Signed-off-by: Jörn Engel Signed-off-by: Jan Blunck fs/ext2/file.c | 1 fs/ext3/file.c | 1 include/linux/fs.h | 2 mm/filemap.c | 172 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 176 insertions(+) Index: linux-2.6/include/linux/fs.h =================================================================== --- linux-2.6.orig/include/linux/fs.h +++ linux-2.6/include/linux/fs.h @@ -1502,6 +1502,8 @@ extern ssize_t do_sync_write(struct file ssize_t generic_file_write_nolock(struct file *file, const struct iovec *iov, unsigned long nr_segs, loff_t *ppos); extern ssize_t generic_file_sendfile(struct file *, loff_t *, size_t, read_actor_t, void *); +extern ssize_t generic_file_sendpage(struct file *, struct page *, int, size_t, + loff_t *, int); extern void do_generic_mapping_read(struct address_space *mapping, struct file_ra_state *, struct file *, loff_t *, read_descriptor_t *, read_actor_t); Index: linux-2.6/mm/filemap.c =================================================================== --- linux-2.6.orig/mm/filemap.c +++ linux-2.6/mm/filemap.c @@ -1086,6 +1086,27 @@ int file_send_actor(read_descriptor_t * return written; } +/* + * Simple generic file sendpage. Just write a kernel buffer to the file. + */ +static ssize_t +__generic_kernel_file_write(struct file *, const char *, size_t, loff_t *); + +ssize_t generic_file_sendpage(struct file *file, struct page *page, + int offset, size_t size, loff_t *ppos, int more) +{ + ssize_t ret; + char *kaddr; + + kaddr = kmap(page); + ret = __generic_kernel_file_write(file, kaddr + offset, size, ppos); + kunmap(page); + + return ret; +} + +EXPORT_SYMBOL(generic_file_sendpage); + ssize_t generic_file_sendfile(struct file *in_file, loff_t *ppos, size_t count, read_actor_t actor, void *target) { @@ -1715,6 +1736,21 @@ int remove_suid(struct dentry *dentry) } EXPORT_SYMBOL(remove_suid); +static inline size_t +filemap_copy_from_kernel(struct page *page, unsigned long offset, + const char *buf, unsigned bytes) +{ + char *kaddr; + + kaddr = kmap_atomic(page, KM_USER0); + memcpy(kaddr + offset, buf, bytes); + kunmap_atomic(page, KM_USER0); + + flush_dcache_page(page); + + return bytes; +} + size_t __filemap_copy_from_user_iovec(char *vaddr, const struct iovec *iov, size_t base, size_t bytes) @@ -1862,6 +1898,142 @@ generic_file_direct_write(struct kiocb * } EXPORT_SYMBOL(generic_file_direct_write); +/* + * TODO: + * This largely tries to copy generic_file_aio_write_nolock(), although it + * doesn't have to be nearly as generic. A real cleanup should either + * merge this into generic_file_aio_write_nolock() as well or keep it special + * and remove as much code as possible. + * + * Check for pending signals here. Otherwise return -EINTR early. + * + * No iov, no kiocb. If you think this is a problem, use the source ;) + */ +static ssize_t +__generic_kernel_file_write(struct file *file, const char *buf, + size_t count, loff_t *ppos) +{ + struct address_space * mapping = file->f_mapping; + struct address_space_operations *a_ops = mapping->a_ops; + struct inode *inode = mapping->host; + long status = 0; + loff_t pos; + struct page *page; + struct page *cached_page = NULL; + const int isblk = S_ISBLK(inode->i_mode); + ssize_t written; + ssize_t err; + size_t bytes; + struct pagevec lru_pvec; + + /* There is no sane reason to use O_DIRECT */ + if (file->f_flags & O_DIRECT) + return -EINVAL; + + if (unlikely(signal_pending(current))) + return -EINTR; + + if (unlikely(count < 0)) + return -EINVAL; + + down(&inode->i_sem); + + pos = *ppos; + pagevec_init(&lru_pvec, 0); + + /* We can write back this queue in page reclaim */ + current->backing_dev_info = mapping->backing_dev_info; + written = 0; + + err = generic_write_checks(file, &pos, &count, isblk); + if (err) + goto out; + + if (count == 0) + goto out; + + remove_suid(file->f_dentry); + inode_update_time(inode, 1); + + do { + unsigned long index; + unsigned long offset; + size_t copied; + + offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */ + index = pos >> PAGE_CACHE_SHIFT; + bytes = PAGE_CACHE_SIZE - offset; + if (bytes > count) + bytes = count; + + page = __grab_cache_page(mapping,index,&cached_page,&lru_pvec); + if (!page) { + status = -ENOMEM; + break; + } + + status = a_ops->prepare_write(file, page, offset, offset+bytes); + if (unlikely(status)) { + loff_t isize = i_size_read(inode); + /* + * prepare_write() may have instantiated a few blocks + * outside i_size. Trim these off again. + */ + unlock_page(page); + page_cache_release(page); + if (pos + bytes > isize) + vmtruncate(inode, isize); + break; + } + + copied = filemap_copy_from_kernel(page, offset, buf, bytes); + + status = a_ops->commit_write(file, page, offset, offset+bytes); + if (likely(copied > 0)) { + if (!status) + status = copied; + + if (status >= 0) { + written += status; + count -= status; + pos += status; + buf += status; + } + } + if (unlikely(copied != bytes)) + if (status >= 0) + status = -EFAULT; + unlock_page(page); + mark_page_accessed(page); + page_cache_release(page); + if (status < 0) + break; + balance_dirty_pages_ratelimited(mapping); + cond_resched(); + } while (count); + *ppos = pos; + + if (cached_page) + page_cache_release(cached_page); + + /* + * For now, when the user asks for O_SYNC, we'll actually give O_DSYNC + */ + if (status >= 0) { + if ((file->f_flags & O_SYNC) || IS_SYNC(inode)) + status = generic_osync_inode(inode, mapping, + OSYNC_METADATA|OSYNC_DATA); + } + + err = written ? written : status; +out: + pagevec_lru_add(&lru_pvec); + current->backing_dev_info = 0; + + up(&inode->i_sem); + return err; +} + ssize_t generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov, unsigned long nr_segs, loff_t pos, loff_t *ppos, Index: linux-2.6/fs/ext2/file.c =================================================================== --- linux-2.6.orig/fs/ext2/file.c +++ linux-2.6/fs/ext2/file.c @@ -53,6 +53,7 @@ struct file_operations ext2_file_operati .readv = generic_file_readv, .writev = generic_file_writev, .sendfile = generic_file_sendfile, + .sendpage = generic_file_sendpage, }; #ifdef CONFIG_EXT2_FS_XIP Index: linux-2.6/fs/ext3/file.c =================================================================== --- linux-2.6.orig/fs/ext3/file.c +++ linux-2.6/fs/ext3/file.c @@ -119,6 +119,7 @@ struct file_operations ext3_file_operati .release = ext3_release_file, .fsync = ext3_sync_file, .sendfile = generic_file_sendfile, + .sendpage = generic_file_sendpage, }; struct inode_operations ext3_file_inode_operations = {