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vfs: vfs: Define new syscalls preadv2,pwritev2
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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>
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Milosz Tanski authored and Al Viro committed Mar 4, 2016
1 parent 793b80e commit f17d8b3
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Showing 3 changed files with 138 additions and 35 deletions.
161 changes: 126 additions & 35 deletions fs/read_write.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand All @@ -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);
Expand All @@ -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;

Expand All @@ -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);
}

Expand All @@ -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;

Expand All @@ -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);
}

Expand All @@ -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,
Expand Down Expand Up @@ -1046,7 +1096,7 @@ static ssize_t compat_do_readv_writev(int type, struct file *file,

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;

Expand All @@ -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)
Expand All @@ -1066,9 +1116,9 @@ static size_t compat_readv(struct file *file,
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;
Expand All @@ -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;
Expand All @@ -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;
}
Expand All @@ -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

Expand All @@ -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;

Expand All @@ -1143,9 +1214,9 @@ static size_t compat_writev(struct file *file,
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;
Expand All @@ -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;
Expand All @@ -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;
}
Expand All @@ -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

Expand All @@ -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,
Expand Down
6 changes: 6 additions & 0 deletions include/linux/compat.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -340,6 +340,12 @@ asmlinkage ssize_t compat_sys_preadv(compat_ulong_t fd,
asmlinkage ssize_t compat_sys_pwritev(compat_ulong_t fd,
const struct compat_iovec __user *vec,
compat_ulong_t vlen, u32 pos_low, u32 pos_high);
asmlinkage ssize_t compat_sys_preadv2(compat_ulong_t fd,
const struct compat_iovec __user *vec,
compat_ulong_t vlen, u32 pos_low, u32 pos_high, int flags);
asmlinkage ssize_t compat_sys_pwritev2(compat_ulong_t fd,
const struct compat_iovec __user *vec,
compat_ulong_t vlen, u32 pos_low, u32 pos_high, int flags);

#ifdef __ARCH_WANT_COMPAT_SYS_PREADV64
asmlinkage long compat_sys_preadv64(unsigned long fd,
Expand Down
6 changes: 6 additions & 0 deletions include/linux/syscalls.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -575,8 +575,14 @@ asmlinkage long sys_pwrite64(unsigned int fd, const char __user *buf,
size_t count, loff_t pos);
asmlinkage long sys_preadv(unsigned long fd, const struct iovec __user *vec,
unsigned long vlen, unsigned long pos_l, unsigned long pos_h);
asmlinkage long sys_preadv2(unsigned long fd, const struct iovec __user *vec,
unsigned long vlen, unsigned long pos_l, unsigned long pos_h,
int flags);
asmlinkage long sys_pwritev(unsigned long fd, const struct iovec __user *vec,
unsigned long vlen, unsigned long pos_l, unsigned long pos_h);
asmlinkage long sys_pwritev2(unsigned long fd, const struct iovec __user *vec,
unsigned long vlen, unsigned long pos_l, unsigned long pos_h,
int flags);
asmlinkage long sys_getcwd(char __user *buf, unsigned long size);
asmlinkage long sys_mkdir(const char __user *pathname, umode_t mode);
asmlinkage long sys_chdir(const char __user *filename);
Expand Down

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