mirror of
https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git
synced 2026-10-28 02:32:09 -04:00
dax,ext2: replace XIP read and write with DAX I/O
Use the generic AIO infrastructure instead of custom read and write methods. In addition to giving us support for AIO, this adds the missing locking between read() and truncate(). Signed-off-by: Matthew Wilcox <[email protected]> Reviewed-by: Ross Zwisler <[email protected]> Reviewed-by: Jan Kara <[email protected]> Cc: Andreas Dilger <[email protected]> Cc: Boaz Harrosh <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Dave Chinner <[email protected]> Cc: Jens Axboe <[email protected]> Cc: Kirill A. Shutemov <[email protected]> Cc: Mathieu Desnoyers <[email protected]> Cc: Randy Dunlap <[email protected]> Cc: Theodore Ts'o <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Matthew Wilcox
Linus Torvalds
parent
fbbbad4bc2
commit
d475c6346a
8 changed files with 214 additions and 245 deletions
|
|
@ -1695,8 +1695,7 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
|
|||
loff_t *ppos = &iocb->ki_pos;
|
||||
loff_t pos = *ppos;
|
||||
|
||||
/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
|
||||
if (file->f_flags & O_DIRECT) {
|
||||
if (io_is_direct(file)) {
|
||||
struct address_space *mapping = file->f_mapping;
|
||||
struct inode *inode = mapping->host;
|
||||
size_t count = iov_iter_count(iter);
|
||||
|
|
@ -2584,8 +2583,7 @@ ssize_t __generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
|
|||
if (err)
|
||||
goto out;
|
||||
|
||||
/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
|
||||
if (unlikely(file->f_flags & O_DIRECT)) {
|
||||
if (io_is_direct(file)) {
|
||||
loff_t endbyte;
|
||||
|
||||
written = generic_file_direct_write(iocb, from, pos);
|
||||
|
|
|
|||
234
mm/filemap_xip.c
234
mm/filemap_xip.c
|
|
@ -42,119 +42,6 @@ static struct page *xip_sparse_page(void)
|
|||
return __xip_sparse_page;
|
||||
}
|
||||
|
||||
/*
|
||||
* This is a file read routine for execute in place files, and uses
|
||||
* the mapping->a_ops->get_xip_mem() function for the actual low-level
|
||||
* stuff.
|
||||
*
|
||||
* Note the struct file* is not used at all. It may be NULL.
|
||||
*/
|
||||
static ssize_t
|
||||
do_xip_mapping_read(struct address_space *mapping,
|
||||
struct file_ra_state *_ra,
|
||||
struct file *filp,
|
||||
char __user *buf,
|
||||
size_t len,
|
||||
loff_t *ppos)
|
||||
{
|
||||
struct inode *inode = mapping->host;
|
||||
pgoff_t index, end_index;
|
||||
unsigned long offset;
|
||||
loff_t isize, pos;
|
||||
size_t copied = 0, error = 0;
|
||||
|
||||
BUG_ON(!mapping->a_ops->get_xip_mem);
|
||||
|
||||
pos = *ppos;
|
||||
index = pos >> PAGE_CACHE_SHIFT;
|
||||
offset = pos & ~PAGE_CACHE_MASK;
|
||||
|
||||
isize = i_size_read(inode);
|
||||
if (!isize)
|
||||
goto out;
|
||||
|
||||
end_index = (isize - 1) >> PAGE_CACHE_SHIFT;
|
||||
do {
|
||||
unsigned long nr, left;
|
||||
void *xip_mem;
|
||||
unsigned long xip_pfn;
|
||||
int zero = 0;
|
||||
|
||||
/* nr is the maximum number of bytes to copy from this page */
|
||||
nr = PAGE_CACHE_SIZE;
|
||||
if (index >= end_index) {
|
||||
if (index > end_index)
|
||||
goto out;
|
||||
nr = ((isize - 1) & ~PAGE_CACHE_MASK) + 1;
|
||||
if (nr <= offset) {
|
||||
goto out;
|
||||
}
|
||||
}
|
||||
nr = nr - offset;
|
||||
if (nr > len - copied)
|
||||
nr = len - copied;
|
||||
|
||||
error = mapping->a_ops->get_xip_mem(mapping, index, 0,
|
||||
&xip_mem, &xip_pfn);
|
||||
if (unlikely(error)) {
|
||||
if (error == -ENODATA) {
|
||||
/* sparse */
|
||||
zero = 1;
|
||||
} else
|
||||
goto out;
|
||||
}
|
||||
|
||||
/* If users can be writing to this page using arbitrary
|
||||
* virtual addresses, take care about potential aliasing
|
||||
* before reading the page on the kernel side.
|
||||
*/
|
||||
if (mapping_writably_mapped(mapping))
|
||||
/* address based flush */ ;
|
||||
|
||||
/*
|
||||
* Ok, we have the mem, so now we can copy it to user space...
|
||||
*
|
||||
* The actor routine returns how many bytes were actually used..
|
||||
* NOTE! This may not be the same as how much of a user buffer
|
||||
* we filled up (we may be padding etc), so we can only update
|
||||
* "pos" here (the actor routine has to update the user buffer
|
||||
* pointers and the remaining count).
|
||||
*/
|
||||
if (!zero)
|
||||
left = __copy_to_user(buf+copied, xip_mem+offset, nr);
|
||||
else
|
||||
left = __clear_user(buf + copied, nr);
|
||||
|
||||
if (left) {
|
||||
error = -EFAULT;
|
||||
goto out;
|
||||
}
|
||||
|
||||
copied += (nr - left);
|
||||
offset += (nr - left);
|
||||
index += offset >> PAGE_CACHE_SHIFT;
|
||||
offset &= ~PAGE_CACHE_MASK;
|
||||
} while (copied < len);
|
||||
|
||||
out:
|
||||
*ppos = pos + copied;
|
||||
if (filp)
|
||||
file_accessed(filp);
|
||||
|
||||
return (copied ? copied : error);
|
||||
}
|
||||
|
||||
ssize_t
|
||||
xip_file_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
|
||||
{
|
||||
if (!access_ok(VERIFY_WRITE, buf, len))
|
||||
return -EFAULT;
|
||||
|
||||
return do_xip_mapping_read(filp->f_mapping, &filp->f_ra, filp,
|
||||
buf, len, ppos);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(xip_file_read);
|
||||
|
||||
/*
|
||||
* __xip_unmap is invoked from xip_unmap and xip_write
|
||||
*
|
||||
|
|
@ -341,127 +228,6 @@ int xip_file_mmap(struct file * file, struct vm_area_struct * vma)
|
|||
}
|
||||
EXPORT_SYMBOL_GPL(xip_file_mmap);
|
||||
|
||||
static ssize_t
|
||||
__xip_file_write(struct file *filp, const char __user *buf,
|
||||
size_t count, loff_t pos, loff_t *ppos)
|
||||
{
|
||||
struct address_space * mapping = filp->f_mapping;
|
||||
const struct address_space_operations *a_ops = mapping->a_ops;
|
||||
struct inode *inode = mapping->host;
|
||||
long status = 0;
|
||||
size_t bytes;
|
||||
ssize_t written = 0;
|
||||
|
||||
BUG_ON(!mapping->a_ops->get_xip_mem);
|
||||
|
||||
do {
|
||||
unsigned long index;
|
||||
unsigned long offset;
|
||||
size_t copied;
|
||||
void *xip_mem;
|
||||
unsigned long xip_pfn;
|
||||
|
||||
offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
|
||||
index = pos >> PAGE_CACHE_SHIFT;
|
||||
bytes = PAGE_CACHE_SIZE - offset;
|
||||
if (bytes > count)
|
||||
bytes = count;
|
||||
|
||||
status = a_ops->get_xip_mem(mapping, index, 0,
|
||||
&xip_mem, &xip_pfn);
|
||||
if (status == -ENODATA) {
|
||||
/* we allocate a new page unmap it */
|
||||
mutex_lock(&xip_sparse_mutex);
|
||||
status = a_ops->get_xip_mem(mapping, index, 1,
|
||||
&xip_mem, &xip_pfn);
|
||||
mutex_unlock(&xip_sparse_mutex);
|
||||
if (!status)
|
||||
/* unmap page at pgoff from all other vmas */
|
||||
__xip_unmap(mapping, index);
|
||||
}
|
||||
|
||||
if (status)
|
||||
break;
|
||||
|
||||
copied = bytes -
|
||||
__copy_from_user_nocache(xip_mem + offset, buf, bytes);
|
||||
|
||||
if (likely(copied > 0)) {
|
||||
status = copied;
|
||||
|
||||
if (status >= 0) {
|
||||
written += status;
|
||||
count -= status;
|
||||
pos += status;
|
||||
buf += status;
|
||||
}
|
||||
}
|
||||
if (unlikely(copied != bytes))
|
||||
if (status >= 0)
|
||||
status = -EFAULT;
|
||||
if (status < 0)
|
||||
break;
|
||||
} while (count);
|
||||
*ppos = pos;
|
||||
/*
|
||||
* No need to use i_size_read() here, the i_size
|
||||
* cannot change under us because we hold i_mutex.
|
||||
*/
|
||||
if (pos > inode->i_size) {
|
||||
i_size_write(inode, pos);
|
||||
mark_inode_dirty(inode);
|
||||
}
|
||||
|
||||
return written ? written : status;
|
||||
}
|
||||
|
||||
ssize_t
|
||||
xip_file_write(struct file *filp, const char __user *buf, size_t len,
|
||||
loff_t *ppos)
|
||||
{
|
||||
struct address_space *mapping = filp->f_mapping;
|
||||
struct inode *inode = mapping->host;
|
||||
size_t count;
|
||||
loff_t pos;
|
||||
ssize_t ret;
|
||||
|
||||
mutex_lock(&inode->i_mutex);
|
||||
|
||||
if (!access_ok(VERIFY_READ, buf, len)) {
|
||||
ret=-EFAULT;
|
||||
goto out_up;
|
||||
}
|
||||
|
||||
pos = *ppos;
|
||||
count = len;
|
||||
|
||||
/* We can write back this queue in page reclaim */
|
||||
current->backing_dev_info = inode_to_bdi(inode);
|
||||
|
||||
ret = generic_write_checks(filp, &pos, &count, S_ISBLK(inode->i_mode));
|
||||
if (ret)
|
||||
goto out_backing;
|
||||
if (count == 0)
|
||||
goto out_backing;
|
||||
|
||||
ret = file_remove_suid(filp);
|
||||
if (ret)
|
||||
goto out_backing;
|
||||
|
||||
ret = file_update_time(filp);
|
||||
if (ret)
|
||||
goto out_backing;
|
||||
|
||||
ret = __xip_file_write (filp, buf, count, pos, ppos);
|
||||
|
||||
out_backing:
|
||||
current->backing_dev_info = NULL;
|
||||
out_up:
|
||||
mutex_unlock(&inode->i_mutex);
|
||||
return ret;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(xip_file_write);
|
||||
|
||||
/*
|
||||
* truncate a page used for execute in place
|
||||
* functionality is analog to block_truncate_page but does use get_xip_mem
|
||||
|
|
|
|||
Loading…
Reference in a new issue