Messages in this thread | | | Date | Sat, 1 Apr 2023 09:00:59 +0800 | From | Chao Yu <> | Subject | Re: [PATCH 2/2] f2fs: add __pack attribute for extent_info |
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On 2023/3/31 17:26, Bo Ye wrote: > From: Qilin Tan <qilin.tan@mediatek.com> > > Need add __pack for struct extent_info to align to memory > layout of struct rb_entry.
Jaegeuk has fixed this bug w/ below patchset, please check it:
https://lore.kernel.org/linux-f2fs-devel/20230313201216.924234-1-jaegeuk@kernel.org/
Thanks,
> > 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.ye@mediatek.com> > Signed-off-by: Qilin Tan <qilin.tan@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 */
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