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-rw-r--r--fs/nfs/blocklayout/extents.c935
1 files changed, 935 insertions, 0 deletions
diff --git a/fs/nfs/blocklayout/extents.c b/fs/nfs/blocklayout/extents.c
new file mode 100644
index 0000000..19fa7b0
--- /dev/null
+++ b/fs/nfs/blocklayout/extents.c
@@ -0,0 +1,935 @@
+/*
+ * 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);
+ }
+ }
+}