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writeback: make wb_writeback() take an argument structure 

We need to be able to pass in range_cyclic as well, so instead
of growing yet another argument, split the arguments into a
struct wb_writeback_args structure that we can use internally.
Also makes it easier to just copy all members to an on-stack
struct, since we can't access work after clearing the pending
bit.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Jens Axboe 2009-09-16 15:18:25 +02:00
parent f0fad8a530
commit c4a77a6c7d
1 changed files with 49 additions and 29 deletions
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78
fs/fs-writeback.c
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@ -34,6 +34,17 @@
*/
int nr_pdflush_threads;
/*
* Passed into wb_writeback(), essentially a subset of writeback_control
*/
struct wb_writeback_args {
long nr_pages;
struct super_block *sb;
enum writeback_sync_modes sync_mode;
int for_kupdate;
int range_cyclic;
};
/*
* Work items for the bdi_writeback threads
*/
@ -45,9 +56,7 @@ struct bdi_work {
unsigned long seen;
atomic_t pending;
struct super_block *sb;
unsigned long nr_pages;
enum writeback_sync_modes sync_mode;
struct wb_writeback_args args;
unsigned long state;
};
@ -69,9 +78,11 @@ static inline void bdi_work_init(struct bdi_work *work,
struct writeback_control *wbc)
{
INIT_RCU_HEAD(&work->rcu_head);
work->sb = wbc->sb;
work->nr_pages = wbc->nr_to_write;
work->sync_mode = wbc->sync_mode;
work->args.sb = wbc->sb;
work->args.nr_pages = wbc->nr_to_write;
work->args.sync_mode = wbc->sync_mode;
work->args.range_cyclic = wbc->range_cyclic;
work->args.for_kupdate = 0;
work->state = WS_USED;
}
@ -106,7 +117,7 @@ static void bdi_work_free(struct rcu_head *head)
static void wb_work_complete(struct bdi_work *work)
{
const enum writeback_sync_modes sync_mode = work->sync_mode;
const enum writeback_sync_modes sync_mode = work->args.sync_mode;
/*
* For allocated work, we can clear the done/seen bit right here.
@ -653,17 +664,16 @@ static inline bool over_bground_thresh(void)
* older_than_this takes precedence over nr_to_write. So we'll only write back
* all dirty pages if they are all attached to "old" mappings.
*/
static long wb_writeback(struct bdi_writeback *wb, long nr_pages,
struct super_block *sb,
enum writeback_sync_modes sync_mode, int for_kupdate)
static long wb_writeback(struct bdi_writeback *wb,
struct wb_writeback_args *args)
{
struct writeback_control wbc = {
.bdi = wb->bdi,
.sb = sb,
.sync_mode = sync_mode,
.sb = args->sb,
.sync_mode = args->sync_mode,
.older_than_this = NULL,
.for_kupdate = for_kupdate,
.range_cyclic = 1,
.for_kupdate = args->for_kupdate,
.range_cyclic = args->range_cyclic,
};
unsigned long oldest_jif;
long wrote = 0;
@ -673,13 +683,18 @@ static long wb_writeback(struct bdi_writeback *wb, long nr_pages,
oldest_jif = jiffies -
msecs_to_jiffies(dirty_expire_interval * 10);
}
if (!wbc.range_cyclic) {
wbc.range_start = 0;
wbc.range_end = LLONG_MAX;
}
for (;;) {
/*
* Don't flush anything for non-integrity writeback where
* no nr_pages was given
*/
if (!for_kupdate && nr_pages <= 0 && sync_mode == WB_SYNC_NONE)
if (!args->for_kupdate && args->nr_pages <= 0 &&
args->sync_mode == WB_SYNC_NONE)
break;
/*
@ -687,7 +702,8 @@ static long wb_writeback(struct bdi_writeback *wb, long nr_pages,
* periodic background writeout and we are below the
* background dirty threshold, don't do anything
*/
if (for_kupdate && nr_pages <= 0 && !over_bground_thresh())
if (args->for_kupdate && args->nr_pages <= 0 &&
!over_bground_thresh())
break;
wbc.more_io = 0;
@ -695,7 +711,7 @@ static long wb_writeback(struct bdi_writeback *wb, long nr_pages,
wbc.nr_to_write = MAX_WRITEBACK_PAGES;
wbc.pages_skipped = 0;
writeback_inodes_wb(wb, &wbc);
nr_pages -= MAX_WRITEBACK_PAGES - wbc.nr_to_write;
args->nr_pages -= MAX_WRITEBACK_PAGES - wbc.nr_to_write;
wrote += MAX_WRITEBACK_PAGES - wbc.nr_to_write;
/*
@ -749,8 +765,16 @@ static long wb_check_old_data_flush(struct bdi_writeback *wb)
global_page_state(NR_UNSTABLE_NFS) +
(inodes_stat.nr_inodes - inodes_stat.nr_unused);
if (nr_pages)
return wb_writeback(wb, nr_pages, NULL, WB_SYNC_NONE, 1);
if (nr_pages) {
struct wb_writeback_args args = {
.nr_pages = nr_pages,
.sync_mode = WB_SYNC_NONE,
.for_kupdate = 1,
.range_cyclic = 1,
};
return wb_writeback(wb, &args);
}
return 0;
}
@ -762,35 +786,31 @@ long wb_do_writeback(struct bdi_writeback *wb, int force_wait)
{
struct backing_dev_info *bdi = wb->bdi;
struct bdi_work *work;
long nr_pages, wrote = 0;
long wrote = 0;
while ((work = get_next_work_item(bdi, wb)) != NULL) {
enum writeback_sync_modes sync_mode;
nr_pages = work->nr_pages;
struct wb_writeback_args args = work->args;
/*
* Override sync mode, in case we must wait for completion
*/
if (force_wait)
work->sync_mode = sync_mode = WB_SYNC_ALL;
else
sync_mode = work->sync_mode;
work->args.sync_mode = args.sync_mode = WB_SYNC_ALL;
/*
* If this isn't a data integrity operation, just notify
* that we have seen this work and we are now starting it.
*/
if (sync_mode == WB_SYNC_NONE)
if (args.sync_mode == WB_SYNC_NONE)
wb_clear_pending(wb, work);
wrote += wb_writeback(wb, nr_pages, work->sb, sync_mode, 0);
wrote += wb_writeback(wb, &args);
/*
* This is a data integrity writeback, so only do the
* notification when we have completed the work.
*/
if (sync_mode == WB_SYNC_ALL)
if (args.sync_mode == WB_SYNC_ALL)
wb_clear_pending(wb, work);
}