From: Zhang Yi <yi.zhang@xxxxxxxxxx>
Now that we update data reserved space for delalloc after allocating
new blocks in ext4_{ind|ext}_map_blocks(), and if bigalloc feature is
enabled, we also need to query the extents_status tree to calculate the
exact reserved clusters. This is complicated now and it appears that
it's better to do this job in ext4_es_insert_extent(), because
__es_remove_extent() have already count delalloc blocks when removing
delalloc extents and __revise_pending() return new adding pending count,
we could update the reserved blocks easily in ext4_es_insert_extent().
We direct reduce the reserved cluster count when replacing a delalloc
extent. However, thers are two special cases need to concern about the
quota claiming when doing direct block allocation (e.g. from fallocate).
A),
fallocate a range that covers a delalloc extent but start with
non-delayed allocated blocks, e.g. a hole.
hhhhhhh+ddddddd+ddddddd
^^^^^^^^^^^^^^^^^^^^^^^ fallocate this range
Current ext4_map_blocks() can't always trim the extent since it may
release i_data_sem before calling ext4_map_create_blocks() and raced by
another delayed allocation. Hence the EXT4_GET_BLOCKS_DELALLOC_RESERVE
may not set even when we are replacing a delalloc extent, without this
flag set, the quota has already been claimed by ext4_mb_new_blocks(), so
we should release the quota reservations instead of claim them again.
B),
bigalloc feature is enabled, fallocate a range that contains non-delayed
allocated blocks.
|< one cluster >|
hhhhhhh+hhhhhhh+hhhhhhh+ddddddd
^^^^^^^ fallocate this range
This case is similar to above case, the EXT4_GET_BLOCKS_DELALLOC_RESERVE
flag is also not set.
Hence we should release the quota reservations if we replace a delalloc
extent but without EXT4_GET_BLOCKS_DELALLOC_RESERVE set.
Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
---
fs/ext4/extents.c | 37 -------------------------------------
fs/ext4/extents_status.c | 25 ++++++++++++++++++++++++-
fs/ext4/indirect.c | 7 -------
3 files changed, 24 insertions(+), 45 deletions(-)
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 671dacd7c873..db8f9d79477c 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4357,43 +4357,6 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
goto out;
}
- /*
- * 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 (test_opt(inode->i_sb, DELALLOC) && allocated_clusters) {
- if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
- /*
- * 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);
- }
- }
-
/*
* Cache the extent and update transaction to commit on fdatasync only
* when it is _not_ an unwritten extent.
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index 0580bc4bc762..41adf0d69959 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -853,6 +853,7 @@ void ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
struct extent_status newes;
ext4_lblk_t end = lblk + len - 1;
int err1 = 0, err2 = 0, err3 = 0;
+ int resv_used = 0, pending = 0;
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
struct extent_status *es1 = NULL;
struct extent_status *es2 = NULL;
@@ -891,7 +892,7 @@ void ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
pr = __alloc_pending(true);
write_lock(&EXT4_I(inode)->i_es_lock);
- err1 = __es_remove_extent(inode, lblk, end, NULL, es1);
+ err1 = __es_remove_extent(inode, lblk, end, &resv_used, es1);
if (err1 != 0)
goto error;
/* Free preallocated extent if it didn't get used. */
@@ -921,9 +922,31 @@ void ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
__free_pending(pr);
pr = NULL;
}
+ pending = err3;
}
error:
write_unlock(&EXT4_I(inode)->i_es_lock);
+ /*
+ * 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.
+ *
+ * When direct allocating (from fallocate, filemap, DIO, or clusters
+ * allocated when delalloc has been disabled by ext4_nonda_switch())
+ * an extent either 1) contains delayed blocks but start with
+ * non-delayed allocated blocks (e.g. hole) or 2) contains non-delayed
+ * allocated blocks which belong to delayed allocated clusters when
+ * bigalloc feature is enabled, quota has already been claimed by
+ * ext4_mb_new_blocks(), so release the quota reservations made for
+ * any previously delayed allocated clusters instead of claim them
+ * again.
+ */
+ resv_used += pending;
+ if (resv_used)
+ ext4_da_update_reserve_space(inode, resv_used,
+ flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE);
+
if (err1 || err2 || err3 < 0)
goto retry;
diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c
index d8ca7f64f952..7404f0935c90 100644
--- a/fs/ext4/indirect.c
+++ b/fs/ext4/indirect.c
@@ -652,13 +652,6 @@ int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
ext4_update_inode_fsync_trans(handle, inode, 1);
count = ar.len;
- /*
- * Update reserved blocks/metadata blocks after successful block
- * allocation which had been deferred till now.
- */
- if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
- ext4_da_update_reserve_space(inode, count, 1);
-
got_it:
map->m_flags |= EXT4_MAP_MAPPED;
map->m_pblk = le32_to_cpu(chain[depth-1].key);
--
2.39.2
