#include <linux/pagevec.h>
#include <linux/writeback.h>
-STATIC void xfs_count_page_state(struct page *, int *, int *, int *);
+
+STATIC void
+xfs_count_page_state(
+ struct page *page,
+ int *delalloc,
+ int *unmapped,
+ int *unwritten)
+{
+ struct buffer_head *bh, *head;
+
+ *delalloc = *unmapped = *unwritten = 0;
+
+ bh = head = page_buffers(page);
+ do {
+ if (buffer_uptodate(bh) && !buffer_mapped(bh))
+ (*unmapped) = 1;
+ else if (buffer_unwritten(bh) && !buffer_delay(bh))
+ clear_buffer_unwritten(bh);
+ else if (buffer_unwritten(bh))
+ (*unwritten) = 1;
+ else if (buffer_delay(bh))
+ (*delalloc) = 1;
+ } while ((bh = bh->b_this_page) != head);
+}
+
+
#if defined(XFS_RW_TRACE)
void
return err;
}
+/*
+ * writepage: Called from one of two places:
+ *
+ * 1. we are flushing a delalloc buffer head.
+ *
+ * 2. we are writing out a dirty page. Typically the page dirty
+ * state is cleared before we get here. In this case is it
+ * conceivable we have no buffer heads.
+ *
+ * For delalloc space on the page we need to allocate space and
+ * flush it. For unmapped buffer heads on the page we should
+ * allocate space if the page is uptodate. For any other dirty
+ * buffer heads on the page we should flush them.
+ *
+ * If we detect that a transaction would be required to flush
+ * the page, we have to check the process flags first, if we
+ * are already in a transaction or disk I/O during allocations
+ * is off, we need to fail the writepage and redirty the page.
+ */
+
+STATIC int
+linvfs_writepage(
+ struct page *page,
+ struct writeback_control *wbc)
+{
+ int error;
+ int need_trans;
+ int delalloc, unmapped, unwritten;
+ struct inode *inode = page->mapping->host;
+
+ xfs_page_trace(XFS_WRITEPAGE_ENTER, inode, page, 0);
+
+ /*
+ * We need a transaction if:
+ * 1. There are delalloc buffers on the page
+ * 2. The page is uptodate and we have unmapped buffers
+ * 3. The page is uptodate and we have no buffers
+ * 4. There are unwritten buffers on the page
+ */
+
+ if (!page_has_buffers(page)) {
+ unmapped = 1;
+ need_trans = 1;
+ } else {
+ xfs_count_page_state(page, &delalloc, &unmapped, &unwritten);
+ if (!PageUptodate(page))
+ unmapped = 0;
+ need_trans = delalloc + unmapped + unwritten;
+ }
+
+ /*
+ * If we need a transaction and the process flags say
+ * we are already in a transaction, or no IO is allowed
+ * then mark the page dirty again and leave the page
+ * as is.
+ */
+ if (PFLAGS_TEST_FSTRANS() && need_trans)
+ goto out_fail;
+
+ /*
+ * Delay hooking up buffer heads until we have
+ * made our go/no-go decision.
+ */
+ if (!page_has_buffers(page))
+ create_empty_buffers(page, 1 << inode->i_blkbits, 0);
+
+ /*
+ * Convert delayed allocate, unwritten or unmapped space
+ * to real space and flush out to disk.
+ */
+ error = xfs_page_state_convert(inode, page, wbc, 1, unmapped);
+ if (error == -EAGAIN)
+ goto out_fail;
+ if (unlikely(error < 0))
+ goto out_unlock;
+
+ return 0;
+
+out_fail:
+ redirty_page_for_writepage(wbc, page);
+ unlock_page(page);
+ return 0;
+out_unlock:
+ unlock_page(page);
+ return error;
+}
+
+/*
+ * Called to move a page into cleanable state - and from there
+ * to be released. Possibly the page is already clean. We always
+ * have buffer heads in this call.
+ *
+ * Returns 0 if the page is ok to release, 1 otherwise.
+ *
+ * Possible scenarios are:
+ *
+ * 1. We are being called to release a page which has been written
+ * to via regular I/O. buffer heads will be dirty and possibly
+ * delalloc. If no delalloc buffer heads in this case then we
+ * can just return zero.
+ *
+ * 2. We are called to release a page which has been written via
+ * mmap, all we need to do is ensure there is no delalloc
+ * state in the buffer heads, if not we can let the caller
+ * free them and we should come back later via writepage.
+ */
+STATIC int
+linvfs_release_page(
+ struct page *page,
+ gfp_t gfp_mask)
+{
+ struct inode *inode = page->mapping->host;
+ int dirty, delalloc, unmapped, unwritten;
+ struct writeback_control wbc = {
+ .sync_mode = WB_SYNC_ALL,
+ .nr_to_write = 1,
+ };
+
+ xfs_page_trace(XFS_RELEASEPAGE_ENTER, inode, page, gfp_mask);
+
+ xfs_count_page_state(page, &delalloc, &unmapped, &unwritten);
+ if (!delalloc && !unwritten)
+ goto free_buffers;
+
+ if (!(gfp_mask & __GFP_FS))
+ return 0;
+
+ /* If we are already inside a transaction or the thread cannot
+ * do I/O, we cannot release this page.
+ */
+ if (PFLAGS_TEST_FSTRANS())
+ return 0;
+
+ /*
+ * Convert delalloc space to real space, do not flush the
+ * data out to disk, that will be done by the caller.
+ * Never need to allocate space here - we will always
+ * come back to writepage in that case.
+ */
+ dirty = xfs_page_state_convert(inode, page, &wbc, 0, 0);
+ if (dirty == 0 && !unwritten)
+ goto free_buffers;
+ return 0;
+
+free_buffers:
+ return try_to_free_buffers(page);
+}
+
STATIC int
__linvfs_get_block(
struct inode *inode,
return ret;
}
+STATIC int
+linvfs_prepare_write(
+ struct file *file,
+ struct page *page,
+ unsigned int from,
+ unsigned int to)
+{
+ return block_prepare_write(page, from, to, linvfs_get_block);
+}
STATIC sector_t
linvfs_bmap(
return mpage_readpages(mapping, pages, nr_pages, linvfs_get_block);
}
-STATIC void
-xfs_count_page_state(
- struct page *page,
- int *delalloc,
- int *unmapped,
- int *unwritten)
-{
- struct buffer_head *bh, *head;
-
- *delalloc = *unmapped = *unwritten = 0;
-
- bh = head = page_buffers(page);
- do {
- if (buffer_uptodate(bh) && !buffer_mapped(bh))
- (*unmapped) = 1;
- else if (buffer_unwritten(bh) && !buffer_delay(bh))
- clear_buffer_unwritten(bh);
- else if (buffer_unwritten(bh))
- (*unwritten) = 1;
- else if (buffer_delay(bh))
- (*delalloc) = 1;
- } while ((bh = bh->b_this_page) != head);
-}
-
-
-/*
- * writepage: Called from one of two places:
- *
- * 1. we are flushing a delalloc buffer head.
- *
- * 2. we are writing out a dirty page. Typically the page dirty
- * state is cleared before we get here. In this case is it
- * conceivable we have no buffer heads.
- *
- * For delalloc space on the page we need to allocate space and
- * flush it. For unmapped buffer heads on the page we should
- * allocate space if the page is uptodate. For any other dirty
- * buffer heads on the page we should flush them.
- *
- * If we detect that a transaction would be required to flush
- * the page, we have to check the process flags first, if we
- * are already in a transaction or disk I/O during allocations
- * is off, we need to fail the writepage and redirty the page.
- */
-
-STATIC int
-linvfs_writepage(
- struct page *page,
- struct writeback_control *wbc)
-{
- int error;
- int need_trans;
- int delalloc, unmapped, unwritten;
- struct inode *inode = page->mapping->host;
-
- xfs_page_trace(XFS_WRITEPAGE_ENTER, inode, page, 0);
-
- /*
- * We need a transaction if:
- * 1. There are delalloc buffers on the page
- * 2. The page is uptodate and we have unmapped buffers
- * 3. The page is uptodate and we have no buffers
- * 4. There are unwritten buffers on the page
- */
-
- if (!page_has_buffers(page)) {
- unmapped = 1;
- need_trans = 1;
- } else {
- xfs_count_page_state(page, &delalloc, &unmapped, &unwritten);
- if (!PageUptodate(page))
- unmapped = 0;
- need_trans = delalloc + unmapped + unwritten;
- }
-
- /*
- * If we need a transaction and the process flags say
- * we are already in a transaction, or no IO is allowed
- * then mark the page dirty again and leave the page
- * as is.
- */
- if (PFLAGS_TEST_FSTRANS() && need_trans)
- goto out_fail;
-
- /*
- * Delay hooking up buffer heads until we have
- * made our go/no-go decision.
- */
- if (!page_has_buffers(page))
- create_empty_buffers(page, 1 << inode->i_blkbits, 0);
-
- /*
- * Convert delayed allocate, unwritten or unmapped space
- * to real space and flush out to disk.
- */
- error = xfs_page_state_convert(inode, page, wbc, 1, unmapped);
- if (error == -EAGAIN)
- goto out_fail;
- if (unlikely(error < 0))
- goto out_unlock;
-
- return 0;
-
-out_fail:
- redirty_page_for_writepage(wbc, page);
- unlock_page(page);
- return 0;
-out_unlock:
- unlock_page(page);
- return error;
-}
-
STATIC int
linvfs_invalidate_page(
struct page *page,
return block_invalidatepage(page, offset);
}
-/*
- * Called to move a page into cleanable state - and from there
- * to be released. Possibly the page is already clean. We always
- * have buffer heads in this call.
- *
- * Returns 0 if the page is ok to release, 1 otherwise.
- *
- * Possible scenarios are:
- *
- * 1. We are being called to release a page which has been written
- * to via regular I/O. buffer heads will be dirty and possibly
- * delalloc. If no delalloc buffer heads in this case then we
- * can just return zero.
- *
- * 2. We are called to release a page which has been written via
- * mmap, all we need to do is ensure there is no delalloc
- * state in the buffer heads, if not we can let the caller
- * free them and we should come back later via writepage.
- */
-STATIC int
-linvfs_release_page(
- struct page *page,
- gfp_t gfp_mask)
-{
- struct inode *inode = page->mapping->host;
- int dirty, delalloc, unmapped, unwritten;
- struct writeback_control wbc = {
- .sync_mode = WB_SYNC_ALL,
- .nr_to_write = 1,
- };
-
- xfs_page_trace(XFS_RELEASEPAGE_ENTER, inode, page, gfp_mask);
-
- xfs_count_page_state(page, &delalloc, &unmapped, &unwritten);
- if (!delalloc && !unwritten)
- goto free_buffers;
-
- if (!(gfp_mask & __GFP_FS))
- return 0;
-
- /* If we are already inside a transaction or the thread cannot
- * do I/O, we cannot release this page.
- */
- if (PFLAGS_TEST_FSTRANS())
- return 0;
-
- /*
- * Convert delalloc space to real space, do not flush the
- * data out to disk, that will be done by the caller.
- * Never need to allocate space here - we will always
- * come back to writepage in that case.
- */
- dirty = xfs_page_state_convert(inode, page, &wbc, 0, 0);
- if (dirty == 0 && !unwritten)
- goto free_buffers;
- return 0;
-
-free_buffers:
- return try_to_free_buffers(page);
-}
-
-STATIC int
-linvfs_prepare_write(
- struct file *file,
- struct page *page,
- unsigned int from,
- unsigned int to)
-{
- return block_prepare_write(page, from, to, linvfs_get_block);
-}
-
struct address_space_operations linvfs_aops = {
.readpage = linvfs_readpage,
.readpages = linvfs_readpages,
projects / linux-beck.git / commitdiff