diff options
| -rw-r--r-- | fs/buffer.c | 194 | ||||
| -rw-r--r-- | include/linux/buffer_head.h | 5 | ||||
| -rw-r--r-- | include/linux/fs.h | 1 | ||||
| -rw-r--r-- | mm/filemap.c | 5 |
4 files changed, 103 insertions, 102 deletions
diff --git a/fs/buffer.c b/fs/buffer.c index 68b8fbdc1b28..1f1577490417 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2156,14 +2156,14 @@ int block_read_full_page(struct page *page, get_block_t *get_block) } /* utility function for filesystems that need to do work on expanding - * truncates. Uses prepare/commit_write to allow the filesystem to + * truncates. Uses filesystem pagecache writes to allow the filesystem to * deal with the hole. */ -static int __generic_cont_expand(struct inode *inode, loff_t size, - pgoff_t index, unsigned int offset) +int generic_cont_expand_simple(struct inode *inode, loff_t size) { struct address_space *mapping = inode->i_mapping; struct page *page; + void *fsdata; unsigned long limit; int err; @@ -2176,140 +2176,134 @@ static int __generic_cont_expand(struct inode *inode, loff_t size, if (size > inode->i_sb->s_maxbytes) goto out; - err = -ENOMEM; - page = grab_cache_page(mapping, index); - if (!page) - goto out; - err = mapping->a_ops->prepare_write(NULL, page, offset, offset); - if (err) { - /* - * ->prepare_write() may have instantiated a few blocks - * outside i_size. Trim these off again. - */ - unlock_page(page); - page_cache_release(page); - vmtruncate(inode, inode->i_size); + err = pagecache_write_begin(NULL, mapping, size, 0, + AOP_FLAG_UNINTERRUPTIBLE|AOP_FLAG_CONT_EXPAND, + &page, &fsdata); + if (err) goto out; - } - err = mapping->a_ops->commit_write(NULL, page, offset, offset); + err = pagecache_write_end(NULL, mapping, size, 0, 0, page, fsdata); + BUG_ON(err > 0); - unlock_page(page); - page_cache_release(page); - if (err > 0) - err = 0; out: return err; } int generic_cont_expand(struct inode *inode, loff_t size) { - pgoff_t index; unsigned int offset; offset = (size & (PAGE_CACHE_SIZE - 1)); /* Within page */ /* ugh. in prepare/commit_write, if from==to==start of block, we - ** skip the prepare. make sure we never send an offset for the start - ** of a block - */ + * skip the prepare. make sure we never send an offset for the start + * of a block. + * XXX: actually, this should be handled in those filesystems by + * checking for the AOP_FLAG_CONT_EXPAND flag. + */ if ((offset & (inode->i_sb->s_blocksize - 1)) == 0) { /* caller must handle this extra byte. */ - offset++; + size++; } - index = size >> PAGE_CACHE_SHIFT; - - return __generic_cont_expand(inode, size, index, offset); -} - -int generic_cont_expand_simple(struct inode *inode, loff_t size) -{ - loff_t pos = size - 1; - pgoff_t index = pos >> PAGE_CACHE_SHIFT; - unsigned int offset = (pos & (PAGE_CACHE_SIZE - 1)) + 1; - - /* prepare/commit_write can handle even if from==to==start of block. */ - return __generic_cont_expand(inode, size, index, offset); + return generic_cont_expand_simple(inode, size); } -/* - * For moronic filesystems that do not allow holes in file. - * We may have to extend the file. - */ - -int cont_prepare_write(struct page *page, unsigned offset, - unsigned to, get_block_t *get_block, loff_t *bytes) +int cont_expand_zero(struct file *file, struct address_space *mapping, + loff_t pos, loff_t *bytes) { - struct address_space *mapping = page->mapping; struct inode *inode = mapping->host; - struct page *new_page; - pgoff_t pgpos; - long status; - unsigned zerofrom; unsigned blocksize = 1 << inode->i_blkbits; + struct page *page; + void *fsdata; + pgoff_t index, curidx; + loff_t curpos; + unsigned zerofrom, offset, len; + int err = 0; - while(page->index > (pgpos = *bytes>>PAGE_CACHE_SHIFT)) { - status = -ENOMEM; - new_page = grab_cache_page(mapping, pgpos); - if (!new_page) - goto out; - /* we might sleep */ - if (*bytes>>PAGE_CACHE_SHIFT != pgpos) { - unlock_page(new_page); - page_cache_release(new_page); - continue; - } - zerofrom = *bytes & ~PAGE_CACHE_MASK; + index = pos >> PAGE_CACHE_SHIFT; + offset = pos & ~PAGE_CACHE_MASK; + + while (index > (curidx = (curpos = *bytes)>>PAGE_CACHE_SHIFT)) { + zerofrom = curpos & ~PAGE_CACHE_MASK; if (zerofrom & (blocksize-1)) { *bytes |= (blocksize-1); (*bytes)++; } - status = __block_prepare_write(inode, new_page, zerofrom, - PAGE_CACHE_SIZE, get_block); - if (status) - goto out_unmap; - zero_user_page(new_page, zerofrom, PAGE_CACHE_SIZE - zerofrom, - KM_USER0); - generic_commit_write(NULL, new_page, zerofrom, PAGE_CACHE_SIZE); - unlock_page(new_page); - page_cache_release(new_page); - } + len = PAGE_CACHE_SIZE - zerofrom; - if (page->index < pgpos) { - /* completely inside the area */ - zerofrom = offset; - } else { - /* page covers the boundary, find the boundary offset */ - zerofrom = *bytes & ~PAGE_CACHE_MASK; + err = pagecache_write_begin(file, mapping, curpos, len, + AOP_FLAG_UNINTERRUPTIBLE, + &page, &fsdata); + if (err) + goto out; + zero_user_page(page, zerofrom, len, KM_USER0); + err = pagecache_write_end(file, mapping, curpos, len, len, + page, fsdata); + if (err < 0) + goto out; + BUG_ON(err != len); + err = 0; + } + /* page covers the boundary, find the boundary offset */ + if (index == curidx) { + zerofrom = curpos & ~PAGE_CACHE_MASK; /* if we will expand the thing last block will be filled */ - if (to > zerofrom && (zerofrom & (blocksize-1))) { + if (offset <= zerofrom) { + goto out; + } + if (zerofrom & (blocksize-1)) { *bytes |= (blocksize-1); (*bytes)++; } + len = offset - zerofrom; - /* starting below the boundary? Nothing to zero out */ - if (offset <= zerofrom) - zerofrom = offset; + err = pagecache_write_begin(file, mapping, curpos, len, + AOP_FLAG_UNINTERRUPTIBLE, + &page, &fsdata); + if (err) + goto out; + zero_user_page(page, zerofrom, len, KM_USER0); + err = pagecache_write_end(file, mapping, curpos, len, len, + page, fsdata); + if (err < 0) + goto out; + BUG_ON(err != len); + err = 0; } - status = __block_prepare_write(inode, page, zerofrom, to, get_block); - if (status) - goto out1; - if (zerofrom < offset) { - zero_user_page(page, zerofrom, offset - zerofrom, KM_USER0); - __block_commit_write(inode, page, zerofrom, offset); +out: + return err; +} + +/* + * For moronic filesystems that do not allow holes in file. + * We may have to extend the file. + */ +int cont_write_begin(struct file *file, struct address_space *mapping, + loff_t pos, unsigned len, unsigned flags, + struct page **pagep, void **fsdata, + get_block_t *get_block, loff_t *bytes) +{ + struct inode *inode = mapping->host; + unsigned blocksize = 1 << inode->i_blkbits; + unsigned zerofrom; + int err; + + err = cont_expand_zero(file, mapping, pos, bytes); + if (err) + goto out; + + zerofrom = *bytes & ~PAGE_CACHE_MASK; + if (pos+len > *bytes && zerofrom & (blocksize-1)) { + *bytes |= (blocksize-1); + (*bytes)++; } - return 0; -out1: - ClearPageUptodate(page); - return status; -out_unmap: - ClearPageUptodate(new_page); - unlock_page(new_page); - page_cache_release(new_page); + *pagep = NULL; + err = block_write_begin(file, mapping, pos, len, + flags, pagep, fsdata, get_block); out: - return status; + return err; } int block_prepare_write(struct page *page, unsigned from, unsigned to, @@ -3191,7 +3185,7 @@ EXPORT_SYMBOL(block_read_full_page); EXPORT_SYMBOL(block_sync_page); EXPORT_SYMBOL(block_truncate_page); EXPORT_SYMBOL(block_write_full_page); -EXPORT_SYMBOL(cont_prepare_write); +EXPORT_SYMBOL(cont_write_begin); EXPORT_SYMBOL(end_buffer_read_sync); EXPORT_SYMBOL(end_buffer_write_sync); EXPORT_SYMBOL(file_fsync); diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index a562ecfb1a14..1caa71d4c95f 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -214,8 +214,9 @@ int generic_write_end(struct file *, struct address_space *, struct page *, void *); void page_zero_new_buffers(struct page *page, unsigned from, unsigned to); int block_prepare_write(struct page*, unsigned, unsigned, get_block_t*); -int cont_prepare_write(struct page*, unsigned, unsigned, get_block_t*, - loff_t *); +int cont_write_begin(struct file *, struct address_space *, loff_t, + unsigned, unsigned, struct page **, void **, + get_block_t *, loff_t *); int generic_cont_expand(struct inode *inode, loff_t size); int generic_cont_expand_simple(struct inode *inode, loff_t size); int block_commit_write(struct page *page, unsigned from, unsigned to); diff --git a/include/linux/fs.h b/include/linux/fs.h index e9344e6f877d..a40557eae2ed 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -395,6 +395,7 @@ enum positive_aop_returns { }; #define AOP_FLAG_UNINTERRUPTIBLE 0x0001 /* will not do a short write */ +#define AOP_FLAG_CONT_EXPAND 0x0002 /* called from cont_expand */ /* * oh the beauties of C type declarations. diff --git a/mm/filemap.c b/mm/filemap.c index ca04226bf1de..195339b27e9a 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1684,6 +1684,7 @@ size_t iov_iter_copy_from_user_atomic(struct page *page, return copied; } +EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); /* * This has the same sideeffects and return value as @@ -1710,6 +1711,7 @@ size_t iov_iter_copy_from_user(struct page *page, kunmap(page); return copied; } +EXPORT_SYMBOL(iov_iter_copy_from_user); static void __iov_iter_advance_iov(struct iov_iter *i, size_t bytes) { @@ -1741,6 +1743,7 @@ void iov_iter_advance(struct iov_iter *i, size_t bytes) __iov_iter_advance_iov(i, bytes); i->count -= bytes; } +EXPORT_SYMBOL(iov_iter_advance); /* * Fault in the first iovec of the given iov_iter, to a maximum length @@ -1757,6 +1760,7 @@ int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) bytes = min(bytes, i->iov->iov_len - i->iov_offset); return fault_in_pages_readable(buf, bytes); } +EXPORT_SYMBOL(iov_iter_fault_in_readable); /* * Return the count of just the current iov_iter segment. @@ -1769,6 +1773,7 @@ size_t iov_iter_single_seg_count(struct iov_iter *i) else return min(i->count, iov->iov_len - i->iov_offset); } +EXPORT_SYMBOL(iov_iter_single_seg_count); /* * Performs necessary checks before doing a write |