On 8/20/25 15:54, Wang Xiaojun wrote:
> This patch fixes missing space reclamation during the recovery process.
>
> In the following scenarios, F2FS cannot reclaim truncated space.
> case 1:
> write file A, size is 1G | CP | truncate A to 1M | fsync A | SPO
>
> case 2:
> CP | write file A, size is 1G | fsync A | truncate A to 1M | fsync A |SPO
>
> During the recovery process, F2FS will recover file A,
> but the 1M-1G space cannot be reclaimed.
>
> But the combination of truncate and falloc complicates the recovery
> process.
> For example, in the following scenario:
> write fileA 2M | fsync | truncate 256K | falloc -k 256K 1M | fsync A | SPO
> The falloc (256K, 1M) need to be recovered as pre-allocated space.
>
> However in the following scenarios, the situation is the opposite.
> write fileA 2M | fsync | falloc -k 2M 10M | fsync A | truncate 256K |
> fsync A | SPO
> In this scenario, the space allocated by falloc needs to be truncated.
>
> During the recovery process, it is difficult to distinguish
> between the above two types of falloc.
>
> So in this case of falloc -k we need to trigger a checkpoint for fsync.
>
> Fixes: d624c96fb3249 ("f2fs: add recovery routines for roll-forward")
>
> Signed-off-by: Wang Xiaojun <[email protected]>
> ---
> v4: Trigger checkpoint for fsync after falloc -k
> v3: Add a Fixes line.
> v2: Apply Chao's suggestion from v1. No logical changes.
> v1: Fix missing space reclamation during the recovery process.
> ---
> fs/f2fs/checkpoint.c | 3 +++
> fs/f2fs/f2fs.h | 3 +++
> fs/f2fs/file.c | 8 ++++++--
> fs/f2fs/recovery.c | 18 +++++++++++++++++-
> 4 files changed, 29 insertions(+), 3 deletions(-)
>
> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> index db3831f7f2f5..775e3333097e 100644
> --- a/fs/f2fs/checkpoint.c
> +++ b/fs/f2fs/checkpoint.c
> @@ -1151,6 +1151,9 @@ static int f2fs_sync_inode_meta(struct f2fs_sb_info
> *sbi)
> if (inode) {
> sync_inode_metadata(inode, 0);
>
> + if (is_inode_flag_set(inode, FI_FALLOC_KEEP_SIZE))
> + clear_inode_flag(inode, FI_FALLOC_KEEP_SIZE);
> +
> /* it's on eviction */
> if (is_inode_flag_set(inode, FI_DIRTY_INODE))
> f2fs_update_inode_page(inode);
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 46be7560548c..f5a54bc848d5 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -459,6 +459,7 @@ struct fsync_inode_entry {
> struct inode *inode; /* vfs inode pointer */
> block_t blkaddr; /* block address locating the last fsync */
> block_t last_dentry; /* block address locating the last dentry */
> + loff_t max_i_size; /* previous max file size for truncate */
> };
>
> #define nats_in_cursum(jnl) (le16_to_cpu((jnl)->n_nats))
> @@ -835,6 +836,7 @@ enum {
> FI_ATOMIC_REPLACE, /* indicate atomic replace */
> FI_OPENED_FILE, /* indicate file has been opened */
> FI_DONATE_FINISHED, /* indicate page donation of file has been
> finished */
> + FI_FALLOC_KEEP_SIZE, /* file allocate reserved space and keep size */
> FI_MAX, /* max flag, never be used */
> };
>
> @@ -1193,6 +1195,7 @@ enum cp_reason_type {
> CP_SPEC_LOG_NUM,
> CP_RECOVER_DIR,
> CP_XATTR_DIR,
> + CP_FALLOC_FILE,
> };
>
> enum iostat_type {
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 42faaed6a02d..f0820f817824 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -236,6 +236,8 @@ static inline enum cp_reason_type
> need_do_checkpoint(struct inode *inode)
> else if (f2fs_exist_written_data(sbi, F2FS_I(inode)->i_pino,
> XATTR_DIR_INO))
> cp_reason = CP_XATTR_DIR;
> + else if (is_inode_flag_set(inode, FI_FALLOC_KEEP_SIZE))
> + cp_reason = CP_FALLOC_FILE;
>
> return cp_reason;
> }
> @@ -1953,10 +1955,12 @@ static int f2fs_expand_inode_data(struct inode
> *inode, loff_t offset,
> }
>
> if (new_size > i_size_read(inode)) {
> - if (mode & FALLOC_FL_KEEP_SIZE)
> + if (mode & FALLOC_FL_KEEP_SIZE) {
> + set_inode_flag(inode, FI_FALLOC_KEEP_SIZE);
Xiaojun,
Well, what about this case?
falloc -k ofs size file
flush all data and metadata of file
evict inode
write file & fsync file won't trigger a checkpoint?
Or am I missing something?
Thanks,
> file_set_keep_isize(inode);
> - else
> + } else {
> f2fs_i_size_write(inode, new_size);
> + }
> }
>
> return err;
> diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
> index 4cb3a91801b4..68b62c8a74d3 100644
> --- a/fs/f2fs/recovery.c
> +++ b/fs/f2fs/recovery.c
> @@ -95,6 +95,7 @@ static struct fsync_inode_entry *add_fsync_inode(struct
> f2fs_sb_info *sbi,
> entry = f2fs_kmem_cache_alloc(fsync_entry_slab,
> GFP_F2FS_ZERO, true, NULL);
> entry->inode = inode;
> + entry->max_i_size = i_size_read(inode);
> list_add_tail(&entry->list, head);
>
> return entry;
> @@ -796,6 +797,7 @@ static int recover_data(struct f2fs_sb_info *sbi, struct
> list_head *inode_list,
> while (1) {
> struct fsync_inode_entry *entry;
> struct folio *folio;
> + loff_t i_size;
>
> if (!f2fs_is_valid_blkaddr(sbi, blkaddr, META_POR))
> break;
> @@ -828,6 +830,9 @@ static int recover_data(struct f2fs_sb_info *sbi, struct
> list_head *inode_list,
> break;
> }
> recovered_inode++;
> + i_size = i_size_read(entry->inode);
> + if (entry->max_i_size < i_size)
> + entry->max_i_size = i_size;
> }
> if (entry->last_dentry == blkaddr) {
> err = recover_dentry(entry->inode, folio, dir_list);
> @@ -844,8 +849,19 @@ static int recover_data(struct f2fs_sb_info *sbi, struct
> list_head *inode_list,
> }
> recovered_dnode++;
>
> - if (entry->blkaddr == blkaddr)
> + if (entry->blkaddr == blkaddr) {
> + i_size = i_size_read(entry->inode);
> + if (entry->max_i_size > i_size) {
> + err = f2fs_truncate_blocks(entry->inode,
> + i_size, false);
> + if (err) {
> + f2fs_folio_put(folio, true);
> + break;
> + }
> + f2fs_mark_inode_dirty_sync(entry->inode, true);
> + }
> list_move_tail(&entry->list, tmp_inode_list);
> + }
> next:
> ra_blocks = adjust_por_ra_blocks(sbi, ra_blocks, blkaddr,
> next_blkaddr_of_node(folio));
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