From: Theodore Ts'o Date: Thu, 28 Oct 2010 01:30:09 +0000 (-0400) Subject: ext4: call mpage_da_submit_io() from mpage_da_map_blocks() X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=5a87b7a5da250c9be6d757758425dfeaf8ed3179;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git ext4: call mpage_da_submit_io() from mpage_da_map_blocks() Eventually we need to completely reorganize the ext4 writepage callpath, but for now, we simplify things a little by calling mpage_da_submit_io() from mpage_da_map_blocks(), since all of the places where we call mpage_da_map_blocks() it is followed up by a call to mpage_da_submit_io(). We're also a wee bit better with respect to error handling, but there are still a number of issues where it's not clear what the right thing is to do with ext4 functions deep in the writeback codepath fails. Signed-off-by: "Theodore Ts'o" --- diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 670ab15e4f9..55961ff4efc 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -60,6 +60,7 @@ static inline int ext4_begin_ordered_truncate(struct inode *inode, } static void ext4_invalidatepage(struct page *page, unsigned long offset); +static int ext4_writepage(struct page *page, struct writeback_control *wbc); /* * Test whether an inode is a fast symlink. @@ -2033,7 +2034,7 @@ static int mpage_da_submit_io(struct mpage_da_data *mpd) BUG_ON(PageWriteback(page)); pages_skipped = mpd->wbc->pages_skipped; - err = mapping->a_ops->writepage(page, mpd->wbc); + err = ext4_writepage(page, mpd->wbc); if (!err && (pages_skipped == mpd->wbc->pages_skipped)) /* * have successfully written the page @@ -2189,14 +2190,15 @@ static void ext4_print_free_blocks(struct inode *inode) } /* - * mpage_da_map_blocks - go through given space + * mpage_da_map_and_submit - go through given space, map them + * if necessary, and then submit them for I/O * * @mpd - bh describing space * * The function skips space we know is already mapped to disk blocks. * */ -static int mpage_da_map_blocks(struct mpage_da_data *mpd) +static void mpage_da_map_and_submit(struct mpage_da_data *mpd) { int err, blks, get_blocks_flags; struct ext4_map_blocks map; @@ -2206,18 +2208,14 @@ static int mpage_da_map_blocks(struct mpage_da_data *mpd) handle_t *handle = NULL; /* - * We consider only non-mapped and non-allocated blocks + * If the blocks are mapped already, or we couldn't accumulate + * any blocks, then proceed immediately to the submission stage. */ - if ((mpd->b_state & (1 << BH_Mapped)) && - !(mpd->b_state & (1 << BH_Delay)) && - !(mpd->b_state & (1 << BH_Unwritten))) - return 0; - - /* - * If we didn't accumulate anything to write simply return - */ - if (!mpd->b_size) - return 0; + if ((mpd->b_size == 0) || + ((mpd->b_state & (1 << BH_Mapped)) && + !(mpd->b_state & (1 << BH_Delay)) && + !(mpd->b_state & (1 << BH_Unwritten)))) + goto submit_io; handle = ext4_journal_current_handle(); BUG_ON(!handle); @@ -2254,17 +2252,18 @@ static int mpage_da_map_blocks(struct mpage_da_data *mpd) err = blks; /* - * If get block returns with error we simply - * return. Later writepage will redirty the page and - * writepages will find the dirty page again + * If get block returns EAGAIN or ENOSPC and there + * appears to be free blocks we will call + * ext4_writepage() for all of the pages which will + * just redirty the pages. */ if (err == -EAGAIN) - return 0; + goto submit_io; if (err == -ENOSPC && ext4_count_free_blocks(sb)) { mpd->retval = err; - return 0; + goto submit_io; } /* @@ -2289,7 +2288,7 @@ static int mpage_da_map_blocks(struct mpage_da_data *mpd) /* invalidate all the pages */ ext4_da_block_invalidatepages(mpd, next, mpd->b_size >> mpd->inode->i_blkbits); - return err; + return; } BUG_ON(blks == 0); @@ -2312,7 +2311,8 @@ static int mpage_da_map_blocks(struct mpage_da_data *mpd) if (ext4_should_order_data(mpd->inode)) { err = ext4_jbd2_file_inode(handle, mpd->inode); if (err) - return err; + /* This only happens if the journal is aborted */ + return; } /* @@ -2323,10 +2323,16 @@ static int mpage_da_map_blocks(struct mpage_da_data *mpd) disksize = i_size_read(mpd->inode); if (disksize > EXT4_I(mpd->inode)->i_disksize) { ext4_update_i_disksize(mpd->inode, disksize); - return ext4_mark_inode_dirty(handle, mpd->inode); + err = ext4_mark_inode_dirty(handle, mpd->inode); + if (err) + ext4_error(mpd->inode->i_sb, + "Failed to mark inode %lu dirty", + mpd->inode->i_ino); } - return 0; +submit_io: + mpage_da_submit_io(mpd); + mpd->io_done = 1; } #define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \ @@ -2403,9 +2409,7 @@ flush_it: * We couldn't merge the block to our extent, so we * need to flush current extent and start new one */ - if (mpage_da_map_blocks(mpd) == 0) - mpage_da_submit_io(mpd); - mpd->io_done = 1; + mpage_da_map_and_submit(mpd); return; } @@ -2437,15 +2441,13 @@ static int __mpage_da_writepage(struct page *page, if (mpd->next_page != page->index) { /* * Nope, we can't. So, we map non-allocated blocks - * and start IO on them using writepage() + * and start IO on them */ if (mpd->next_page != mpd->first_page) { - if (mpage_da_map_blocks(mpd) == 0) - mpage_da_submit_io(mpd); + mpage_da_map_and_submit(mpd); /* * skip rest of the page in the page_vec */ - mpd->io_done = 1; redirty_page_for_writepage(wbc, page); unlock_page(page); return MPAGE_DA_EXTENT_TAIL; @@ -3071,9 +3073,7 @@ retry: * them for I/O. */ if (!mpd.io_done && mpd.next_page != mpd.first_page) { - if (mpage_da_map_blocks(&mpd) == 0) - mpage_da_submit_io(&mpd); - mpd.io_done = 1; + mpage_da_map_and_submit(&mpd); ret = MPAGE_DA_EXTENT_TAIL; } trace_ext4_da_write_pages(inode, &mpd);