diff mbox series

[2/2] f2fs: add __pack attribute for extent_info

Message ID 20230331092658.72386-2-bo.ye@mediatek.com (mailing list archive)
State New, archived
Headers show
Series [1/2] f2fs: fix iostat lock protection | expand

Commit Message

Bo Ye March 31, 2023, 9:26 a.m. UTC
From: Qilin Tan <qilin.tan@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.ye@mediatek.com>
Signed-off-by: Qilin Tan <qilin.tan@mediatek.com>
---
 fs/f2fs/f2fs.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Chao Yu April 1, 2023, 1 a.m. UTC | #1
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 */
Bo Ye April 7, 2023, 9:38 a.m. UTC | #2
On Sat, 2023-04-01 at 09:00 +0800, Chao Yu wrote:
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
> 
> 
> 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,
> 
  OK, under verifying, I will reply with test result. 
  Thanks a lot!
> > 
> > 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 
> > */
diff mbox series

Patch

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 */