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-rw-r--r--fs/ext4/extents.c188
1 files changed, 28 insertions, 160 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 26481e543312..b52ac813ca20 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3819,83 +3819,6 @@ out:
return ext4_mark_inode_dirty(handle, inode);
}
-/**
- * Determines how many complete clusters (out of those specified by the 'map')
- * are under delalloc and were reserved quota for.
- * This function is called when we are writing out the blocks that were
- * originally written with their allocation delayed, but then the space was
- * allocated using fallocate() before the delayed allocation could be resolved.
- * The cases to look for are:
- * ('=' indicated delayed allocated blocks
- * '-' indicates non-delayed allocated blocks)
- * (a) partial clusters towards beginning and/or end outside of allocated range
- * are not delalloc'ed.
- * Ex:
- * |----c---=|====c====|====c====|===-c----|
- * |++++++ allocated ++++++|
- * ==> 4 complete clusters in above example
- *
- * (b) partial cluster (outside of allocated range) towards either end is
- * marked for delayed allocation. In this case, we will exclude that
- * cluster.
- * Ex:
- * |----====c========|========c========|
- * |++++++ allocated ++++++|
- * ==> 1 complete clusters in above example
- *
- * Ex:
- * |================c================|
- * |++++++ allocated ++++++|
- * ==> 0 complete clusters in above example
- *
- * The ext4_da_update_reserve_space will be called only if we
- * determine here that there were some "entire" clusters that span
- * this 'allocated' range.
- * In the non-bigalloc case, this function will just end up returning num_blks
- * without ever calling ext4_find_delalloc_range.
- */
-static unsigned int
-get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start,
- unsigned int num_blks)
-{
- struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
- ext4_lblk_t alloc_cluster_start, alloc_cluster_end;
- ext4_lblk_t lblk_from, lblk_to, c_offset;
- unsigned int allocated_clusters = 0;
-
- alloc_cluster_start = EXT4_B2C(sbi, lblk_start);
- alloc_cluster_end = EXT4_B2C(sbi, lblk_start + num_blks - 1);
-
- /* max possible clusters for this allocation */
- allocated_clusters = alloc_cluster_end - alloc_cluster_start + 1;
-
- trace_ext4_get_reserved_cluster_alloc(inode, lblk_start, num_blks);
-
- /* Check towards left side */
- c_offset = EXT4_LBLK_COFF(sbi, lblk_start);
- if (c_offset) {
- lblk_from = EXT4_LBLK_CMASK(sbi, lblk_start);
- lblk_to = lblk_from + c_offset - 1;
-
- if (ext4_es_scan_range(inode, &ext4_es_is_delayed, lblk_from,
- lblk_to))
- allocated_clusters--;
- }
-
- /* Now check towards right. */
- c_offset = EXT4_LBLK_COFF(sbi, lblk_start + num_blks);
- if (allocated_clusters && c_offset) {
- lblk_from = lblk_start + num_blks;
- lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1;
-
- if (ext4_es_scan_range(inode, &ext4_es_is_delayed, lblk_from,
- lblk_to))
- allocated_clusters--;
- }
-
- return allocated_clusters;
-}
-
static int
convert_initialized_extent(handle_t *handle, struct inode *inode,
struct ext4_map_blocks *map,
@@ -4077,23 +4000,6 @@ out:
}
map->m_len = allocated;
- /*
- * If we have done fallocate with the offset that is already
- * delayed allocated, we would have block reservation
- * and quota reservation done in the delayed write path.
- * But fallocate would have already updated quota and block
- * count for this offset. So cancel these reservation
- */
- if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
- unsigned int reserved_clusters;
- reserved_clusters = get_reserved_cluster_alloc(inode,
- map->m_lblk, map->m_len);
- if (reserved_clusters)
- ext4_da_update_reserve_space(inode,
- reserved_clusters,
- 0);
- }
-
map_out:
map->m_flags |= EXT4_MAP_MAPPED;
if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) {
@@ -4482,77 +4388,39 @@ got_allocated_blocks:
map->m_flags |= EXT4_MAP_NEW;
/*
- * Update reserved blocks/metadata blocks after successful
- * block allocation which had been deferred till now.
+ * Reduce the reserved cluster count to reflect successful deferred
+ * allocation of delayed allocated clusters or direct allocation of
+ * clusters discovered to be delayed allocated. Once allocated, a
+ * cluster is not included in the reserved count.
*/
- if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
- unsigned int reserved_clusters;
- /*
- * Check how many clusters we had reserved this allocated range
- */
- reserved_clusters = get_reserved_cluster_alloc(inode,
- map->m_lblk, allocated);
- if (!map_from_cluster) {
- BUG_ON(allocated_clusters < reserved_clusters);
- if (reserved_clusters < allocated_clusters) {
- struct ext4_inode_info *ei = EXT4_I(inode);
- int reservation = allocated_clusters -
- reserved_clusters;
- /*
- * It seems we claimed few clusters outside of
- * the range of this allocation. We should give
- * it back to the reservation pool. This can
- * happen in the following case:
- *
- * * Suppose s_cluster_ratio is 4 (i.e., each
- * cluster has 4 blocks. Thus, the clusters
- * are [0-3],[4-7],[8-11]...
- * * First comes delayed allocation write for
- * logical blocks 10 & 11. Since there were no
- * previous delayed allocated blocks in the
- * range [8-11], we would reserve 1 cluster
- * for this write.
- * * Next comes write for logical blocks 3 to 8.
- * In this case, we will reserve 2 clusters
- * (for [0-3] and [4-7]; and not for [8-11] as
- * that range has a delayed allocated blocks.
- * Thus total reserved clusters now becomes 3.
- * * Now, during the delayed allocation writeout
- * time, we will first write blocks [3-8] and
- * allocate 3 clusters for writing these
- * blocks. Also, we would claim all these
- * three clusters above.
- * * Now when we come here to writeout the
- * blocks [10-11], we would expect to claim
- * the reservation of 1 cluster we had made
- * (and we would claim it since there are no
- * more delayed allocated blocks in the range
- * [8-11]. But our reserved cluster count had
- * already gone to 0.
- *
- * Thus, at the step 4 above when we determine
- * that there are still some unwritten delayed
- * allocated blocks outside of our current
- * block range, we should increment the
- * reserved clusters count so that when the
- * remaining blocks finally gets written, we
- * could claim them.
- */
- dquot_reserve_block(inode,
- EXT4_C2B(sbi, reservation));
- spin_lock(&ei->i_block_reservation_lock);
- ei->i_reserved_data_blocks += reservation;
- spin_unlock(&ei->i_block_reservation_lock);
- }
+ if (test_opt(inode->i_sb, DELALLOC) && !map_from_cluster) {
+ if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
/*
- * We will claim quota for all newly allocated blocks.
- * We're updating the reserved space *after* the
- * correction above so we do not accidentally free
- * all the metadata reservation because we might
- * actually need it later on.
+ * When allocating delayed allocated clusters, simply
+ * reduce the reserved cluster count and claim quota
*/
ext4_da_update_reserve_space(inode, allocated_clusters,
1);
+ } else {
+ ext4_lblk_t lblk, len;
+ unsigned int n;
+
+ /*
+ * When allocating non-delayed allocated clusters
+ * (from fallocate, filemap, DIO, or clusters
+ * allocated when delalloc has been disabled by
+ * ext4_nonda_switch), reduce the reserved cluster
+ * count by the number of allocated clusters that
+ * have previously been delayed allocated. Quota
+ * has been claimed by ext4_mb_new_blocks() above,
+ * so release the quota reservations made for any
+ * previously delayed allocated clusters.
+ */
+ lblk = EXT4_LBLK_CMASK(sbi, map->m_lblk);
+ len = allocated_clusters << sbi->s_cluster_bits;
+ n = ext4_es_delayed_clu(inode, lblk, len);
+ if (n > 0)
+ ext4_da_update_reserve_space(inode, (int) n, 0);
}
}