| Message ID | 20171111172155.31941-1-zlang@redhat.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On 11/11/17 11:21 AM, Zorro Lang wrote: > The 'Coverity Scan' found a problem in new write_once() function: > > 272 size_t bytes; > 273 bytes = do_pwrite(file->fd, offset, count, count, pwritev2_flags); >>>> CID 1420710: Control flow issues (NO_EFFECT) >>>> This less-than-zero comparison of an unsigned value is never true. "bytes < 0UL". > 274 if (bytes < 0) > 275 return -1; > > That's unreasonable. do_pwrite return 'ssize_t' type value, which can > be less than zero, but we use a 'size_t' to get the return value. So > change the size_t to ssize_t for it can store the return value > correctly. > > By the chance, correct all 'ssize_t' type problems in pwrite/pread > related functions. > > Signed-off-by: Zorro Lang <zlang@redhat.com> I may rewrite the changelog a bit because this now touches much more than write_once, but the content seems fine: Reviewed-by: Eric Sandeen <sandeen@redhat.com> > --- > > Actrually, this's V3. V3 did more changes in io/pread.c, fix 'ssize_t' > problem in io/pread.c (V2 only did in io/pwrite.c). > > Thanks, > Zorro > > io/pread.c | 12 ++++++------ > io/pwrite.c | 14 +++++++------- > 2 files changed, 13 insertions(+), 13 deletions(-) > > diff --git a/io/pread.c b/io/pread.c > index 7591276d..60650aa3 100644 > --- a/io/pread.c > +++ b/io/pread.c > @@ -172,12 +172,12 @@ dump_buffer( > } > > #ifdef HAVE_PREADV > -static int > +static ssize_t > do_preadv( > int fd, > off64_t offset, > - ssize_t count, > - ssize_t buffer_size) > + size_t count, > + size_t buffer_size) > { > int vecs = 0; > ssize_t oldlen = 0; > @@ -208,12 +208,12 @@ do_preadv( > #define do_preadv(fd, offset, count, buffer_size) (0) > #endif > > -static int > +static ssize_t > do_pread( > int fd, > off64_t offset, > - ssize_t count, > - ssize_t buffer_size) > + size_t count, > + size_t buffer_size) > { > if (!vectors) > return pread(fd, buffer, min(count, buffer_size), offset); > diff --git a/io/pwrite.c b/io/pwrite.c > index 26f79579..3df976a8 100644 > --- a/io/pwrite.c > +++ b/io/pwrite.c > @@ -61,12 +61,12 @@ pwrite_help(void) > } > > #ifdef HAVE_PWRITEV > -static int > +static ssize_t > do_pwritev( > int fd, > off64_t offset, > - ssize_t count, > - ssize_t buffer_size, > + size_t count, > + size_t buffer_size, > int pwritev2_flags) > { > int vecs = 0; > @@ -105,12 +105,12 @@ do_pwritev( > #define do_pwritev(fd, offset, count, buffer_size) (0) > #endif > > -static int > +static ssize_t > do_pwrite( > int fd, > off64_t offset, > - ssize_t count, > - ssize_t buffer_size, > + size_t count, > + size_t buffer_size, > int pwritev2_flags) > { > if (!vectors) > @@ -269,7 +269,7 @@ write_once( > long long *total, > int pwritev2_flags) > { > - size_t bytes; > + ssize_t bytes; > bytes = do_pwrite(file->fd, offset, count, count, pwritev2_flags); > if (bytes < 0) > return -1; > -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/io/pread.c b/io/pread.c index 7591276d..60650aa3 100644 --- a/io/pread.c +++ b/io/pread.c @@ -172,12 +172,12 @@ dump_buffer( } #ifdef HAVE_PREADV -static int +static ssize_t do_preadv( int fd, off64_t offset, - ssize_t count, - ssize_t buffer_size) + size_t count, + size_t buffer_size) { int vecs = 0; ssize_t oldlen = 0; @@ -208,12 +208,12 @@ do_preadv( #define do_preadv(fd, offset, count, buffer_size) (0) #endif -static int +static ssize_t do_pread( int fd, off64_t offset, - ssize_t count, - ssize_t buffer_size) + size_t count, + size_t buffer_size) { if (!vectors) return pread(fd, buffer, min(count, buffer_size), offset); diff --git a/io/pwrite.c b/io/pwrite.c index 26f79579..3df976a8 100644 --- a/io/pwrite.c +++ b/io/pwrite.c @@ -61,12 +61,12 @@ pwrite_help(void) } #ifdef HAVE_PWRITEV -static int +static ssize_t do_pwritev( int fd, off64_t offset, - ssize_t count, - ssize_t buffer_size, + size_t count, + size_t buffer_size, int pwritev2_flags) { int vecs = 0; @@ -105,12 +105,12 @@ do_pwritev( #define do_pwritev(fd, offset, count, buffer_size) (0) #endif -static int +static ssize_t do_pwrite( int fd, off64_t offset, - ssize_t count, - ssize_t buffer_size, + size_t count, + size_t buffer_size, int pwritev2_flags) { if (!vectors) @@ -269,7 +269,7 @@ write_once( long long *total, int pwritev2_flags) { - size_t bytes; + ssize_t bytes; bytes = do_pwrite(file->fd, offset, count, count, pwritev2_flags); if (bytes < 0) return -1;