Am Mittwoch, den 23.09.2020, 20:27 +0200 schrieb Mauro Condarelli:
Thanks for the review, I'll prepare a v2 ASAP.
On 9/23/20 12:05 AM, Daniel Schwierzeck wrote:
Am Sonntag, den 20.09.2020, 21:21 -0400 schrieb Tom Rini:
On Sun, Sep 20, 2020 at 06:29:01PM +0200, Mauro Condarelli wrote:
Signed-off-by: Mauro Condarelli mc5686@mclink.it
fs/squashfs/sqfs.c | 45 +++++++++++++++++++++++++-------------- fs/squashfs/sqfs_inode.c | 8 +++---- include/configs/vocore2.h | 2 +-
remove that file which is unrelated to this patch
I will as this is fixing things just for my target and that is clearly wrong. OTOH I feel some provision should be implemented (probably at Config.in level) to ensure SquashFS has enough malloc space for its needs. What are the best practices to handle this?
3 files changed, 34 insertions(+), 21 deletions(-)
diff --git a/fs/squashfs/sqfs.c b/fs/squashfs/sqfs.c index 15208b4dab..b49331ce93 100644 --- a/fs/squashfs/sqfs.c +++ b/fs/squashfs/sqfs.c @@ -18,6 +18,8 @@ #include <string.h> #include <squashfs.h> #include <part.h> +#include <div64.h> +#include <stdio.h>
#include "sqfs_decompressor.h" #include "sqfs_filesystem.h" @@ -82,13 +84,16 @@ static int sqfs_count_tokens(const char *filename) */ static int sqfs_calc_n_blks(__le64 start, __le64 end, u64 *offset) {
- u64 start_, table_size;
u64 start_, table_size, blks;
table_size = le64_to_cpu(end) - le64_to_cpu(start);
- start_ = le64_to_cpu(start) / ctxt.cur_dev->blksz;
- start_ = le64_to_cpu(start);
- do_div(start_, ctxt.cur_dev->blksz);
have you tried with lldiv() which returns the 64bit result? Also it would be a little cleaner:
start_ = lldiv(le64_to_cpu(start), ctxt.cur_dev->blksz);I thought of that (actually my first attempt was quite similar, but I noticed that lldiv() actually uses do_div() internally and so I decided to go directly for the lower level (and presumably faster) solution. If You (or the maintainers) feel otherwise I can revert with no problems.
because do_div() replaces the dividend with the division remainder and lldiv() returns the division result without modifying the dividend.
Anyway I had a look at the Linux code and other U-Boot file systems and there is a better solution. "struct blk_desc" has a member "int log2blksz" which is initialized as "desc->log2blksz = LOG2(desc-
blksz) in blk-uclass.c. With that you can replace all divisions with
"desc->blksz" as divisor with a simple right bit shift like so:
start_ = le64_to_cpu(start) >> ctxt.cur_dev->log2blksz;
Likewise all multiplications can be replaced with a left bit shift, e.g.:
*offset = le64_to_cpu(start) - (start_ << ctxt.cur_dev->log2blksz);
Also the Linux code never uses DIV_ROUND_UP() for any block related calculations. So maybe all DIV_ROUND_UP() calls can be replaced with a bit shift too.