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From: Jens Axboe <axboe@kernel.dk>
To: linux-kernel@vger.kernel.org
Cc: Jens Axboe <axboe@kernel.dk>
Subject: [PATCH 353/437] arch/s390: convert to read/write iterators
Date: Thu, 11 Apr 2024 09:18:13 -0600
Message-ID: <20240411153126.16201-354-axboe@kernel.dk>
In-Reply-To: <20240411153126.16201-1-axboe@kernel.dk>
References: <20240411153126.16201-1-axboe@kernel.dk>
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Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 arch/s390/crypto/prng.c      | 18 ++++++++----------
 arch/s390/hypfs/hypfs_dbfs.c | 11 +++++------
 arch/s390/kernel/debug.c     | 29 +++++++++++++----------------
 arch/s390/kernel/sysinfo.c   |  6 +++---
 arch/s390/pci/pci_debug.c    | 12 ++++++------
 5 files changed, 35 insertions(+), 41 deletions(-)

diff --git a/arch/s390/crypto/prng.c b/arch/s390/crypto/prng.c
index a077087bc6cc..472ff3fe73a9 100644
--- a/arch/s390/crypto/prng.c
+++ b/arch/s390/crypto/prng.c
@@ -509,9 +509,9 @@ static int prng_open(struct inode *inode, struct file *file)
 }
 
 
-static ssize_t prng_tdes_read(struct file *file, char __user *ubuf,
-			      size_t nbytes, loff_t *ppos)
+static ssize_t prng_tdes_read(struct kiocb *iocb, struct iov_iter *to)
 {
+	size_t nbytes = iov_iter_count(to);
 	int chunk, n, ret = 0;
 
 	/* lock prng_data struct */
@@ -570,14 +570,13 @@ static ssize_t prng_tdes_read(struct file *file, char __user *ubuf,
 		prng_data->prngws.byte_counter += n;
 		prng_data->prngws.reseed_counter += n;
 
-		if (copy_to_user(ubuf, prng_data->buf, chunk)) {
+		if (!copy_to_iter_full(prng_data->buf, chunk, to)) {
 			ret = -EFAULT;
 			break;
 		}
 
 		nbytes -= chunk;
 		ret += chunk;
-		ubuf += chunk;
 	}
 
 	/* unlock prng_data struct */
@@ -587,9 +586,9 @@ static ssize_t prng_tdes_read(struct file *file, char __user *ubuf,
 }
 
 
-static ssize_t prng_sha512_read(struct file *file, char __user *ubuf,
-				size_t nbytes, loff_t *ppos)
+static ssize_t prng_sha512_read(struct kiocb *iocb, struct iov_iter *to)
 {
+	size_t nbytes = iov_iter_count(to);
 	int n, ret = 0;
 	u8 *p;
 
@@ -640,12 +639,11 @@ static ssize_t prng_sha512_read(struct file *file, char __user *ubuf,
 				prng_data->rest = 0;
 			}
 		}
-		if (copy_to_user(ubuf, p, n)) {
+		if (!copy_to_iter_full(p, n, to)) {
 			ret = -EFAULT;
 			break;
 		}
 		memzero_explicit(p, n);
-		ubuf += n;
 		nbytes -= n;
 		ret += n;
 	}
@@ -663,14 +661,14 @@ static const struct file_operations prng_sha512_fops = {
 	.owner		= THIS_MODULE,
 	.open		= &prng_open,
 	.release	= NULL,
-	.read		= &prng_sha512_read,
+	.read_iter	= &prng_sha512_read,
 	.llseek		= noop_llseek,
 };
 static const struct file_operations prng_tdes_fops = {
 	.owner		= THIS_MODULE,
 	.open		= &prng_open,
 	.release	= NULL,
-	.read		= &prng_tdes_read,
+	.read_iter	= &prng_tdes_read,
 	.llseek		= noop_llseek,
 };
 
diff --git a/arch/s390/hypfs/hypfs_dbfs.c b/arch/s390/hypfs/hypfs_dbfs.c
index 4024599eb448..964247caf5fb 100644
--- a/arch/s390/hypfs/hypfs_dbfs.c
+++ b/arch/s390/hypfs/hypfs_dbfs.c
@@ -28,17 +28,16 @@ static void hypfs_dbfs_data_free(struct hypfs_dbfs_data *data)
 	kfree(data);
 }
 
-static ssize_t dbfs_read(struct file *file, char __user *buf,
-			 size_t size, loff_t *ppos)
+static ssize_t dbfs_read(struct kiocb *iocb, struct iov_iter *to)
 {
 	struct hypfs_dbfs_data *data;
 	struct hypfs_dbfs_file *df;
 	ssize_t rc;
 
-	if (*ppos != 0)
+	if (iocb->ki_pos != 0)
 		return 0;
 
-	df = file_inode(file)->i_private;
+	df = file_inode(iocb->ki_filp)->i_private;
 	mutex_lock(&df->lock);
 	data = hypfs_dbfs_data_alloc(df);
 	if (!data) {
@@ -53,7 +52,7 @@ static ssize_t dbfs_read(struct file *file, char __user *buf,
 	}
 	mutex_unlock(&df->lock);
 
-	rc = simple_read_from_buffer(buf, size, ppos, data->buf, data->size);
+	rc = simple_copy_to_iter(data->buf, &iocb->ki_pos, data->size, to);
 	hypfs_dbfs_data_free(data);
 	return rc;
 }
@@ -73,7 +72,7 @@ static long dbfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 }
 
 static const struct file_operations dbfs_ops = {
-	.read		= dbfs_read,
+	.read_iter	= dbfs_read,
 	.llseek		= no_llseek,
 	.unlocked_ioctl = dbfs_ioctl,
 };
diff --git a/arch/s390/kernel/debug.c b/arch/s390/kernel/debug.c
index 85328a0ef3b6..2ba1ee0a0f1d 100644
--- a/arch/s390/kernel/debug.c
+++ b/arch/s390/kernel/debug.c
@@ -66,10 +66,8 @@ typedef struct {
 /* internal function prototyes */
 
 static int debug_init(void);
-static ssize_t debug_output(struct file *file, char __user *user_buf,
-			    size_t user_len, loff_t *offset);
-static ssize_t debug_input(struct file *file, const char __user *user_buf,
-			   size_t user_len, loff_t *offset);
+static ssize_t debug_output(struct kiocb *iocb, struct iov_iter *to);
+static ssize_t debug_input_iter(struct kiocb *iocb, struct iov_iter *from);
 static int debug_open(struct inode *inode, struct file *file);
 static int debug_close(struct inode *inode, struct file *file);
 static debug_info_t *debug_info_create(const char *name, int pages_per_area,
@@ -159,8 +157,8 @@ static int debug_critical;
 
 static const struct file_operations debug_file_ops = {
 	.owner	 = THIS_MODULE,
-	.read	 = debug_output,
-	.write	 = debug_input,
+	.read_iter	 = debug_output,
+	.write_iter	 = debug_input_iter,
 	.open	 = debug_open,
 	.release = debug_close,
 	.llseek  = no_llseek,
@@ -452,17 +450,15 @@ static inline int debug_next_entry(file_private_info_t *p_info)
  * - called for user read()
  * - copies formated debug entries to the user buffer
  */
-static ssize_t debug_output(struct file *file,		/* file descriptor */
-			    char __user *user_buf,	/* user buffer */
-			    size_t len,			/* length of buffer */
-			    loff_t *offset)		/* offset in the file */
+static ssize_t debug_output(struct kiocb *iocb, struct iov_iter *to)
 {
 	size_t count = 0;
 	size_t entry_offset;
 	file_private_info_t *p_info;
+	size_t len = iov_iter_count(to);
 
-	p_info = (file_private_info_t *) file->private_data;
-	if (*offset != p_info->offset)
+	p_info = (file_private_info_t *) iocb->ki_filp->private_data;
+	if (iocb->ki_pos != p_info->offset)
 		return -EPIPE;
 	if (p_info->act_area >= p_info->debug_info_snap->nr_areas)
 		return 0;
@@ -478,8 +474,8 @@ static ssize_t debug_output(struct file *file,		/* file descriptor */
 		user_buf_residue = len-count;
 		copy_size = min(user_buf_residue, formatted_line_residue);
 		if (copy_size) {
-			if (copy_to_user(user_buf + count, p_info->temp_buf
-					 + entry_offset, copy_size))
+			if (!copy_to_iter_full(p_info->temp_buf
+					 + entry_offset, copy_size, to))
 				return -EFAULT;
 			count += copy_size;
 			entry_offset += copy_size;
@@ -491,9 +487,9 @@ static ssize_t debug_output(struct file *file,		/* file descriptor */
 		}
 	}
 out:
-	p_info->offset		 = *offset + count;
+	p_info->offset		 = iocb->ki_pos + count;
 	p_info->act_entry_offset = entry_offset;
-	*offset = p_info->offset;
+	iocb->ki_pos = p_info->offset;
 	return count;
 }
 
@@ -520,6 +516,7 @@ static ssize_t debug_input(struct file *file, const char __user *user_buf,
 	mutex_unlock(&debug_mutex);
 	return rc; /* number of input characters */
 }
+FOPS_WRITE_ITER_HELPER(debug_input);
 
 /*
  * debug_open:
diff --git a/arch/s390/kernel/sysinfo.c b/arch/s390/kernel/sysinfo.c
index 2be30a96696a..84cca91e86ff 100644
--- a/arch/s390/kernel/sysinfo.c
+++ b/arch/s390/kernel/sysinfo.c
@@ -497,7 +497,7 @@ static int stsi_open_##fc##_##s1##_##s2(struct inode *inode, struct file *file)\
 static const struct file_operations stsi_##fc##_##s1##_##s2##_fs_ops = {       \
 	.open		= stsi_open_##fc##_##s1##_##s2,			       \
 	.release	= stsi_release,					       \
-	.read		= stsi_read,					       \
+	.read_iter	= stsi_read,					       \
 	.llseek		= no_llseek,					       \
 };
 
@@ -507,9 +507,9 @@ static int stsi_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
-static ssize_t stsi_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
+static ssize_t stsi_read(struct kiocb *iocb, struct iov_iter *to)
 {
-	return simple_read_from_buffer(buf, size, ppos, file->private_data, PAGE_SIZE);
+	return simple_copy_to_iter(iocb->ki_filp->private_data, &iocb->ki_pos, PAGE_SIZE, to);
 }
 
 STSI_FILE( 1, 1, 1);
diff --git a/arch/s390/pci/pci_debug.c b/arch/s390/pci/pci_debug.c
index 2cb5043a997d..9c4b1eb26103 100644
--- a/arch/s390/pci/pci_debug.c
+++ b/arch/s390/pci/pci_debug.c
@@ -134,17 +134,17 @@ static int pci_perf_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static ssize_t pci_perf_seq_write(struct file *file, const char __user *ubuf,
-				  size_t count, loff_t *off)
+static ssize_t pci_perf_seq_write(struct kiocb *iocb, struct iov_iter *from)
 {
-	struct zpci_dev *zdev = ((struct seq_file *) file->private_data)->private;
+	struct zpci_dev *zdev = ((struct seq_file *) iocb->ki_filp->private_data)->private;
+	size_t count = iov_iter_count(from);
 	unsigned long val;
 	int rc;
 
 	if (!zdev)
 		return 0;
 
-	rc = kstrtoul_from_user(ubuf, count, 10, &val);
+	rc = kstrtoul_from_iter(from, count, 10, &val);
 	if (rc)
 		return rc;
 
@@ -169,8 +169,8 @@ static int pci_perf_seq_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations debugfs_pci_perf_fops = {
 	.open	 = pci_perf_seq_open,
-	.read	 = seq_read,
-	.write	 = pci_perf_seq_write,
+	.read_iter = seq_read_iter,
+	.write_iter = pci_perf_seq_write,
 	.llseek  = seq_lseek,
 	.release = single_release,
 };
-- 
2.43.0