From fd5821404e6823997666d668f62c76eae228abc9 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 12 Jun 2007 21:20:37 +0200 Subject: loop: convert to using splice_direct_to_actor() instead of sendfile() This gets rid of the dependency on ->sendfile() for receiving data and converts loop to ->splice_read() instead. Also includes an IV offset fix from Hugh Dickins. Signed-off-by: Jens Axboe --- drivers/block/loop.c | 64 ++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 44 insertions(+), 20 deletions(-) (limited to 'drivers/block/loop.c') diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 0ed5470d253..87d84e7d543 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -74,6 +74,7 @@ #include #include #include +#include #include @@ -401,50 +402,73 @@ struct lo_read_data { }; static int -lo_read_actor(read_descriptor_t *desc, struct page *page, - unsigned long offset, unsigned long size) +lo_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf, + struct splice_desc *sd) { - unsigned long count = desc->count; - struct lo_read_data *p = desc->arg.data; + struct lo_read_data *p = sd->u.data; struct loop_device *lo = p->lo; + struct page *page = buf->page; sector_t IV; + size_t size; + int ret; - IV = ((sector_t) page->index << (PAGE_CACHE_SHIFT - 9))+(offset >> 9); + ret = buf->ops->pin(pipe, buf); + if (unlikely(ret)) + return ret; - if (size > count) - size = count; + IV = ((sector_t) page->index << (PAGE_CACHE_SHIFT - 9)) + + (buf->offset >> 9); + size = sd->len; + if (size > p->bsize) + size = p->bsize; - if (lo_do_transfer(lo, READ, page, offset, p->page, p->offset, size, IV)) { - size = 0; + if (lo_do_transfer(lo, READ, page, buf->offset, p->page, p->offset, size, IV)) { printk(KERN_ERR "loop: transfer error block %ld\n", page->index); - desc->error = -EINVAL; + size = -EINVAL; } flush_dcache_page(p->page); - desc->count = count - size; - desc->written += size; - p->offset += size; + if (size > 0) + p->offset += size; + return size; } +static int +lo_direct_splice_actor(struct pipe_inode_info *pipe, struct splice_desc *sd) +{ + return __splice_from_pipe(pipe, sd, lo_splice_actor); +} + static int do_lo_receive(struct loop_device *lo, struct bio_vec *bvec, int bsize, loff_t pos) { struct lo_read_data cookie; + struct splice_desc sd; struct file *file; - int retval; + long retval; cookie.lo = lo; cookie.page = bvec->bv_page; cookie.offset = bvec->bv_offset; cookie.bsize = bsize; + + sd.len = 0; + sd.total_len = bvec->bv_len; + sd.flags = 0; + sd.pos = pos; + sd.u.data = &cookie; + file = lo->lo_backing_file; - retval = file->f_op->sendfile(file, &pos, bvec->bv_len, - lo_read_actor, &cookie); - return (retval < 0)? retval: 0; + retval = splice_direct_to_actor(file, &sd, lo_direct_splice_actor); + + if (retval < 0) + return retval; + + return 0; } static int @@ -679,8 +703,8 @@ static int loop_change_fd(struct loop_device *lo, struct file *lo_file, if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode)) goto out_putf; - /* new backing store needs to support loop (eg sendfile) */ - if (!inode->i_fop->sendfile) + /* new backing store needs to support loop (eg splice_read) */ + if (!inode->i_fop->splice_read) goto out_putf; /* size of the new backing store needs to be the same */ @@ -760,7 +784,7 @@ static int loop_set_fd(struct loop_device *lo, struct file *lo_file, * If we can't read - sorry. If we only can't write - well, * it's going to be read-only. */ - if (!file->f_op->sendfile) + if (!file->f_op->splice_read) goto out_putf; if (aops->prepare_write && aops->commit_write) lo_flags |= LO_FLAGS_USE_AOPS; -- cgit v1.2.3