2024-06-01 03:44:14

by Zhang Yi

[permalink] [raw]
Subject: [PATCH 06/10] ext4: update delalloc data reserve spcae in ext4_es_insert_extent()

From: Zhang Yi <[email protected]>

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().

Thers is one special case needs to concern is the quota claiming, when
bigalloc is enabled, if the delayed cluster allocation has been raced
by another no-delayed allocation(e.g. from fallocate) which doesn't
cover the delayed blocks:

|< one cluster >|
hhhhhhhhhhhhhhhhhhhdddddddddd
^ ^
|< >| < fallocate this range, don't claim quota again

We can't claim quota as usual because the fallocate has already claimed
it in ext4_mb_new_blocks(), we could notice this case through the
removed delalloc blocks count.

Signed-off-by: Zhang Yi <[email protected]>
---
fs/ext4/extents.c | 37 -------------------------------------
fs/ext4/extents_status.c | 22 +++++++++++++++++++++-
fs/ext4/indirect.c | 7 -------
3 files changed, 21 insertions(+), 45 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index e57054bdc5fd..8bc8a519f745 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4355,43 +4355,6 @@ 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 ced9826682bb..841f2f6d536d 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -856,6 +856,8 @@ 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;
+ struct rsvd_info rinfo;
+ int resv_used, pending = 0;
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
struct extent_status *es1 = NULL;
struct extent_status *es2 = NULL;
@@ -894,7 +896,7 @@ 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, &rinfo, es1);
if (err1 != 0)
goto error;
/* Free preallocated extent if it didn't get used. */
@@ -924,9 +926,27 @@ 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 bigalloc is enabled, allocating non-delayed allocated blocks
+ * which belong to delayed allocated clusters (from fallocate, filemap,
+ * DIO, or clusters allocated when delalloc has been disabled by
+ * ext4_nonda_switch()). Quota has been claimed by ext4_mb_new_blocks(),
+ * so release the quota reservations made for any previously delayed
+ * allocated clusters.
+ */
+ resv_used = rinfo.delonly_cluster + pending;
+ if (resv_used)
+ ext4_da_update_reserve_space(inode, resv_used,
+ rinfo.delonly_block);
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);
--
2.31.1