When active_logs == 6, dentry blocks can be allocated to HOT, WARM, or
COLD segments based on various conditions in __get_segment_type_6():
- age extent cache (if enabled)
- FI_HOT_DATA flag (set when dirty_pages <= min_hot_blocks)
- rw_hint (defaults to WARM via f2fs_rw_hint_to_seg_type)
- file_is_hot(), FI_NEED_IPU, f2fs_is_cow_file(), etc.
However, has_curseg_enough_space() only checked CURSEG_HOT_DATA segment
for dentry blocks, which could lead to incorrect space calculation when
dentry blocks are actually allocated to WARM or COLD segments.
Reproducer:
Note: This reproducer requires adding a tracepoint to observe segment
type. Add the following tracepoint to include/trace/events/f2fs.h:
TRACE_EVENT(f2fs_allocate_data_block,
TP_PROTO(struct f2fs_sb_info *sbi, struct inode *inode,
enum log_type type, block_t blkaddr),
TP_ARGS(sbi, inode, type, blkaddr),
TP_STRUCT__entry(
__field(dev_t, dev)
__field(ino_t, ino)
__field(int, type)
__field(block_t, blkaddr)
__field(int, is_dir)
),
TP_fast_assign(
__entry->dev = sbi->sb->s_dev;
__entry->ino = inode ? inode->i_ino : 0;
__entry->type = type;
__entry->blkaddr = blkaddr;
__entry->is_dir = inode ? S_ISDIR(inode->i_mode) : 0;
),
TP_printk("dev = (%d,%d), ino = %lu, %s, blkaddr = %u, is_dir = %d",
show_dev(__entry->dev),
(unsigned long)__entry->ino,
show_data_type(__entry->type),
__entry->blkaddr,
__entry->is_dir)
);
And add the tracepoint call in fs/f2fs/segment.c in
f2fs_allocate_data_block() function. Find the location after
locate_dirty_segment() calls and before IS_DATASEG() check:
locate_dirty_segment(sbi, GET_SEGNO(sbi, old_blkaddr));
locate_dirty_segment(sbi, GET_SEGNO(sbi, *new_blkaddr));
trace_f2fs_allocate_data_block(sbi, folio ? folio->mapping->host : NULL,
type, *new_blkaddr);
if (IS_DATASEG(curseg->seg_type))
1. Mount F2FS with active_logs=6 and age extent cache disabled:
# mkfs.f2fs -f /dev/sdb1
# mount -t f2fs -o active_logs=6 /dev/sdb1 /mnt/f2fs-test
2. Enable tracing and f2fs_allocate_data_block tracepoint:
# echo 1 >
/sys/kernel/debug/tracing/events/f2fs/f2fs_allocate_data_block/enable
# echo 1 > /sys/kernel/debug/tracing/tracing_on
# echo > /sys/kernel/debug/tracing/trace
3. Create a directory and write enough files to trigger dirty_pages >
min_hot_blocks (default 16), which will clear FI_HOT_DATA flag:
# mkdir /mnt/f2fs-test/testdir
# cd /mnt/f2fs-test/testdir
# seq 1 8192 | xargs touch
# sync
4. Observe dentry block allocation:
# cat /sys/kernel/debug/tracing/trace
The trace output shows dentry blocks (is_dir = 1) allocated to WARM
segment because FI_HOT_DATA is cleared when dirty_pages >
min_hot_blocks (default 16). However, has_curseg_enough_space() only
checked HOT_DATA segment space.
Fix by checking all three data segments (HOT, WARM, COLD) when
active_logs == 6, similar to how __get_segment_type_6() can return
any of these segment types for dentry blocks.
Fixes: ef095d19e82f ("f2fs: write small sized IO to hot log")
Cc: [email protected]
Signed-off-by: Xiaole He <[email protected]>
---
fs/f2fs/segment.h | 31 +++++++++++++++++++++++++------
1 file changed, 25 insertions(+), 6 deletions(-)
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index 1ce2c8abaf48..c13400a53013 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -632,15 +632,34 @@ static inline bool has_curseg_enough_space(struct
f2fs_sb_info *sbi,
}
/* check current data section for dentry blocks. */
- segno = CURSEG_I(sbi, CURSEG_HOT_DATA)->segno;
+ if (F2FS_OPTION(sbi).active_logs == 6) {
+ /*
+ * With active_logs == 6, dentry blocks can be allocated to
+ * HOT, WARM, or COLD segments based on age extent cache,
+ * FI_HOT_DATA flag, rw_hint, etc. Check all three.
+ */
+ for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
+ segno = CURSEG_I(sbi, i)->segno;
+
+ if (unlikely(segno == NULL_SEGNO))
+ return false;
+
+ left_blocks = get_left_section_blocks(sbi, i, segno);
+
+ if (dent_blocks > left_blocks)
+ return false;
+ }
+ } else {
+ segno = CURSEG_I(sbi, CURSEG_HOT_DATA)->segno;
- if (unlikely(segno == NULL_SEGNO))
- return false;
+ if (unlikely(segno == NULL_SEGNO))
+ return false;
- left_blocks = get_left_section_blocks(sbi, CURSEG_HOT_DATA, segno);
+ left_blocks = get_left_section_blocks(sbi, CURSEG_HOT_DATA,
segno);
- if (dent_blocks > left_blocks)
- return false;
+ if (dent_blocks > left_blocks)
+ return false;
+ }
return true;
}
--
2.43.0
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