return 0;
}
+struct orlov_stats {
+ __u32 free_inodes;
+ __u32 free_blocks;
+ __u32 used_dirs;
+};
+
+/*
+ * Helper function for Orlov's allocator; returns critical information
+ * for a particular block group or flex_bg. If flex_size is 1, then g
+ * is a block group number; otherwise it is flex_bg number.
+ */
+void get_orlov_stats(struct super_block *sb, ext4_group_t g,
+ int flex_size, struct orlov_stats *stats)
+{
+ struct ext4_group_desc *desc;
+ ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
+ int i;
+
+ stats->free_inodes = 0;
+ stats->free_blocks = 0;
+ stats->used_dirs = 0;
+
+ g *= flex_size;
+
+ for (i = 0; i < flex_size; i++) {
+ if (g >= ngroups)
+ break;
+ desc = ext4_get_group_desc(sb, g++, NULL);
+ if (!desc)
+ continue;
+
+ stats->free_inodes += ext4_free_inodes_count(sb, desc);
+ stats->free_blocks += ext4_free_blks_count(sb, desc);
+ stats->used_dirs += ext4_used_dirs_count(sb, desc);
+ }
+}
+
/*
* Orlov's allocator for directories.
*
* it has too many directories already (max_dirs) or
* it has too few free inodes left (min_inodes) or
* it has too few free blocks left (min_blocks) or
- * it's already running too large debt (max_debt).
* Parent's group is preferred, if it doesn't satisfy these
* conditions we search cyclically through the rest. If none
* of the groups look good we just look for a group with more
* free inodes than average (starting at parent's group).
- *
- * Debt is incremented each time we allocate a directory and decremented
- * when we allocate an inode, within 0--255.
*/
-#define INODE_COST 64
-#define BLOCK_COST 256
-
static int find_group_orlov(struct super_block *sb, struct inode *parent,
- ext4_group_t *group)
+ ext4_group_t *group, int mode)
{
ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
struct ext4_sb_info *sbi = EXT4_SB(sb);
- struct ext4_super_block *es = sbi->s_es;
ext4_group_t ngroups = sbi->s_groups_count;
int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
unsigned int freei, avefreei;
ext4_fsblk_t freeb, avefreeb;
- ext4_fsblk_t blocks_per_dir;
unsigned int ndirs;
- int max_debt, max_dirs, min_inodes;
+ int max_dirs, min_inodes;
ext4_grpblk_t min_blocks;
- ext4_group_t i;
+ ext4_group_t i, grp, g;
struct ext4_group_desc *desc;
+ struct orlov_stats stats;
+ int flex_size = ext4_flex_bg_size(sbi);
+
+ if (flex_size > 1) {
+ ngroups = (ngroups + flex_size - 1) >>
+ sbi->s_log_groups_per_flex;
+ parent_group >>= sbi->s_log_groups_per_flex;
+ }
freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
avefreei = freei / ngroups;
do_div(avefreeb, ngroups);
ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
- if ((parent == sb->s_root->d_inode) ||
- (EXT4_I(parent)->i_flags & EXT4_TOPDIR_FL)) {
+ if (S_ISDIR(mode) &&
+ ((parent == sb->s_root->d_inode) ||
+ (EXT4_I(parent)->i_flags & EXT4_TOPDIR_FL))) {
int best_ndir = inodes_per_group;
- ext4_group_t grp;
int ret = -1;
get_random_bytes(&grp, sizeof(grp));
parent_group = (unsigned)grp % ngroups;
for (i = 0; i < ngroups; i++) {
- grp = (parent_group + i) % ngroups;
- desc = ext4_get_group_desc(sb, grp, NULL);
- if (!desc || !ext4_free_inodes_count(sb, desc))
+ g = (parent_group + i) % ngroups;
+ get_orlov_stats(sb, g, flex_size, &stats);
+ if (!stats.free_inodes)
continue;
- if (ext4_used_dirs_count(sb, desc) >= best_ndir)
+ if (stats.used_dirs >= best_ndir)
continue;
- if (ext4_free_inodes_count(sb, desc) < avefreei)
+ if (stats.free_inodes < avefreei)
continue;
- if (ext4_free_blks_count(sb, desc) < avefreeb)
+ if (stats.free_blocks < avefreeb)
continue;
- *group = grp;
+ grp = g;
ret = 0;
- best_ndir = ext4_used_dirs_count(sb, desc);
+ best_ndir = stats.used_dirs;
+ }
+ if (ret)
+ goto fallback;
+ found_flex_bg:
+ if (flex_size == 1) {
+ *group = grp;
+ return 0;
+ }
+
+ /*
+ * We pack inodes at the beginning of the flexgroup's
+ * inode tables. Block allocation decisions will do
+ * something similar, although regular files will
+ * start at 2nd block group of the flexgroup. See
+ * ext4_ext_find_goal() and ext4_find_near().
+ */
+ grp *= flex_size;
+ for (i = 0; i < flex_size; i++) {
+ if (grp+i >= sbi->s_groups_count)
+ break;
+ desc = ext4_get_group_desc(sb, grp+i, NULL);
+ if (desc && ext4_free_inodes_count(sb, desc)) {
+ *group = grp+i;
+ return 0;
+ }
}
- if (ret == 0)
- return ret;
goto fallback;
}
- blocks_per_dir = ext4_blocks_count(es) - freeb;
- do_div(blocks_per_dir, ndirs);
-
max_dirs = ndirs / ngroups + inodes_per_group / 16;
- min_inodes = avefreei - inodes_per_group / 4;
- min_blocks = avefreeb - EXT4_BLOCKS_PER_GROUP(sb) / 4;
-
- max_debt = EXT4_BLOCKS_PER_GROUP(sb);
- max_debt /= max_t(int, blocks_per_dir, BLOCK_COST);
- if (max_debt * INODE_COST > inodes_per_group)
- max_debt = inodes_per_group / INODE_COST;
- if (max_debt > 255)
- max_debt = 255;
- if (max_debt == 0)
- max_debt = 1;
+ min_inodes = avefreei - inodes_per_group*flex_size / 4;
+ if (min_inodes < 1)
+ min_inodes = 1;
+ min_blocks = avefreeb - EXT4_BLOCKS_PER_GROUP(sb)*flex_size / 4;
+
+ /*
+ * Start looking in the flex group where we last allocated an
+ * inode for this parent directory
+ */
+ if (EXT4_I(parent)->i_last_alloc_group != ~0) {
+ parent_group = EXT4_I(parent)->i_last_alloc_group;
+ if (flex_size > 1)
+ parent_group >>= sbi->s_log_groups_per_flex;
+ }
for (i = 0; i < ngroups; i++) {
- *group = (parent_group + i) % ngroups;
- desc = ext4_get_group_desc(sb, *group, NULL);
- if (!desc || !ext4_free_inodes_count(sb, desc))
- continue;
- if (ext4_used_dirs_count(sb, desc) >= max_dirs)
+ grp = (parent_group + i) % ngroups;
+ get_orlov_stats(sb, grp, flex_size, &stats);
+ if (stats.used_dirs >= max_dirs)
continue;
- if (ext4_free_inodes_count(sb, desc) < min_inodes)
+ if (stats.free_inodes < min_inodes)
continue;
- if (ext4_free_blks_count(sb, desc) < min_blocks)
+ if (stats.free_blocks < min_blocks)
continue;
- return 0;
+ goto found_flex_bg;
}
fallback:
+ ngroups = sbi->s_groups_count;
+ avefreei = freei / ngroups;
+ parent_group = EXT4_I(parent)->i_block_group;
for (i = 0; i < ngroups; i++) {
- *group = (parent_group + i) % ngroups;
- desc = ext4_get_group_desc(sb, *group, NULL);
+ grp = (parent_group + i) % ngroups;
+ desc = ext4_get_group_desc(sb, grp, NULL);
if (desc && ext4_free_inodes_count(sb, desc) &&
- ext4_free_inodes_count(sb, desc) >= avefreei)
+ ext4_free_inodes_count(sb, desc) >= avefreei) {
+ *group = grp;
return 0;
+ }
}
if (avefreei) {
}
static int find_group_other(struct super_block *sb, struct inode *parent,
- ext4_group_t *group)
+ ext4_group_t *group, int mode)
{
ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
struct ext4_group_desc *desc;
- ext4_group_t i;
+ ext4_group_t i, last;
+ int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
+
+ /*
+ * Try to place the inode is the same flex group as its
+ * parent. If we can't find space, use the Orlov algorithm to
+ * find another flex group, and store that information in the
+ * parent directory's inode information so that use that flex
+ * group for future allocations.
+ */
+ if (flex_size > 1) {
+ int retry = 0;
+
+ try_again:
+ parent_group &= ~(flex_size-1);
+ last = parent_group + flex_size;
+ if (last > ngroups)
+ last = ngroups;
+ for (i = parent_group; i < last; i++) {
+ desc = ext4_get_group_desc(sb, i, NULL);
+ if (desc && ext4_free_inodes_count(sb, desc)) {
+ *group = i;
+ return 0;
+ }
+ }
+ if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
+ retry = 1;
+ parent_group = EXT4_I(parent)->i_last_alloc_group;
+ goto try_again;
+ }
+ /*
+ * If this didn't work, use the Orlov search algorithm
+ * to find a new flex group; we pass in the mode to
+ * avoid the topdir algorithms.
+ */
+ *group = parent_group + flex_size;
+ if (*group > ngroups)
+ *group = 0;
+ return find_group_orlov(sb, parent, group, mode);
+ }
/*
* Try to place the inode in its parent directory
sbi = EXT4_SB(sb);
es = sbi->s_es;
- if (sbi->s_log_groups_per_flex) {
+ if (sbi->s_log_groups_per_flex && test_opt(sb, OLDALLOC)) {
ret2 = find_group_flex(sb, dir, &group);
if (ret2 == -1) {
- ret2 = find_group_other(sb, dir, &group);
+ ret2 = find_group_other(sb, dir, &group, mode);
if (ret2 == 0 && once)
once = 0;
printk(KERN_NOTICE "ext4: find_group_flex "
if (test_opt(sb, OLDALLOC))
ret2 = find_group_dir(sb, dir, &group);
else
- ret2 = find_group_orlov(sb, dir, &group);
+ ret2 = find_group_orlov(sb, dir, &group, mode);
} else
- ret2 = find_group_other(sb, dir, &group);
+ ret2 = find_group_other(sb, dir, &group, mode);
got_group:
+ EXT4_I(dir)->i_last_alloc_group = group;
err = -ENOSPC;
if (ret2 == -1)
goto out;
ei->i_file_acl = 0;
ei->i_dtime = 0;
ei->i_block_group = group;
+ ei->i_last_alloc_group = ~0;
ext4_set_inode_flags(inode);
if (IS_DIRSYNC(inode))
projects / linux-2.6-omap-h63xx.git / commitdiff