/*
* 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
/* Bit numbers */
#define EXTENT_INITIALIZED 0
#define EXTENT_WRITTEN 1
#define EXTENT_IN_COMMIT 2
#define INTERNAL_EXISTS MY_MAX_TAGS
#define INTERNAL_MASK ((1 << INTERNAL_EXISTS) - 1)
/* Returns largest t<=s s.t. t%base==0 */
static inline sector_t normalize(sector_t s, int base)
{
sector_t tmp = s; /* Since do_div modifies its argument */
return s - do_div(tmp, base);
}
static inline sector_t normalize_up(sector_t s, int base)
{
return normalize(s + base - 1, base);
}
/* Complete stub using list while determine API wanted */
/* Returns tags, or negative */
static int32_t _find_entry(struct my_tree *tree, u64 s)
{
struct pnfs_inval_tracking *pos;
dprintk("%s(%llu) enter\n", __func__, s);
list_for_each_entry_reverse(pos, &tree->mtt_stub, it_link) {
if (pos->it_sector > s)
continue;
else if (pos->it_sector == s)
return pos->it_tags & INTERNAL_MASK;
else
break;
}
return -ENOENT;
}
static inline
int _has_tag(struct my_tree *tree, u64 s, int32_t tag)
{
int32_t tags;
dprintk("%s(%llu, %i) enter\n", __func__, s, tag);
s = normalize(s, tree->mtt_step_size);
tags = _find_entry(tree, s);
if ((tags < 0) || !(tags & (1 << tag)))
return 0;
else
return 1;
}
/* Creates entry with tag, or if entry already exists, unions tag to it.
* If storage is not NULL, newly created entry will use it.
* Returns number of entries added, or negative on error.
*/
static int _add_entry(struct my_tree *tree, u64 s, int32_t tag,
struct pnfs_inval_tracking *storage)
{
int found = 0;
struct pnfs_inval_tracking *pos;
dprintk("%s(%llu, %i, %p) enter\n", __func__, s, tag, storage);
list_for_each_entry_reverse(pos, &tree->mtt_stub, it_link) {
if (pos->it_sector > s)
continue;
else if (pos->it_sector == s) {
found = 1;
break;
} else
break;
}
if (found) {
pos->it_tags |= (1 << tag);
return 0;
} else {
struct pnfs_inval_tracking *new;
if (storage)
new = storage;
else {
new = kmalloc(sizeof(*new), GFP_NOFS);
if (!new)
return -ENOMEM;
}
new->it_sector = s;
new->it_tags = (1 << tag);
list_add(&new->it_link, &pos->it_link);
return 1;
}
}
/* XXXX Really want option to not create */
/* Over range, unions tag with existing entries, else creates entry with tag */
static int _set_range(struct my_tree *tree, int32_t tag, u64 s, u64 length)
{
u64 i;
dprintk("%s(%i, %llu, %llu) enter\n", __func__, tag, s, length);
for (i = normalize(s, tree->mtt_step_size); i < s + length;
i += tree->mtt_step_size)
if (_add_entry(tree, i, tag, NULL))
return -ENOMEM;
return 0;
}
/* Ensure that future operations on given range of tree will not malloc */
static int _preload_range(struct my_tree *tree, u64 offset, u64 length)
{
u64 start, end, s;
int count, i, used = 0, status = -ENOMEM;
struct pnfs_inval_tracking **storage;
dprintk("%s(%llu, %llu) enter\n", __func__, offset, length);
start = normalize(offset, tree->mtt_step_size);
end = normalize_up(offset + length, tree->mtt_step_size);
count = (int)(end - start) / (int)tree->mtt_step_size;
/* Pre-malloc what memory we might need */
storage = kmalloc(sizeof(*storage) * count, GFP_NOFS);
if (!storage)
return -ENOMEM;
for (i = 0; i < count; i++) {
storage[i] = kmalloc(sizeof(struct pnfs_inval_tracking),
GFP_NOFS);
if (!storage[i])
goto out_cleanup;
}
/* Now need lock - HOW??? */
for (s = start; s < end; s += tree->mtt_step_size)
used += _add_entry(tree, s, INTERNAL_EXISTS, storage[used]);
/* Unlock - HOW??? */
status = 0;
out_cleanup:
for (i = used; i < count; i++) {
if (!storage[i])
break;
kfree(storage[i]);
}
kfree(storage);
return status;
}
static void set_needs_init(sector_t *array, sector_t offset)
{
sector_t *p = array;
dprintk("%s enter\n", __func__);
if (!p)
return;
while (*p < offset)
p++;
if (*p == offset)
return;
else if (*p == ~0) {
*p++ = offset;
*p = ~0;
return;
} else {
sector_t *save = p;
dprintk("%s Adding %llu\n", __func__, (u64)offset);
while (*p != ~0)
p++;
p++;
memmove(save + 1, save, (char *)p - (char *)save);
*save = offset;
return;
}
}
/* We are relying on page lock to serialize this */
int bl_is_sector_init(struct pnfs_inval_markings *marks, sector_t isect)
{
int rv;
spin_lock(&marks->im_lock);
rv = _has_tag(&marks->im_tree, isect, EXTENT_INITIALIZED);
spin_unlock(&marks->im_lock);
return rv;
}
/* Assume start, end already sector aligned */
static int
_range_has_tag(struct my_tree *tree, u64 start, u64 end, int32_t tag)
{
struct pnfs_inval_tracking *pos;
u64 expect = 0;
dprintk("%s(%llu, %llu, %i) enter\n", __func__, start, end, tag);
list_for_each_entry_reverse(pos, &tree->mtt_stub, it_link) {
if (pos->it_sector >= end)
continue;
if (!expect) {
if ((pos->it_sector == end - tree->mtt_step_size) &&
(pos->it_tags & (1 << tag))) {
expect = pos->it_sector - tree->mtt_step_size;
if (pos->it_sector < tree->mtt_step_size || expect < start)
return 1;
continue;
} else {
return 0;
}
}
if (pos->it_sector != expect || !(pos->it_tags & (1 << tag)))
return 0;
expect -= tree->mtt_step_size;
if (expect < start)
return 1;
}
return 0;
}
static int is_range_written(struct pnfs_inval_markings *marks,
sector_t start, sector_t end)
{
int rv;
spin_lock(&marks->im_lock);
rv = _range_has_tag(&marks->im_tree, start, end, EXTENT_WRITTEN);
spin_unlock(&marks->im_lock);
return rv;
}
/* Marks sectors in [offest, offset_length) as having been initialized.
* All lengths are step-aligned, where step is min(pagesize, blocksize).
* Notes where partial block is initialized, and helps prepare it for
* complete initialization later.
*/
/* Currently assumes offset is page-aligned */
int bl_mark_sectors_init(struct pnfs_inval_markings *marks,
sector_t offset, sector_t length,
sector_t **pages)
{
sector_t s, start, end;
sector_t *array = NULL; /* Pages to mark */
dprintk("%s(offset=%llu,len=%llu) enter\n",
__func__, (u64)offset, (u64)length);
s = max((sector_t) 3,
2 * (marks->im_block_size / (PAGE_CACHE_SECTORS)));
dprintk("%s set max=%llu\n", __func__, (u64)s);
if (pages) {
array = kmalloc(s * sizeof(sector_t), GFP_NOFS);
if (!array)
goto outerr;
array[0] = ~0;
}
start = normalize(offset, marks->im_block_size);
end = normalize_up(offset + length, marks->im_block_size);
if (_preload_range(&marks->im_tree, start, end - start))
goto outerr;
spin_lock(&marks->im_lock);
for (s = normalize_up(start, PAGE_CACHE_SECTORS);
s < offset; s += PAGE_CACHE_SECTORS) {
dprintk("%s pre-area pages\n", __func__);
/* Portion of used block is not initialized */
if (!_has_tag(&marks->im_tree, s, EXTENT_INITIALIZED))
set_needs_init(array, s);
}
if (_set_range(&marks->im_tree, EXTENT_INITIALIZED, offset, length))
goto out_unlock;
for (s = normalize_up(offset + length, PAGE_CACHE_SECTORS);
s < end; s += PAGE_CACHE_SECTORS) {
dprintk("%s post-area pages\n", __func__);
if (!_has_tag(&marks->im_tree, s, EXTENT_INITIALIZED))
set_needs_init(array, s);
}
spin_unlock(&marks->im_lock);
if (pages) {
if (array[0] == ~0) {
kfree(array);
*pages = NULL;
} else
*pages = array;
}
return 0;
out_unlock:
spin_unlock(&marks->im_lock);
outerr:
if (pages) {
kfree(array);
*pages = NULL;
}
return -ENOMEM;
}
/* Marks sectors in [offest, offset+length) as having been written to disk.
* All lengths should be block aligned.
*/
static int mark_written_sectors(struct pnfs_inval_markings *marks,
sector_t offset, sector_t length)
{
int status;
dprintk("%s(offset=%llu,len=%llu) enter\n", __func__,
(u64)offset, (u64)length);
spin_lock(&marks->im_lock);
status = _set_range(&marks->im_tree, EXTENT_WRITTEN, offset, length);
spin_unlock(&marks->im_lock);
return status;
}
static void print_short_extent(struct pnfs_block_short_extent *be)
{
dprintk("PRINT SHORT EXTENT extent %p\n", be);
if (be) {
dprintk(" be_f_offset %llu\n", (u64)be->bse_f_offset);
dprintk(" be_length %llu\n", (u64)be->bse_length);
}
}
static void print_clist(struct list_head *list, unsigned int count)
{
struct pnfs_block_short_extent *be;
unsigned int i = 0;
ifdebug(FACILITY) {
printk(KERN_DEBUG "****************\n");
printk(KERN_DEBUG "Extent list looks like:\n");
list_for_each_entry(be, list, bse_node) {
i++;
print_short_extent(be);
}
if (i != count)
printk(KERN_DEBUG "\n\nExpected %u entries\n\n\n", count);
printk(KERN_DEBUG "****************\n");
}
}
/* Note: In theory, we should do more checking that devid's match between
* old and new, but if they don't, the lists are too corrupt to salvage anyway.
*/
/* Note this is very similar to bl_add_merge_extent */
static void add_to_commitlist(struct pnfs_block_layout *bl,
struct pnfs_block_short_extent *new)
{
struct list_head *clist = &bl->bl_commit;
struct pnfs_block_short_extent *old, *save;
sector_t end = new->bse_f_offset + new->bse_length;
dprintk("%s enter\n", __func__);
print_short_extent(new);
print_clist(clist, bl->bl_count);
bl->bl_count++;
/* Scan for proper place to insert, extending new to the left
* as much as possible.
*/
list_for_each_entry_safe(old, save, clist, bse_node) {
if (new->bse_f_offset < old->bse_f_offset)
break;
if (end <= old->bse_f_offset + old->bse_length) {
/* Range is already in list */
bl->bl_count--;
kfree(new);
return;
} else if (new->bse_f_offset <=
old->bse_f_offset + old->bse_length) {
/* new overlaps or abuts existing be */
if (new->bse_mdev == old->bse_mdev) {
/* extend new to fully replace old */
new->bse_length += new->bse_f_offset -
old->bse_f_offset;
new->bse_f_offset = old->bse_f_offset;
list_del(&old->bse_node);
bl->bl_count--;
kfree(old);
}
}
}
/* Note that if we never hit the above break, old will not point to a
* valid extent. However, in that case &old->bse_node==list.
*/
list_add_tail(&new->bse_node, &old->bse_node);
/* Scan forward for overlaps. If we find any, extend new and
* remove the overlapped extent.
*/
old = list_prepare_entry(new, clist, bse_node);
list_for_each_entry_safe_continue(old, save, clist, bse_node) {
if (end < old->bse_f_offset)
break;
/* new overlaps or abuts old */
if (new->bse_mdev == old->bse_mdev) {
if (end < old->bse_f_offset + old->bse_length) {
/* extend new to fully cover old */
end = old->bse_f_offset + old->bse_length;
new->bse_length = end - new->bse_f_offset;
}
list_del(&old->bse_node);
bl->bl_count--;
kfree(old);
}
}
dprintk("%s: after merging\n", __func__);
print_clist(clist, bl->bl_count);
}
/* Note the range described by offset, length is guaranteed to be contained
* within be.
*/
int bl_mark_for_commit(struct pnfs_block_extent *be,
sector_t offset, sector_t length)
{
sector_t new_end, end = offset + length;
struct pnfs_block_short_extent *new;
struct pnfs_block_layout *bl = container_of(be->be_inval,
struct pnfs_block_layout,
bl_inval);
new = kmalloc(sizeof(*new), GFP_NOFS);
if (!new)
return -ENOMEM;
mark_written_sectors(be->be_inval, offset, length);
/* We want to add the range to commit list, but it must be
* block-normalized, and verified that the normalized range has
* been entirely written to disk.
*/
new->bse_f_offset = offset;
offset = normalize(offset, bl->bl_blocksize);
if (offset < new->bse_f_offset) {
if (is_range_written(be->be_inval, offset, new->bse_f_offset))
new->bse_f_offset = offset;
else
new->bse_f_offset = offset + bl->bl_blocksize;
}
new_end = normalize_up(end, bl->bl_blocksize);
if (end < new_end) {
if (is_range_written(be->be_inval, end, new_end))
end = new_end;
else
end = new_end - bl->bl_blocksize;
}
if (end <= new->bse_f_offset) {
kfree(new);
return 0;
}
new->bse_length = end - new->bse_f_offset;
new->bse_devid = be->be_devid;
new->bse_mdev = be->be_mdev;
spin_lock(&bl->bl_ext_lock);
/* new will be freed, either by add_to_commitlist if it decides not
* to use it, or after LAYOUTCOMMIT uses it in the commitlist.
*/
add_to_commitlist(bl, new);
spin_unlock(&bl->bl_ext_lock);
return 0;
}
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_reverse(be, tmp, list, be_node) {
if (new->be_f_offset >= be->be_f_offset + be->be_length)
break;
if (new->be_f_offset >= be->be_f_offset) {
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 {
/* |<-- be -->|
* |<-- new -->| */
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 {
goto out_err;
}
}
} else if (end >= be->be_f_offset + be->be_length) {
/* new extent overlap existing be */
if (extents_consistent(be, new)) {
/* extend new to fully replace be */
dprintk("%s: removing %p\n", __func__, be);
list_del(&be->be_node);
bl_put_extent(be);
} else {
goto out_err;
}
} else if (end > be->be_f_offset) {
/* |<-- be -->|
*|<-- new -->| */
if (extents_consistent(new, be)) {
/* extend new to fully replace be */
new->be_length += be->be_f_offset + be->be_length -
new->be_f_offset - new->be_length;
dprintk("%s: removing %p\n", __func__, be);
list_del(&be->be_node);
bl_put_extent(be);
} else {
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(&new->be_node, &be->be_node);
dprintk("%s: inserting new\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;
}
/* 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;
}
/* Similar to bl_find_get_extent, but called with lock held, and ignores cow */
static struct pnfs_block_extent *
bl_find_get_extent_locked(struct pnfs_block_layout *bl, sector_t isect)
{
struct pnfs_block_extent *be, *ret = NULL;
int i;
dprintk("%s enter with isect %llu\n", __func__, (u64)isect);
for (i = 0; i < EXTENT_LISTS; i++) {
if (ret)
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);
ret = be;
break;
}
}
}
print_bl_extent(ret);
return ret;
}
int
encode_pnfs_block_layoutupdate(struct pnfs_block_layout *bl,
struct xdr_stream *xdr,
const struct nfs4_layoutcommit_args *arg)
{
struct pnfs_block_short_extent *lce, *save;
unsigned int count = 0;
__be32 *p, *xdr_start;
dprintk("%s enter\n", __func__);
/* BUG - creation of bl_commit is buggy - need to wait for
* entire block to be marked WRITTEN before it can be added.
*/
spin_lock(&bl->bl_ext_lock);
/* Want to adjust for possible truncate */
/* We now want to adjust argument range */
/* XDR encode the ranges found */
xdr_start = xdr_reserve_space(xdr, 8);
if (!xdr_start)
goto out;
list_for_each_entry_safe(lce, save, &bl->bl_commit, bse_node) {
p = xdr_reserve_space(xdr, 7 * 4 + sizeof(lce->bse_devid.data));
if (!p)
break;
p = xdr_encode_opaque_fixed(p, lce->bse_devid.data, NFS4_DEVICEID4_SIZE);
p = xdr_encode_hyper(p, lce->bse_f_offset << SECTOR_SHIFT);
p = xdr_encode_hyper(p, lce->bse_length << SECTOR_SHIFT);
p = xdr_encode_hyper(p, 0LL);
*p++ = cpu_to_be32(PNFS_BLOCK_READWRITE_DATA);
list_del(&lce->bse_node);
list_add_tail(&lce->bse_node, &bl->bl_committing);
bl->bl_count--;
count++;
}
xdr_start[0] = cpu_to_be32((xdr->p - xdr_start - 1) * 4);
xdr_start[1] = cpu_to_be32(count);
out:
spin_unlock(&bl->bl_ext_lock);
dprintk("%s found %i ranges\n", __func__, count);
return 0;
}
/* Helper function to set_to_rw that initialize a new extent */
static void
_prep_new_extent(struct pnfs_block_extent *new,
struct pnfs_block_extent *orig,
sector_t offset, sector_t length, int state)
{
kref_init(&new->be_refcnt);
/* don't need to INIT_LIST_HEAD(&new->be_node) */
memcpy(&new->be_devid, &orig->be_devid, sizeof(struct nfs4_deviceid));
new->be_mdev = orig->be_mdev;
new->be_f_offset = offset;
new->be_length = length;
new->be_v_offset = orig->be_v_offset - orig->be_f_offset + offset;
new->be_state = state;
new->be_inval = orig->be_inval;
}
/* Tries to merge be with extent in front of it in list.
* Frees storage if not used.
*/
static struct pnfs_block_extent *
_front_merge(struct pnfs_block_extent *be, struct list_head *head,
struct pnfs_block_extent *storage)
{
struct pnfs_block_extent *prev;
if (!storage)
goto no_merge;
if (&be->be_node == head || be->be_node.prev == head)
goto no_merge;
prev = list_entry(be->be_node.prev, struct pnfs_block_extent, be_node);
if ((prev->be_f_offset + prev->be_length != be->be_f_offset) ||
!extents_consistent(prev, be))
goto no_merge;
_prep_new_extent(storage, prev, prev->be_f_offset,
prev->be_length + be->be_length, prev->be_state);
list_replace(&prev->be_node, &storage->be_node);
bl_put_extent(prev);
list_del(&be->be_node);
bl_put_extent(be);
return storage;
no_merge:
kfree(storage);
return be;
}
static u64
set_to_rw(struct pnfs_block_layout *bl, u64 offset, u64 length)
{
u64 rv = offset + length;
struct pnfs_block_extent *be, *e1, *e2, *e3, *new, *old;
struct pnfs_block_extent *children[3];
struct pnfs_block_extent *merge1 = NULL, *merge2 = NULL;
int i = 0, j;
dprintk("%s(%llu, %llu)\n", __func__, offset, length);
/* Create storage for up to three new extents e1, e2, e3 */
e1 = kmalloc(sizeof(*e1), GFP_ATOMIC);
e2 = kmalloc(sizeof(*e2), GFP_ATOMIC);
e3 = kmalloc(sizeof(*e3), GFP_ATOMIC);
/* BUG - we are ignoring any failure */
if (!e1 || !e2 || !e3)
goto out_nosplit;
spin_lock(&bl->bl_ext_lock);
be = bl_find_get_extent_locked(bl, offset);
rv = be->be_f_offset + be->be_length;
if (be->be_state != PNFS_BLOCK_INVALID_DATA) {
spin_unlock(&bl->bl_ext_lock);
goto out_nosplit;
}
/* Add e* to children, bumping e*'s krefs */
if (be->be_f_offset != offset) {
_prep_new_extent(e1, be, be->be_f_offset,
offset - be->be_f_offset,
PNFS_BLOCK_INVALID_DATA);
children[i++] = e1;
print_bl_extent(e1);
} else
merge1 = e1;
_prep_new_extent(e2, be, offset,
min(length, be->be_f_offset + be->be_length - offset),
PNFS_BLOCK_READWRITE_DATA);
children[i++] = e2;
print_bl_extent(e2);
if (offset + length < be->be_f_offset + be->be_length) {
_prep_new_extent(e3, be, e2->be_f_offset + e2->be_length,
be->be_f_offset + be->be_length -
offset - length,
PNFS_BLOCK_INVALID_DATA);
children[i++] = e3;
print_bl_extent(e3);
} else
merge2 = e3;
/* Remove be from list, and insert the e* */
/* We don't get refs on e*, since this list is the base reference
* set when init'ed.
*/
if (i < 3)
children[i] = NULL;
new = children[0];
list_replace(&be->be_node, &new->be_node);
bl_put_extent(be);
new = _front_merge(new, &bl->bl_extents[RW_EXTENT], merge1);
for (j = 1; j < i; j++) {
old = new;
new = children[j];
list_add(&new->be_node, &old->be_node);
}
if (merge2) {
/* This is a HACK, should just create a _back_merge function */
new = list_entry(new->be_node.next,
struct pnfs_block_extent, be_node);
new = _front_merge(new, &bl->bl_extents[RW_EXTENT], merge2);
}
spin_unlock(&bl->bl_ext_lock);
/* Since we removed the base reference above, be is now scheduled for
* destruction.
*/
bl_put_extent(be);
dprintk("%s returns %llu after split\n", __func__, rv);
return rv;
out_nosplit:
kfree(e1);
kfree(e2);
kfree(e3);
dprintk("%s returns %llu without splitting\n", __func__, rv);
return rv;
}
void
clean_pnfs_block_layoutupdate(struct pnfs_block_layout *bl,
const struct nfs4_layoutcommit_args *arg,
int status)
{
struct pnfs_block_short_extent *lce, *save;
dprintk("%s status %d\n", __func__, status);
list_for_each_entry_safe(lce, save, &bl->bl_committing, bse_node) {
if (likely(!status)) {
u64 offset = lce->bse_f_offset;
u64 end = offset + lce->bse_length;
do {
offset = set_to_rw(bl, offset, end - offset);
} while (offset < end);
list_del(&lce->bse_node);
kfree(lce);
} else {
list_del(&lce->bse_node);
spin_lock(&bl->bl_ext_lock);
add_to_commitlist(bl, lce);
spin_unlock(&bl->bl_ext_lock);
}
}
}
