forked from Minki/linux
03341d2cc9
Replace a stub, so that extents underlying the layouts are properly added, merged, or ignored as necessary. Signed-off-by: Fred Isaman <iisaman@citi.umich.edu> [pnfsblock: delete the new node before put it] Signed-off-by: Mingyang Guo <guomingyang@nrchpc.ac.cn> Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: Peng Tao <peng_tao@emc.com> Signed-off-by: Benny Halevy <bhalevy@tonian.com> Signed-off-by: Jim Rees <rees@umich.edu> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
196 lines
5.9 KiB
C
196 lines
5.9 KiB
C
/*
|
|
* linux/fs/nfs/blocklayout/blocklayout.h
|
|
*
|
|
* Module for the NFSv4.1 pNFS block 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 "blocklayout.h"
|
|
#define NFSDBG_FACILITY NFSDBG_PNFS_LD
|
|
|
|
static void print_bl_extent(struct pnfs_block_extent *be)
|
|
{
|
|
dprintk("PRINT EXTENT extent %p\n", be);
|
|
if (be) {
|
|
dprintk(" be_f_offset %llu\n", (u64)be->be_f_offset);
|
|
dprintk(" be_length %llu\n", (u64)be->be_length);
|
|
dprintk(" be_v_offset %llu\n", (u64)be->be_v_offset);
|
|
dprintk(" be_state %d\n", be->be_state);
|
|
}
|
|
}
|
|
|
|
static void
|
|
destroy_extent(struct kref *kref)
|
|
{
|
|
struct pnfs_block_extent *be;
|
|
|
|
be = container_of(kref, struct pnfs_block_extent, be_refcnt);
|
|
dprintk("%s be=%p\n", __func__, be);
|
|
kfree(be);
|
|
}
|
|
|
|
void
|
|
bl_put_extent(struct pnfs_block_extent *be)
|
|
{
|
|
if (be) {
|
|
dprintk("%s enter %p (%i)\n", __func__, be,
|
|
atomic_read(&be->be_refcnt.refcount));
|
|
kref_put(&be->be_refcnt, destroy_extent);
|
|
}
|
|
}
|
|
|
|
struct pnfs_block_extent *bl_alloc_extent(void)
|
|
{
|
|
struct pnfs_block_extent *be;
|
|
|
|
be = kmalloc(sizeof(struct pnfs_block_extent), GFP_NOFS);
|
|
if (!be)
|
|
return NULL;
|
|
INIT_LIST_HEAD(&be->be_node);
|
|
kref_init(&be->be_refcnt);
|
|
be->be_inval = NULL;
|
|
return be;
|
|
}
|
|
|
|
static void print_elist(struct list_head *list)
|
|
{
|
|
struct pnfs_block_extent *be;
|
|
dprintk("****************\n");
|
|
dprintk("Extent list looks like:\n");
|
|
list_for_each_entry(be, list, be_node) {
|
|
print_bl_extent(be);
|
|
}
|
|
dprintk("****************\n");
|
|
}
|
|
|
|
static inline int
|
|
extents_consistent(struct pnfs_block_extent *old, struct pnfs_block_extent *new)
|
|
{
|
|
/* Note this assumes new->be_f_offset >= old->be_f_offset */
|
|
return (new->be_state == old->be_state) &&
|
|
((new->be_state == PNFS_BLOCK_NONE_DATA) ||
|
|
((new->be_v_offset - old->be_v_offset ==
|
|
new->be_f_offset - old->be_f_offset) &&
|
|
new->be_mdev == old->be_mdev));
|
|
}
|
|
|
|
/* Adds new to appropriate list in bl, modifying new and removing existing
|
|
* extents as appropriate to deal with overlaps.
|
|
*
|
|
* See bl_find_get_extent for list constraints.
|
|
*
|
|
* Refcount on new is already set. If end up not using it, or error out,
|
|
* need to put the reference.
|
|
*
|
|
* bl->bl_ext_lock is held by caller.
|
|
*/
|
|
int
|
|
bl_add_merge_extent(struct pnfs_block_layout *bl,
|
|
struct pnfs_block_extent *new)
|
|
{
|
|
struct pnfs_block_extent *be, *tmp;
|
|
sector_t end = new->be_f_offset + new->be_length;
|
|
struct list_head *list;
|
|
|
|
dprintk("%s enter with be=%p\n", __func__, new);
|
|
print_bl_extent(new);
|
|
list = &bl->bl_extents[bl_choose_list(new->be_state)];
|
|
print_elist(list);
|
|
|
|
/* Scan for proper place to insert, extending new to the left
|
|
* as much as possible.
|
|
*/
|
|
list_for_each_entry_safe(be, tmp, list, be_node) {
|
|
if (new->be_f_offset < be->be_f_offset)
|
|
break;
|
|
if (end <= be->be_f_offset + be->be_length) {
|
|
/* new is a subset of existing be*/
|
|
if (extents_consistent(be, new)) {
|
|
dprintk("%s: new is subset, ignoring\n",
|
|
__func__);
|
|
bl_put_extent(new);
|
|
return 0;
|
|
} else
|
|
goto out_err;
|
|
} else if (new->be_f_offset <=
|
|
be->be_f_offset + be->be_length) {
|
|
/* new overlaps or abuts existing be */
|
|
if (extents_consistent(be, new)) {
|
|
/* extend new to fully replace be */
|
|
new->be_length += new->be_f_offset -
|
|
be->be_f_offset;
|
|
new->be_f_offset = be->be_f_offset;
|
|
new->be_v_offset = be->be_v_offset;
|
|
dprintk("%s: removing %p\n", __func__, be);
|
|
list_del(&be->be_node);
|
|
bl_put_extent(be);
|
|
} else if (new->be_f_offset !=
|
|
be->be_f_offset + be->be_length)
|
|
goto out_err;
|
|
}
|
|
}
|
|
/* Note that if we never hit the above break, be will not point to a
|
|
* valid extent. However, in that case &be->be_node==list.
|
|
*/
|
|
list_add_tail(&new->be_node, &be->be_node);
|
|
dprintk("%s: inserting new\n", __func__);
|
|
print_elist(list);
|
|
/* Scan forward for overlaps. If we find any, extend new and
|
|
* remove the overlapped extent.
|
|
*/
|
|
be = list_prepare_entry(new, list, be_node);
|
|
list_for_each_entry_safe_continue(be, tmp, list, be_node) {
|
|
if (end < be->be_f_offset)
|
|
break;
|
|
/* new overlaps or abuts existing be */
|
|
if (extents_consistent(be, new)) {
|
|
if (end < be->be_f_offset + be->be_length) {
|
|
/* extend new to fully cover be */
|
|
end = be->be_f_offset + be->be_length;
|
|
new->be_length = end - new->be_f_offset;
|
|
}
|
|
dprintk("%s: removing %p\n", __func__, be);
|
|
list_del(&be->be_node);
|
|
bl_put_extent(be);
|
|
} else if (end != be->be_f_offset) {
|
|
list_del(&new->be_node);
|
|
goto out_err;
|
|
}
|
|
}
|
|
dprintk("%s: after merging\n", __func__);
|
|
print_elist(list);
|
|
/* FIXME - The per-list consistency checks have all been done,
|
|
* should now check cross-list consistency.
|
|
*/
|
|
return 0;
|
|
|
|
out_err:
|
|
bl_put_extent(new);
|
|
return -EIO;
|
|
}
|