vfs: vfs: Define new syscalls preadv2,pwritev2

New syscalls that take an flag argument.   No flags are added yet in this
patch.

Signed-off-by: Milosz Tanski <milosz@adfin.com>
[hch: rebased on top of my kiocb changes]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Stephen Bates <stephen.bates@pmcs.com>
Tested-by: Stephen Bates <stephen.bates@pmcs.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 126 insertions, 35 deletions

diff --git a/fs/read_write.c b/fs/read_write.c
index 7d453c3e1cb6..e9c9e2a667ce 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -895,15 +895,15 @@ ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
 
 EXPORT_SYMBOL(vfs_writev);
 
-SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,
-                unsigned long, vlen)
+static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec,
+                        unsigned long vlen, int flags)
 {
         struct fd f = fdget_pos(fd);
         ssize_t ret = -EBADF;
 
         if (f.file) {
                 loff_t pos = file_pos_read(f.file);
-                ret = vfs_readv(f.file, vec, vlen, &pos, 0);
+                ret = vfs_readv(f.file, vec, vlen, &pos, flags);
                 if (ret >= 0)
                         file_pos_write(f.file, pos);
                 fdput_pos(f);
@@ -915,15 +915,15 @@ SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,
         return ret;
 }
 
-SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec,
-                unsigned long, vlen)
+static ssize_t do_writev(unsigned long fd, const struct iovec __user *vec,
+                         unsigned long vlen, int flags)
 {
         struct fd f = fdget_pos(fd);
         ssize_t ret = -EBADF;
 
         if (f.file) {
                 loff_t pos = file_pos_read(f.file);
-                ret = vfs_writev(f.file, vec, vlen, &pos, 0);
+                ret = vfs_writev(f.file, vec, vlen, &pos, flags);
                 if (ret >= 0)
                         file_pos_write(f.file, pos);
                 fdput_pos(f);
@@ -941,10 +941,9 @@ static inline loff_t pos_from_hilo(unsigned long high, unsigned long low)
         return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low;
 }
 
-SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
-                unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
+static ssize_t do_preadv(unsigned long fd, const struct iovec __user *vec,
+                         unsigned long vlen, loff_t pos, int flags)
 {
-        loff_t pos = pos_from_hilo(pos_h, pos_l);
         struct fd f;
         ssize_t ret = -EBADF;
 
@@ -955,7 +954,7 @@ SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
         if (f.file) {
                 ret = -ESPIPE;
                 if (f.file->f_mode & FMODE_PREAD)
-                        ret = vfs_readv(f.file, vec, vlen, &pos, 0);
+                        ret = vfs_readv(f.file, vec, vlen, &pos, flags);
                 fdput(f);
         }
 
@@ -965,10 +964,9 @@ SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
         return ret;
 }
 
-SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec,
-                unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
+static ssize_t do_pwritev(unsigned long fd, const struct iovec __user *vec,
+                          unsigned long vlen, loff_t pos, int flags)
 {
-        loff_t pos = pos_from_hilo(pos_h, pos_l);
         struct fd f;
         ssize_t ret = -EBADF;
 
@@ -979,7 +977,7 @@ SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec,
         if (f.file) {
                 ret = -ESPIPE;
                 if (f.file->f_mode & FMODE_PWRITE)
-                        ret = vfs_writev(f.file, vec, vlen, &pos, 0);
+                        ret = vfs_writev(f.file, vec, vlen, &pos, flags);
                 fdput(f);
         }
 
@@ -989,6 +987,58 @@ SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec,
         return ret;
 }
 
+SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,
+                unsigned long, vlen)
+{
+        return do_readv(fd, vec, vlen, 0);
+}
+
+SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec,
+                unsigned long, vlen)
+{
+        return do_writev(fd, vec, vlen, 0);
+}
+
+SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
+                unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
+{
+        loff_t pos = pos_from_hilo(pos_h, pos_l);
+
+        return do_preadv(fd, vec, vlen, pos, 0);
+}
+
+SYSCALL_DEFINE6(preadv2, unsigned long, fd, const struct iovec __user *, vec,
+                unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h,
+                int, flags)
+{
+        loff_t pos = pos_from_hilo(pos_h, pos_l);
+
+        if (pos == -1)
+                return do_readv(fd, vec, vlen, flags);
+
+        return do_preadv(fd, vec, vlen, pos, flags);
+}
+
+SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec,
+                unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
+{
+        loff_t pos = pos_from_hilo(pos_h, pos_l);
+
+        return do_pwritev(fd, vec, vlen, pos, 0);
+}
+
+SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec,
+                unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h,
+                int, flags)
+{
+        loff_t pos = pos_from_hilo(pos_h, pos_l);
+
+        if (pos == -1)
+                return do_writev(fd, vec, vlen, flags);
+
+        return do_pwritev(fd, vec, vlen, pos, flags);
+}
+
 #ifdef CONFIG_COMPAT
 
 static ssize_t compat_do_readv_writev(int type, struct file *file,
@@ -1046,7 +1096,7 @@ out:
 
 static size_t compat_readv(struct file *file,
                            const struct compat_iovec __user *vec,
-                           unsigned long vlen, loff_t *pos)
+                           unsigned long vlen, loff_t *pos, int flags)
 {
         ssize_t ret = -EBADF;
 
@@ -1057,7 +1107,7 @@ static size_t compat_readv(struct file *file,
         if (!(file->f_mode & FMODE_CAN_READ))
                 goto out;
 
-        ret = compat_do_readv_writev(READ, file, vec, vlen, pos, 0);
+        ret = compat_do_readv_writev(READ, file, vec, vlen, pos, flags);
 
 out:
         if (ret > 0)
@@ -1066,9 +1116,9 @@ out:
         return ret;
 }
 
-COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
-                const struct compat_iovec __user *,vec,
-                compat_ulong_t, vlen)
+static size_t do_compat_readv(compat_ulong_t fd,
+                                 const struct compat_iovec __user *vec,
+                                 compat_ulong_t vlen, int flags)
 {
         struct fd f = fdget_pos(fd);
         ssize_t ret;
@@ -1077,16 +1127,24 @@ COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
         if (!f.file)
                 return -EBADF;
         pos = f.file->f_pos;
-        ret = compat_readv(f.file, vec, vlen, &pos);
+        ret = compat_readv(f.file, vec, vlen, &pos, flags);
         if (ret >= 0)
                 f.file->f_pos = pos;
         fdput_pos(f);
         return ret;
+
 }
 
-static long __compat_sys_preadv64(unsigned long fd,
+COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
+                const struct compat_iovec __user *,vec,
+                compat_ulong_t, vlen)
+{
+        return do_compat_readv(fd, vec, vlen, 0);
+}
+
+static long do_compat_preadv64(unsigned long fd,
                                   const struct compat_iovec __user *vec,
-                                  unsigned long vlen, loff_t pos)
+                                  unsigned long vlen, loff_t pos, int flags)
 {
         struct fd f;
         ssize_t ret;
@@ -1098,7 +1156,7 @@ static long __compat_sys_preadv64(unsigned long fd,
                 return -EBADF;
         ret = -ESPIPE;
         if (f.file->f_mode & FMODE_PREAD)
-                ret = compat_readv(f.file, vec, vlen, &pos);
+                ret = compat_readv(f.file, vec, vlen, &pos, flags);
         fdput(f);
         return ret;
 }
@@ -1108,7 +1166,7 @@ COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
                 const struct compat_iovec __user *,vec,
                 unsigned long, vlen, loff_t, pos)
 {
-        return __compat_sys_preadv64(fd, vec, vlen, pos);
+        return do_compat_preadv64(fd, vec, vlen, pos, 0);
 }
 #endif
 
@@ -1118,12 +1176,25 @@ COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd,
 {
         loff_t pos = ((loff_t)pos_high << 32) | pos_low;
 
-        return __compat_sys_preadv64(fd, vec, vlen, pos);
+        return do_compat_preadv64(fd, vec, vlen, pos, 0);
+}
+
+COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd,
+                const struct compat_iovec __user *,vec,
+                compat_ulong_t, vlen, u32, pos_low, u32, pos_high,
+                int, flags)
+{
+        loff_t pos = ((loff_t)pos_high << 32) | pos_low;
+
+        if (pos == -1)
+                return do_compat_readv(fd, vec, vlen, flags);
+
+        return do_compat_preadv64(fd, vec, vlen, pos, flags);
 }
 
 static size_t compat_writev(struct file *file,
                             const struct compat_iovec __user *vec,
-                            unsigned long vlen, loff_t *pos)
+                            unsigned long vlen, loff_t *pos, int flags)
 {
         ssize_t ret = -EBADF;
 
@@ -1143,9 +1214,9 @@ out:
         return ret;
 }
 
-COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
-                const struct compat_iovec __user *, vec,
-                compat_ulong_t, vlen)
+static size_t do_compat_writev(compat_ulong_t fd,
+                                  const struct compat_iovec __user* vec,
+                                  compat_ulong_t vlen, int flags)
 {
         struct fd f = fdget_pos(fd);
         ssize_t ret;
@@ -1154,16 +1225,23 @@ COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
         if (!f.file)
                 return -EBADF;
         pos = f.file->f_pos;
-        ret = compat_writev(f.file, vec, vlen, &pos);
+        ret = compat_writev(f.file, vec, vlen, &pos, flags);
         if (ret >= 0)
                 f.file->f_pos = pos;
         fdput_pos(f);
         return ret;
 }
 
-static long __compat_sys_pwritev64(unsigned long fd,
+COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
+                const struct compat_iovec __user *, vec,
+                compat_ulong_t, vlen)
+{
+        return do_compat_writev(fd, vec, vlen, 0);
+}
+
+static long do_compat_pwritev64(unsigned long fd,
                                    const struct compat_iovec __user *vec,
-                                   unsigned long vlen, loff_t pos)
+                                   unsigned long vlen, loff_t pos, int flags)
 {
         struct fd f;
         ssize_t ret;
@@ -1175,7 +1253,7 @@ static long __compat_sys_pwritev64(unsigned long fd,
                 return -EBADF;
         ret = -ESPIPE;
         if (f.file->f_mode & FMODE_PWRITE)
-                ret = compat_writev(f.file, vec, vlen, &pos);
+                ret = compat_writev(f.file, vec, vlen, &pos, flags);
         fdput(f);
         return ret;
 }
@@ -1185,7 +1263,7 @@ COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
                 const struct compat_iovec __user *,vec,
                 unsigned long, vlen, loff_t, pos)
 {
-        return __compat_sys_pwritev64(fd, vec, vlen, pos);
+        return do_compat_pwritev64(fd, vec, vlen, pos, 0);
 }
 #endif
 
@@ -1195,8 +1273,21 @@ COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
 {
         loff_t pos = ((loff_t)pos_high << 32) | pos_low;
 
-        return __compat_sys_pwritev64(fd, vec, vlen, pos);
+        return do_compat_pwritev64(fd, vec, vlen, pos, 0);
+}
+
+COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd,
+                const struct compat_iovec __user *,vec,
+                compat_ulong_t, vlen, u32, pos_low, u32, pos_high, int, flags)
+{
+        loff_t pos = ((loff_t)pos_high << 32) | pos_low;
+
+        if (pos == -1)
+                return do_compat_writev(fd, vec, vlen, flags);
+
+        return do_compat_pwritev64(fd, vec, vlen, pos, flags);
 }
+
 #endif
 
 static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,