| Message ID | YG4OIhChOrVTPgdN@localhost.localdomain (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | proc: smoke test lseek() | expand |
On Wed, Apr 07, 2021 at 10:55:14PM +0300, Alexey Dobriyan wrote: > Now that ->proc_lseek has been made mandatory it would be nice to test > that nothing has been forgotten. > @@ -45,6 +45,8 @@ static void f_reg(DIR *d, const char *filename) > fd = openat(dirfd(d), filename, O_RDONLY|O_NONBLOCK); > if (fd == -1) > return; > + /* struct proc_ops::proc_lseek is mandatory if file is seekable. */ > + (void)lseek(fd, 0, SEEK_SET); > rv = read(fd, buf, sizeof(buf)); > assert((0 <= rv && rv <= sizeof(buf)) || rv == -1); > close(fd); why throw away the return value? if it returns an error seeking to offset 0, something is terribly wrong.
On Wed, Apr 07, 2021 at 08:58:09PM +0100, Matthew Wilcox wrote: > On Wed, Apr 07, 2021 at 10:55:14PM +0300, Alexey Dobriyan wrote: > > Now that ->proc_lseek has been made mandatory it would be nice to test > > that nothing has been forgotten. > > > @@ -45,6 +45,8 @@ static void f_reg(DIR *d, const char *filename) > > fd = openat(dirfd(d), filename, O_RDONLY|O_NONBLOCK); > > if (fd == -1) > > return; > > + /* struct proc_ops::proc_lseek is mandatory if file is seekable. */ > > + (void)lseek(fd, 0, SEEK_SET); > > rv = read(fd, buf, sizeof(buf)); > > assert((0 <= rv && rv <= sizeof(buf)) || rv == -1); > > close(fd); > > why throw away the return value? if it returns an error seeking to > offset 0, something is terribly wrong. Some files may use nonseekable_open(). This smoke test doesn't verify that seeking is done correctly anyway.
--- a/tools/testing/selftests/proc/read.c +++ b/tools/testing/selftests/proc/read.c @@ -14,7 +14,7 @@ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ // Test -// 1) read of every file in /proc +// 1) read and lseek on every file in /proc // 2) readlink of every symlink in /proc // 3) recursively (1) + (2) for every directory in /proc // 4) write to /proc/*/clear_refs and /proc/*/task/*/clear_refs @@ -45,6 +45,8 @@ static void f_reg(DIR *d, const char *filename) fd = openat(dirfd(d), filename, O_RDONLY|O_NONBLOCK); if (fd == -1) return; + /* struct proc_ops::proc_lseek is mandatory if file is seekable. */ + (void)lseek(fd, 0, SEEK_SET); rv = read(fd, buf, sizeof(buf)); assert((0 <= rv && rv <= sizeof(buf)) || rv == -1); close(fd);
Now that ->proc_lseek has been made mandatory it would be nice to test that nothing has been forgotten. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> --- May want to fold into proc-mandate-proc_lseek-in-struct-proc_ops.patch tools/testing/selftests/proc/read.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)