diff options
Diffstat (limited to 'fs/xfs/linux-2.6/xfs_aops.c')
| -rw-r--r-- | fs/xfs/linux-2.6/xfs_aops.c | 367 |
1 files changed, 183 insertions, 184 deletions
diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c index 74d8be8..58fc7ad 100644 --- a/fs/xfs/linux-2.6/xfs_aops.c +++ b/fs/xfs/linux-2.6/xfs_aops.c @@ -43,7 +43,32 @@ #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 @@ -1040,6 +1065,154 @@ error: 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, @@ -1223,6 +1396,15 @@ linvfs_direct_IO( 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( @@ -1259,118 +1441,6 @@ linvfs_readpages( 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, @@ -1381,77 +1451,6 @@ linvfs_invalidate_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, |
