Viewing: ext4-give-warning-with-dir-htree-growing.patch
commit 07660ad33a7d109cced29b6400f99f25adab3f54
Author: Wang Shilong <wshilong@whamcloud.com>
AuthorDate: Thu Jul 2 21:04:45 2015 -0400
LU-6824 ldiskfs: give warning with dir htree growing
Currently without large dir feature, ldiskfs directory hash tree
will be limited 2 height, this means directory size is limited about
1GB, and in fact users are likely to hit ENOSPC when reaching half of
limit because of bad hash. tested by following scripts.
i=0
filename="aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaabbbbbbbbbbbbbbbbbbbbbbbb"
while [ 1 ]
do
touch $filename"$i"
if [ $? -ne 0 ];then
break
fi
((i++))
done
When directoy size grow about 590M, we hit ENOSPC. Better way is to
add support to e2fsprogs so that we can use large dir feature.
As a walkaround way, this patch try to give warning messages to
console when 10/16 and 11/16 of limit reach.
So this patch will try to give following messages when warning
limit or hash index tree limit reach:
Directory (inode: 8388610 FID: [0x200000401:0x1:0x0]) has approached
maximum limit.
Directory (inode: 8388610 FID: [0x200000401:0x1:0x0]) is approaching
maximum limit.
FID output here is useful for administrators to locate lustre
file path
Signed-off-by: Wang Shilong <wshilong@ddn.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Yang Sheng <yang.sheng@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Change-Id: I7f78c421bbb89f76298e0174cc46d774ea82eb06
Reviewed-on: http://review.whamcloud.com/15548
Index: linux-4.15.0/fs/ext4/ext4.h
===================================================================
--- linux-4.15.0.orig/fs/ext4/ext4.h
+++ linux-4.15.0/fs/ext4/ext4.h
@@ -1450,6 +1450,7 @@ struct ext4_sb_info {
unsigned long s_mb_prealloc_table_size;
unsigned int s_mb_group_prealloc;
unsigned int s_max_dir_size_kb;
+ unsigned long s_warning_dir_size;
/* where last allocation was done - for stream allocation */
unsigned long s_mb_last_group;
unsigned long s_mb_last_start;
Index: linux-4.15.0/fs/ext4/namei.c
===================================================================
--- linux-4.15.0.orig/fs/ext4/namei.c
+++ linux-4.15.0/fs/ext4/namei.c
@@ -751,12 +751,20 @@ struct ext4_dir_lock_data {
#define ext4_htree_lock_data(l) ((struct ext4_dir_lock_data *)(l)->lk_private)
#define ext4_find_entry(dir, name, dirent, inline) \
__ext4_find_entry(dir, name, dirent, inline, NULL)
-#define ext4_add_entry(handle, dentry, inode) \
- __ext4_add_entry(handle, dentry, inode, NULL)
/* NB: ext4_lblk_t is 32 bits so we use high bits to identify invalid blk */
#define EXT4_HTREE_NODE_CHANGED (0xcafeULL << 32)
+inline int ext4_add_entry(handle_t *handle, struct dentry *dentry,
+ struct inode *inode)
+{
+ int ret = __ext4_add_entry(handle, dentry, inode, NULL);
+
+ if (ret == -ENOBUFS)
+ ret = 0;
+ return ret;
+}
+
static void ext4_htree_event_cb(void *target, void *event)
{
u64 *block = (u64 *)target;
@@ -2508,6 +2516,54 @@ out:
return err;
}
+static unsigned long __ext4_max_dir_size(struct dx_frame *frames,
+ struct dx_frame *frame, struct inode *dir)
+{
+ unsigned long max_dir_size;
+
+ if (EXT4_SB(dir->i_sb)->s_max_dir_size_kb) {
+ max_dir_size = EXT4_SB(dir->i_sb)->s_max_dir_size_kb << 10;
+ } else {
+ max_dir_size = EXT4_BLOCK_SIZE(dir->i_sb);
+ while (frame >= frames) {
+ max_dir_size *= dx_get_limit(frame->entries);
+ if (frame == frames)
+ break;
+ frame--;
+ }
+ /* use 75% of max dir size in average */
+ max_dir_size = max_dir_size / 4 * 3;
+ }
+ return max_dir_size;
+}
+
+/*
+ * With hash tree growing, it is easy to hit ENOSPC, but it is hard
+ * to predict when it will happen. let's give administrators warning
+ * when reaching 3/5 and 2/3 of limit
+ */
+static inline bool dir_size_in_warning_range(struct dx_frame *frames,
+ struct dx_frame *frame,
+ struct inode *dir)
+{
+ unsigned long size1, size2;
+ struct super_block *sb = dir->i_sb;
+
+ if (unlikely(!EXT4_SB(sb)->s_warning_dir_size))
+ EXT4_SB(sb)->s_warning_dir_size =
+ __ext4_max_dir_size(frames, frame, dir);
+
+ size1 = EXT4_SB(sb)->s_warning_dir_size / 16 * 10;
+ size1 = size1 & ~(EXT4_BLOCK_SIZE(sb) - 1);
+ size2 = EXT4_SB(sb)->s_warning_dir_size / 16 * 11;
+ size2 = size2 & ~(EXT4_BLOCK_SIZE(sb) - 1);
+ if (in_range(dir->i_size, size1, EXT4_BLOCK_SIZE(sb)) ||
+ in_range(dir->i_size, size2, EXT4_BLOCK_SIZE(sb)))
+ return true;
+
+ return false;
+}
+
/*
* ext4_add_entry()
*
@@ -2629,6 +2685,7 @@ static int ext4_dx_add_entry(handle_t *h
struct ext4_dir_entry_2 *de;
int restart;
int err;
+ bool ret_warn = false;
again:
restart = 0;
@@ -2657,6 +2714,11 @@ again:
/* Block full, should compress but for now just split */
dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
dx_get_count(entries), dx_get_limit(entries)));
+
+ if (frame - frames + 1 >= ext4_dir_htree_level(sb) ||
+ EXT4_SB(sb)->s_warning_dir_size)
+ ret_warn = dir_size_in_warning_range(frames, frame, dir);
+
/* Need to split index? */
if (dx_get_count(entries) == dx_get_limit(entries)) {
ext4_lblk_t newblock;
@@ -2819,6 +2881,8 @@ cleanup:
*/
if (restart && err == 0)
goto again;
+ if (err == 0 && ret_warn)
+ err = -ENOBUFS;
return err;
}
Index: linux-4.15.0/fs/ext4/super.c
===================================================================
--- linux-4.15.0.orig/fs/ext4/super.c
+++ linux-4.15.0/fs/ext4/super.c
@@ -1804,6 +1804,8 @@ static int handle_mount_opt(struct super
sbi->s_li_wait_mult = arg;
} else if (token == Opt_max_dir_size_kb) {
sbi->s_max_dir_size_kb = arg;
+ /* reset s_warning_dir_size and make it re-calculated */
+ sbi->s_warning_dir_size = 0;
} else if (token == Opt_stripe) {
sbi->s_stripe = arg;
} else if (token == Opt_resuid) {
Index: linux-4.15.0/fs/ext4/sysfs.c
===================================================================
--- linux-4.15.0.orig/fs/ext4/sysfs.c
+++ linux-4.15.0/fs/ext4/sysfs.c
@@ -173,6 +173,7 @@ EXT4_ATTR_OFFSET(inode_readahead_blks, 0
EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
EXT4_RW_ATTR_SBI_UI(max_dir_size, s_max_dir_size_kb);
EXT4_RW_ATTR_SBI_UI(max_dir_size_kb, s_max_dir_size_kb);
+EXT4_RW_ATTR_SBI_UI(warning_dir_size, s_warning_dir_size);
EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
@@ -204,6 +205,7 @@ static struct attribute *ext4_attrs[] =
ATTR_LIST(inode_goal),
ATTR_LIST(max_dir_size),
ATTR_LIST(max_dir_size_kb),
+ ATTR_LIST(warning_dir_size),
ATTR_LIST(mb_stats),
ATTR_LIST(mb_max_to_scan),
ATTR_LIST(mb_min_to_scan),
