Messages in this thread | | | Subject | Re: [PATCH v2] f2fs: fix out-of-free problem caused by atomic write | From | Yunlong Song <> | Date | Fri, 3 Nov 2017 12:48:39 +0800 |
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Because I found that it will still lead to out-of-free problem with out that check. I trace and find that it is possible that the committing date pages of the atomic file is bigger than the sbi->user_block_count - valid_user_blocks(sbi), so I add this check.
On 2017/11/3 11:46, Jaegeuk Kim wrote: > On 10/30, Yunlong Song wrote: >> f2fs_balance_fs only actives once in the commit_inmem_pages, but there >> are more than one page to commit, so all the other pages will miss the >> check. This will lead to out-of-free problem when commit a very large >> file. However, we cannot do f2fs_balance_fs for each inmem page, since >> this will break atomicity. As a result, we should collect prefree >> segments if needed and stop atomic commit when there are not enough >> available blocks to write atomic pages. >> >> Signed-off-by: Yunlong Song <yunlong.song@huawei.com> >> --- >> fs/f2fs/f2fs.h | 1 + >> fs/f2fs/segment.c | 29 ++++++++++++++++++++++++++++- >> 2 files changed, 29 insertions(+), 1 deletion(-) >> >> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h >> index 13a96b8..04ce48f 100644 >> --- a/fs/f2fs/f2fs.h >> +++ b/fs/f2fs/f2fs.h >> @@ -610,6 +610,7 @@ struct f2fs_inode_info { >> struct list_head inmem_pages; /* inmemory pages managed by f2fs */ >> struct task_struct *inmem_task; /* store inmemory task */ >> struct mutex inmem_lock; /* lock for inmemory pages */ >> + unsigned long inmem_blocks; /* inmemory blocks */ >> struct extent_tree *extent_tree; /* cached extent_tree entry */ >> struct rw_semaphore dio_rwsem[2];/* avoid racing between dio and gc */ >> struct rw_semaphore i_mmap_sem; >> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c >> index 46dfbca..813c110 100644 >> --- a/fs/f2fs/segment.c >> +++ b/fs/f2fs/segment.c >> @@ -210,6 +210,7 @@ void register_inmem_page(struct inode *inode, struct page *page) >> list_add_tail(&fi->inmem_ilist, &sbi->inode_list[ATOMIC_FILE]); >> spin_unlock(&sbi->inode_lock[ATOMIC_FILE]); >> inc_page_count(F2FS_I_SB(inode), F2FS_INMEM_PAGES); >> + fi->inmem_blocks++; >> mutex_unlock(&fi->inmem_lock); >> >> trace_f2fs_register_inmem_page(page, INMEM); >> @@ -221,6 +222,7 @@ static int __revoke_inmem_pages(struct inode *inode, >> struct f2fs_sb_info *sbi = F2FS_I_SB(inode); >> struct inmem_pages *cur, *tmp; >> int err = 0; >> + struct f2fs_inode_info *fi = F2FS_I(inode); >> >> list_for_each_entry_safe(cur, tmp, head, list) { >> struct page *page = cur->page; >> @@ -263,6 +265,7 @@ static int __revoke_inmem_pages(struct inode *inode, >> list_del(&cur->list); >> kmem_cache_free(inmem_entry_slab, cur); >> dec_page_count(F2FS_I_SB(inode), F2FS_INMEM_PAGES); >> + fi->inmem_blocks--; >> } >> return err; >> } >> @@ -302,6 +305,10 @@ void drop_inmem_pages(struct inode *inode) >> if (!list_empty(&fi->inmem_ilist)) >> list_del_init(&fi->inmem_ilist); >> spin_unlock(&sbi->inode_lock[ATOMIC_FILE]); >> + if (fi->inmem_blocks) { >> + f2fs_bug_on(sbi, 1); >> + fi->inmem_blocks = 0; >> + } >> mutex_unlock(&fi->inmem_lock); >> >> clear_inode_flag(inode, FI_ATOMIC_FILE); >> @@ -326,6 +333,7 @@ void drop_inmem_page(struct inode *inode, struct page *page) >> >> f2fs_bug_on(sbi, !cur || cur->page != page); >> list_del(&cur->list); >> + fi->inmem_blocks--; >> mutex_unlock(&fi->inmem_lock); >> >> dec_page_count(sbi, F2FS_INMEM_PAGES); >> @@ -410,11 +418,26 @@ int commit_inmem_pages(struct inode *inode) >> >> INIT_LIST_HEAD(&revoke_list); >> f2fs_balance_fs(sbi, true); >> + if (prefree_segments(sbi) >> + && has_not_enough_free_secs(sbi, 0, >> + fi->inmem_blocks / BLKS_PER_SEC(sbi))) { >> + struct cp_control cpc; >> + >> + cpc.reason = __get_cp_reason(sbi); >> + err = write_checkpoint(sbi, &cpc); >> + if (err) >> + goto drop; >> + } >> f2fs_lock_op(sbi); >> >> set_inode_flag(inode, FI_ATOMIC_COMMIT); >> >> mutex_lock(&fi->inmem_lock); >> + if ((sbi->user_block_count - valid_user_blocks(sbi)) < > What does this mean? We already allocated blocks successfully? > >> + fi->inmem_blocks) { >> + err = -ENOSPC; >> + goto drop; >> + } >> err = __commit_inmem_pages(inode, &revoke_list); >> if (err) { >> int ret; >> @@ -429,7 +452,7 @@ int commit_inmem_pages(struct inode *inode) >> ret = __revoke_inmem_pages(inode, &revoke_list, false, true); >> if (ret) >> err = ret; >> - >> +drop: >> /* drop all uncommitted pages */ >> __revoke_inmem_pages(inode, &fi->inmem_pages, true, false); >> } >> @@ -437,6 +460,10 @@ int commit_inmem_pages(struct inode *inode) >> if (!list_empty(&fi->inmem_ilist)) >> list_del_init(&fi->inmem_ilist); >> spin_unlock(&sbi->inode_lock[ATOMIC_FILE]); >> + if (fi->inmem_blocks) { >> + f2fs_bug_on(sbi, 1); >> + fi->inmem_blocks = 0; >> + } >> mutex_unlock(&fi->inmem_lock); >> >> clear_inode_flag(inode, FI_ATOMIC_COMMIT); >> -- >> 1.8.5.2 > . >
-- Thanks, Yunlong Song
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