#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/spinlock.h>
+#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/mm.h>
int for_kupdate:1;
int range_cyclic:1;
int for_background:1;
+ int sb_pinned:1;
};
/*
.sync_mode = WB_SYNC_ALL,
.nr_pages = LONG_MAX,
.range_cyclic = 0,
+ /*
+ * Setting sb_pinned is not necessary for WB_SYNC_ALL, but
+ * lets make it explicitly clear.
+ */
+ .sb_pinned = 1,
};
struct bdi_work work;
* @bdi: the backing device to write from
* @sb: write inodes from this super_block
* @nr_pages: the number of pages to write
+ * @sb_locked: caller already holds sb umount sem.
*
* Description:
* This does WB_SYNC_NONE opportunistic writeback. The IO is only
* started when this function returns, we make no guarentees on
- * completion. Caller need not hold sb s_umount semaphore.
+ * completion. Caller specifies whether sb umount sem is held already or not.
*
*/
void bdi_start_writeback(struct backing_dev_info *bdi, struct super_block *sb,
- long nr_pages)
+ long nr_pages, int sb_locked)
{
struct wb_writeback_args args = {
.sb = sb,
.sync_mode = WB_SYNC_NONE,
.nr_pages = nr_pages,
.range_cyclic = 1,
+ .sb_pinned = sb_locked,
};
/*
/*
* Caller must already hold the ref for this
*/
- if (wbc->sync_mode == WB_SYNC_ALL) {
+ if (wbc->sync_mode == WB_SYNC_ALL || wbc->sb_pinned) {
WARN_ON(!rwsem_is_locked(&sb->s_umount));
return SB_NOT_PINNED;
}
.for_kupdate = args->for_kupdate,
.for_background = args->for_background,
.range_cyclic = args->range_cyclic,
+ .sb_pinned = args->sb_pinned,
};
unsigned long oldest_jif;
long wrote = 0;
unsigned long expired;
long nr_pages;
+ /*
+ * When set to zero, disable periodic writeback
+ */
+ if (!dirty_writeback_interval)
+ return 0;
+
expired = wb->last_old_flush +
msecs_to_jiffies(dirty_writeback_interval * 10);
if (time_before(jiffies, expired))
break;
}
- wait_jiffies = msecs_to_jiffies(dirty_writeback_interval * 10);
- schedule_timeout_interruptible(wait_jiffies);
+ if (dirty_writeback_interval) {
+ wait_jiffies = msecs_to_jiffies(dirty_writeback_interval * 10);
+ schedule_timeout_interruptible(wait_jiffies);
+ } else
+ schedule();
+
try_to_freeze();
}
iput(old_inode);
}
+static void __writeback_inodes_sb(struct super_block *sb, int sb_locked)
+{
+ unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY);
+ unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS);
+ long nr_to_write;
+
+ nr_to_write = nr_dirty + nr_unstable +
+ (inodes_stat.nr_inodes - inodes_stat.nr_unused);
+
+ bdi_start_writeback(sb->s_bdi, sb, nr_to_write, sb_locked);
+}
+
/**
* writeback_inodes_sb - writeback dirty inodes from given super_block
* @sb: the superblock
*/
void writeback_inodes_sb(struct super_block *sb)
{
- unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY);
- unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS);
- long nr_to_write;
-
- nr_to_write = nr_dirty + nr_unstable +
- (inodes_stat.nr_inodes - inodes_stat.nr_unused);
-
- bdi_start_writeback(sb->s_bdi, sb, nr_to_write);
+ __writeback_inodes_sb(sb, 0);
}
EXPORT_SYMBOL(writeback_inodes_sb);
+/**
+ * writeback_inodes_sb_locked - writeback dirty inodes from given super_block
+ * @sb: the superblock
+ *
+ * Like writeback_inodes_sb(), except the caller already holds the
+ * sb umount sem.
+ */
+void writeback_inodes_sb_locked(struct super_block *sb)
+{
+ __writeback_inodes_sb(sb, 1);
+}
+
/**
* writeback_inodes_sb_if_idle - start writeback if none underway
* @sb: the superblock