fscache_wait_bit_interruptible,
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TASK_INTERRUPTIBLE) != 0) {
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fscache_stat(&fscache_n_retrievals_intr);
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_leave(" = -ERESTARTSYS");
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return -ERESTARTSYS;
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}
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ASSERT(!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags));
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smp_rmb();
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fscache_hist(fscache_retrieval_delay_histogram, jif);
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_leave(" = 0 [dly]");
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return 0;
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}
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/*
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* wait for an object to become active (or dead)
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*/
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static int fscache_wait_for_retrieval_activation(struct fscache_object *object,
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struct fscache_retrieval *op,
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atomic_t *stat_op_waits,
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atomic_t *stat_object_dead)
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{
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int ret;
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if (!test_bit(FSCACHE_OP_WAITING, &op->op.flags))
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goto check_if_dead;
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_debug(">>> WT");
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fscache_stat(stat_op_waits);
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if (wait_on_bit(&op->op.flags, FSCACHE_OP_WAITING,
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fscache_wait_bit_interruptible,
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TASK_INTERRUPTIBLE) < 0) {
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ret = fscache_cancel_op(&op->op);
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if (ret == 0)
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return -ERESTARTSYS;
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/* it's been removed from the pending queue by another party,
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* so we should get to run shortly */
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wait_on_bit(&op->op.flags, FSCACHE_OP_WAITING,
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fscache_wait_bit, TASK_UNINTERRUPTIBLE);
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}
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_debug("<<< GO");
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check_if_dead:
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if (unlikely(fscache_object_is_dead(object))) {
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fscache_stat(stat_object_dead);
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return -ENOBUFS;
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}
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return 0;
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}
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/*
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* read a page from the cache or allocate a block in which to store it
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* - we return:
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* -ENOMEM - out of memory, nothing done
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* -ERESTARTSYS - interrupted
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* -ENOBUFS - no backing object available in which to cache the block
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* -ENODATA - no data available in the backing object for this block
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* 0 - dispatched a read - it'll call end_io_func() when finished
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*/
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int __fscache_read_or_alloc_page(struct fscache_cookie *cookie,
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struct page *page,
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fscache_rw_complete_t end_io_func,
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void *context,
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gfp_t gfp)
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{
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struct fscache_retrieval *op;
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struct fscache_object *object;
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int ret;
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_enter("%p,%p,,,", cookie, page);
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fscache_stat(&fscache_n_retrievals);
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if (hlist_empty(&cookie->backing_objects))
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goto nobufs;
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ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);
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ASSERTCMP(page, !=, NULL);
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if (fscache_wait_for_deferred_lookup(cookie) < 0)
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return -ERESTARTSYS;
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op = fscache_alloc_retrieval(page->mapping, end_io_func, context);
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if (!op) {
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_leave(" = -ENOMEM");
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return -ENOMEM;
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}
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fscache_set_op_name(&op->op, "RetrRA1");
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spin_lock(&cookie->lock);
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if (hlist_empty(&cookie->backing_objects))
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goto nobufs_unlock;
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object = hlist_entry(cookie->backing_objects.first,
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struct fscache_object, cookie_link);
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ASSERTCMP(object->state, >, FSCACHE_OBJECT_LOOKING_UP);
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atomic_inc(&object->n_reads);
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set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags);
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if (fscache_submit_op(object, &op->op) < 0)
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goto nobufs_unlock;
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spin_unlock(&cookie->lock);
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fscache_stat(&fscache_n_retrieval_ops);
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/* pin the netfs read context in case we need to do the actual netfs
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* read because we've encountered a cache read failure */
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fscache_get_context(object->cookie, op->context);
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/* we wait for the operation to become active, and then process it
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* *here*, in this thread, and not in the thread pool */
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ret = fscache_wait_for_retrieval_activation(
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object, op,
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__fscache_stat(&fscache_n_retrieval_op_waits),
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__fscache_stat(&fscache_n_retrievals_object_dead));
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if (ret < 0)
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goto error;
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/* ask the cache to honour the operation */
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if (test_bit(FSCACHE_COOKIE_NO_DATA_YET, &object->cookie->flags)) {
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fscache_stat(&fscache_n_cop_allocate_page);
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ret = object->cache->ops->allocate_page(op, page, gfp);
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fscache_stat_d(&fscache_n_cop_allocate_page);
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if (ret == 0)
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ret = -ENODATA;
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} else {
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fscache_stat(&fscache_n_cop_read_or_alloc_page);
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ret = object->cache->ops->read_or_alloc_page(op, page, gfp);
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fscache_stat_d(&fscache_n_cop_read_or_alloc_page);
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}
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error:
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if (ret == -ENOMEM)
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fscache_stat(&fscache_n_retrievals_nomem);
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else if (ret == -ERESTARTSYS)
|
|
fscache_stat(&fscache_n_retrievals_intr);
|
|
else if (ret == -ENODATA)
|
|
fscache_stat(&fscache_n_retrievals_nodata);
|
|
else if (ret < 0)
|
|
fscache_stat(&fscache_n_retrievals_nobufs);
|
|
else
|
|
fscache_stat(&fscache_n_retrievals_ok);
|
|
|
|
fscache_put_retrieval(op);
|
|
_leave(" = %d", ret);
|
|
return ret;
|
|
|
|
nobufs_unlock:
|
|
spin_unlock(&cookie->lock);
|
|
kfree(op);
|
|
nobufs:
|
|
fscache_stat(&fscache_n_retrievals_nobufs);
|
|
_leave(" = -ENOBUFS");
|
|
return -ENOBUFS;
|
|
}
|
|
EXPORT_SYMBOL(__fscache_read_or_alloc_page);
|
|
|
|
/*
|
|
* read a list of page from the cache or allocate a block in which to store
|
|
* them
|
|
* - we return:
|
|
* -ENOMEM - out of memory, some pages may be being read
|
|
* -ERESTARTSYS - interrupted, some pages may be being read
|
|
* -ENOBUFS - no backing object or space available in which to cache any
|
|
* pages not being read
|
|
* -ENODATA - no data available in the backing object for some or all of
|
|
* the pages
|
|
* 0 - dispatched a read on all pages
|
|
*
|
|
* end_io_func() will be called for each page read from the cache as it is
|
|
* finishes being read
|
|
*
|
|
* any pages for which a read is dispatched will be removed from pages and
|
|
* nr_pages
|
|
*/
|
|
int __fscache_read_or_alloc_pages(struct fscache_cookie *cookie,
|
|
struct address_space *mapping,
|
|
struct list_head *pages,
|
|
unsigned *nr_pages,
|
|
fscache_rw_complete_t end_io_func,
|
|
void *context,
|
|
gfp_t gfp)
|
|
{
|
|
struct fscache_retrieval *op;
|
|
struct fscache_object *object;
|
|
int ret;
|
|
|
|
_enter("%p,,%d,,,", cookie, *nr_pages);
|
|
|
|
fscache_stat(&fscache_n_retrievals);
|
|
|
|
if (hlist_empty(&cookie->backing_objects))
|
|
goto nobufs;
|
|
|
|
ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);
|
|
ASSERTCMP(*nr_pages, >, 0);
|
|
ASSERT(!list_empty(pages));
|
|
|
|
if (fscache_wait_for_deferred_lookup(cookie) < 0)
|
|
return -ERESTARTSYS;
|
|
|
|
op = fscache_alloc_retrieval(mapping, end_io_func, context);
|
|
if (!op)
|
|
return -ENOMEM;
|
|
fscache_set_op_name(&op->op, "RetrRAN");
|
|
|
|
spin_lock(&cookie->lock);
|
|
|
|
if (hlist_empty(&cookie->backing_objects))
|
|
goto nobufs_unlock;
|
|
object = hlist_entry(cookie->backing_objects.first,
|
|
struct fscache_object, cookie_link);
|
|
|
|
atomic_inc(&object->n_reads);
|
|
set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags);
|
|
|
|
if (fscache_submit_op(object, &op->op) < 0)
|
|
goto nobufs_unlock;
|
|
spin_unlock(&cookie->lock);
|
|
|
|
fscache_stat(&fscache_n_retrieval_ops);
|
|
|
|
/* pin the netfs read context in case we need to do the actual netfs
|
|
* read because we've encountered a cache read failure */
|
|
fscache_get_context(object->cookie, op->context);
|
|
|
|
/* we wait for the operation to become active, and then process it
|
|
* *here*, in this thread, and not in the thread pool */
|
|
ret = fscache_wait_for_retrieval_activation(
|
|
object, op,
|
|
__fscache_stat(&fscache_n_retrieval_op_waits),
|
|
__fscache_stat(&fscache_n_retrievals_object_dead));
|
|
if (ret < 0)
|
|
goto error;
|
|
|
|
/* ask the cache to honour the operation */
|
|
if (test_bit(FSCACHE_COOKIE_NO_DATA_YET, &object->cookie->flags)) {
|
|
fscache_stat(&fscache_n_cop_allocate_pages);
|
|
ret = object->cache->ops->allocate_pages(
|
|
op, pages, nr_pages, gfp);
|
|
fscache_stat_d(&fscache_n_cop_allocate_pages);
|
|
} else {
|
|
fscache_stat(&fscache_n_cop_read_or_alloc_pages);
|
|
ret = object->cache->ops->read_or_alloc_pages(
|
|
op, pages, nr_pages, gfp);
|
|
fscache_stat_d(&fscache_n_cop_read_or_alloc_pages);
|
|
}
|
|
|
|
error:
|
|
if (ret == -ENOMEM)
|
|
fscache_stat(&fscache_n_retrievals_nomem);
|
|
else if (ret == -ERESTARTSYS)
|
|
fscache_stat(&fscache_n_retrievals_intr);
|
|
else if (ret == -ENODATA)
|
|
fscache_stat(&fscache_n_retrievals_nodata);
|
|
else if (ret < 0)
|
|
fscache_stat(&fscache_n_retrievals_nobufs);
|
|
else
|
|
fscache_stat(&fscache_n_retrievals_ok);
|
|
|
|
fscache_put_retrieval(op);
|
|
_leave(" = %d", ret);
|
|
return ret;
|
|
|
|
nobufs_unlock:
|
|
spin_unlock(&cookie->lock);
|
|
kfree(op);
|
|
nobufs:
|
|
fscache_stat(&fscache_n_retrievals_nobufs);
|
|
_leave(" = -ENOBUFS");
|
|
return -ENOBUFS;
|
|
}
|
|
EXPORT_SYMBOL(__fscache_read_or_alloc_pages);
|
|
|
|
/*
|
|
* allocate a block in the cache on which to store a page
|
|
* - we return:
|
|
* -ENOMEM - out of memory, nothing done
|
|
* -ERESTARTSYS - interrupted
|
|
* -ENOBUFS - no backing object available in which to cache the block
|
|
* 0 - block allocated
|
|
*/
|
|
int __fscache_alloc_page(struct fscache_cookie *cookie,
|
|
struct page *page,
|
|
gfp_t gfp)
|
|
{
|
|
struct fscache_retrieval *op;
|
|
struct fscache_object *object;
|
|
int ret;
|
|
|
|
_enter("%p,%p,,,", cookie, page);
|
|
|
|
fscache_stat(&fscache_n_allocs);
|
|
|
|
if (hlist_empty(&cookie->backing_objects))
|
|
goto nobufs;
|
|
|
|
ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);
|
|
ASSERTCMP(page, !=, NULL);
|
|
|
|
if (fscache_wait_for_deferred_lookup(cookie) < 0)
|
|
return -ERESTARTSYS;
|
|
|
|
op = fscache_alloc_retrieval(page->mapping, NULL, NULL);
|
|
if (!op)
|
|
return -ENOMEM;
|
|
fscache_set_op_name(&op->op, "RetrAL1");
|
|
|
|
spin_lock(&cookie->lock);
|
|
|
|
if (hlist_empty(&cookie->backing_objects))
|
|
goto nobufs_unlock;
|
|
object = hlist_entry(cookie->backing_objects.first,
|
|
struct fscache_object, cookie_link);
|
|
|
|
if (fscache_submit_op(object, &op->op) < 0)
|
|
goto nobufs_unlock;
|
|
spin_unlock(&cookie->lock);
|
|
|
|
fscache_stat(&fscache_n_alloc_ops);
|
|
|
|
ret = fscache_wait_for_retrieval_activation(
|
|
object, op,
|
|
__fscache_stat(&fscache_n_alloc_op_waits),
|
|
__fscache_stat(&fscache_n_allocs_object_dead));
|
|
if (ret < 0)
|
|
goto error;
|
|
|
|
/* ask the cache to honour the operation */
|
|
fscache_stat(&fscache_n_cop_allocate_page);
|
|
ret = object->cache->ops->allocate_page(op, page, gfp);
|
|
fscache_stat_d(&fscache_n_cop_allocate_page);
|
|
|
|
error:
|
|
if (ret == -ERESTARTSYS)
|
|
fscache_stat(&fscache_n_allocs_intr);
|
|
else if (ret < 0)
|
|
fscache_stat(&fscache_n_allocs_nobufs);
|
|
else
|
|
fscache_stat(&fscache_n_allocs_ok);
|
|
|
|
fscache_put_retrieval(op);
|
|
_leave(" = %d", ret);
|
|
return ret;
|
|
|
|
nobufs_unlock:
|
|
spin_unlock(&cookie->lock);
|
|
kfree(op);
|
|
nobufs:
|
|
fscache_stat(&fscache_n_allocs_nobufs);
|
|
_leave(" = -ENOBUFS");
|
|
return -ENOBUFS;
|
|
}
|
|
EXPORT_SYMBOL(__fscache_alloc_page);
|
|
|
|
/*
|
|
* release a write op reference
|
|
*/
|
|
static void fscache_release_write_op(struct fscache_operation *_op)
|
|
{
|
|
_enter("{OP%x}", _op->debug_id);
|
|
}
|
|
|
|
/*
|
|
* perform the background storage of a page into the cache
|
|
*/
|
|
static void fscache_write_op(struct fscache_operation *_op)
|
|
{
|
|
struct fscache_storage *op =
|
|
container_of(_op, struct fscache_storage, op);
|
|
struct fscache_object *object = op->op.object;
|
|
struct fscache_cookie *cookie;
|
|
struct page *page;
|
|
unsigned n;
|
|
void *results[1];
|
|
int ret;
|
|
|
|
_enter("{OP%x,%d}", op->op.debug_id, atomic_read(&op->op.usage));
|
|
|
|
fscache_set_op_state(&op->op, "GetPage");
|
|
|
|
spin_lock(&object->lock);
|
|
cookie = object->cookie;
|
|
|
|
if (!fscache_object_is_active(object) || !cookie) {
|
|
spin_unlock(&object->lock);
|
|
_leave("");
|
|
return;
|
|
}
|
|
|
|
spin_lock(&cookie->stores_lock);
|
|
|
|
fscache_stat(&fscache_n_store_calls);
|
|
|
|
/* find a page to store */
|
|
page = NULL;
|
|
n = radix_tree_gang_lookup_tag(&cookie->stores, results, 0, 1,
|
|
FSCACHE_COOKIE_PENDING_TAG);
|
|
if (n != 1)
|
|
goto superseded;
|
|
page = results[0];
|
|
_debug("gang %d [%lx]", n, page->index);
|
|
if (page->index > op->store_limit) {
|
|
fscache_stat(&fscache_n_store_pages_over_limit);
|
|
goto superseded;
|
|
}
|
|
|
|
if (page) {
|
|
radix_tree_tag_set(&cookie->stores, page->index,
|
|
FSCACHE_COOKIE_STORING_TAG);
|
|
radix_tree_tag_clear(&cookie->stores, page->index,
|
|
FSCACHE_COOKIE_PENDING_TAG);
|
|
}
|
|
|
|
spin_unlock(&cookie->stores_lock);
|
|
spin_unlock(&object->lock);
|
|
|
|
if (page) {
|
|
fscache_set_op_state(&op->op, "Store");
|
|
fscache_stat(&fscache_n_store_pages);
|
|
fscache_stat(&fscache_n_cop_write_page);
|
|
ret = object->cache->ops->write_page(op, page);
|
|
fscache_stat_d(&fscache_n_cop_write_page);
|
|
fscache_set_op_state(&op->op, "EndWrite");
|
|
fscache_end_page_write(object, page);
|
|
if (ret < 0) {
|
|
fscache_set_op_state(&op->op, "Abort");
|
|
fscache_abort_object(object);
|
|
} else {
|
|
fscache_enqueue_operation(&op->op);
|
|
}
|
|
}
|
|
|
|
_leave("");
|
|
return;
|
|
|
|
superseded:
|
|
/* this writer is going away and there aren't any more things to
|
|
* write */
|
|
_debug("cease");
|
|
spin_unlock(&cookie->stores_lock);
|
|
clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
|
|
spin_unlock(&object->lock);
|
|
_leave("");
|
|
}
|
|
|
|
/*
|
|
* request a page be stored in the cache
|
|
* - returns:
|
|
* -ENOMEM - out of memory, nothing done
|
|
* -ENOBUFS - no backing object available in which to cache the page
|
|
* 0 - dispatched a write - it'll call end_io_func() when finished
|
|
*
|
|
* if the cookie still has a backing object at this point, that object can be
|
|
* in one of a few states with respect to storage processing:
|
|
*
|
|
* (1) negative lookup, object not yet created (FSCACHE_COOKIE_CREATING is
|
|
* set)
|
|
*
|
|
* (a) no writes yet (set FSCACHE_COOKIE_PENDING_FILL and queue deferred
|
|
* fill op)
|
|
*
|
|
* (b) writes deferred till post-creation (mark page for writing and
|
|
* return immediately)
|
|
*
|
|
* (2) negative lookup, object created, initial fill being made from netfs
|
|
* (FSCACHE_COOKIE_INITIAL_FILL is set)
|
|
*
|
|
* (a) fill point not yet reached this page (mark page for writing and
|
|
* return)
|
|
*
|
|
* (b) fill point passed this page (queue op to store this page)
|
|
*
|
|
* (3) object extant (queue op to store this page)
|
|
*
|
|
* any other state is invalid
|
|
*/
|
|
int __fscache_write_page(struct fscache_cookie *cookie,
|
|
struct page *page,
|
|
gfp_t gfp)
|
|
{
|
|
struct fscache_storage *op;
|
|
struct fscache_object *object;
|
|
int ret;
|
|
|
|
_enter("%p,%x,", cookie, (u32) page->flags);
|
|
|
|
ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);
|
|
ASSERT(PageFsCache(page));
|
|
|
|
fscache_stat(&fscache_n_stores);
|
|
|
|
op = kzalloc(sizeof(*op), GFP_NOIO);
|
|
if (!op)
|
|
goto nomem;
|
|
|
|
fscache_operation_init(&op->op, fscache_release_write_op);
|
|
fscache_operation_init_slow(&op->op, fscache_write_op);
|
|
op->op.flags = FSCACHE_OP_SLOW | (1 << FSCACHE_OP_WAITING);
|
|
fscache_set_op_name(&op->op, "Write1");
|
|
|
|
ret = radix_tree_preload(gfp & ~__GFP_HIGHMEM);
|
|
if (ret < 0)
|
|
goto nomem_free;
|
|
|
|
ret = -ENOBUFS;
|
|
spin_lock(&cookie->lock);
|
|
|
|
if (hlist_empty(&cookie->backing_objects))
|
|
goto nobufs;
|
|
object = hlist_entry(cookie->backing_objects.first,
|
|
struct fscache_object, cookie_link);
|
|
if (test_bit(FSCACHE_IOERROR, &object->cache->flags))
|
|
goto nobufs;
|
|
|
|
/* add the page to the pending-storage radix tree on the backing
|
|
* object */
|
|
spin_lock(&object->lock);
|
|
spin_lock(&cookie->stores_lock);
|
|
|
|
_debug("store limit %llx", (unsigned long long) object->store_limit);
|
|
|
|
ret = radix_tree_insert(&cookie->stores, page->index, page);
|
|
if (ret < 0) {
|
|
if (ret == -EEXIST)
|
|
goto already_queued;
|
|
_debug("insert failed %d", ret);
|
|
goto nobufs_unlock_obj;
|
|
}
|
|
|
|
radix_tree_tag_set(&cookie->stores, page->index,
|
|
FSCACHE_COOKIE_PENDING_TAG);
|
|
page_cache_get(page);
|
|
|
|
/* we only want one writer at a time, but we do need to queue new
|
|
* writers after exclusive ops */
|
|
if (test_and_set_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags))
|
|
goto already_pending;
|
|
|
|
spin_unlock(&cookie->stores_lock);
|
|
spin_unlock(&object->lock);
|
|
|
|
op->op.debug_id = atomic_inc_return(&fscache_op_debug_id);
|
|
op->store_limit = object->store_limit;
|
|
|
|
if (fscache_submit_op(object, &op->op) < 0)
|
|
goto submit_failed;
|
|
|
|
spin_unlock(&cookie->lock);
|
|
radix_tree_preload_end();
|
|
fscache_stat(&fscache_n_store_ops);
|
|
fscache_stat(&fscache_n_stores_ok);
|
|
|
|
/* the slow work queue now carries its own ref on the object */
|
|
fscache_put_operation(&op->op);
|
|
_leave(" = 0");
|
|
return 0;
|
|
|
|
already_queued:
|
|
fscache_stat(&fscache_n_stores_again);
|
|
already_pending:
|
|
spin_unlock(&cookie->stores_lock);
|
|
spin_unlock(&object->lock);
|
|
spin_unlock(&cookie->lock);
|
|
radix_tree_preload_end();
|
|
kfree(op);
|
|
fscache_stat(&fscache_n_stores_ok);
|
|
_leave(" = 0");
|
|
return 0;
|
|
|
|
submit_failed:
|
|
spin_lock(&cookie->stores_lock);
|
|
radix_tree_delete(&cookie->stores, page->index);
|
|
spin_unlock(&cookie->stores_lock);
|
|
page_cache_release(page);
|
|
ret = -ENOBUFS;
|
|
goto nobufs;
|
|
|
|
nobufs_unlock_obj:
|
|
spin_unlock(&cookie->stores_lock);
|
|
spin_unlock(&object->lock);
|
|
nobufs:
|
|
spin_unlock(&cookie->lock);
|
|
radix_tree_preload_end();
|
|
kfree(op);
|
|
fscache_stat(&fscache_n_stores_nobufs);
|
|
_leave(" = -ENOBUFS");
|
|
return -ENOBUFS;
|
|
|
|
nomem_free:
|
|
kfree(op);
|
|
nomem:
|
|
fscache_stat(&fscache_n_stores_oom);
|
|
_leave(" = -ENOMEM");
|
|
return -ENOMEM;
|
|
}
|
|
EXPORT_SYMBOL(__fscache_write_page);
|
|
|
|
/*
|
|
* remove a page from the cache
|
|
*/
|
|
void __fscache_uncache_page(struct fscache_cookie *cookie, struct page *page)
|
|
{
|
|
struct fscache_object *object;
|
|
|
|
_enter(",%p", page);
|
|
|
|
ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);
|
|
ASSERTCMP(page, !=, NULL);
|
|
|
|
fscache_stat(&fscache_n_uncaches);
|
|
|
|
/* cache withdrawal may beat us to it */
|
|
if (!PageFsCache(page))
|
|
goto done;
|
|
|
|
/* get the object */
|
|
spin_lock(&cookie->lock);
|
|
|
|
if (hlist_empty(&cookie->backing_objects)) {
|
|
ClearPageFsCache(page);
|
|
goto done_unlock;
|
|
}
|
|
|
|
object = hlist_entry(cookie->backing_objects.first,
|
|
struct fscache_object, cookie_link);
|
|
|
|
/* there might now be stuff on disk we could read */
|
|
clear_bit(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags);
|
|
|
|
/* only invoke the cache backend if we managed to mark the page
|
|
* uncached here; this deals with synchronisation vs withdrawal */
|
|
if (TestClearPageFsCache(page) &&
|
|
object->cache->ops->uncache_page) {
|
|
/* the cache backend releases the cookie lock */
|
|
fscache_stat(&fscache_n_cop_uncache_page);
|
|
object->cache->ops->uncache_page(object, page);
|
|
fscache_stat_d(&fscache_n_cop_uncache_page);
|
|
goto done;
|
|
}
|
|
|
|
done_unlock:
|
|
spin_unlock(&cookie->lock);
|
|
done:
|
|
_leave("");
|
|
}
|
|
EXPORT_SYMBOL(__fscache_uncache_page);
|
|
|
|
/**
|
|
* fscache_mark_pages_cached - Mark pages as being cached
|
|
* @op: The retrieval op pages are being marked for
|
|
* @pagevec: The pages to be marked
|
|
*
|
|
* Mark a bunch of netfs pages as being cached. After this is called,
|
|
* the netfs must call fscache_uncache_page() to remove the mark.
|
|
*/
|
|
void fscache_mark_pages_cached(struct fscache_retrieval *op,
|
|
struct pagevec *pagevec)
|
|
{
|
|
struct fscache_cookie *cookie = op->op.object->cookie;
|
|
unsigned long loop;
|
|
|
|
#ifdef CONFIG_FSCACHE_STATS
|
|
atomic_add(pagevec->nr, &fscache_n_marks);
|
|
#endif
|
|
|
|
for (loop = 0; loop < pagevec->nr; loop++) {
|
|
struct page *page = pagevec->pages[loop];
|
|
|
|
_debug("- mark %p{%lx}", page, page->index);
|
|
if (TestSetPageFsCache(page)) {
|
|
static bool once_only;
|
|
if (!once_only) {
|
|
once_only = true;
|
|
printk(KERN_WARNING "FS-Cache:"
|
|
" Cookie type %s marked page %lx"
|
|
" multiple times\n",
|
|
cookie->def->name, page->index);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (cookie->def->mark_pages_cached)
|
|
cookie->def->mark_pages_cached(cookie->netfs_data,
|
|
op->mapping, pagevec);
|
|
pagevec_reinit(pagevec);
|
|
}
|
|
EXPORT_SYMBOL(fscache_mark_pages_cached);
|