[PATCH] remove kiobufs

This patch from Christoph Hellwig removes the kiobuf/kiovec
infrastructure.

This affects three subsystems:

video-buf.c:

   This patch includes an earlier diff from Gerd which converts
    video-buf.c to use get_user_pages() directly.

   Gerd has acked this patch.

LVM1:

   Is now even more broken.

drivers/mtd/devices/blkmtd.c:

   blkmtd is broken by this change.  I contacted Simon Evans, who
   said "I had done a rewrite of blkmtd anyway and just need to convert
   it to BIO.  Feel free to break it in the 2.5 tree, it will force me
   to finish my code."

Neither EVMS nor LVM2 use kiobufs.  The only remaining breakage
of which I am aware is a proprietary MPEG2 streaming module.  It
could use get_user_pages().

arch/cris/drivers/examples/kiobuftest.c

-/*
- * Example showing how to pin down a range of virtual pages from user-space
- * to be able to do for example DMA directly into them.
- *
- * It is necessary because the pages the virtual pointers reference, might
- * not exist in memory (could be mapped to the zero-page, filemapped etc)
- * and DMA cannot trigger the MMU to force them in (and would have time 
- * contraints making it impossible to wait for it anyway).
- *
- * Author:  Bjorn Wesen
- *
- * $Log: kiobuftest.c,v $
- * Revision 1.1.1.1  2001/12/17 13:59:27  bjornw
- * Import of Linux 2.5.1
- *
- * Revision 1.2  2001/02/27 13:52:50  bjornw
- * malloc.h -> slab.h
- *
- * Revision 1.1  2001/01/19 15:57:49  bjornw
- * Example of how to do direct HW -> user-mode DMA
- *
- *
- */
-
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/slab.h>
-#include <linux/errno.h>
-#include <linux/kernel.h>
-#include <linux/fs.h>
-#include <linux/string.h>
-#include <linux/init.h>
-#include <linux/mm.h>
-#include <linux/iobuf.h>
-
-#define KIOBUFTEST_MAJOR 124  /* in the local range, experimental */
-
-
-static ssize_t
-kiobuf_read(struct file *filp, char *buf, size_t len, loff_t *ppos)
-{
-
-     struct kiobuf *iobuf;
-     int res, i;
- 
-     /* Make a kiobuf that maps the entire length the reader has given
-      * us
-      */
-
-     res = alloc_kiovec(1, &iobuf);
-     if (res)
-	     return res;
-     
-     if((res = map_user_kiobuf(READ, iobuf, (unsigned long)buf, len))) {
-	     printk("map_user_kiobuf failed, return %d\n", res);
-	     return res;
-     }
-
-     /* At this point, the virtual area buf[0] -> buf[len-1] will
-      * have corresponding pages mapped in physical memory and locked
-      * until we unmap the kiobuf. They cannot be swapped out or moved
-      * around.
-      */
-
-     printk("nr_pages == %d\noffset == %d\nlength == %d\n",
-	    iobuf->nr_pages, iobuf->offset, iobuf->length);
-
-     for(i = 0; i < iobuf->nr_pages; i++) {
-	     printk("page_add(maplist[%d]) == 0x%x\n", i,
-		    page_address(iobuf->maplist[i]));
-     }
-
-     /* This is the place to create the necessary scatter-gather vector
-      * for the DMA using the iobuf->maplist array and page_address
-      * (don't forget __pa if the DMA needs the actual physical DRAM address)
-      * and run it.
-      */
-
-
-
-
-     /* Release the mapping and exit */
-
-     unmap_kiobuf(iobuf); /* The unlock_kiobuf is implicit here */
-
-     return len;
-}
-
-
-static struct file_operations kiobuf_fops = {
-	owner:    THIS_MODULE,
-	read:     kiobuf_read
-};
-
-static int __init
-kiobuftest_init(void)
-{
-	int res;
-
-	/* register char device */
-
-	res = register_chrdev(KIOBUFTEST_MAJOR, "kiobuftest", &kiobuf_fops);
-	if(res < 0) {
-		printk(KERN_ERR "kiobuftest: couldn't get a major number.\n");
-		return res;
-	}
-
-	printk("Initializing kiobuf-test device\n");
-}
-
-module_init(kiobuftest_init);

drivers/media/video/bttv-risc.c

@@ -29,7 +29,6 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/pci.h>
-#include <linux/iobuf.h>
 #include <linux/vmalloc.h>
 #include <linux/interrupt.h>
 #include <asm/page.h>

drivers/media/video/bttvp.h

@@ -31,7 +31,6 @@
 #include <linux/i2c.h>
 #include <linux/i2c-algo-bit.h>
 #include <linux/videodev.h>
-#include <linux/iobuf.h>
 #include <linux/pci.h>
 #include <asm/scatterlist.h>
 

drivers/media/video/video-buf.c

@@ -18,8 +18,8 @@
 
 #include <linux/init.h>
 #include <linux/module.h>
-#include <linux/iobuf.h>
 #include <linux/vmalloc.h>
+#include <linux/pagemap.h>
 #include <linux/slab.h>
 #include <linux/pci.h>
 #include <linux/interrupt.h>
@@ -65,32 +65,31 @@ videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages)
 	return NULL;
 }
 
-struct scatterlist*
-videobuf_iobuf_to_sg(struct kiobuf *iobuf)
+struct scatterlist *
+videobuf_pages_to_sg(struct page **pages, int nr_pages, int offset)
 {
 	struct scatterlist *sglist;
 	int i = 0;
-
-	sglist = kmalloc(sizeof(struct scatterlist) * iobuf->nr_pages,
-			 GFP_KERNEL);
+	
+	if (NULL == pages[0])
+		return NULL;
+	sglist = kmalloc(sizeof(*sglist) * nr_pages, GFP_KERNEL);
 	if (NULL == sglist)
 		return NULL;
-	memset(sglist,0,sizeof(struct scatterlist) * iobuf->nr_pages);
+	memset(sglist, 0, sizeof(*sglist) * nr_pages);
 
-	if (NULL == iobuf->maplist[0])
-		goto err;
-	if (PageHighMem(iobuf->maplist[0]))
+	if (PageHighMem(pages[0]))
 		/* DMA to highmem pages might not work */
 		goto err;
-	sglist[0].page   = iobuf->maplist[0];
-	sglist[0].offset = iobuf->offset;
-	sglist[0].length = PAGE_SIZE - iobuf->offset;
-	for (i = 1; i < iobuf->nr_pages; i++) {
-		if (NULL == iobuf->maplist[i])
+	sglist[0].page   = pages[0];
+	sglist[0].offset = offset;
+	sglist[0].length = PAGE_SIZE - offset;
+	for (i = 1; i < nr_pages; i++) {
+		if (NULL == pages[i])
 			goto err;
-		if (PageHighMem(iobuf->maplist[i]))
+		if (PageHighMem(pages[i]))
 			goto err;
-		sglist[i].page   = iobuf->maplist[i];
+		sglist[i].page   = pages[i];
 		sglist[i].length = PAGE_SIZE;
 	}
 	return sglist;
@@ -100,6 +99,30 @@ videobuf_iobuf_to_sg(struct kiobuf *iobuf)
 	return NULL;
 }
 
+int videobuf_lock(struct page **pages, int nr_pages)
+{
+	int i;
+
+	for (i = 0; i < nr_pages; i++)
+		if (TestSetPageLocked(pages[i]))
+			goto err;
+	return 0;
+
+ err:
+	while (i > 0)
+		unlock_page(pages[--i]);
+	return -EINVAL;
+}
+
+int videobuf_unlock(struct page **pages, int nr_pages)
+{
+	int i;
+
+	for (i = 0; i < nr_pages; i++)
+		unlock_page(pages[i]);
+	return 0;
+}
+
 /* --------------------------------------------------------------------- */
 
 int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
@@ -113,14 +136,21 @@ int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
 	case PCI_DMA_TODEVICE:   rw = WRITE; break;
 	default:                 BUG();
 	}
-	if (0 != (err = alloc_kiovec(1,&dma->iobuf)))
-		return err;
-	if (0 != (err = map_user_kiobuf(rw, dma->iobuf, data, size))) {
-		dprintk(1,"map_user_kiobuf: %d\n",err);
-		return err;
-	}
-	dma->nr_pages = dma->iobuf->nr_pages;
-	return 0;
+
+	dma->offset   = data & PAGE_MASK;
+	dma->nr_pages = ((((data+size) & ~PAGE_MASK) -
+			  (data & ~PAGE_MASK)) >> PAGE_SHIFT) +1;
+	dma->pages    = kmalloc(dma->nr_pages * sizeof(struct page*),
+				GFP_KERNEL);
+	if (NULL == dma->pages)
+		return -ENOMEM;
+	down_read(&current->mm->mmap_sem);
+        err = get_user_pages(current,current->mm,
+			     data, dma->nr_pages,
+			     rw == READ, 0, /* don't force */
+			     dma->pages, NULL);
+	up_read(&current->mm->mmap_sem);
+	return err;
 }
 
 int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
@@ -144,13 +174,15 @@ int videobuf_dma_pci_map(struct pci_dev *dev, struct videobuf_dmabuf *dma)
 	if (0 == dma->nr_pages)
 		BUG();
 	
-	if (dma->iobuf) {
-		if (0 != (err = lock_kiovec(1,&dma->iobuf,1))) {
-			dprintk(1,"lock_kiovec: %d\n",err);
+	if (dma->pages) {
+		if (0 != (err = videobuf_lock(dma->pages, dma->nr_pages))) {
+			dprintk(1,"videobuf_lock_pages: %d\n",err);
 			return err;
 		}
-		dma->sglist = videobuf_iobuf_to_sg(dma->iobuf);
+		dma->sglist = videobuf_pages_to_sg(dma->pages, dma->nr_pages,
+						   dma->offset);
 	}
+
 	if (dma->vmalloc) {
 		dma->sglist = videobuf_vmalloc_to_sg
 			(dma->vmalloc,dma->nr_pages);
@@ -160,7 +192,7 @@ int videobuf_dma_pci_map(struct pci_dev *dev, struct videobuf_dmabuf *dma)
 		return -ENOMEM;
 	}
 	dma->sglen = pci_map_sg(dev,dma->sglist,dma->nr_pages,
-				 dma->direction);
+				dma->direction);
 	return 0;
 }
 
@@ -182,8 +214,8 @@ int videobuf_dma_pci_unmap(struct pci_dev *dev, struct videobuf_dmabuf *dma)
 	kfree(dma->sglist);
 	dma->sglist = NULL;
 	dma->sglen = 0;
-	if (dma->iobuf)
-		unlock_kiovec(1,&dma->iobuf);
+	if (dma->pages)
+		videobuf_lock(dma->pages, dma->nr_pages);
 	return 0;
 }
 
@@ -192,11 +224,14 @@ int videobuf_dma_free(struct videobuf_dmabuf *dma)
 	if (dma->sglen)
 		BUG();
 
-	if (dma->iobuf) {
-		unmap_kiobuf(dma->iobuf);
-		free_kiovec(1,&dma->iobuf);
-		dma->iobuf = NULL;
+	if (dma->pages) {
+		int i;
+		for (i=0; i < dma->nr_pages; i++)
+			page_cache_release(dma->pages[i]);
+		kfree(dma->pages);
+		dma->pages = NULL;
 	}
+
 	if (dma->vmalloc) {
 		vfree(dma->vmalloc);
 		dma->vmalloc = NULL;
@@ -959,6 +994,7 @@ int videobuf_mmap_mapper(struct vm_area_struct *vma,
 	map->q       = q;
 	vma->vm_ops  = &videobuf_vm_ops;
 	vma->vm_flags |= VM_DONTEXPAND;
+	vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */
 	vma->vm_private_data = map;
 	dprintk(1,"mmap %p: %08lx-%08lx pgoff %08lx bufs %d-%d\n",
 		map,vma->vm_start,vma->vm_end,vma->vm_pgoff,first,last);
@@ -972,7 +1008,6 @@ int videobuf_mmap_mapper(struct vm_area_struct *vma,
 /* --------------------------------------------------------------------- */
 
 EXPORT_SYMBOL_GPL(videobuf_vmalloc_to_sg);
-EXPORT_SYMBOL_GPL(videobuf_iobuf_to_sg);
 
 EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
 EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);

drivers/media/video/video-buf.h

@@ -28,11 +28,12 @@
 struct scatterlist* videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages);
 
 /*
- * Return a scatterlist for a locked iobuf (NULL on errors).  Memory
+ * Return a scatterlist for a an array of userpages (NULL on errors).  Memory
  * for the scatterlist is allocated using kmalloc.  The caller must
  * free the memory.
  */
-struct scatterlist* videobuf_iobuf_to_sg(struct kiobuf *iobuf);
+struct scatterlist *videobuf_pages_to_sg(struct page **pages, int nr_pages,
+					 int offset);
 
 /* --------------------------------------------------------------------- */
 
@@ -57,7 +58,8 @@ struct scatterlist* videobuf_iobuf_to_sg(struct kiobuf *iobuf);
 
 struct videobuf_dmabuf {
 	/* for userland buffer */
-	struct kiobuf       *iobuf;
+	struct page         **pages;
+	int                 offset;
 
 	/* for kernel buffers */
 	void                *vmalloc;

fs/Makefile

@@ -11,7 +11,7 @@ export-objs :=	open.o dcache.o buffer.o bio.o inode.o dquot.o mpage.o aio.o \
 obj-y :=	open.o read_write.o devices.o file_table.o buffer.o \
 		bio.o super.o block_dev.o char_dev.o stat.o exec.o pipe.o \
 		namei.o fcntl.o ioctl.o readdir.o select.o fifo.o locks.o \
-		dcache.o inode.o attr.o bad_inode.o file.o iobuf.o dnotify.o \
+		dcache.o inode.o attr.o bad_inode.o file.o dnotify.o \
 		filesystems.o namespace.o seq_file.o xattr.o libfs.o \
 		fs-writeback.o mpage.o direct-io.o aio.o
 

fs/aio.c

@@ -9,6 +9,7 @@
  *	See ../COPYING for licensing terms.
  */
 #include <linux/kernel.h>
+#include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/time.h>
 #include <linux/aio_abi.h>
@@ -21,15 +22,9 @@
 #include <linux/file.h>
 #include <linux/mm.h>
 #include <linux/mman.h>
-#include <linux/vmalloc.h>
-#include <linux/iobuf.h>
 #include <linux/slab.h>
 #include <linux/timer.h>
-#include <linux/brlock.h>
 #include <linux/aio.h>
-#include <linux/smp_lock.h>
-#include <linux/compiler.h>
-#include <linux/brlock.h>
 #include <linux/module.h>
 #include <linux/highmem.h>
 #include <linux/workqueue.h>

fs/bio.c

@@ -20,7 +20,7 @@
 #include <linux/bio.h>
 #include <linux/blk.h>
 #include <linux/slab.h>
-#include <linux/iobuf.h>
+#include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/mempool.h>
@@ -438,128 +438,6 @@ int bio_add_page(struct bio *bio, struct page *page, unsigned int len,
 	return 0;
 }
 
-static int bio_end_io_kio(struct bio *bio, unsigned int bytes_done, int error)
-{
-	struct kiobuf *kio = (struct kiobuf *) bio->bi_private;
-
-	if (bio->bi_size)
-		return 1;
-
-	end_kio_request(kio, error);
-	bio_put(bio);
-	return 0;
-}
-
-/**
- * ll_rw_kio - submit a &struct kiobuf for I/O
- * @rw:   %READ or %WRITE
- * @kio:   the kiobuf to do I/O on
- * @bdev:   target device
- * @sector:   start location on disk
- *
- * Description:
- *   ll_rw_kio will map the page list inside the &struct kiobuf to
- *   &struct bio and queue them for I/O. The kiobuf given must describe
- *   a continous range of data, and must be fully prepared for I/O.
- **/
-void ll_rw_kio(int rw, struct kiobuf *kio, struct block_device *bdev, sector_t sector)
-{
-	int i, offset, size, err, map_i, total_nr_pages, nr_pages;
-	struct bio *bio;
-
-	err = 0;
-	if ((rw & WRITE) && bdev_read_only(bdev)) {
-		printk("ll_rw_bio: WRITE to ro device %s\n", bdevname(bdev));
-		err = -EPERM;
-		goto out;
-	}
-
-	if (!kio->nr_pages) {
-		err = -EINVAL;
-		goto out;
-	}
-
-	/*
-	 * maybe kio is bigger than the max we can easily map into a bio.
-	 * if so, split it up in appropriately sized chunks.
-	 */
-	total_nr_pages = kio->nr_pages;
-	offset = kio->offset & ~PAGE_MASK;
-	size = kio->length;
-
-	atomic_set(&kio->io_count, 1);
-
-	map_i = 0;
-
-next_chunk:
-	nr_pages = BIO_MAX_PAGES;
-	if (nr_pages > total_nr_pages)
-		nr_pages = total_nr_pages;
-
-	atomic_inc(&kio->io_count);
-
-	/*
-	 * allocate bio and do initial setup
-	 */
-	if ((bio = bio_alloc(GFP_NOIO, nr_pages)) == NULL) {
-		err = -ENOMEM;
-		goto out;
-	}
-
-	bio->bi_sector = sector;
-	bio->bi_bdev = bdev;
-	bio->bi_idx = 0;
-	bio->bi_end_io = bio_end_io_kio;
-	bio->bi_private = kio;
-
-	for (i = 0; i < nr_pages; i++, map_i++) {
-		int nbytes = PAGE_SIZE - offset;
-
-		if (nbytes > size)
-			nbytes = size;
-
-		BUG_ON(kio->maplist[map_i] == NULL);
-
-		/*
-		 * if we can't add this page to the bio, submit for i/o
-		 * and alloc a new one if needed
-		 */
-		if (bio_add_page(bio, kio->maplist[map_i], nbytes, offset))
-			break;
-
-		/*
-		 * kiobuf only has an offset into the first page
-		 */
-		offset = 0;
-
-		sector += nbytes >> 9;
-		size -= nbytes;
-		total_nr_pages--;
-		kio->offset += nbytes;
-	}
-
-	submit_bio(rw, bio);
-
-	if (total_nr_pages)
-		goto next_chunk;
-
-	if (size) {
-		printk("ll_rw_kio: size %d left (kio %d)\n", size, kio->length);
-		BUG();
-	}
-
-out:
-	if (err)
-		kio->errno = err;
-
-	/*
-	 * final atomic_dec of io_count to match our initial setting of 1.
-	 * I/O may or may not have completed at this point, final completion
-	 * handler is only run on last decrement.
-	 */
-	end_kio_request(kio, !err);
-}
-
 /**
  * bio_endio - end I/O on a bio
  * @bio:	bio
@@ -662,7 +540,6 @@ module_init(init_bio);
 
 EXPORT_SYMBOL(bio_alloc);
 EXPORT_SYMBOL(bio_put);
-EXPORT_SYMBOL(ll_rw_kio);
 EXPORT_SYMBOL(bio_endio);
 EXPORT_SYMBOL(bio_init);
 EXPORT_SYMBOL(bio_copy);

fs/block_dev.c

@@ -14,7 +14,6 @@
 #include <linux/major.h>
 #include <linux/devfs_fs_kernel.h>
 #include <linux/smp_lock.h>
-#include <linux/iobuf.h>
 #include <linux/highmem.h>
 #include <linux/blkdev.h>
 #include <linux/module.h>

fs/buffer.c

@@ -28,7 +28,6 @@
 #include <linux/blkdev.h>
 #include <linux/file.h>
 #include <linux/quotaops.h>
-#include <linux/iobuf.h>
 #include <linux/highmem.h>
 #include <linux/module.h>
 #include <linux/writeback.h>
@@ -2300,65 +2299,6 @@ sector_t generic_block_bmap(struct address_space *mapping, sector_t block,
 	return tmp.b_blocknr;
 }
 
-/*
- * Start I/O on a physical range of kernel memory, defined by a vector
- * of kiobuf structs (much like a user-space iovec list).
- *
- * The kiobuf must already be locked for IO.  IO is submitted
- * asynchronously: you need to check page->locked and page->uptodate.
- *
- * It is up to the caller to make sure that there are enough blocks
- * passed in to completely map the iobufs to disk.
- */
-int brw_kiovec(int rw, int nr, struct kiobuf *iovec[],
-	       struct block_device *bdev, sector_t b[], int size)
-{
-	int		transferred;
-	int		i;
-	int		err;
-	struct kiobuf *	iobuf;
-
-	if (!nr)
-		return 0;
-	
-	/* 
-	 * First, do some alignment and validity checks 
-	 */
-	for (i = 0; i < nr; i++) {
-		iobuf = iovec[i];
-		if ((iobuf->offset & (size-1)) || (iobuf->length & (size-1)))
-			return -EINVAL;
-		if (!iobuf->nr_pages)
-			panic("brw_kiovec: iobuf not initialised");
-	}
-
-	/* 
-	 * OK to walk down the iovec doing page IO on each page we find. 
-	 */
-	for (i = 0; i < nr; i++) {
-		iobuf = iovec[i];
-		iobuf->errno = 0;
-
-		ll_rw_kio(rw, iobuf, bdev, b[i] * (size >> 9));
-	}
-
-	/*
-	 * now they are all submitted, wait for completion
-	 */
-	transferred = 0;
-	err = 0;
-	for (i = 0; i < nr; i++) {
-		iobuf = iovec[i];
-		kiobuf_wait_for_io(iobuf);
-		if (iobuf->errno && !err)
-			err = iobuf->errno;
-		if (!err)
-			transferred += iobuf->length;
-	}
-
-	return err ? err : transferred;
-}
-
 static int end_bio_bh_io_sync(struct bio *bio, unsigned int bytes_done, int err)
 {
 	struct buffer_head *bh = bio->bi_private;

fs/fcntl.c

@@ -10,7 +10,6 @@
 #include <linux/dnotify.h>
 #include <linux/smp_lock.h>
 #include <linux/slab.h>
-#include <linux/iobuf.h>
 #include <linux/module.h>
 #include <linux/security.h>
 

fs/file_table.c

@@ -11,7 +11,6 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/smp_lock.h>
-#include <linux/iobuf.h>
 #include <linux/fs.h>
 #include <linux/security.h>
 

fs/iobuf.c

-/*
- * iobuf.c
- *
- * Keep track of the general-purpose IO-buffer structures used to track
- * abstract kernel-space io buffers.
- * 
- */
-
-#include <linux/iobuf.h>
-#include <linux/slab.h>
-
-int end_kio_request(struct kiobuf *kiobuf, int uptodate)
-{
-	int ret = 1;
-
-	if ((!uptodate) && !kiobuf->errno)
-		kiobuf->errno = -EIO;
-
-	if (atomic_dec_and_test(&kiobuf->io_count)) {
-		ret = 0;
-		if (kiobuf->end_io)
-			kiobuf->end_io(kiobuf);
-		wake_up(&kiobuf->wait_queue);
-	}
-
-	return ret;
-}
-
-static void kiobuf_init(struct kiobuf *iobuf)
-{
-	init_waitqueue_head(&iobuf->wait_queue);
-	atomic_set(&iobuf->io_count, 0);
-	iobuf->array_len = KIO_STATIC_PAGES;
-	iobuf->maplist   = iobuf->map_array;
-	iobuf->nr_pages   = 0;
-	iobuf->locked   = 0;
-	iobuf->io_count.counter   = 0;
-	iobuf->end_io = NULL;
-}
-
-int alloc_kiovec(int nr, struct kiobuf **bufp)
-{
-	int i;
-	struct kiobuf *iobuf;
-	
-	for (i = 0; i < nr; i++) {
-		iobuf = kmalloc(sizeof(struct kiobuf), GFP_KERNEL);
-		if (!iobuf) {
-			free_kiovec(i, bufp);
-			return -ENOMEM;
-		}
-		kiobuf_init(iobuf);
-		bufp[i] = iobuf;
-	}
-	
-	return 0;
-}
-
-void free_kiovec(int nr, struct kiobuf **bufp) 
-{
-	int i;
-	struct kiobuf *iobuf;
-	
-	for (i = 0; i < nr; i++) {
-		iobuf = bufp[i];
-		if (iobuf->locked)
-			unlock_kiovec(1, &iobuf);
-		if (iobuf->array_len > KIO_STATIC_PAGES)
-			kfree (iobuf->maplist);
-		kfree(bufp[i]);
-	}
-}
-
-int expand_kiobuf(struct kiobuf *iobuf, int wanted)
-{
-	struct page ** maplist;
-	
-	if (iobuf->array_len >= wanted)
-		return 0;
-	
-	maplist = (struct page **) 
-		kmalloc(wanted * sizeof(struct page **), GFP_KERNEL);
-	if (!maplist)
-		return -ENOMEM;
-
-	/* Did it grow while we waited? */
-	if (iobuf->array_len >= wanted) {
-		kfree(maplist);
-		return 0;
-	}
-	
-	memcpy (maplist, iobuf->maplist, iobuf->array_len * sizeof(struct page **));
-
-	if (iobuf->array_len > KIO_STATIC_PAGES)
-		kfree (iobuf->maplist);
-	
-	iobuf->maplist   = maplist;
-	iobuf->array_len = wanted;
-	return 0;
-}
-
-
-void kiobuf_wait_for_io(struct kiobuf *kiobuf)
-{
-	struct task_struct *tsk = current;
-	DECLARE_WAITQUEUE(wait, tsk);
-
-	if (atomic_read(&kiobuf->io_count) == 0)
-		return;
-
-	add_wait_queue(&kiobuf->wait_queue, &wait);
-repeat:
-	set_task_state(tsk, TASK_UNINTERRUPTIBLE);
-	if (atomic_read(&kiobuf->io_count) != 0) {
-		blk_run_queues();
-		schedule();
-		if (atomic_read(&kiobuf->io_count) != 0)
-			goto repeat;
-	}
-	tsk->state = TASK_RUNNING;
-	remove_wait_queue(&kiobuf->wait_queue, &wait);
-}
-
-
-

fs/open.c

@@ -14,7 +14,6 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/tty.h>
-#include <linux/iobuf.h>
 #include <linux/namei.h>
 #include <linux/backing-dev.h>
 #include <linux/security.h>

fs/xfs/linux/xfs_aops.c

@@ -34,7 +34,6 @@
 #include <linux/mm.h>
 #include <linux/pagemap.h>
 #include <linux/mpage.h>
-#include <linux/iobuf.h>
 
 
 STATIC int delalloc_convert(struct inode *, struct page *, int, int);

fs/xfs/linux/xfs_ioctl.c

@@ -35,7 +35,6 @@
 #include <xfs_dfrag.h>
 #include <linux/dcache.h>
 #include <linux/namei.h>
-#include <linux/iobuf.h>
 
 
 extern int xfs_change_file_space(bhv_desc_t *, int,
@@ -605,6 +604,7 @@ xfs_ioctl(
 		 * it is set to the file system block size to
 		 * avoid having to do block zeroing on short writes.
 		 */
+#define KIO_MAX_ATOMIC_IO 512	/* FIXME: what do we really want here? */
 		da.d_maxiosz = XFS_FSB_TO_B(mp,
 				XFS_B_TO_FSBT(mp, KIO_MAX_ATOMIC_IO << 10));
 

include/linux/buffer_head.h

@@ -32,7 +32,6 @@ enum bh_state_bits {
 #define MAX_BUF_PER_PAGE (PAGE_CACHE_SIZE / 512)
 
 struct page;
-struct kiobuf;
 struct buffer_head;
 struct address_space;
 typedef void (bh_end_io_t)(struct buffer_head *bh, int uptodate);

include/linux/iobuf.h

-/*
- * iobuf.h
- *
- * Defines the structures used to track abstract kernel-space io buffers.
- *
- */
-
-#ifndef __LINUX_IOBUF_H
-#define __LINUX_IOBUF_H
-
-#include <linux/mm.h>
-#include <linux/init.h>
-#include <linux/wait.h>
-#include <asm/atomic.h>
-
-/*
- * The kiobuf structure describes a physical set of pages reserved
- * locked for IO.  The reference counts on each page will have been
- * incremented, and the flags field will indicate whether or not we have
- * pre-locked all of the pages for IO.
- *
- * kiobufs may be passed in arrays to form a kiovec, but we must
- * preserve the property that no page is present more than once over the
- * entire iovec.
- */
-
-#define KIO_MAX_ATOMIC_IO	512 /* in kb */
-#define KIO_STATIC_PAGES	(KIO_MAX_ATOMIC_IO / (PAGE_SIZE >> 10) + 1)
-#define KIO_MAX_SECTORS		(KIO_MAX_ATOMIC_IO * 2)
-
-/* The main kiobuf struct */
-
-struct kiobuf 
-{
-	int		nr_pages;	/* Pages actually referenced */
-	int		array_len;	/* Space in the allocated lists */
-	int		offset;		/* Offset to start of valid data */
-	int		length;		/* Number of valid bytes of data */
-
-	/* Keep separate track of the physical addresses and page
-	 * structs involved.  If we do IO to a memory-mapped device
-	 * region, there won't necessarily be page structs defined for
-	 * every address. */
-
-	struct page **	maplist;
-
-	unsigned int	locked : 1;	/* If set, pages has been locked */
-	
-	/* Always embed enough struct pages for atomic IO */
-	struct page *	map_array[KIO_STATIC_PAGES];
-	sector_t	blocks[KIO_MAX_SECTORS];
-
-	/* Dynamic state for IO completion: */
-	atomic_t	io_count;	/* IOs still in progress */
-	int		errno;		/* Status of completed IO */
-	void		(*end_io) (struct kiobuf *); /* Completion callback */
-	wait_queue_head_t wait_queue;
-};
-
-
-/* mm/memory.c */
-
-int	map_user_kiobuf(int rw, struct kiobuf *, unsigned long va, size_t len);
-void	unmap_kiobuf(struct kiobuf *iobuf);
-int	lock_kiovec(int nr, struct kiobuf *iovec[], int wait);
-int	unlock_kiovec(int nr, struct kiobuf *iovec[]);
-void	mark_dirty_kiobuf(struct kiobuf *iobuf, int bytes);
-
-/* fs/iobuf.c */
-
-int	end_kio_request(struct kiobuf *, int);
-void	simple_wakeup_kiobuf(struct kiobuf *);
-int	alloc_kiovec(int nr, struct kiobuf **);
-void	free_kiovec(int nr, struct kiobuf **);
-int	expand_kiobuf(struct kiobuf *, int);
-void	kiobuf_wait_for_io(struct kiobuf *);
-extern int alloc_kiobuf_bhs(struct kiobuf *);
-extern void free_kiobuf_bhs(struct kiobuf *);
-
-/* fs/buffer.c */
-
-int	brw_kiovec(int rw, int nr, struct kiobuf *iovec[], 
-		   struct block_device *bdev, sector_t [], int size);
-
-/* fs/bio.c */
-void	ll_rw_kio(int rw, struct kiobuf *kio, struct block_device *bdev, sector_t block);
-
-#endif /* __LINUX_IOBUF_H */

init/main.c

@@ -24,7 +24,6 @@
 #include <linux/smp_lock.h>
 #include <linux/blk.h>
 #include <linux/hdreg.h>
-#include <linux/iobuf.h>
 #include <linux/bootmem.h>
 #include <linux/tty.h>
 #include <linux/percpu.h>

kernel/ksyms.c

@@ -33,7 +33,6 @@
 #include <linux/swap.h>
 #include <linux/ctype.h>
 #include <linux/file.h>
-#include <linux/iobuf.h>
 #include <linux/console.h>
 #include <linux/poll.h>
 #include <linux/mmzone.h>
@@ -439,18 +438,6 @@ EXPORT_SYMBOL(__br_write_lock);
 EXPORT_SYMBOL(__br_write_unlock);
 #endif
 
-/* Kiobufs */
-EXPORT_SYMBOL(alloc_kiovec);
-EXPORT_SYMBOL(free_kiovec);
-EXPORT_SYMBOL(expand_kiobuf);
-
-EXPORT_SYMBOL(map_user_kiobuf);
-EXPORT_SYMBOL(unmap_kiobuf);
-EXPORT_SYMBOL(lock_kiovec);
-EXPORT_SYMBOL(unlock_kiovec);
-EXPORT_SYMBOL(brw_kiovec);
-EXPORT_SYMBOL(kiobuf_wait_for_io);
-
 #ifdef HAVE_DISABLE_HLT
 EXPORT_SYMBOL(disable_hlt);
 EXPORT_SYMBOL(enable_hlt);

mm/filemap.c

@@ -20,7 +20,6 @@
 #include <linux/pagemap.h>
 #include <linux/file.h>
 #include <linux/uio.h>
-#include <linux/iobuf.h>
 #include <linux/hash.h>
 #include <linux/writeback.h>
 #include <linux/pagevec.h>

mm/memory.c

@@ -40,7 +40,6 @@
 #include <linux/mm.h>
 #include <linux/mman.h>
 #include <linux/swap.h>
-#include <linux/iobuf.h>
 #include <linux/highmem.h>
 #include <linux/pagemap.h>
 #include <linux/vcache.h>
@@ -504,7 +503,7 @@ follow_page(struct mm_struct *mm, unsigned long address, int write)
 /* 
  * Given a physical address, is there a useful struct page pointing to
  * it?  This may become more complex in the future if we start dealing
- * with IO-aperture pages in kiobufs.
+ * with IO-aperture pages for direct-IO.
  */
 
 static inline struct page *get_page_map(struct page *page)
@@ -589,224 +588,6 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 	return i;
 }
 
-/*
- * Force in an entire range of pages from the current process's user VA,
- * and pin them in physical memory.  
- */
-#define dprintk(x...)
-
-int map_user_kiobuf(int rw, struct kiobuf *iobuf, unsigned long va, size_t len)
-{
-	int pgcount, err;
-	struct mm_struct *	mm;
-	
-	/* Make sure the iobuf is not already mapped somewhere. */
-	if (iobuf->nr_pages)
-		return -EINVAL;
-
-	mm = current->mm;
-	dprintk ("map_user_kiobuf: begin\n");
-	
-	pgcount = (va + len + PAGE_SIZE - 1)/PAGE_SIZE - va/PAGE_SIZE;
-	/* mapping 0 bytes is not permitted */
-	if (!pgcount) BUG();
-	err = expand_kiobuf(iobuf, pgcount);
-	if (err)
-		return err;
-
-	iobuf->locked = 0;
-	iobuf->offset = va & (PAGE_SIZE-1);
-	iobuf->length = len;
-	
-	/* Try to fault in all of the necessary pages */
-	down_read(&mm->mmap_sem);
-	/* rw==READ means read from disk, write into memory area */
-	err = get_user_pages(current, mm, va, pgcount,
-			(rw==READ), 0, iobuf->maplist, NULL);
-	up_read(&mm->mmap_sem);
-	if (err < 0) {
-		unmap_kiobuf(iobuf);
-		dprintk ("map_user_kiobuf: end %d\n", err);
-		return err;
-	}
-	iobuf->nr_pages = err;
-	while (pgcount--) {
-		/* FIXME: flush superflous for rw==READ,
-		 * probably wrong function for rw==WRITE
-		 */
-		flush_dcache_page(iobuf->maplist[pgcount]);
-	}
-	dprintk ("map_user_kiobuf: end OK\n");
-	return 0;
-}
-
-/*
- * Mark all of the pages in a kiobuf as dirty 
- *
- * We need to be able to deal with short reads from disk: if an IO error
- * occurs, the number of bytes read into memory may be less than the
- * size of the kiobuf, so we have to stop marking pages dirty once the
- * requested byte count has been reached.
- */
-
-void mark_dirty_kiobuf(struct kiobuf *iobuf, int bytes)
-{
-	int index, offset, remaining;
-	struct page *page;
-	
-	index = iobuf->offset >> PAGE_SHIFT;
-	offset = iobuf->offset & ~PAGE_MASK;
-	remaining = bytes;
-	if (remaining > iobuf->length)
-		remaining = iobuf->length;
-	
-	while (remaining > 0 && index < iobuf->nr_pages) {
-		page = iobuf->maplist[index];
-		
-		if (!PageReserved(page))
-			set_page_dirty(page);
-
-		remaining -= (PAGE_SIZE - offset);
-		offset = 0;
-		index++;
-	}
-}
-
-/*
- * Unmap all of the pages referenced by a kiobuf.  We release the pages,
- * and unlock them if they were locked. 
- */
-
-void unmap_kiobuf (struct kiobuf *iobuf) 
-{
-	int i;
-	struct page *map;
-	
-	for (i = 0; i < iobuf->nr_pages; i++) {
-		map = iobuf->maplist[i];
-		if (map) {
-			if (iobuf->locked)
-				unlock_page(map);
-			/* FIXME: cache flush missing for rw==READ
-			 * FIXME: call the correct reference counting function
-			 */
-			page_cache_release(map);
-		}
-	}
-	
-	iobuf->nr_pages = 0;
-	iobuf->locked = 0;
-}
-
-
-/*
- * Lock down all of the pages of a kiovec for IO.
- *
- * If any page is mapped twice in the kiovec, we return the error -EINVAL.
- *
- * The optional wait parameter causes the lock call to block until all
- * pages can be locked if set.  If wait==0, the lock operation is
- * aborted if any locked pages are found and -EAGAIN is returned.
- */
-
-int lock_kiovec(int nr, struct kiobuf *iovec[], int wait)
-{
-	struct kiobuf *iobuf;
-	int i, j;
-	struct page *page, **ppage;
-	int doublepage = 0;
-	int repeat = 0;
-	
- repeat:
-	
-	for (i = 0; i < nr; i++) {
-		iobuf = iovec[i];
-
-		if (iobuf->locked)
-			continue;
-
-		ppage = iobuf->maplist;
-		for (j = 0; j < iobuf->nr_pages; ppage++, j++) {
-			page = *ppage;
-			if (!page)
-				continue;
-			
-			if (TestSetPageLocked(page)) {
-				while (j--) {
-					struct page *tmp = *--ppage;
-					if (tmp)
-						unlock_page(tmp);
-				}
-				goto retry;
-			}
-		}
-		iobuf->locked = 1;
-	}
-
-	return 0;
-	
- retry:
-	
-	/* 
-	 * We couldn't lock one of the pages.  Undo the locking so far,
-	 * wait on the page we got to, and try again.  
-	 */
-	
-	unlock_kiovec(nr, iovec);
-	if (!wait)
-		return -EAGAIN;
-	
-	/* 
-	 * Did the release also unlock the page we got stuck on?
-	 */
-	if (!PageLocked(page)) {
-		/* 
-		 * If so, we may well have the page mapped twice
-		 * in the IO address range.  Bad news.  Of
-		 * course, it _might_ just be a coincidence,
-		 * but if it happens more than once, chances
-		 * are we have a double-mapped page. 
-		 */
-		if (++doublepage >= 3) 
-			return -EINVAL;
-		
-		/* Try again...  */
-		wait_on_page_locked(page);
-	}
-	
-	if (++repeat < 16)
-		goto repeat;
-	return -EAGAIN;
-}
-
-/*
- * Unlock all of the pages of a kiovec after IO.
- */
-
-int unlock_kiovec(int nr, struct kiobuf *iovec[])
-{
-	struct kiobuf *iobuf;
-	int i, j;
-	struct page *page, **ppage;
-	
-	for (i = 0; i < nr; i++) {
-		iobuf = iovec[i];
-
-		if (!iobuf->locked)
-			continue;
-		iobuf->locked = 0;
-		
-		ppage = iobuf->maplist;
-		for (j = 0; j < iobuf->nr_pages; ppage++, j++) {
-			page = *ppage;
-			if (!page)
-				continue;
-			unlock_page(page);
-		}
-	}
-	return 0;
-}
-
 static inline void zeromap_pte_range(pte_t * pte, unsigned long address,
                                      unsigned long size, pgprot_t prot)
 {