summaryrefslogtreecommitdiffstats
path: root/fs/ext4/super.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/ext4/super.c')
-rw-r--r--fs/ext4/super.c180
1 files changed, 130 insertions, 50 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index eb7aa3e..41598ee 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -976,6 +976,7 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
ei->i_reserved_meta_blocks = 0;
ei->i_allocated_meta_blocks = 0;
ei->i_da_metadata_calc_len = 0;
+ ei->i_da_metadata_calc_last_lblock = 0;
spin_lock_init(&(ei->i_block_reservation_lock));
#ifdef CONFIG_QUOTA
ei->i_reserved_quota = 0;
@@ -3085,6 +3086,118 @@ static int set_journal_csum_feature_set(struct super_block *sb)
return ret;
}
+/*
+ * Note: calculating the overhead so we can be compatible with
+ * historical BSD practice is quite difficult in the face of
+ * clusters/bigalloc. This is because multiple metadata blocks from
+ * different block group can end up in the same allocation cluster.
+ * Calculating the exact overhead in the face of clustered allocation
+ * requires either O(all block bitmaps) in memory or O(number of block
+ * groups**2) in time. We will still calculate the superblock for
+ * older file systems --- and if we come across with a bigalloc file
+ * system with zero in s_overhead_clusters the estimate will be close to
+ * correct especially for very large cluster sizes --- but for newer
+ * file systems, it's better to calculate this figure once at mkfs
+ * time, and store it in the superblock. If the superblock value is
+ * present (even for non-bigalloc file systems), we will use it.
+ */
+static int count_overhead(struct super_block *sb, ext4_group_t grp,
+ char *buf)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_group_desc *gdp;
+ ext4_fsblk_t first_block, last_block, b;
+ ext4_group_t i, ngroups = ext4_get_groups_count(sb);
+ int s, j, count = 0;
+
+ if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
+ return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
+ sbi->s_itb_per_group + 2);
+
+ first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
+ (grp * EXT4_BLOCKS_PER_GROUP(sb));
+ last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
+ for (i = 0; i < ngroups; i++) {
+ gdp = ext4_get_group_desc(sb, i, NULL);
+ b = ext4_block_bitmap(sb, gdp);
+ if (b >= first_block && b <= last_block) {
+ ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
+ count++;
+ }
+ b = ext4_inode_bitmap(sb, gdp);
+ if (b >= first_block && b <= last_block) {
+ ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
+ count++;
+ }
+ b = ext4_inode_table(sb, gdp);
+ if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
+ for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
+ int c = EXT4_B2C(sbi, b - first_block);
+ ext4_set_bit(c, buf);
+ count++;
+ }
+ if (i != grp)
+ continue;
+ s = 0;
+ if (ext4_bg_has_super(sb, grp)) {
+ ext4_set_bit(s++, buf);
+ count++;
+ }
+ for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
+ ext4_set_bit(EXT4_B2C(sbi, s++), buf);
+ count++;
+ }
+ }
+ if (!count)
+ return 0;
+ return EXT4_CLUSTERS_PER_GROUP(sb) -
+ ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
+}
+
+/*
+ * Compute the overhead and stash it in sbi->s_overhead
+ */
+int ext4_calculate_overhead(struct super_block *sb)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_super_block *es = sbi->s_es;
+ ext4_group_t i, ngroups = ext4_get_groups_count(sb);
+ ext4_fsblk_t overhead = 0;
+ char *buf = (char *) get_zeroed_page(GFP_KERNEL);
+
+ memset(buf, 0, PAGE_SIZE);
+ if (!buf)
+ return -ENOMEM;
+
+ /*
+ * Compute the overhead (FS structures). This is constant
+ * for a given filesystem unless the number of block groups
+ * changes so we cache the previous value until it does.
+ */
+
+ /*
+ * All of the blocks before first_data_block are overhead
+ */
+ overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
+
+ /*
+ * Add the overhead found in each block group
+ */
+ for (i = 0; i < ngroups; i++) {
+ int blks;
+
+ blks = count_overhead(sb, i, buf);
+ overhead += blks;
+ if (blks)
+ memset(buf, 0, PAGE_SIZE);
+ cond_resched();
+ }
+ sbi->s_overhead = overhead;
+ smp_wmb();
+ free_page((unsigned long) buf);
+ return 0;
+}
+
static int ext4_fill_super(struct super_block *sb, void *data, int silent)
{
char *orig_data = kstrdup(data, GFP_KERNEL);
@@ -3735,6 +3848,18 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
no_journal:
/*
+ * Get the # of file system overhead blocks from the
+ * superblock if present.
+ */
+ if (es->s_overhead_clusters)
+ sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
+ else {
+ ret = ext4_calculate_overhead(sb);
+ if (ret)
+ goto failed_mount_wq;
+ }
+
+ /*
* The maximum number of concurrent works can be high and
* concurrency isn't really necessary. Limit it to 1.
*/
@@ -4286,6 +4411,7 @@ static void ext4_clear_journal_err(struct super_block *sb,
ext4_commit_super(sb, 1);
jbd2_journal_clear_err(journal);
+ jbd2_journal_update_sb_errno(journal);
}
}
@@ -4600,67 +4726,21 @@ restore_opts:
return err;
}
-/*
- * Note: calculating the overhead so we can be compatible with
- * historical BSD practice is quite difficult in the face of
- * clusters/bigalloc. This is because multiple metadata blocks from
- * different block group can end up in the same allocation cluster.
- * Calculating the exact overhead in the face of clustered allocation
- * requires either O(all block bitmaps) in memory or O(number of block
- * groups**2) in time. We will still calculate the superblock for
- * older file systems --- and if we come across with a bigalloc file
- * system with zero in s_overhead_clusters the estimate will be close to
- * correct especially for very large cluster sizes --- but for newer
- * file systems, it's better to calculate this figure once at mkfs
- * time, and store it in the superblock. If the superblock value is
- * present (even for non-bigalloc file systems), we will use it.
- */
static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
struct ext4_sb_info *sbi = EXT4_SB(sb);
struct ext4_super_block *es = sbi->s_es;
- struct ext4_group_desc *gdp;
+ ext4_fsblk_t overhead = 0;
u64 fsid;
s64 bfree;
- if (test_opt(sb, MINIX_DF)) {
- sbi->s_overhead_last = 0;
- } else if (es->s_overhead_clusters) {
- sbi->s_overhead_last = le32_to_cpu(es->s_overhead_clusters);
- } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
- ext4_group_t i, ngroups = ext4_get_groups_count(sb);
- ext4_fsblk_t overhead = 0;
-
- /*
- * Compute the overhead (FS structures). This is constant
- * for a given filesystem unless the number of block groups
- * changes so we cache the previous value until it does.
- */
-
- /*
- * All of the blocks before first_data_block are
- * overhead
- */
- overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
-
- /*
- * Add the overhead found in each block group
- */
- for (i = 0; i < ngroups; i++) {
- gdp = ext4_get_group_desc(sb, i, NULL);
- overhead += ext4_num_overhead_clusters(sb, i, gdp);
- cond_resched();
- }
- sbi->s_overhead_last = overhead;
- smp_wmb();
- sbi->s_blocks_last = ext4_blocks_count(es);
- }
+ if (!test_opt(sb, MINIX_DF))
+ overhead = sbi->s_overhead;
buf->f_type = EXT4_SUPER_MAGIC;
buf->f_bsize = sb->s_blocksize;
- buf->f_blocks = (ext4_blocks_count(es) -
- EXT4_C2B(sbi, sbi->s_overhead_last));
+ buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, sbi->s_overhead);
bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
/* prevent underflow in case that few free space is available */