[PATCH v7 1/5] vfs: Prepare for adding a new preadv/pwritev with user flags.

Milosz Tanski
2015-03-16T18:27:29Z

Plumbing the flags argument through the vfs code so they can be passed down to
__generic_file_(read/write)_iter function that do the acctual work.

Signed-off-by: Milosz Tanski <milosz@adfin.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
---
drivers/target/target_core_file.c | 6 +++---
fs/nfsd/vfs.c | 4 ++--
fs/read_write.c | 27 +++++++++++++++------------
fs/splice.c | 2 +-
include/linux/aio.h | 2 ++
include/linux/fs.h | 4 ++--
6 files changed, 25 insertions(+), 20 deletions(-)

diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index 44620fb..fdd0a10 100644
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -351,9 +351,9 @@ static int fd_do_rw(struct se_cmd *cmd, struct scatterlist *sgl,
set_fs(get_ds());

if (is_write)
- ret = vfs_writev(fd, &iov[0], sgl_nents, &pos);
+ ret = vfs_writev(fd, &iov[0], sgl_nents, &pos, 0);
else
- ret = vfs_readv(fd, &iov[0], sgl_nents, &pos);
+ ret = vfs_readv(fd, &iov[0], sgl_nents, &pos, 0);

set_fs(old_fs);

@@ -534,7 +534,7 @@ fd_execute_write_same(struct se_cmd *cmd)

old_fs = get_fs();
set_fs(get_ds());
- rc = vfs_writev(f, &iov[0], iov_num, &pos);
+ rc = vfs_writev(f, &iov[0], iov_num, &pos, 0);
set_fs(old_fs);

vfree(iov);
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 3685265..1c6faaa 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -893,7 +893,7 @@ __be32 nfsd_readv(struct file *file, loff_t offset, struct kvec *vec, int vlen,

oldfs = get_fs();
set_fs(KERNEL_DS);
- host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset);
+ host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset, 0);
set_fs(oldfs);
return nfsd_finish_read(file, count, host_err);
}
@@ -980,7 +980,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,

/* Write the data. */
oldfs = get_fs(); set_fs(KERNEL_DS);
- host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &pos);
+ host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &pos, 0);
set_fs(oldfs);
if (host_err < 0)
goto out_nfserr;
diff --git a/fs/read_write.c b/fs/read_write.c
index 8e1b687..b53bb59 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -711,7 +711,8 @@ unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to)
EXPORT_SYMBOL(iov_shorten);

static ssize_t do_iter_readv_writev(struct file *filp, int rw, const struct iovec *iov,
- unsigned long nr_segs, size_t len, loff_t *ppos, iter_fn_t fn)
+ unsigned long nr_segs, size_t len, loff_t *ppos, iter_fn_t fn,
+ int flags)
{
struct kiocb kiocb;
struct iov_iter iter;
@@ -720,6 +721,7 @@ static ssize_t do_iter_readv_writev(struct file *filp, int rw, const struct iove
init_sync_kiocb(&kiocb, filp);
kiocb.ki_pos = *ppos;
kiocb.ki_nbytes = len;
+ kiocb.ki_rwflags = flags;

iov_iter_init(&iter, rw, iov, nr_segs, len);
ret = fn(&kiocb, &iter);
@@ -858,7 +860,8 @@ out:

static ssize_t do_readv_writev(int type, struct file *file,
const struct iovec __user * uvector,
- unsigned long nr_segs, loff_t *pos)
+ unsigned long nr_segs, loff_t *pos,
+ int flags)
{
size_t tot_len;
struct iovec iovstack[UIO_FASTIOV];
@@ -892,7 +895,7 @@ static ssize_t do_readv_writev(int type, struct file *file,

if (iter_fn)
ret = do_iter_readv_writev(file, type, iov, nr_segs, tot_len,
- pos, iter_fn);
+ pos, iter_fn, flags);
else if (fnv)
ret = do_sync_readv_writev(file, iov, nr_segs, tot_len,
pos, fnv);
@@ -915,27 +918,27 @@ out:
}

ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
- unsigned long vlen, loff_t *pos)
+ unsigned long vlen, loff_t *pos, int flags)
{
if (!(file->f_mode & FMODE_READ))
return -EBADF;
if (!(file->f_mode & FMODE_CAN_READ))
return -EINVAL;

- return do_readv_writev(READ, file, vec, vlen, pos);
+ return do_readv_writev(READ, file, vec, vlen, pos, flags);
}

EXPORT_SYMBOL(vfs_readv);

ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
- unsigned long vlen, loff_t *pos)
+ unsigned long vlen, loff_t *pos, int flags)
{
if (!(file->f_mode & FMODE_WRITE))
return -EBADF;
if (!(file->f_mode & FMODE_CAN_WRITE))
return -EINVAL;

- return do_readv_writev(WRITE, file, vec, vlen, pos);
+ return do_readv_writev(WRITE, file, vec, vlen, pos, flags);
}

EXPORT_SYMBOL(vfs_writev);
@@ -948,7 +951,7 @@ SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,

if (f.file) {
loff_t pos = file_pos_read(f.file);
- ret = vfs_readv(f.file, vec, vlen, &pos);
+ ret = vfs_readv(f.file, vec, vlen, &pos, 0);
if (ret >= 0)
file_pos_write(f.file, pos);
fdput_pos(f);
@@ -968,7 +971,7 @@ SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec,

if (f.file) {
loff_t pos = file_pos_read(f.file);
- ret = vfs_writev(f.file, vec, vlen, &pos);
+ ret = vfs_writev(f.file, vec, vlen, &pos, 0);
if (ret >= 0)
file_pos_write(f.file, pos);
fdput_pos(f);
@@ -1000,7 +1003,7 @@ 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);
+ ret = vfs_readv(f.file, vec, vlen, &pos, 0);
fdput(f);
}

@@ -1024,7 +1027,7 @@ 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);
+ ret = vfs_writev(f.file, vec, vlen, &pos, 0);
fdput(f);
}

@@ -1072,7 +1075,7 @@ static ssize_t compat_do_readv_writev(int type, struct file *file,

if (iter_fn)
ret = do_iter_readv_writev(file, type, iov, nr_segs, tot_len,
- pos, iter_fn);
+ pos, iter_fn, 0);
else if (fnv)
ret = do_sync_readv_writev(file, iov, nr_segs, tot_len,
pos, fnv);
diff --git a/fs/splice.c b/fs/splice.c
index 7968da9..ee3fd4c 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -576,7 +576,7 @@ static ssize_t kernel_readv(struct file *file, const struct iovec *vec,
old_fs = get_fs();
set_fs(get_ds());
/* The cast to a user pointer is valid due to the set_fs() */
- res = vfs_readv(file, (const struct iovec __user *)vec, vlen, &pos);
+ res = vfs_readv(file, (const struct iovec __user *)vec, vlen, &pos, 0);
set_fs(old_fs);

return res;
diff --git a/include/linux/aio.h b/include/linux/aio.h
index d9c92da..9c1d499 100644
--- a/include/linux/aio.h
+++ b/include/linux/aio.h
@@ -52,6 +52,8 @@ struct kiocb {
* this is the underlying eventfd context to deliver events to.
*/
struct eventfd_ctx *ki_eventfd;
+
+ int ki_rwflags;
};

static inline bool is_sync_kiocb(struct kiocb *kiocb)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index b4d71b5..c018335 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1619,9 +1619,9 @@ extern ssize_t __vfs_read(struct file *, char __user *, size_t, loff_t *);
extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
extern ssize_t vfs_readv(struct file *, const struct iovec __user *,
- unsigned long, loff_t *);
+ unsigned long, loff_t *, int);
extern ssize_t vfs_writev(struct file *, const struct iovec __user *,
- unsigned long, loff_t *);
+ unsigned long, loff_t *, int);

struct super_operations {
struct inode *(*alloc_inode)(struct super_block *sb);
--
1.9.1