mirrors/scoutfs
1
0
Fork 0
mirror of https://github.com/versity/scoutfs.git synced 2026-09-10 01:56:09 +00:00
Code Issues Packages Projects Releases Wiki Activity

scoutfs: maintain free_blocks in one place

Browse Source 
The free_blocks counter in the super is meant to track the number of
total blocks in the primary free extent index.  Callers of extent
manipulation were trying to keep it in sync with the extents.

Segment allocation was allocating extents manually using a cursor.  It
forgot to update free_blocks.  Segment freeing then freed the segment as
an extent which did update free_blocks.  This created ever accumulating
free blocks over time which eventually pushed it greater than total
blocks and caused df to report negative usage.

This updates the free_blocks count in server extent io which is the only
place we update the extent items themselves.  This ensures that we'll
keep the count in sync with the extent items.  Callers don't have to
worry about it.

Signed-off-by: Zach Brown <zab@versity.com>

T# with '#' will be ignored, and an empty message aborts the commit.
This commit is contained in:
Zach Brown
2018-08-21 13:25:05 -07:00
committed by Zach Brown
parent a72b7a9001
commit a25b6324d2
1 changed files with 11 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files
kmod/src/server.c
+11 -4
View File
@@ -120,6 +120,10 @@ static int init_extent_from_btree_key(struct scoutfs_extent *ext, u8 type,
* This is called by the extent core on behalf of the server who holds
* the appropriate locks to protect the many btree items that can be
* accessed on behalf of one extent operation.
*
* The free_blocks count in the super tracks the number of blocks in
* the primary extent index. We update it here instead of expecting
* callers to remember.
*/
static int server_extent_io(struct super_block *sb, int op,
struct scoutfs_extent *ext, void *data)
@@ -192,6 +196,13 @@ static int server_extent_io(struct super_block *sb, int op,
}
}
if (ret == 0 && ext->type == SCOUTFS_FREE_EXTENT_BLKNO_TYPE) {
if (op == SEI_INSERT)
le64_add_cpu(&super->free_blocks, ext->len);
else if (op == SEI_DELETE)
le64_add_cpu(&super->free_blocks, -ext->len);
}
return ret;
}
@@ -209,7 +220,6 @@ static int alloc_extent(struct super_block *sb, u64 blocks,
u64 *start, u64 *len)
{
struct server_info *server = SCOUTFS_SB(sb)->server_info;
struct scoutfs_super_block *super = &SCOUTFS_SB(sb)->super;
struct scoutfs_extent ext;
int ret;
@@ -244,7 +254,6 @@ static int alloc_extent(struct super_block *sb, u64 blocks,
goto out;
trace_scoutfs_server_alloc_extent_allocated(sb, &ext);
le64_add_cpu(&super->free_blocks, -ext.len);
*start = ext.start;
*len = ext.len;
@@ -278,7 +287,6 @@ struct pending_free_extent {
*/
static int apply_pending_frees(struct super_block *sb)
{
struct scoutfs_super_block *super = &SCOUTFS_SB(sb)->super;
struct server_info *server = SCOUTFS_SB(sb)->server_info;
struct pending_free_extent *pfe;
struct pending_free_extent *tmp;
@@ -298,7 +306,6 @@ static int apply_pending_frees(struct super_block *sb)
break;
}
le64_add_cpu(&super->free_blocks, pfe->len);
list_del_init(&pfe->head);
kfree(pfe);
}