H A D | ioctl.c | fdde368e Thu Feb 11 22:57:21 CST 2016 Anton Protopopov <a.s.protopopov@gmail.com> ext4: ioctl: fix erroneous return value
The ext4_ioctl_setflags() function which is used in the ioctls EXT4_IOC_SETFLAGS and EXT4_IOC_FSSETXATTR may return the positive value EPERM instead of -EPERM in case of error. This bug was introduced by a recent commit 9b7365fc.
The following program can be used to illustrate the wrong behavior:
#include <sys/types.h> #include <sys/ioctl.h> #include <sys/stat.h> #include <fcntl.h> #include <err.h>
#define FS_IOC_GETFLAGS _IOR('f', 1, long) #define FS_IOC_SETFLAGS _IOW('f', 2, long) #define FS_IMMUTABLE_FL 0x00000010
int main(void) { int fd; long flags;
fd = open("file", O_RDWR|O_CREAT, 0600); if (fd < 0) err(1, "open");
if (ioctl(fd, FS_IOC_GETFLAGS, &flags) < 0) err(1, "ioctl: FS_IOC_GETFLAGS");
flags |= FS_IMMUTABLE_FL;
if (ioctl(fd, FS_IOC_SETFLAGS, &flags) < 0) err(1, "ioctl: FS_IOC_SETFLAGS");
warnx("ioctl returned no error");
return 0; }
Running it gives the following result:
$ strace -e ioctl ./test ioctl(3, FS_IOC_GETFLAGS, 0x7ffdbd8bfd38) = 0 ioctl(3, FS_IOC_SETFLAGS, 0x7ffdbd8bfd38) = 1 test: ioctl returned no error +++ exited with 0 +++
Running the program on a kernel with the bug fixed gives the proper result:
$ strace -e ioctl ./test ioctl(3, FS_IOC_GETFLAGS, 0x7ffdd2768258) = 0 ioctl(3, FS_IOC_SETFLAGS, 0x7ffdd2768258) = -1 EPERM (Operation not permitted) test: ioctl: FS_IOC_SETFLAGS: Operation not permitted +++ exited with 1 +++
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> 9b7365fc Fri Jan 08 15:01:22 CST 2016 Li Xi <pkuelelixi@gmail.com> ext4: add FS_IOC_FSSETXATTR/FS_IOC_FSGETXATTR interface support
This patch adds FS_IOC_FSSETXATTR/FS_IOC_FSGETXATTR ioctl interface support for ext4. The interface is kept consistent with XFS_IOC_FSGETXATTR/XFS_IOC_FSGETXATTR.
Signed-off-by: Li Xi <lixi@ddn.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Reviewed-by: Jan Kara <jack@suse.cz> fdde368e Thu Feb 11 22:57:21 CST 2016 Anton Protopopov <a.s.protopopov@gmail.com> ext4: ioctl: fix erroneous return value The ext4_ioctl_setflags() function which is used in the ioctls EXT4_IOC_SETFLAGS and EXT4_IOC_FSSETXATTR may return the positive value EPERM instead of -EPERM in case of error. This bug was introduced by a recent commit 9b7365fc. The following program can be used to illustrate the wrong behavior: #include <sys/types.h> #include <sys/ioctl.h> #include <sys/stat.h> #include <fcntl.h> #include <err.h> #define FS_IOC_GETFLAGS _IOR('f', 1, long) #define FS_IOC_SETFLAGS _IOW('f', 2, long) #define FS_IMMUTABLE_FL 0x00000010 int main(void) { int fd; long flags; fd = open("file", O_RDWR|O_CREAT, 0600); if (fd < 0) err(1, "open"); if (ioctl(fd, FS_IOC_GETFLAGS, &flags) < 0) err(1, "ioctl: FS_IOC_GETFLAGS"); flags |= FS_IMMUTABLE_FL; if (ioctl(fd, FS_IOC_SETFLAGS, &flags) < 0) err(1, "ioctl: FS_IOC_SETFLAGS"); warnx("ioctl returned no error"); return 0; } Running it gives the following result: $ strace -e ioctl ./test ioctl(3, FS_IOC_GETFLAGS, 0x7ffdbd8bfd38) = 0 ioctl(3, FS_IOC_SETFLAGS, 0x7ffdbd8bfd38) = 1 test: ioctl returned no error +++ exited with 0 +++ Running the program on a kernel with the bug fixed gives the proper result: $ strace -e ioctl ./test ioctl(3, FS_IOC_GETFLAGS, 0x7ffdd2768258) = 0 ioctl(3, FS_IOC_SETFLAGS, 0x7ffdd2768258) = -1 EPERM (Operation not permitted) test: ioctl: FS_IOC_SETFLAGS: Operation not permitted +++ exited with 1 +++ Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> 9b7365fc Fri Jan 08 15:01:22 CST 2016 Li Xi <pkuelelixi@gmail.com> ext4: add FS_IOC_FSSETXATTR/FS_IOC_FSGETXATTR interface support This patch adds FS_IOC_FSSETXATTR/FS_IOC_FSGETXATTR ioctl interface support for ext4. The interface is kept consistent with XFS_IOC_FSGETXATTR/XFS_IOC_FSGETXATTR. Signed-off-by: Li Xi <lixi@ddn.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Reviewed-by: Jan Kara <jack@suse.cz>
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