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@xxxxxxxxxx>
> ---
> 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
