configfs updates for Linux 5.13
- fix a memleak in configfs_release_bin_file (Chung-Chiang Cheng) - implement the .read_iter and .write_iter (Bart Van Assche) - minor cleanups (Bart Van Assche, me) -----BEGIN PGP SIGNATURE----- iQI/BAABCgApFiEEgdbnc3r/njty3Iq9D55TZVIEUYMFAmDfOe8LHGhjaEBsc3Qu ZGUACgkQD55TZVIEUYNbuA//dTCwt9U8+XIDeWatRJY2BFSTorNhaeayYiGDDnVo 7NVN/vw5qtt7UHo7hFBi918gh9IGSIbgyYZIZAV4/qCqnveNMnD/Zuwd8j0FHzu4 OvmjORj52cpzXiyJ87vJ+fGVjqe9/Vtrzr4IFyhJZQnz+c1L0NOgReAiLJtE+1C/ 8RvecwCvIxZVjw8SRjOZNCd/DFBx6nPbwsh0ZLkAiL6TQkV5erOUmFyoOAiXRQwB H+6fcrjGteoXXciGmvRtfIaJEO5o2yE4pXEsoYv2aDBF5dtpq/wti8CV7bWSIXiV HI90UrVDO+bK94DKC0JmYFEAxi7HmX073OWu0xBgXjpUnc1kepJ+9DJ74Y43QwwF C0eHKu4b/nP/50c/7UxqUSmS23c9YiJawkYZjxbnxklN9QhRs8v61htOO6i9CFnu KjePcLs07sn6AEa16taCV/+iwfgyul047jegrZZSTNioBPgpdMX+j2fzt2FTWioJ zfVLsiBqvKDKXEkulsTMMFmO4Un2kcX7cTX7v9DclGvpCuEoOpPUDERS5H8+DkqV q+O2HPohFdFItcWge58eCvZ0OJ43Px07Mpn6WH48VLCDLTg7H7Z/85yEO6Wg+a6V JlgwdoAlHo5BHfS2w7PtkblbaJH9MQRc6dvSuv/sE1x8AouWze7wkfVb0ZH0X1GF Xjo= =dquw -----END PGP SIGNATURE----- Merge tag 'configfs-5.13' of git://git.infradead.org/users/hch/configfs Pull configfs updates from Christoph Hellwig: - fix a memleak in configfs_release_bin_file (Chung-Chiang Cheng) - implement the .read_iter and .write_iter (Bart Van Assche) - minor cleanups (Bart Van Assche, me) * tag 'configfs-5.13' of git://git.infradead.org/users/hch/configfs: configfs: simplify configfs_release_bin_file configfs: fix memleak in configfs_release_bin_file configfs: implement the .read_iter and .write_iter methods configfs: drop pointless kerneldoc comments configfs: fix the kerneldoc comment for configfs_create_bin_file
This commit is contained in:
Linus Torvalds
commit
ced4cca754
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@ -14,7 +14,7 @@
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#include <linux/mutex.h>
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#include <linux/vmalloc.h>
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#include <linux/uaccess.h>
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#include <linux/uio.h>
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#include <linux/configfs.h>
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#include "configfs_internal.h"
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@ -77,28 +77,9 @@ static int fill_read_buffer(struct file *file, struct configfs_buffer *buffer)
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return 0;
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}
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/**
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* configfs_read_file - read an attribute.
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* @file: file pointer.
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* @buf: buffer to fill.
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* @count: number of bytes to read.
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* @ppos: starting offset in file.
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*
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* Userspace wants to read an attribute file. The attribute descriptor
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* is in the file's ->d_fsdata. The target item is in the directory's
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* ->d_fsdata.
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*
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* We call fill_read_buffer() to allocate and fill the buffer from the
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* item's show() method exactly once (if the read is happening from
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* the beginning of the file). That should fill the entire buffer with
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* all the data the item has to offer for that attribute.
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* We then call flush_read_buffer() to copy the buffer to userspace
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* in the increments specified.
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*/
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static ssize_t
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configfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos)
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static ssize_t configfs_read_iter(struct kiocb *iocb, struct iov_iter *to)
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{
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struct file *file = iocb->ki_filp;
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struct configfs_buffer *buffer = file->private_data;
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ssize_t retval = 0;
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@ -108,43 +89,24 @@ configfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *pp
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if (retval)
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goto out;
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}
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pr_debug("%s: count = %zd, ppos = %lld, buf = %s\n",
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__func__, count, *ppos, buffer->page);
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retval = simple_read_from_buffer(buf, count, ppos, buffer->page,
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buffer->count);
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pr_debug("%s: count = %zd, pos = %lld, buf = %s\n",
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__func__, iov_iter_count(to), iocb->ki_pos, buffer->page);
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retval = copy_to_iter(buffer->page, buffer->count, to);
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iocb->ki_pos += retval;
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if (retval == 0)
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retval = -EFAULT;
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out:
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mutex_unlock(&buffer->mutex);
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return retval;
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}
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/**
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* configfs_read_bin_file - read a binary attribute.
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* @file: file pointer.
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* @buf: buffer to fill.
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* @count: number of bytes to read.
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* @ppos: starting offset in file.
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*
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* Userspace wants to read a binary attribute file. The attribute
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* descriptor is in the file's ->d_fsdata. The target item is in the
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* directory's ->d_fsdata.
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*
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* We check whether we need to refill the buffer. If so we will
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* call the attributes' attr->read() twice. The first time we
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* will pass a NULL as a buffer pointer, which the attributes' method
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* will use to return the size of the buffer required. If no error
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* occurs we will allocate the buffer using vmalloc and call
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* attr->read() again passing that buffer as an argument.
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* Then we just copy to user-space using simple_read_from_buffer.
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*/
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static ssize_t
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configfs_read_bin_file(struct file *file, char __user *buf,
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size_t count, loff_t *ppos)
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static ssize_t configfs_bin_read_iter(struct kiocb *iocb, struct iov_iter *to)
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{
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struct file *file = iocb->ki_filp;
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struct configfs_fragment *frag = to_frag(file);
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struct configfs_buffer *buffer = file->private_data;
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ssize_t retval = 0;
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ssize_t len = min_t(size_t, count, PAGE_SIZE);
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ssize_t len;
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mutex_lock(&buffer->mutex);
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@ -200,42 +162,31 @@ configfs_read_bin_file(struct file *file, char __user *buf,
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buffer->needs_read_fill = 0;
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}
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retval = simple_read_from_buffer(buf, count, ppos, buffer->bin_buffer,
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buffer->bin_buffer_size);
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retval = copy_to_iter(buffer->bin_buffer, buffer->bin_buffer_size, to);
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iocb->ki_pos += retval;
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if (retval == 0)
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retval = -EFAULT;
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out:
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mutex_unlock(&buffer->mutex);
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return retval;
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}
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/**
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* fill_write_buffer - copy buffer from userspace.
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* @buffer: data buffer for file.
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* @buf: data from user.
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* @count: number of bytes in @userbuf.
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*
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* Allocate @buffer->page if it hasn't been already, then
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* copy the user-supplied buffer into it.
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*/
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static int
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fill_write_buffer(struct configfs_buffer * buffer, const char __user * buf, size_t count)
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static int fill_write_buffer(struct configfs_buffer *buffer,
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struct iov_iter *from)
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{
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int error;
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int copied;
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if (!buffer->page)
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buffer->page = (char *)__get_free_pages(GFP_KERNEL, 0);
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if (!buffer->page)
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return -ENOMEM;
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if (count >= SIMPLE_ATTR_SIZE)
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count = SIMPLE_ATTR_SIZE - 1;
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error = copy_from_user(buffer->page,buf,count);
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copied = copy_from_iter(buffer->page, SIMPLE_ATTR_SIZE - 1, from);
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buffer->needs_read_fill = 1;
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/* if buf is assumed to contain a string, terminate it by \0,
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* so e.g. sscanf() can scan the string easily */
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buffer->page[count] = 0;
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return error ? -EFAULT : count;
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buffer->page[copied] = 0;
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return copied ? : -EFAULT;
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}
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static int
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@ -252,58 +203,36 @@ flush_write_buffer(struct file *file, struct configfs_buffer *buffer, size_t cou
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}
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/**
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* configfs_write_file - write an attribute.
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* @file: file pointer
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* @buf: data to write
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* @count: number of bytes
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* @ppos: starting offset
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*
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* Similar to configfs_read_file(), though working in the opposite direction.
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* We allocate and fill the data from the user in fill_write_buffer(),
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* then push it to the config_item in flush_write_buffer().
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* There is no easy way for us to know if userspace is only doing a partial
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* write, so we don't support them. We expect the entire buffer to come
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* on the first write.
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* Hint: if you're writing a value, first read the file, modify only
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* the value you're changing, then write entire buffer back.
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/*
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* There is no easy way for us to know if userspace is only doing a partial
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* write, so we don't support them. We expect the entire buffer to come on the
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* first write.
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* Hint: if you're writing a value, first read the file, modify only the value
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* you're changing, then write entire buffer back.
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*/
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static ssize_t
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configfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
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static ssize_t configfs_write_iter(struct kiocb *iocb, struct iov_iter *from)
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{
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struct file *file = iocb->ki_filp;
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struct configfs_buffer *buffer = file->private_data;
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ssize_t len;
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mutex_lock(&buffer->mutex);
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len = fill_write_buffer(buffer, buf, count);
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len = fill_write_buffer(buffer, from);
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if (len > 0)
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len = flush_write_buffer(file, buffer, len);
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if (len > 0)
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*ppos += len;
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iocb->ki_pos += len;
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mutex_unlock(&buffer->mutex);
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return len;
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}
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/**
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* configfs_write_bin_file - write a binary attribute.
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* @file: file pointer
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* @buf: data to write
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* @count: number of bytes
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* @ppos: starting offset
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*
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* Writing to a binary attribute file is similar to a normal read.
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* We buffer the consecutive writes (binary attribute files do not
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* support lseek) in a continuously growing buffer, but we don't
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* commit until the close of the file.
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*/
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static ssize_t
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configfs_write_bin_file(struct file *file, const char __user *buf,
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size_t count, loff_t *ppos)
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static ssize_t configfs_bin_write_iter(struct kiocb *iocb,
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struct iov_iter *from)
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{
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struct file *file = iocb->ki_filp;
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struct configfs_buffer *buffer = file->private_data;
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void *tbuf = NULL;
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size_t end_offset;
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ssize_t len;
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mutex_lock(&buffer->mutex);
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@ -316,15 +245,14 @@ configfs_write_bin_file(struct file *file, const char __user *buf,
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buffer->write_in_progress = true;
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/* buffer grows? */
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if (*ppos + count > buffer->bin_buffer_size) {
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if (buffer->cb_max_size &&
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*ppos + count > buffer->cb_max_size) {
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end_offset = iocb->ki_pos + iov_iter_count(from);
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if (end_offset > buffer->bin_buffer_size) {
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if (buffer->cb_max_size && end_offset > buffer->cb_max_size) {
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len = -EFBIG;
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goto out;
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}
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tbuf = vmalloc(*ppos + count);
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tbuf = vmalloc(end_offset);
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if (tbuf == NULL) {
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len = -ENOMEM;
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goto out;
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@ -339,16 +267,15 @@ configfs_write_bin_file(struct file *file, const char __user *buf,
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/* clear the new area */
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memset(tbuf + buffer->bin_buffer_size, 0,
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*ppos + count - buffer->bin_buffer_size);
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end_offset - buffer->bin_buffer_size);
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buffer->bin_buffer = tbuf;
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buffer->bin_buffer_size = *ppos + count;
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buffer->bin_buffer_size = end_offset;
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}
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len = simple_write_to_buffer(buffer->bin_buffer,
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buffer->bin_buffer_size, ppos, buf, count);
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len = copy_from_iter(buffer->bin_buffer, buffer->bin_buffer_size, from);
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out:
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mutex_unlock(&buffer->mutex);
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return len;
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return len ? : -EFAULT;
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}
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static int __configfs_open_file(struct inode *inode, struct file *file, int type)
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@ -466,11 +393,8 @@ static int configfs_release_bin_file(struct inode *inode, struct file *file)
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{
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struct configfs_buffer *buffer = file->private_data;
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buffer->read_in_progress = false;
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if (buffer->write_in_progress) {
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struct configfs_fragment *frag = to_frag(file);
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buffer->write_in_progress = false;
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down_read(&frag->frag_sem);
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if (!frag->frag_dead) {
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@ -480,29 +404,26 @@ static int configfs_release_bin_file(struct inode *inode, struct file *file)
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buffer->bin_buffer_size);
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}
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up_read(&frag->frag_sem);
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/* vfree on NULL is safe */
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vfree(buffer->bin_buffer);
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buffer->bin_buffer = NULL;
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buffer->bin_buffer_size = 0;
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buffer->needs_read_fill = 1;
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}
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vfree(buffer->bin_buffer);
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configfs_release(inode, file);
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return 0;
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}
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const struct file_operations configfs_file_operations = {
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.read = configfs_read_file,
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.write = configfs_write_file,
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.read_iter = configfs_read_iter,
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.write_iter = configfs_write_iter,
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.llseek = generic_file_llseek,
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.open = configfs_open_file,
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.release = configfs_release,
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};
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const struct file_operations configfs_bin_file_operations = {
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.read = configfs_read_bin_file,
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.write = configfs_write_bin_file,
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.read_iter = configfs_bin_read_iter,
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.write_iter = configfs_bin_write_iter,
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.llseek = NULL, /* bin file is not seekable */
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.open = configfs_open_bin_file,
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.release = configfs_release_bin_file,
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@ -532,7 +453,7 @@ int configfs_create_file(struct config_item * item, const struct configfs_attrib
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/**
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* configfs_create_bin_file - create a binary attribute file for an item.
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* @item: item we're creating for.
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* @attr: atrribute descriptor.
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* @bin_attr: atrribute descriptor.
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*/
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int configfs_create_bin_file(struct config_item *item,
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