From 2070ad1aebfff2c26190188844c38e55d2df2ae2 Mon Sep 17 00:00:00 2001 From: Eric Ren Date: Tue, 2 Aug 2016 14:02:10 -0700 Subject: [PATCH] ocfs2: retry on ENOSPC if sufficient space in truncate log The testcase "mmaptruncate" in ocfs2 test suite always fails with ENOSPC error on small volume (say less than 10G). This testcase repeatedly performs "extend" and "truncate" on a file. Continuously, it truncates the file to 1/2 of the size, and then extends to 100% of the size. The main bitmap will quickly run out of space because the "truncate" code prevent truncate log from being flushed by ocfs2_schedule_truncate_log_flush(osb, 1), while truncate log may have cached lots of clusters. So retry to allocate after flushing truncate log when ENOSPC is returned. And we cannot reuse the deleted blocks before the transaction committed. Fortunately, we already have a function to do this - ocfs2_try_to_free_truncate_log(). Just need to remove the "static" modifier and put it into the right place. The "unlock"/"lock" code isn't elegant, but there seems to be no better option. [zren@suse.com: locking fix] Link: http://lkml.kernel.org/r/1468031546-4797-1-git-send-email-zren@suse.com Link: http://lkml.kernel.org/r/1466586469-5541-1-git-send-email-zren@suse.com Signed-off-by: Eric Ren Reviewed-by: Gang He Reviewed-by: Joseph Qi Reviewed-by: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ocfs2/alloc.c | 37 +++++++++++++++++++++++++++++++++++++ fs/ocfs2/alloc.h | 2 ++ fs/ocfs2/aops.c | 37 ------------------------------------- fs/ocfs2/suballoc.c | 20 +++++++++++++++++++- 4 files changed, 58 insertions(+), 38 deletions(-) diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c index 460c0cedab3a..7dabbc31060e 100644 --- a/fs/ocfs2/alloc.c +++ b/fs/ocfs2/alloc.c @@ -6106,6 +6106,43 @@ void ocfs2_schedule_truncate_log_flush(struct ocfs2_super *osb, } } +/* + * Try to flush truncate logs if we can free enough clusters from it. + * As for return value, "< 0" means error, "0" no space and "1" means + * we have freed enough spaces and let the caller try to allocate again. + */ +int ocfs2_try_to_free_truncate_log(struct ocfs2_super *osb, + unsigned int needed) +{ + tid_t target; + int ret = 0; + unsigned int truncated_clusters; + + inode_lock(osb->osb_tl_inode); + truncated_clusters = osb->truncated_clusters; + inode_unlock(osb->osb_tl_inode); + + /* + * Check whether we can succeed in allocating if we free + * the truncate log. + */ + if (truncated_clusters < needed) + goto out; + + ret = ocfs2_flush_truncate_log(osb); + if (ret) { + mlog_errno(ret); + goto out; + } + + if (jbd2_journal_start_commit(osb->journal->j_journal, &target)) { + jbd2_log_wait_commit(osb->journal->j_journal, target); + ret = 1; + } +out: + return ret; +} + static int ocfs2_get_truncate_log_info(struct ocfs2_super *osb, int slot_num, struct inode **tl_inode, diff --git a/fs/ocfs2/alloc.h b/fs/ocfs2/alloc.h index f3dc1b0dfffc..4a5152ec88a3 100644 --- a/fs/ocfs2/alloc.h +++ b/fs/ocfs2/alloc.h @@ -188,6 +188,8 @@ int ocfs2_truncate_log_append(struct ocfs2_super *osb, u64 start_blk, unsigned int num_clusters); int __ocfs2_flush_truncate_log(struct ocfs2_super *osb); +int ocfs2_try_to_free_truncate_log(struct ocfs2_super *osb, + unsigned int needed); /* * Process local structure which describes the block unlinks done diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c index af2adfcb0f6f..98d36548153d 100644 --- a/fs/ocfs2/aops.c +++ b/fs/ocfs2/aops.c @@ -1645,43 +1645,6 @@ static int ocfs2_zero_tail(struct inode *inode, struct buffer_head *di_bh, return ret; } -/* - * Try to flush truncate logs if we can free enough clusters from it. - * As for return value, "< 0" means error, "0" no space and "1" means - * we have freed enough spaces and let the caller try to allocate again. - */ -static int ocfs2_try_to_free_truncate_log(struct ocfs2_super *osb, - unsigned int needed) -{ - tid_t target; - int ret = 0; - unsigned int truncated_clusters; - - inode_lock(osb->osb_tl_inode); - truncated_clusters = osb->truncated_clusters; - inode_unlock(osb->osb_tl_inode); - - /* - * Check whether we can succeed in allocating if we free - * the truncate log. - */ - if (truncated_clusters < needed) - goto out; - - ret = ocfs2_flush_truncate_log(osb); - if (ret) { - mlog_errno(ret); - goto out; - } - - if (jbd2_journal_start_commit(osb->journal->j_journal, &target)) { - jbd2_log_wait_commit(osb->journal->j_journal, target); - ret = 1; - } -out: - return ret; -} - int ocfs2_write_begin_nolock(struct address_space *mapping, loff_t pos, unsigned len, ocfs2_write_type_t type, struct page **pagep, void **fsdata, diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c index 2f19aeec5482..ea47120a85ff 100644 --- a/fs/ocfs2/suballoc.c +++ b/fs/ocfs2/suballoc.c @@ -1164,7 +1164,8 @@ static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb, int flags, struct ocfs2_alloc_context **ac) { - int status; + int status, ret = 0; + int retried = 0; *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL); if (!(*ac)) { @@ -1189,7 +1190,24 @@ static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb, } if (status == -ENOSPC) { +retry: status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac); + /* Retry if there is sufficient space cached in truncate log */ + if (status == -ENOSPC && !retried) { + retried = 1; + ocfs2_inode_unlock((*ac)->ac_inode, 1); + inode_unlock((*ac)->ac_inode); + + ret = ocfs2_try_to_free_truncate_log(osb, bits_wanted); + if (ret == 1) + goto retry; + + if (ret < 0) + mlog_errno(ret); + + inode_lock((*ac)->ac_inode); + ocfs2_inode_lock((*ac)->ac_inode, NULL, 1); + } if (status < 0) { if (status != -ENOSPC) mlog_errno(status); -- GitLab