struct completion *done; /* set if the caller waits */
};
-const char *wb_reason_name[] = {
- [WB_REASON_BACKGROUND] = "background",
- [WB_REASON_TRY_TO_FREE_PAGES] = "try_to_free_pages",
- [WB_REASON_SYNC] = "sync",
- [WB_REASON_PERIODIC] = "periodic",
- [WB_REASON_LAPTOP_TIMER] = "laptop_timer",
- [WB_REASON_FREE_MORE_MEM] = "free_more_memory",
- [WB_REASON_FS_FREE_SPACE] = "fs_free_space",
- [WB_REASON_FORKER_THREAD] = "forker_thread"
-};
-
-/*
- * Include the creation of the trace points after defining the
- * wb_writeback_work structure so that the definition remains local to this
- * file.
- */
-#define CREATE_TRACE_POINTS
-#include <trace/events/writeback.h>
-
/*
* We don't actually have pdflush, but this one is exported though /proc...
*/
{
return test_bit(BDI_writeback_running, &bdi->state);
}
+EXPORT_SYMBOL(writeback_in_progress);
static inline struct backing_dev_info *inode_to_bdi(struct inode *inode)
{
return list_entry(head, struct inode, i_wb_list);
}
+/*
+ * Include the creation of the trace points after defining the
+ * wb_writeback_work structure and inline functions so that the definition
+ * remains local to this file.
+ */
+#define CREATE_TRACE_POINTS
+#include <trace/events/writeback.h>
+
/* Wakeup flusher thread or forker thread to fork it. Requires bdi->wb_lock. */
static void bdi_wakeup_flusher(struct backing_dev_info *bdi)
{
* bdi_start_writeback - start writeback
* @bdi: the backing device to write from
* @nr_pages: the number of pages to write
+ * @reason: reason why some writeback work was initiated
*
* Description:
* This does WB_SYNC_NONE opportunistic writeback. The IO is only
/* Set I_SYNC, reset I_DIRTY_PAGES */
inode->i_state |= I_SYNC;
- inode->i_state &= ~I_DIRTY_PAGES;
spin_unlock(&inode->i_lock);
spin_unlock(&wb->list_lock);
* write_inode()
*/
spin_lock(&inode->i_lock);
+
dirty = inode->i_state & I_DIRTY;
- inode->i_state &= ~(I_DIRTY_SYNC | I_DIRTY_DATASYNC);
+ inode->i_state &= ~I_DIRTY;
+
+ /*
+ * Paired with smp_mb() in __mark_inode_dirty(). This allows
+ * __mark_inode_dirty() to test i_state without grabbing i_lock -
+ * either they see the I_DIRTY bits cleared or we see the dirtied
+ * inode.
+ *
+ * I_DIRTY_PAGES is always cleared together above even if @mapping
+ * still has dirty pages. The flag is reinstated after smp_mb() if
+ * necessary. This guarantees that either __mark_inode_dirty()
+ * sees clear I_DIRTY_PAGES or we see PAGECACHE_TAG_DIRTY.
+ */
+ smp_mb();
+
+ if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
+ inode->i_state |= I_DIRTY_PAGES;
+
spin_unlock(&inode->i_lock);
+
/* Don't write the inode if only I_DIRTY_PAGES was set */
if (dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) {
int err = write_inode(inode, wbc);
* We didn't write back all the pages. nfs_writepages()
* sometimes bales out without doing anything.
*/
- inode->i_state |= I_DIRTY_PAGES;
if (wbc->nr_to_write <= 0) {
/*
* slice used up: queue for next turn
}
/*
- * make sure that changes are seen by all cpus before we test i_state
- * -- mikulas
+ * Paired with smp_mb() in __writeback_single_inode() for the
+ * following lockless i_state test. See there for details.
*/
smp_mb();
- /* avoid the locking if we can */
if ((inode->i_state & flags) == flags)
return;
* writeback_inodes_sb_nr - writeback dirty inodes from given super_block
* @sb: the superblock
* @nr: the number of pages to write
+ * @reason: reason why some writeback work initiated
*
* Start writeback on some inodes on this super_block. No guarantees are made
* on how many (if any) will be written, and this function does not wait
/**
* writeback_inodes_sb - writeback dirty inodes from given super_block
* @sb: the superblock
+ * @reason: reason why some writeback work was initiated
*
* Start writeback on some inodes on this super_block. No guarantees are made
* on how many (if any) will be written, and this function does not wait
/**
* writeback_inodes_sb_if_idle - start writeback if none underway
* @sb: the superblock
+ * @reason: reason why some writeback work was initiated
*
* Invoke writeback_inodes_sb if no writeback is currently underway.
* Returns 1 if writeback was started, 0 if not.
* writeback_inodes_sb_if_idle - start writeback if none underway
* @sb: the superblock
* @nr: the number of pages to write
+ * @reason: reason why some writeback work was initiated
*
* Invoke writeback_inodes_sb if no writeback is currently underway.
* Returns 1 if writeback was started, 0 if not.