[PATCH 287/437] cachefiles: convert to read/write iterators

Jens Axboe
2024-04-11T15:39:37Z

fs/cachefiles/daemon.c | 35 ++++++++++++++++-------------------
fs/cachefiles/internal.h | 4 ++--
fs/cachefiles/ondemand.c | 5 +++--
3 files changed, 21 insertions(+), 23 deletions(-)

diff --git a/fs/cachefiles/daemon.c b/fs/cachefiles/daemon.c
index 6465e2574230..4a6a31a76d35 100644
--- a/fs/cachefiles/daemon.c
+++ b/fs/cachefiles/daemon.c
@@ -23,10 +23,8 @@

static int cachefiles_daemon_open(struct inode *, struct file *);
static int cachefiles_daemon_release(struct inode *, struct file *);
-static ssize_t cachefiles_daemon_read(struct file *, char __user *, size_t,
- loff_t *);
-static ssize_t cachefiles_daemon_write(struct file *, const char __user *,
- size_t, loff_t *);
+static ssize_t cachefiles_daemon_read(struct kiocb *, struct iov_iter *);
+static ssize_t cachefiles_daemon_write(struct kiocb *, struct iov_iter *);
static __poll_t cachefiles_daemon_poll(struct file *,
struct poll_table_struct *);
static int cachefiles_daemon_frun(struct cachefiles_cache *, char *);
@@ -50,8 +48,8 @@ const struct file_operations cachefiles_daemon_fops = {
.owner = THIS_MODULE,
.open = cachefiles_daemon_open,
.release = cachefiles_daemon_release,
- .read = cachefiles_daemon_read,
- .write = cachefiles_daemon_write,
+ .read_iter = cachefiles_daemon_read,
+ .write_iter = cachefiles_daemon_write,
.poll = cachefiles_daemon_poll,
.llseek = noop_llseek,
};
@@ -207,8 +205,9 @@ static int cachefiles_daemon_release(struct inode *inode, struct file *file)
}

static ssize_t cachefiles_do_daemon_read(struct cachefiles_cache *cache,
- char __user *_buffer, size_t buflen)
+ struct iov_iter *to)
{
+ size_t buflen = iov_iter_count(to);
unsigned long long b_released;
unsigned f_released;
char buffer[256];
@@ -245,7 +244,7 @@ static ssize_t cachefiles_do_daemon_read(struct cachefiles_cache *cache,
if (n > buflen)
return -EMSGSIZE;

- if (copy_to_user(_buffer, buffer, n) != 0)
+ if (!copy_to_iter_full(buffer, n, to) != 0)
return -EFAULT;

return n;
@@ -254,10 +253,9 @@ static ssize_t cachefiles_do_daemon_read(struct cachefiles_cache *cache,
/*
* Read the cache state.
*/
-static ssize_t cachefiles_daemon_read(struct file *file, char __user *_buffer,
- size_t buflen, loff_t *pos)
+static ssize_t cachefiles_daemon_read(struct kiocb *iocb, struct iov_iter *to)
{
- struct cachefiles_cache *cache = file->private_data;
+ struct cachefiles_cache *cache = iocb->ki_filp->private_data;

//_enter(",,%zu,", buflen);

@@ -265,21 +263,20 @@ static ssize_t cachefiles_daemon_read(struct file *file, char __user *_buffer,
return 0;

if (cachefiles_in_ondemand_mode(cache))
- return cachefiles_ondemand_daemon_read(cache, _buffer, buflen);
+ return cachefiles_ondemand_daemon_read(cache, to);
else
- return cachefiles_do_daemon_read(cache, _buffer, buflen);
+ return cachefiles_do_daemon_read(cache, to);
}

/*
* Take a command from cachefilesd, parse it and act on it.
*/
-static ssize_t cachefiles_daemon_write(struct file *file,
- const char __user *_data,
- size_t datalen,
- loff_t *pos)
+static ssize_t cachefiles_daemon_write(struct kiocb *iocb,
+ struct iov_iter *from)
{
const struct cachefiles_daemon_cmd *cmd;
- struct cachefiles_cache *cache = file->private_data;
+ struct cachefiles_cache *cache = iocb->ki_filp->private_data;
+ size_t datalen = iov_iter_count(from);
ssize_t ret;
char *data, *args, *cp;

@@ -294,7 +291,7 @@ static ssize_t cachefiles_daemon_write(struct file *file,
return -EOPNOTSUPP;

/* drag the command string into the kernel so we can parse it */
- data = memdup_user_nul(_data, datalen);
+ data = iterdup_nul(from, datalen);
if (IS_ERR(data))
return PTR_ERR(data);

diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h
index d33169f0018b..2b5565d38cb3 100644
--- a/fs/cachefiles/internal.h
+++ b/fs/cachefiles/internal.h
@@ -298,7 +298,7 @@ extern bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache,
*/
#ifdef CONFIG_CACHEFILES_ONDEMAND
extern ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,
- char __user *_buffer, size_t buflen);
+ struct iov_iter *to);

extern int cachefiles_ondemand_copen(struct cachefiles_cache *cache,
char *args);
@@ -341,7 +341,7 @@ static inline bool cachefiles_ondemand_is_reopening_read(struct cachefiles_req *

#else
static inline ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,
- char __user *_buffer, size_t buflen)
+ struct iov_iter *to)
{
return -EOPNOTSUPP;
}
diff --git a/fs/cachefiles/ondemand.c b/fs/cachefiles/ondemand.c
index 4ba42f1fa3b4..e27144ff2050 100644
--- a/fs/cachefiles/ondemand.c
+++ b/fs/cachefiles/ondemand.c
@@ -295,8 +295,9 @@ static struct cachefiles_req *cachefiles_ondemand_select_req(struct xa_state *xa
}

ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,
- char __user *_buffer, size_t buflen)
+ struct iov_iter *to)
{
+ size_t buflen = iov_iter_count(to);
struct cachefiles_req *req;
struct cachefiles_msg *msg;
unsigned long id = 0;
@@ -345,7 +346,7 @@ ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,
msg->msg_id = id;
msg->object_id = req->object->ondemand->ondemand_id;

- if (copy_to_user(_buffer, msg, n) != 0) {
+ if (!copy_to_iter_full(msg, n, to) != 0) {
ret = -EFAULT;
goto err_put_fd;
}
--
2.43.0