From d8218c9442655f8bdebb912483d425dded654bfd Mon Sep 17 00:00:00 2001 From: Fan Deng Date: Wed, 18 Oct 2017 10:54:54 -0700 Subject: [PATCH] Use int64_t as offset to ext4_fseek. This change makes it possible to fseek backwards in fseek. Tested: make test_all --- include/ext4.h | 2 +- src/ext4.c | 10 ++++++---- 2 files changed, 7 insertions(+), 5 deletions(-) diff --git a/include/ext4.h b/include/ext4.h index 3694410..516bbdd 100644 --- a/include/ext4.h +++ b/include/ext4.h @@ -368,7 +368,7 @@ int ext4_fwrite(ext4_file *file, const void *buf, size_t size, size_t *wcnt); * @ref SEEK_END * * @return Standard error code.*/ -int ext4_fseek(ext4_file *file, uint64_t offset, uint32_t origin); +int ext4_fseek(ext4_file *file, int64_t offset, uint32_t origin); /**@brief Get file position. * diff --git a/src/ext4.c b/src/ext4.c index b27ae6b..a6d3e23 100644 --- a/src/ext4.c +++ b/src/ext4.c @@ -2016,23 +2016,25 @@ Finish: return r; } -int ext4_fseek(ext4_file *file, uint64_t offset, uint32_t origin) +int ext4_fseek(ext4_file *file, int64_t offset, uint32_t origin) { switch (origin) { case SEEK_SET: - if (offset > file->fsize) + if (offset < 0 || (uint64_t)offset > file->fsize) return EINVAL; file->fpos = offset; return EOK; case SEEK_CUR: - if ((offset + file->fpos) > file->fsize) + if ((offset < 0 && (uint64_t)(-offset) > file->fpos) || + (offset > 0 && + (uint64_t)offset > (file->fsize - file->fpos))) return EINVAL; file->fpos += offset; return EOK; case SEEK_END: - if (offset > file->fsize) + if (offset < 0 || (uint64_t)offset > file->fsize) return EINVAL; file->fpos = file->fsize - offset; -- 2.30.2