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authorFred Isaman <iisaman@citi.umich.edu>2011-07-30 20:52:49 -0400
committerTrond Myklebust <Trond.Myklebust@netapp.com>2011-07-31 12:18:17 -0400
commitc1c2a4cd352269f1fb585b4a5c63abe24dd946c6 (patch)
tree0fc7470702b0fc3e7d156ac49285ec58de797fa3 /fs/nfs/blocklayout/extents.c
parent6d742ba538f98164f3c5e05cdcadb4ec6ddf504f (diff)
pnfsblock: add extent manipulation functions
Adds working implementations of various support functions to handle INVAL extents, needed by writes, such as bl_mark_sectors_init and bl_is_sector_init. [pnfsblock: fix 64-bit compiler warnings for extent manipulation] Signed-off-by: Fred Isaman <iisaman@citi.umich.edu> Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: Benny Halevy <bhalevy@tonian.com> [Implement release_inval_marks] Signed-off-by: Zhang Jingwang <zhangjingwang@nrchpc.ac.cn> Signed-off-by: Jim Rees <rees@umich.edu> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/blocklayout/extents.c')
-rw-r--r--fs/nfs/blocklayout/extents.c253
1 files changed, 253 insertions, 0 deletions
diff --git a/fs/nfs/blocklayout/extents.c b/fs/nfs/blocklayout/extents.c
index 8fa93e23cb2..473faee9cde 100644
--- a/fs/nfs/blocklayout/extents.c
+++ b/fs/nfs/blocklayout/extents.c
@@ -33,6 +33,259 @@
#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;
+}
+
+/* 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;
+}
+
static void print_bl_extent(struct pnfs_block_extent *be)
{
dprintk("PRINT EXTENT extent %p\n", be);