pnfs/blocklayout: refactor extent processing

Factor out a helper for all per-extent work, and merge the now trivial
functions for lseg allocation and parsing.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
index 61a858cd54fe3f215e6bfaf2f3ea694200afe183..76ec017a6f0a47bdf10cf632c3f8a0cfd58f0304 100644 (file)
--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -513,144 +513,147 @@ static int decode_sector_number(__be32 **rp, sector_t *sp)
        return 0;
 }
 
-/* XDR decode pnfs_block_layout4 structure */
 static int
-nfs4_blk_process_layoutget(struct pnfs_layout_hdr *lo,
-                          struct nfs4_layoutget_res *lgr, gfp_t gfp_flags)
+bl_alloc_extent(struct xdr_stream *xdr, struct pnfs_layout_hdr *lo,
+               struct layout_verification *lv, struct list_head *extents,
+               gfp_t gfp_mask)
 {
-       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;
+       struct pnfs_block_extent *be;
+       struct nfs4_deviceid id;
+       int error;
        __be32 *p;
+
+       p = xdr_inline_decode(xdr, 28 + NFS4_DEVICEID4_SIZE);
+       if (!p)
+               return -EIO;
+
+       be = kzalloc(sizeof(*be), GFP_NOFS);
+       if (!be)
+               return -ENOMEM;
+
+       memcpy(&id, p, NFS4_DEVICEID4_SIZE);
+       p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
+
+       error = -EIO;
+       be->be_device = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode), &id,
+                                               lo->plh_lc_cred, gfp_mask);
+       if (!be->be_device)
+               goto out_free_be;
+
+       /*
+        * The next three values are read in as bytes, but stored in the
+        * extent structure in 512-byte granularity.
+        */
+       if (decode_sector_number(&p, &be->be_f_offset) < 0)
+               goto out_put_deviceid;
+       if (decode_sector_number(&p, &be->be_length) < 0)
+               goto out_put_deviceid;
+       if (decode_sector_number(&p, &be->be_v_offset) < 0)
+               goto out_put_deviceid;
+       be->be_state = be32_to_cpup(p++);
+
+       error = verify_extent(be, lv);
+       if (error) {
+               dprintk("%s: extent verification failed\n", __func__);
+               goto out_put_deviceid;
+       }
+
+       list_add_tail(&be->be_list, extents);
+       return 0;
+
+out_put_deviceid:
+       nfs4_put_deviceid_node(be->be_device);
+out_free_be:
+       kfree(be);
+       return error;
+}
+
+static struct pnfs_layout_segment *
+bl_alloc_lseg(struct pnfs_layout_hdr *lo, struct nfs4_layoutget_res *lgr,
+               gfp_t gfp_mask)
+{
        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,
        };
+       struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
+       struct pnfs_layout_segment *lseg;
+       struct xdr_buf buf;
+       struct xdr_stream xdr;
+       struct page *scratch;
+       int status, i;
+       uint32_t count;
+       __be32 *p;
        LIST_HEAD(extents);
 
        dprintk("---> %s\n", __func__);
 
-       scratch = alloc_page(gfp_flags);
+       lseg = kzalloc(sizeof(*lseg), gfp_mask);
+       if (!lseg)
+               return ERR_PTR(-ENOMEM);
+
+       status = -ENOMEM;
+       scratch = alloc_page(gfp_mask);
        if (!scratch)
-               return -ENOMEM;
+               goto out;
 
-       xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages, lgr->layoutp->len);
-       xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
+       xdr_init_decode_pages(&xdr, &buf,
+                       lgr->layoutp->pages, lgr->layoutp->len);
+       xdr_set_scratch_buffer(&xdr, page_address(scratch), PAGE_SIZE);
 
-       p = xdr_inline_decode(&stream, 4);
+       status = -EIO;
+       p = xdr_inline_decode(&xdr, 4);
        if (unlikely(!p))
-               goto out_err;
+               goto out_free_scratch;
 
        count = be32_to_cpup(p++);
+       dprintk("%s: number of extents %d\n", __func__, count);
 
-       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.
+       /*
+        * 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++) {
-               struct nfs4_deviceid id;
-
-               be = kzalloc(sizeof(struct pnfs_block_extent), GFP_NOFS);
-               if (!be) {
-                       status = -ENOMEM;
-                       goto out_err;
-               }
-               memcpy(&id, p, NFS4_DEVICEID4_SIZE);
-               p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
-
-               be->be_device =
-                       nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode), &id,
-                                               lo->plh_lc_cred, gfp_flags);
-               if (!be->be_device)
-                       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 (verify_extent(be, &lv)) {
-                       dprintk("%s verify failed\n", __func__);
-                       goto out_err;
-               }
-               list_add_tail(&be->be_list, &extents);
+               status = bl_alloc_extent(&xdr, lo, &lv, &extents, gfp_mask);
+               if (status)
+                       goto process_extents;
        }
+
        if (lgr->range.offset + lgr->range.length !=
                        lv.start << SECTOR_SHIFT) {
                dprintk("%s Final length mismatch\n", __func__);
-               be = NULL;
-               goto out_err;
+               status = -EIO;
+               goto process_extents;
        }
+
        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.
-        */
-       list_for_each_entry_safe(be, save, &extents, be_list) {
-               list_del(&be->be_list);
-
-               status = ext_tree_insert(bl, be);
-               if (status)
-                       goto out_free_list;
+               status = -EIO;
        }
-       status = 0;
- out:
-       __free_page(scratch);
-       dprintk("%s returns %i\n", __func__, status);
-       return status;
 
- out_err:
-       nfs4_put_deviceid_node(be->be_device);
-       kfree(be);
- out_free_list:
+process_extents:
        while (!list_empty(&extents)) {
-               be = list_first_entry(&extents, struct pnfs_block_extent,
-                                     be_list);
+               struct pnfs_block_extent *be =
+                       list_first_entry(&extents, struct pnfs_block_extent,
+                                        be_list);
                list_del(&be->be_list);
-               nfs4_put_deviceid_node(be->be_device);
-               kfree(be);
-       }
-       goto out;
-}
 
-/* We pretty much ignore lseg, and store all data layout wide, so we
- * can correctly merge.
- */
-static struct pnfs_layout_segment *bl_alloc_lseg(struct pnfs_layout_hdr *lo,
-                                                struct nfs4_layoutget_res *lgr,
-                                                gfp_t gfp_flags)
-{
-       struct pnfs_layout_segment *lseg;
-       int status;
+               if (!status)
+                       status = ext_tree_insert(bl, be);
 
-       dprintk("%s enter\n", __func__);
-       lseg = kzalloc(sizeof(*lseg), gfp_flags);
-       if (!lseg)
-               return ERR_PTR(-ENOMEM);
-       status = nfs4_blk_process_layoutget(lo, lgr, gfp_flags);
+               if (status) {
+                       nfs4_put_deviceid_node(be->be_device);
+                       kfree(be);
+               }
+       }
+
+out_free_scratch:
+       __free_page(scratch);
+out:
+       dprintk("%s returns %d\n", __func__, status);
        if (status) {
-               /* We don't want to call the full-blown bl_free_lseg,
-                * since on error extents were not touched.
-                */
                kfree(lseg);
                return ERR_PTR(status);
        }