1 files changed, 391 insertions, 0 deletions

diff --git a/fs/nfs/blocklayout/blocklayoutdev.c b/fs/nfs/blocklayout/blocklayoutdev.c
new file mode 100644
index 00000000000..d08ba9107fd
--- /dev/null
+++ b/fs/nfs/blocklayout/blocklayoutdev.c
@@ -0,0 +1,391 @@
+/*
+ *  linux/fs/nfs/blocklayout/blocklayoutdev.c
+ *
+ *  Device operations for the pnfs nfs4 file layout driver.
+ *
+ *  Copyright (c) 2006 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Andy Adamson <andros@citi.umich.edu>
+ *  Fred Isaman <iisaman@umich.edu>
+ *
+ * permission is granted to use, copy, create derivative works and
+ * redistribute this software and such derivative works for any purpose,
+ * so long as the name of the university of michigan is not used in
+ * any advertising or publicity pertaining to the use or distribution
+ * of this software without specific, written prior authorization.  if
+ * the above copyright notice or any other identification of the
+ * university of michigan is included in any copy of any portion of
+ * this software, then the disclaimer below must also be included.
+ *
+ * this software is provided as is, without representation from the
+ * university of michigan as to its fitness for any purpose, and without
+ * warranty by the university of michigan of any kind, either express
+ * or implied, including without limitation the implied warranties of
+ * merchantability and fitness for a particular purpose.  the regents
+ * of the university of michigan shall not be liable for any damages,
+ * including special, indirect, incidental, or consequential damages,
+ * with respect to any claim arising out or in connection with the use
+ * of the software, even if it has been or is hereafter advised of the
+ * possibility of such damages.
+ */
+#include <linux/module.h>
+#include <linux/buffer_head.h> /* __bread */
+
+#include <linux/genhd.h>
+#include <linux/blkdev.h>
+#include <linux/hash.h>
+
+#include "blocklayout.h"
+
+#define NFSDBG_FACILITY         NFSDBG_PNFS_LD
+
+static int decode_sector_number(__be32 **rp, sector_t *sp)
+{
+        uint64_t s;
+
+        *rp = xdr_decode_hyper(*rp, &s);
+        if (s & 0x1ff) {
+                printk(KERN_WARNING "%s: sector not aligned\n", __func__);
+                return -1;
+        }
+        *sp = s >> SECTOR_SHIFT;
+        return 0;
+}
+
+/* Open a block_device by device number. */
+struct block_device *nfs4_blkdev_get(dev_t dev)
+{
+        struct block_device *bd;
+
+        dprintk("%s enter\n", __func__);
+        bd = blkdev_get_by_dev(dev, FMODE_READ, NULL);
+        if (IS_ERR(bd))
+                goto fail;
+        return bd;
+fail:
+        dprintk("%s failed to open device : %ld\n",
+                        __func__, PTR_ERR(bd));
+        return NULL;
+}
+
+/*
+ * Release the block device
+ */
+int nfs4_blkdev_put(struct block_device *bdev)
+{
+        dprintk("%s for device %d:%d\n", __func__, MAJOR(bdev->bd_dev),
+                        MINOR(bdev->bd_dev));
+        return blkdev_put(bdev, FMODE_READ);
+}
+
+static struct bl_dev_msg bl_mount_reply;
+
+ssize_t bl_pipe_downcall(struct file *filp, const char __user *src,
+                         size_t mlen)
+{
+        if (mlen != sizeof (struct bl_dev_msg))
+                return -EINVAL;
+
+        if (copy_from_user(&bl_mount_reply, src, mlen) != 0)
+                return -EFAULT;
+
+        wake_up(&bl_wq);
+
+        return mlen;
+}
+
+void bl_pipe_destroy_msg(struct rpc_pipe_msg *msg)
+{
+        if (msg->errno >= 0)
+                return;
+        wake_up(&bl_wq);
+}
+
+/*
+ * Decodes pnfs_block_deviceaddr4 which is XDR encoded in dev->dev_addr_buf.
+ */
+struct pnfs_block_dev *
+nfs4_blk_decode_device(struct nfs_server *server,
+                       struct pnfs_device *dev)
+{
+        struct pnfs_block_dev *rv;
+        struct block_device *bd = NULL;
+        struct rpc_pipe_msg msg;
+        struct bl_msg_hdr bl_msg = {
+                .type = BL_DEVICE_MOUNT,
+                .totallen = dev->mincount,
+        };
+        uint8_t *dataptr;
+        DECLARE_WAITQUEUE(wq, current);
+        struct bl_dev_msg *reply = &bl_mount_reply;
+        int offset, len, i, rc;
+
+        dprintk("%s CREATING PIPEFS MESSAGE\n", __func__);
+        dprintk("%s: deviceid: %s, mincount: %d\n", __func__, dev->dev_id.data,
+                dev->mincount);
+
+        memset(&msg, 0, sizeof(msg));
+        msg.data = kzalloc(sizeof(bl_msg) + dev->mincount, GFP_NOFS);
+        if (!msg.data) {
+                rv = ERR_PTR(-ENOMEM);
+                goto out;
+        }
+
+        memcpy(msg.data, &bl_msg, sizeof(bl_msg));
+        dataptr = (uint8_t *) msg.data;
+        len = dev->mincount;
+        offset = sizeof(bl_msg);
+        for (i = 0; len > 0; i++) {
+                memcpy(&dataptr[offset], page_address(dev->pages[i]),
+                                len < PAGE_CACHE_SIZE ? len : PAGE_CACHE_SIZE);
+                len -= PAGE_CACHE_SIZE;
+                offset += PAGE_CACHE_SIZE;
+        }
+        msg.len = sizeof(bl_msg) + dev->mincount;
+
+        dprintk("%s CALLING USERSPACE DAEMON\n", __func__);
+        add_wait_queue(&bl_wq, &wq);
+        rc = rpc_queue_upcall(bl_device_pipe->d_inode, &msg);
+        if (rc < 0) {
+                remove_wait_queue(&bl_wq, &wq);
+                rv = ERR_PTR(rc);
+                goto out;
+        }
+
+        set_current_state(TASK_UNINTERRUPTIBLE);
+        schedule();
+        __set_current_state(TASK_RUNNING);
+        remove_wait_queue(&bl_wq, &wq);
+
+        if (reply->status != BL_DEVICE_REQUEST_PROC) {
+                dprintk("%s failed to open device: %d\n",
+                        __func__, reply->status);
+                rv = ERR_PTR(-EINVAL);
+                goto out;
+        }
+
+        bd = nfs4_blkdev_get(MKDEV(reply->major, reply->minor));
+        if (IS_ERR(bd)) {
+                rc = PTR_ERR(bd);
+                dprintk("%s failed to open device : %d\n", __func__, rc);
+                rv = ERR_PTR(rc);
+                goto out;
+        }
+
+        rv = kzalloc(sizeof(*rv), GFP_NOFS);
+        if (!rv) {
+                rv = ERR_PTR(-ENOMEM);
+                goto out;
+        }
+
+        rv->bm_mdev = bd;
+        memcpy(&rv->bm_mdevid, &dev->dev_id, sizeof(struct nfs4_deviceid));
+        dprintk("%s Created device %s with bd_block_size %u\n",
+                __func__,
+                bd->bd_disk->disk_name,
+                bd->bd_block_size);
+
+out:
+        kfree(msg.data);
+        return rv;
+}
+
+/* Map deviceid returned by the server to constructed block_device */
+static struct block_device *translate_devid(struct pnfs_layout_hdr *lo,
+                                            struct nfs4_deviceid *id)
+{
+        struct block_device *rv = NULL;
+        struct block_mount_id *mid;
+        struct pnfs_block_dev *dev;
+
+        dprintk("%s enter, lo=%p, id=%p\n", __func__, lo, id);
+        mid = BLK_ID(lo);
+        spin_lock(&mid->bm_lock);
+        list_for_each_entry(dev, &mid->bm_devlist, bm_node) {
+                if (memcmp(id->data, dev->bm_mdevid.data,
+                           NFS4_DEVICEID4_SIZE) == 0) {
+                        rv = dev->bm_mdev;
+                        goto out;
+                }
+        }
+ out:
+        spin_unlock(&mid->bm_lock);
+        dprintk("%s returning %p\n", __func__, rv);
+        return rv;
+}
+
+/* Tracks info needed to ensure extents in layout obey constraints of spec */
+struct layout_verification {
+        u32 mode;       /* R or RW */
+        u64 start;      /* Expected start of next non-COW extent */
+        u64 inval;      /* Start of INVAL coverage */
+        u64 cowread;    /* End of COW read coverage */
+};
+
+/* Verify the extent meets the layout requirements of the pnfs-block draft,
+ * section 2.3.1.
+ */
+static int verify_extent(struct pnfs_block_extent *be,
+                         struct layout_verification *lv)
+{
+        if (lv->mode == IOMODE_READ) {
+                if (be->be_state == PNFS_BLOCK_READWRITE_DATA ||
+                    be->be_state == PNFS_BLOCK_INVALID_DATA)
+                        return -EIO;
+                if (be->be_f_offset != lv->start)
+                        return -EIO;
+                lv->start += be->be_length;
+                return 0;
+        }
+        /* lv->mode == IOMODE_RW */
+        if (be->be_state == PNFS_BLOCK_READWRITE_DATA) {
+                if (be->be_f_offset != lv->start)
+                        return -EIO;
+                if (lv->cowread > lv->start)
+                        return -EIO;
+                lv->start += be->be_length;
+                lv->inval = lv->start;
+                return 0;
+        } else if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
+                if (be->be_f_offset != lv->start)
+                        return -EIO;
+                lv->start += be->be_length;
+                return 0;
+        } else if (be->be_state == PNFS_BLOCK_READ_DATA) {
+                if (be->be_f_offset > lv->start)
+                        return -EIO;
+                if (be->be_f_offset < lv->inval)
+                        return -EIO;
+                if (be->be_f_offset < lv->cowread)
+                        return -EIO;
+                /* It looks like you might want to min this with lv->start,
+                 * but you really don't.
+                 */
+                lv->inval = lv->inval + be->be_length;
+                lv->cowread = be->be_f_offset + be->be_length;
+                return 0;
+        } else
+                return -EIO;
+}
+
+/* XDR decode pnfs_block_layout4 structure */
+int
+nfs4_blk_process_layoutget(struct pnfs_layout_hdr *lo,
+                           struct nfs4_layoutget_res *lgr, gfp_t gfp_flags)
+{
+        struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
+        int i, status = -EIO;
+        uint32_t count;
+        struct pnfs_block_extent *be = NULL, *save;
+        struct xdr_stream stream;
+        struct xdr_buf buf;
+        struct page *scratch;
+        __be32 *p;
+        struct layout_verification lv = {
+                .mode = lgr->range.iomode,
+                .start = lgr->range.offset >> SECTOR_SHIFT,
+                .inval = lgr->range.offset >> SECTOR_SHIFT,
+                .cowread = lgr->range.offset >> SECTOR_SHIFT,
+        };
+        LIST_HEAD(extents);
+
+        dprintk("---> %s\n", __func__);
+
+        scratch = alloc_page(gfp_flags);
+        if (!scratch)
+                return -ENOMEM;
+
+        xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages, lgr->layoutp->len);
+        xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
+
+        p = xdr_inline_decode(&stream, 4);
+        if (unlikely(!p))
+                goto out_err;
+
+        count = be32_to_cpup(p++);
+
+        dprintk("%s enter, number of extents %i\n", __func__, count);
+        p = xdr_inline_decode(&stream, (28 + NFS4_DEVICEID4_SIZE) * count);
+        if (unlikely(!p))
+                goto out_err;
+
+        /* Decode individual extents, putting them in temporary
+         * staging area until whole layout is decoded to make error
+         * recovery easier.
+         */
+        for (i = 0; i < count; i++) {
+                be = bl_alloc_extent();
+                if (!be) {
+                        status = -ENOMEM;
+                        goto out_err;
+                }
+                memcpy(&be->be_devid, p, NFS4_DEVICEID4_SIZE);
+                p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
+                be->be_mdev = translate_devid(lo, &be->be_devid);
+                if (!be->be_mdev)
+                        goto out_err;
+
+                /* The next three values are read in as bytes,
+                 * but stored as 512-byte sector lengths
+                 */
+                if (decode_sector_number(&p, &be->be_f_offset) < 0)
+                        goto out_err;
+                if (decode_sector_number(&p, &be->be_length) < 0)
+                        goto out_err;
+                if (decode_sector_number(&p, &be->be_v_offset) < 0)
+                        goto out_err;
+                be->be_state = be32_to_cpup(p++);
+                if (be->be_state == PNFS_BLOCK_INVALID_DATA)
+                        be->be_inval = &bl->bl_inval;
+                if (verify_extent(be, &lv)) {
+                        dprintk("%s verify failed\n", __func__);
+                        goto out_err;
+                }
+                list_add_tail(&be->be_node, &extents);
+        }
+        if (lgr->range.offset + lgr->range.length !=
+                        lv.start << SECTOR_SHIFT) {
+                dprintk("%s Final length mismatch\n", __func__);
+                be = NULL;
+                goto out_err;
+        }
+        if (lv.start < lv.cowread) {
+                dprintk("%s Final uncovered COW extent\n", __func__);
+                be = NULL;
+                goto out_err;
+        }
+        /* Extents decoded properly, now try to merge them in to
+         * existing layout extents.
+         */
+        spin_lock(&bl->bl_ext_lock);
+        list_for_each_entry_safe(be, save, &extents, be_node) {
+                list_del(&be->be_node);
+                status = bl_add_merge_extent(bl, be);
+                if (status) {
+                        spin_unlock(&bl->bl_ext_lock);
+                        /* This is a fairly catastrophic error, as the
+                         * entire layout extent lists are now corrupted.
+                         * We should have some way to distinguish this.
+                         */
+                        be = NULL;
+                        goto out_err;
+                }
+        }
+        spin_unlock(&bl->bl_ext_lock);
+        status = 0;
+ out:
+        __free_page(scratch);
+        dprintk("%s returns %i\n", __func__, status);
+        return status;
+
+ out_err:
+        bl_put_extent(be);
+        while (!list_empty(&extents)) {
+                be = list_first_entry(&extents, struct pnfs_block_extent,
+                                      be_node);
+                list_del(&be->be_node);
+                bl_put_extent(be);
+        }
+        goto out;
+}