Re: [PATCH 15/31] e2fsck: Teach EA refcounting code to handle 48bit block addresses

Lukáš Czerner
2013-10-07T15:44:32Z

On Mon, 30 Sep 2013, Darrick J. Wong wrote:

> Date: Mon, 30 Sep 2013 18:28:18 -0700
> From: Darrick J. Wong <darrick.wong@oracle.com>
> To: tytso@mit.edu, darrick.wong@oracle.com
> Cc: linux-ext4@vger.kernel.org
> Subject: [PATCH 15/31] e2fsck: Teach EA refcounting code to handle 48bit block
> addresses

Did you meant to say 64bit ?

>
> The extended attribute refcounting code only accepts blk_t, which is dangerous
> because EA blocks can exist at high addresses (> 2^32) as well. Therefore,
> widen the block fields to 64 bits.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
> e2fsck/e2fsck.h | 12 ++++++------
> e2fsck/ea_refcount.c | 36 ++++++++++++++++++------------------
> 2 files changed, 24 insertions(+), 24 deletions(-)
>
>
> diff --git a/e2fsck/e2fsck.h b/e2fsck/e2fsck.h
> index 13d70f1..f1df525 100644
> --- a/e2fsck/e2fsck.h
> +++ b/e2fsck/e2fsck.h
> @@ -432,17 +432,17 @@ extern struct dx_dir_info *e2fsck_dx_dir_info_iter(e2fsck_t ctx, int *control);
> /* ea_refcount.c */
> extern errcode_t ea_refcount_create(int size, ext2_refcount_t *ret);
> extern void ea_refcount_free(ext2_refcount_t refcount);
> -extern errcode_t ea_refcount_fetch(ext2_refcount_t refcount, blk_t blk,
> +extern errcode_t ea_refcount_fetch(ext2_refcount_t refcount, blk64_t blk,
> int *ret);
> extern errcode_t ea_refcount_increment(ext2_refcount_t refcount,
> - blk_t blk, int *ret);
> + blk64_t blk, int *ret);
> extern errcode_t ea_refcount_decrement(ext2_refcount_t refcount,
> - blk_t blk, int *ret);
> + blk64_t blk, int *ret);
> extern errcode_t ea_refcount_store(ext2_refcount_t refcount,
> - blk_t blk, int count);
> -extern blk_t ext2fs_get_refcount_size(ext2_refcount_t refcount);
> + blk64_t blk, int count);
> +extern blk64_t ext2fs_get_refcount_size(ext2_refcount_t refcount);
> extern void ea_refcount_intr_begin(ext2_refcount_t refcount);
> -extern blk_t ea_refcount_intr_next(ext2_refcount_t refcount, int *ret);
> +extern blk64_t ea_refcount_intr_next(ext2_refcount_t refcount, int *ret);
>
> /* ehandler.c */
> extern const char *ehandler_operation(const char *op);
> diff --git a/e2fsck/ea_refcount.c b/e2fsck/ea_refcount.c
> index e66e636..bcce6a0 100644
> --- a/e2fsck/ea_refcount.c
> +++ b/e2fsck/ea_refcount.c
> @@ -25,14 +25,14 @@
> * checked, its bit is set in the block_ea_map bitmap.
> */
> struct ea_refcount_el {
> - blk_t ea_blk;
> + blk64_t ea_blk;
> int ea_count;
> };
>
> struct ea_refcount {
> - blk_t count;
> - blk_t size;
> - blk_t cursor;
> + blk64_t count;
> + blk64_t size;
> + blk64_t cursor;

I am not sure if we really need count, size and cursor to be blk_t
let alone blk64_t. It's a bit misleading because AFAICT those
variable does not represent block numbers at all. Maybe it should be
changed to something less confusing, preferably matching the actual
xattr implementation ?

Thanks!
-Lukas

> struct ea_refcount_el *list;
> };
>
> @@ -111,11 +111,11 @@ static void refcount_collapse(ext2_refcount_t refcount)
> * specified position.
> */
> static struct ea_refcount_el *insert_refcount_el(ext2_refcount_t refcount,
> - blk_t blk, int pos)
> + blk64_t blk, int pos)
> {
> struct ea_refcount_el *el;
> errcode_t retval;
> - blk_t new_size = 0;
> + blk64_t new_size = 0;
> int num;
>
> if (refcount->count >= refcount->size) {
> @@ -153,7 +153,7 @@ static struct ea_refcount_el *insert_refcount_el(ext2_refcount_t refcount,
> * and we can't find an entry, create one in the sorted list.
> */
> static struct ea_refcount_el *get_refcount_el(ext2_refcount_t refcount,
> - blk_t blk, int create)
> + blk64_t blk, int create)
> {
> int low, high, mid;
>
> @@ -206,7 +206,7 @@ retry:
> return 0;
> }
>
> -errcode_t ea_refcount_fetch(ext2_refcount_t refcount, blk_t blk,
> +errcode_t ea_refcount_fetch(ext2_refcount_t refcount, blk64_t blk,
> int *ret)
> {
> struct ea_refcount_el *el;
> @@ -220,7 +220,7 @@ errcode_t ea_refcount_fetch(ext2_refcount_t refcount, blk_t blk,
> return 0;
> }
>
> -errcode_t ea_refcount_increment(ext2_refcount_t refcount, blk_t blk, int *ret)
> +errcode_t ea_refcount_increment(ext2_refcount_t refcount, blk64_t blk, int *ret)
> {
> struct ea_refcount_el *el;
>
> @@ -234,7 +234,7 @@ errcode_t ea_refcount_increment(ext2_refcount_t refcount, blk_t blk, int *ret)
> return 0;
> }
>
> -errcode_t ea_refcount_decrement(ext2_refcount_t refcount, blk_t blk, int *ret)
> +errcode_t ea_refcount_decrement(ext2_refcount_t refcount, blk64_t blk, int *ret)
> {
> struct ea_refcount_el *el;
>
> @@ -249,7 +249,7 @@ errcode_t ea_refcount_decrement(ext2_refcount_t refcount, blk_t blk, int *ret)
> return 0;
> }
>
> -errcode_t ea_refcount_store(ext2_refcount_t refcount, blk_t blk, int count)
> +errcode_t ea_refcount_store(ext2_refcount_t refcount, blk64_t blk, int count)
> {
> struct ea_refcount_el *el;
>
> @@ -263,7 +263,7 @@ errcode_t ea_refcount_store(ext2_refcount_t refcount, blk_t blk, int count)
> return 0;
> }
>
> -blk_t ext2fs_get_refcount_size(ext2_refcount_t refcount)
> +blk64_t ext2fs_get_refcount_size(ext2_refcount_t refcount)
> {
> if (!refcount)
> return 0;
> @@ -277,7 +277,7 @@ void ea_refcount_intr_begin(ext2_refcount_t refcount)
> }
>
>
> -blk_t ea_refcount_intr_next(ext2_refcount_t refcount,
> +blk64_t ea_refcount_intr_next(ext2_refcount_t refcount,
> int *ret)
> {
> struct ea_refcount_el *list;
> @@ -370,7 +370,7 @@ int main(int argc, char **argv)
> int i = 0;
> ext2_refcount_t refcount;
> int size, arg;
> - blk_t blk;
> + blk64_t blk;
> errcode_t retval;
>
> while (1) {
> @@ -394,7 +394,7 @@ int main(int argc, char **argv)
> printf("Freeing refcount\n");
> break;
> case BCODE_STORE:
> - blk = (blk_t) bcode_program[i++];
> + blk = (blk64_t) bcode_program[i++];
> arg = bcode_program[i++];
> printf("Storing blk %u with value %d\n", blk, arg);
> retval = ea_refcount_store(refcount, blk, arg);
> @@ -403,7 +403,7 @@ int main(int argc, char **argv)
> "while storing blk %u", blk);
> break;
> case BCODE_FETCH:
> - blk = (blk_t) bcode_program[i++];
> + blk = (blk64_t) bcode_program[i++];
> retval = ea_refcount_fetch(refcount, blk, &arg);
> if (retval)
> com_err("ea_refcount_fetch", retval,
> @@ -413,7 +413,7 @@ int main(int argc, char **argv)
> blk, arg);
> break;
> case BCODE_INCR:
> - blk = (blk_t) bcode_program[i++];
> + blk = (blk64_t) bcode_program[i++];
> retval = ea_refcount_increment(refcount, blk, &arg);
> if (retval)
> com_err("ea_refcount_increment", retval,
> @@ -423,7 +423,7 @@ int main(int argc, char **argv)
> blk, arg);
> break;
> case BCODE_DECR:
> - blk = (blk_t) bcode_program[i++];
> + blk = (blk64_t) bcode_program[i++];
> retval = ea_refcount_decrement(refcount, blk, &arg);
> if (retval)
> com_err("ea_refcount_decrement", retval,
>
> --
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