From: Fred <iisaman@xxxxxxxxxxxxxx>
Implement find_get_extent(), one of the core extent manipulation
routines.
[pnfsblock: Lookup list entry of layouts and tags in reverse order]
Signed-off-by: Zhang Jingwang <zhangjingwang@xxxxxxxxxxxx>
Signed-off-by: Fred Isaman <iisaman@xxxxxxxxxxxxxx>
Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx>
pnfsblock: fix print format warnings for sector_t and size_t
gcc spews warnings about these on x86_64, e.g.:
fs/nfs/blocklayout/blocklayout.c:74: warning: format â%Luâ expects type âlong long unsigned intâ, but argument 2 has type âsector_tâ
fs/nfs/blocklayout/blocklayout.c:388: warning: format â%dâ expects type âintâ, but argument 5 has type âsize_tâ
Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx>
---
fs/nfs/blocklayout/blocklayout.h | 3 ++
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 0a54feb..04eb6de 100644
--- a/fs/nfs/blocklayout/blocklayout.h
+++ b/fs/nfs/blocklayout/blocklayout.h
@@ -219,6 +219,9 @@ int nfs4_blk_process_layoutget(struct pnfs_layout_hdr *lo,
/* blocklayoutdm.c */
void free_block_dev(struct pnfs_block_dev *bdev);
/* extents.c */
+struct pnfs_block_extent *
+find_get_extent(struct pnfs_block_layout *bl, sector_t isect,
+ struct pnfs_block_extent **cow_read);
void put_extent(struct pnfs_block_extent *be);
struct pnfs_block_extent *alloc_extent(void);
int add_and_merge_extent(struct pnfs_block_layout *bl,
diff --git a/fs/nfs/blocklayout/extents.c b/fs/nfs/blocklayout/extents.c
index 26c263f..f0b3f13 100644
--- a/fs/nfs/blocklayout/extents.c
+++ b/fs/nfs/blocklayout/extents.c
@@ -201,3 +201,50 @@ add_and_merge_extent(struct pnfs_block_layout *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 *
+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++) {
+ if (ret &&
+ (!cow_read || ret->be_state != PNFS_BLOCK_INVALID_DATA))
+ break;
+ 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)
+ put_extent(be);
+ else
+ cow = be;
+ break;
+ }
+ }
+ }
+ spin_unlock(&bl->bl_ext_lock);
+ if (cow_read)
+ *cow_read = cow;
+ print_bl_extent(ret);
+ return ret;
+}
--
1.7.4.1
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