diff options
Diffstat (limited to 'fs/nfs')
| -rw-r--r-- | fs/nfs/blocklayout/blocklayout.h | 3 | ||||
| -rw-r--r-- | fs/nfs/blocklayout/extents.c | 47 |
2 files changed, 50 insertions, 0 deletions
diff --git a/fs/nfs/blocklayout/blocklayout.h b/fs/nfs/blocklayout/blocklayout.h index d645880f61a0..3e1b5fc152d7 100644 --- a/fs/nfs/blocklayout/blocklayout.h +++ b/fs/nfs/blocklayout/blocklayout.h @@ -153,6 +153,9 @@ int nfs4_blk_process_layoutget(struct pnfs_layout_hdr *lo, void bl_free_block_dev(struct pnfs_block_dev *bdev); /* extents.c */ +struct pnfs_block_extent * +bl_find_get_extent(struct pnfs_block_layout *bl, sector_t isect, + struct pnfs_block_extent **cow_read); void bl_put_extent(struct pnfs_block_extent *be); struct pnfs_block_extent *bl_alloc_extent(void); int bl_add_merge_extent(struct pnfs_block_layout *bl, diff --git a/fs/nfs/blocklayout/extents.c b/fs/nfs/blocklayout/extents.c index ee4891f32492..8fa93e23cb24 100644 --- a/fs/nfs/blocklayout/extents.c +++ b/fs/nfs/blocklayout/extents.c @@ -193,3 +193,50 @@ bl_add_merge_extent(struct pnfs_block_layout *bl, bl_put_extent(new); return -EIO; } + +/* Returns extent, or NULL. If a second READ extent exists, it is returned + * in cow_read, if given. + * + * The extents are kept in two seperate ordered lists, one for READ and NONE, + * one for READWRITE and INVALID. Within each list, we assume: + * 1. Extents are ordered by file offset. + * 2. For any given isect, there is at most one extents that matches. + */ +struct pnfs_block_extent * +bl_find_get_extent(struct pnfs_block_layout *bl, sector_t isect, + struct pnfs_block_extent **cow_read) +{ + struct pnfs_block_extent *be, *cow, *ret; + int i; + + dprintk("%s enter with isect %llu\n", __func__, (u64)isect); + cow = ret = NULL; + spin_lock(&bl->bl_ext_lock); + for (i = 0; i < EXTENT_LISTS; i++) { + list_for_each_entry_reverse(be, &bl->bl_extents[i], be_node) { + if (isect >= be->be_f_offset + be->be_length) + break; + if (isect >= be->be_f_offset) { + /* We have found an extent */ + dprintk("%s Get %p (%i)\n", __func__, be, + atomic_read(&be->be_refcnt.refcount)); + kref_get(&be->be_refcnt); + if (!ret) + ret = be; + else if (be->be_state != PNFS_BLOCK_READ_DATA) + bl_put_extent(be); + else + cow = be; + break; + } + } + if (ret && + (!cow_read || ret->be_state != PNFS_BLOCK_INVALID_DATA)) + break; + } + spin_unlock(&bl->bl_ext_lock); + if (cow_read) + *cow_read = cow; + print_bl_extent(ret); + return ret; +} |