diff options
Diffstat (limited to 'fs/nfs/blocklayout/extents.c')
| -rw-r--r-- | fs/nfs/blocklayout/extents.c | 935 |
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 000000000000..19fa7b0b8c00 --- /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); + } + } +} |