From: Theodore Ts'o Subject: [PATCH 13/42] ext4: Retry block allocation if we have free blocks left Date: Thu, 9 Oct 2008 00:05:31 -0400 Message-ID: <1223525160-9887-14-git-send-email-tytso@mit.edu> References: <1223525160-9887-1-git-send-email-tytso@mit.edu> <1223525160-9887-2-git-send-email-tytso@mit.edu> <1223525160-9887-3-git-send-email-tytso@mit.edu> <1223525160-9887-4-git-send-email-tytso@mit.edu> <1223525160-9887-5-git-send-email-tytso@mit.edu> <1223525160-9887-6-git-send-email-tytso@mit.edu> <1223525160-9887-7-git-send-email-tytso@mit.edu> <1223525160-9887-8-git-send-email-tytso@mit.edu> <1223525160-9887-9-git-send-email-tytso@mit.edu> <1223525160-9887-10-git-send-email-tytso@mit.edu> <1223525160-9887-11-git-send-email-tytso@mit.edu> <1223525160-9887-12-git-send-email-tytso@mit.edu> <1223525160-9887-13-git-send-email-tytso@mit.edu> Cc: "Aneesh Kumar K.V" , Mingming Cao , "Theodore Ts'o" To: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: Received: from www.church-of-our-saviour.org ([69.25.196.31]:54524 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1757610AbYJIEGN (ORCPT ); Thu, 9 Oct 2008 00:06:13 -0400 In-Reply-To: <1223525160-9887-13-git-send-email-tytso@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: From: Aneesh Kumar K.V When we truncate files, the meta-data blocks released are not reused untill we commit the truncate transaction. That means delayed get_block request will return ENOSPC even if we have free blocks left. Force a journal commit and retry block allocation if we get ENOSPC with free blocks left. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Mingming Cao Signed-off-by: "Theodore Ts'o" --- fs/ext4/inode.c | 81 ++++++++++++++++++++++++++++++++++++++---------------- 1 files changed, 57 insertions(+), 24 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index b567e71..f97b347 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1634,6 +1634,7 @@ struct mpage_da_data { struct writeback_control *wbc; int io_done; long pages_written; + int retval; }; /* @@ -1820,6 +1821,24 @@ static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd, return; } +static void ext4_print_free_blocks(struct inode *inode) +{ + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + printk(KERN_EMERG "Total free blocks count %lld\n", + ext4_count_free_blocks(inode->i_sb)); + printk(KERN_EMERG "Free/Dirty block details\n"); + printk(KERN_EMERG "free_blocks=%lld\n", + percpu_counter_sum(&sbi->s_freeblocks_counter)); + printk(KERN_EMERG "dirty_blocks=%lld\n", + percpu_counter_sum(&sbi->s_dirtyblocks_counter)); + printk(KERN_EMERG "Block reservation details\n"); + printk(KERN_EMERG "i_reserved_data_blocks=%lu\n", + EXT4_I(inode)->i_reserved_data_blocks); + printk(KERN_EMERG "i_reserved_meta_blocks=%lu\n", + EXT4_I(inode)->i_reserved_meta_blocks); + return; +} + /* * mpage_da_map_blocks - go through given space * @@ -1834,7 +1853,7 @@ static int mpage_da_map_blocks(struct mpage_da_data *mpd) int err = 0; struct buffer_head new; struct buffer_head *lbh = &mpd->lbh; - sector_t next = lbh->b_blocknr; + sector_t next; /* * We consider only non-mapped and non-allocated blocks @@ -1844,6 +1863,7 @@ static int mpage_da_map_blocks(struct mpage_da_data *mpd) new.b_state = lbh->b_state; new.b_blocknr = 0; new.b_size = lbh->b_size; + next = lbh->b_blocknr; /* * If we didn't accumulate anything * to write simply return @@ -1860,6 +1880,13 @@ static int mpage_da_map_blocks(struct mpage_da_data *mpd) */ if (err == -EAGAIN) return 0; + + if (err == -ENOSPC && + ext4_count_free_blocks(mpd->inode->i_sb)) { + mpd->retval = err; + return 0; + } + /* * get block failure will cause us * to loop in writepages. Because @@ -1877,8 +1904,7 @@ static int mpage_da_map_blocks(struct mpage_da_data *mpd) printk(KERN_EMERG "This should not happen.!! " "Data will be lost\n"); if (err == -ENOSPC) { - printk(KERN_CRIT "Total free blocks count %lld\n", - ext4_count_free_blocks(mpd->inode->i_sb)); + ext4_print_free_blocks(mpd->inode); } /* invlaidate all the pages */ ext4_da_block_invalidatepages(mpd, next, @@ -2085,39 +2111,36 @@ static int __mpage_da_writepage(struct page *page, */ static int mpage_da_writepages(struct address_space *mapping, struct writeback_control *wbc, - get_block_t get_block) + struct mpage_da_data *mpd) { - struct mpage_da_data mpd; long to_write; int ret; - if (!get_block) + if (!mpd->get_block) return generic_writepages(mapping, wbc); - mpd.wbc = wbc; - mpd.inode = mapping->host; - mpd.lbh.b_size = 0; - mpd.lbh.b_state = 0; - mpd.lbh.b_blocknr = 0; - mpd.first_page = 0; - mpd.next_page = 0; - mpd.get_block = get_block; - mpd.io_done = 0; - mpd.pages_written = 0; + mpd->lbh.b_size = 0; + mpd->lbh.b_state = 0; + mpd->lbh.b_blocknr = 0; + mpd->first_page = 0; + mpd->next_page = 0; + mpd->io_done = 0; + mpd->pages_written = 0; + mpd->retval = 0; to_write = wbc->nr_to_write; - ret = write_cache_pages(mapping, wbc, __mpage_da_writepage, &mpd); + ret = write_cache_pages(mapping, wbc, __mpage_da_writepage, mpd); /* * Handle last extent of pages */ - if (!mpd.io_done && mpd.next_page != mpd.first_page) { - if (mpage_da_map_blocks(&mpd) == 0) - mpage_da_submit_io(&mpd); + if (!mpd->io_done && mpd->next_page != mpd->first_page) { + if (mpage_da_map_blocks(mpd) == 0) + mpage_da_submit_io(mpd); } - wbc->nr_to_write = to_write - mpd.pages_written; + wbc->nr_to_write = to_write - mpd->pages_written; return ret; } @@ -2357,6 +2380,7 @@ static int ext4_da_writepages(struct address_space *mapping, { handle_t *handle = NULL; loff_t range_start = 0; + struct mpage_da_data mpd; struct inode *inode = mapping->host; int needed_blocks, ret = 0, nr_to_writebump = 0; long to_write, pages_skipped = 0; @@ -2390,6 +2414,9 @@ static int ext4_da_writepages(struct address_space *mapping, range_start = wbc->range_start; pages_skipped = wbc->pages_skipped; + mpd.wbc = wbc; + mpd.inode = mapping->host; + restart_loop: to_write = wbc->nr_to_write; while (!ret && to_write > 0) { @@ -2413,11 +2440,17 @@ restart_loop: dump_stack(); goto out_writepages; }