From d475c6346a38aef3058eba96867bfa726a3cc940 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Mon, 16 Feb 2015 15:58:56 -0800 Subject: 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 Reviewed-by: Ross Zwisler Reviewed-by: Jan Kara Cc: Andreas Dilger Cc: Boaz Harrosh Cc: Christoph Hellwig Cc: Dave Chinner Cc: Jens Axboe Cc: Kirill A. Shutemov Cc: Mathieu Desnoyers Cc: Randy Dunlap Cc: Theodore Ts'o Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/filemap_xip.c | 234 ------------------------------------------------------- 1 file changed, 234 deletions(-) (limited to 'mm/filemap_xip.c') diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c index 59e1c5585748..9c869f402c07 100644 --- a/mm/filemap_xip.c +++ b/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 -- cgit v1.2.3