From: Qilin Tan <qilin....@mediatek.com>
Need add __pack for struct extent_info to align to memory
layout of struct rb_entry.
struct rb_entry {
struct rb_node rb_node; /* rb node located in rb-tree */
union {
struct {
unsigned int ofs; /* start offset of the entry */
unsigned int len; /* length of the entry */
};
unsigned long long key; /* 64-bits key */
} __packed;
};
struct extent_info {
unsigned int fofs; /* start offset in a file */
unsigned int len; /* length of the extent */
union {
...
/* block age extent_cache */
struct {
/* block age of the extent */
unsigned long long age;
/* last total blocks allocated */
unsigned long long last_blocks;
};
};
The new fields(age, last_blocks) are u64 in change 71644dff4811, it
cause the memory alignment based on 8 bytes in some complier. So the
field fofs and len are alloced with 8 bytes and using the last 4 byts.
Its memory is not aligned with struct rb_entry. the ofs of rb_entry
pointer to a invalid value and cause writing file failed.
struct extent_info's offset should be 12 rather than 16 from the
beginning of struct rb_entry.
The offset dump for the bad case as:
kworker/u16:6: [name:f2fs&]f2fs_lookup_rb_tree_for_insert:MTK_DEBUG: ino=1629
re=0xc675dc08 ofs=0 re->ofs=0, re->len=68 ei=0xc675dc18 ei.fofs=68 ei.len=277
Fixes: 71644dff4811 ("f2fs: add block_age-based extent cache")
Signed-off-by: Bo Ye <bo...@mediatek.com>
Signed-off-by: Qilin Tan <qilin....@mediatek.com>
---
fs/f2fs/f2fs.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index b0ab2062038a..7c690667a42f 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -660,7 +660,7 @@ struct extent_info {
unsigned long long last_blocks;
};
};
-};
+} __packed;
struct extent_node {
struct rb_node rb_node; /* rb node located in rb-tree */
--
2.17.0
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