[PATCH 1/9] vfs: extract common parts of {compat_,}do_readv_writev()

Miklos Szeredi
2017-02-17T16:12:48Z

fs/read_write.c | 80 +++++++++++++++++++++------------------------------------
1 file changed, 29 insertions(+), 51 deletions(-)

diff --git a/fs/read_write.c b/fs/read_write.c
index 5816d4c4cab0..b7cf7e2cb8c5 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -834,25 +834,15 @@ ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
return ret;
}

-static ssize_t do_readv_writev(int type, struct file *file,
- const struct iovec __user * uvector,
- unsigned long nr_segs, loff_t *pos,
- int flags)
+static ssize_t __do_readv_writev(int type, struct file *file,
+ struct iov_iter *iter, loff_t *pos, int flags)
{
size_t tot_len;
- struct iovec iovstack[UIO_FASTIOV];
- struct iovec *iov = iovstack;
- struct iov_iter iter;
- ssize_t ret;
+ ssize_t ret = 0;
io_fn_t fn;
iter_fn_t iter_fn;

- ret = import_iovec(type, uvector, nr_segs,
- ARRAY_SIZE(iovstack), &iov, &iter);
- if (ret < 0)
- return ret;
-
- tot_len = iov_iter_count(&iter);
+ tot_len = iov_iter_count(iter);
if (!tot_len)
goto out;
ret = rw_verify_area(type, file, pos, tot_len);
@@ -869,15 +859,14 @@ static ssize_t do_readv_writev(int type, struct file *file,
}

if (iter_fn)
- ret = do_iter_readv_writev(file, &iter, pos, iter_fn, flags);
+ ret = do_iter_readv_writev(file, iter, pos, iter_fn, flags);
else
- ret = do_loop_readv_writev(file, &iter, pos, fn, flags);
+ ret = do_loop_readv_writev(file, iter, pos, fn, flags);

if (type != READ)
file_end_write(file);

out:
- kfree(iov);
if ((ret + (type == READ)) > 0) {
if (type == READ)
fsnotify_access(file);
@@ -887,6 +876,27 @@ static ssize_t do_readv_writev(int type, struct file *file,
return ret;
}

+static ssize_t do_readv_writev(int type, struct file *file,
+ const struct iovec __user *uvector,
+ unsigned long nr_segs, loff_t *pos,
+ int flags)
+{
+ struct iovec iovstack[UIO_FASTIOV];
+ struct iovec *iov = iovstack;
+ struct iov_iter iter;
+ ssize_t ret;
+
+ ret = import_iovec(type, uvector, nr_segs,
+ ARRAY_SIZE(iovstack), &iov, &iter);
+ if (ret < 0)
+ return ret;
+
+ ret = __do_readv_writev(type, file, &iter, pos, flags);
+ kfree(iov);
+
+ return ret;
+}
+
ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
unsigned long vlen, loff_t *pos, int flags)
{
@@ -1064,51 +1074,19 @@ static ssize_t compat_do_readv_writev(int type, struct file *file,
unsigned long nr_segs, loff_t *pos,
int flags)
{
- compat_ssize_t tot_len;
struct iovec iovstack[UIO_FASTIOV];
struct iovec *iov = iovstack;
struct iov_iter iter;
ssize_t ret;
- io_fn_t fn;
- iter_fn_t iter_fn;

ret = compat_import_iovec(type, uvector, nr_segs,
UIO_FASTIOV, &iov, &iter);
if (ret < 0)
return ret;

- tot_len = iov_iter_count(&iter);
- if (!tot_len)
- goto out;
- ret = rw_verify_area(type, file, pos, tot_len);
- if (ret < 0)
- goto out;
-
- if (type == READ) {
- fn = file->f_op->read;
- iter_fn = file->f_op->read_iter;
- } else {
- fn = (io_fn_t)file->f_op->write;
- iter_fn = file->f_op->write_iter;
- file_start_write(file);
- }
-
- if (iter_fn)
- ret = do_iter_readv_writev(file, &iter, pos, iter_fn, flags);
- else
- ret = do_loop_readv_writev(file, &iter, pos, fn, flags);
-
- if (type != READ)
- file_end_write(file);
-
-out:
+ ret = __do_readv_writev(type, file, &iter, pos, flags);
kfree(iov);
- if ((ret + (type == READ)) > 0) {
- if (type == READ)
- fsnotify_access(file);
- else
- fsnotify_modify(file);
- }
+
return ret;
}

--
2.5.5