ext4: teach the inode allocator to use a goal inode number
Enhance the inode allocator to take a goal inode number as a
paremeter; if it is specified, it takes precedence over Orlov or
parent directory inode allocation algorithms.
The extents migration function uses the goal inode number so that the
extent trees allocated the migration function use the correct flex_bg.
In the future, the goal inode functionality will also be used to
allocate an adjacent inode for the extended attributes.
Also, for testing purposes the goal inode number can be specified via
/sys/fs/{dev}/inode_goal. This can be useful for testing inode
allocation beyond 2^32 blocks on very large filesystems.
Signed-off-by: Andreas Dilger <adilger@sun.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/Documentation/ABI/testing/sysfs-fs-ext4 b/Documentation/ABI/testing/sysfs-fs-ext4
index 4e79074..5fb7099 100644
--- a/Documentation/ABI/testing/sysfs-fs-ext4
+++ b/Documentation/ABI/testing/sysfs-fs-ext4
@@ -79,3 +79,13 @@
This file is read-only and shows the number of
kilobytes of data that have been written to this
filesystem since it was mounted.
+
+What: /sys/fs/ext4/<disk>/inode_goal
+Date: June 2008
+Contact: "Theodore Ts'o" <tytso@mit.edu>
+Description:
+ Tuning parameter which (if non-zero) controls the goal
+ inode used by the inode allocator in p0reference to
+ all other allocation hueristics. This is intended for
+ debugging use only, and should be 0 on production
+ systems.
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index d035cf1..746cdcb 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -863,6 +863,7 @@
int s_inode_size;
int s_first_ino;
unsigned int s_inode_readahead_blks;
+ unsigned int s_inode_goal;
spinlock_t s_next_gen_lock;
u32 s_next_generation;
u32 s_hash_seed[4];
@@ -1316,7 +1317,7 @@
/* ialloc.c */
extern struct inode *ext4_new_inode(handle_t *, struct inode *, int,
- const struct qstr *qstr);
+ const struct qstr *qstr, __u32 goal);
extern void ext4_free_inode(handle_t *, struct inode *);
extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
extern unsigned long ext4_count_free_inodes(struct super_block *);
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 3f98ee7..2f64573 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -799,7 +799,7 @@
* group to find a free inode.
*/
struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, int mode,
- const struct qstr *qstr)
+ const struct qstr *qstr, __u32 goal)
{
struct super_block *sb;
struct buffer_head *inode_bitmap_bh = NULL;
@@ -830,6 +830,16 @@
ei = EXT4_I(inode);
sbi = EXT4_SB(sb);
+ if (!goal)
+ goal = sbi->s_inode_goal;
+
+ if (goal && goal < le32_to_cpu(sbi->s_es->s_inodes_count)) {
+ group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
+ ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
+ ret2 = 0;
+ goto got_group;
+ }
+
if (sbi->s_log_groups_per_flex && test_opt(sb, OLDALLOC)) {
ret2 = find_group_flex(sb, dir, &group);
if (ret2 == -1) {
@@ -858,7 +868,7 @@
if (ret2 == -1)
goto out;
- for (i = 0; i < ngroups; i++) {
+ for (i = 0; i < ngroups; i++, ino = 0) {
err = -EIO;
gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
@@ -870,8 +880,6 @@
if (!inode_bitmap_bh)
goto fail;
- ino = 0;
-
repeat_in_this_group:
ino = ext4_find_next_zero_bit((unsigned long *)
inode_bitmap_bh->b_data,
diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index 80d075b..313a50b 100644
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -458,6 +458,7 @@
struct inode *tmp_inode = NULL;
struct list_blocks_struct lb;
unsigned long max_entries;
+ __u32 goal;
/*
* If the filesystem does not support extents, or the inode
@@ -483,8 +484,10 @@
retval = PTR_ERR(handle);
return retval;
}
+ goal = (((inode->i_ino - 1) / EXT4_INODES_PER_GROUP(inode->i_sb)) *
+ EXT4_INODES_PER_GROUP(inode->i_sb)) + 1;
tmp_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
- S_IFREG, 0);
+ S_IFREG, 0, goal);
if (IS_ERR(tmp_inode)) {
retval = -ENOMEM;
ext4_journal_stop(handle);
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 5f00d24..de04013 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1782,7 +1782,7 @@
if (IS_DIRSYNC(dir))
ext4_handle_sync(handle);
- inode = ext4_new_inode(handle, dir, mode, &dentry->d_name);
+ inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
inode->i_op = &ext4_file_inode_operations;
@@ -1816,7 +1816,7 @@
if (IS_DIRSYNC(dir))
ext4_handle_sync(handle);
- inode = ext4_new_inode(handle, dir, mode, &dentry->d_name);
+ inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0);
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
init_special_inode(inode, inode->i_mode, rdev);
@@ -1853,7 +1853,8 @@
if (IS_DIRSYNC(dir))
ext4_handle_sync(handle);
- inode = ext4_new_inode(handle, dir, S_IFDIR | mode, &dentry->d_name);
+ inode = ext4_new_inode(handle, dir, S_IFDIR | mode,
+ &dentry->d_name, 0);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_stop;
@@ -2264,7 +2265,8 @@
if (IS_DIRSYNC(dir))
ext4_handle_sync(handle);
- inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO, &dentry->d_name);
+ inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO,
+ &dentry->d_name, 0);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_stop;
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 04486a5..23013d3 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2206,6 +2206,7 @@
EXT4_RO_ATTR(lifetime_write_kbytes);
EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
inode_readahead_blks_store, s_inode_readahead_blks);
+EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
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);
@@ -2218,6 +2219,7 @@
ATTR_LIST(session_write_kbytes),
ATTR_LIST(lifetime_write_kbytes),
ATTR_LIST(inode_readahead_blks),
+ ATTR_LIST(inode_goal),
ATTR_LIST(mb_stats),
ATTR_LIST(mb_max_to_scan),
ATTR_LIST(mb_min_to_scan),