desc = ext4_get_group_desc(sb, block_group, NULL);
if (!desc)
return NULL;
+
bitmap_blk = ext4_inode_bitmap(sb, desc);
bh = sb_getblk(sb, bitmap_blk);
if (unlikely(!bh)) {
unlock_buffer(bh);
return bh;
}
+
ext4_lock_group(sb, block_group);
if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
ext4_init_inode_bitmap(sb, bh, block_group, desc);
return bh;
}
ext4_unlock_group(sb, block_group);
+
if (buffer_uptodate(bh)) {
/*
* if not uninit if bh is uptodate,
{
int free = 0, retval = 0, count;
struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_group_info *grp = ext4_get_group_info(sb, group);
struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
+ /*
+ * We have to be sure that new inode allocation does not race with
+ * inode table initialization, because otherwise we may end up
+ * allocating and writing new inode right before sb_issue_zeroout
+ * takes place and overwriting our new inode with zeroes. So we
+ * take alloc_sem to prevent it.
+ */
+ down_read(&grp->alloc_sem);
ext4_lock_group(sb, group);
if (ext4_set_bit(ino, inode_bitmap_bh->b_data)) {
/* not a free inode */
if ((group == 0 && ino < EXT4_FIRST_INO(sb)) ||
ino > EXT4_INODES_PER_GROUP(sb)) {
ext4_unlock_group(sb, group);
+ up_read(&grp->alloc_sem);
ext4_error(sb, "reserved inode or inode > inodes count - "
"block_group = %u, inode=%lu", group,
ino + group * EXT4_INODES_PER_GROUP(sb));
gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
err_ret:
ext4_unlock_group(sb, group);
+ up_read(&grp->alloc_sem);
return retval;
}
}
return count;
}
+
+/*
+ * Zeroes not yet zeroed inode table - just write zeroes through the whole
+ * inode table. Must be called without any spinlock held. The only place
+ * where it is called from on active part of filesystem is ext4lazyinit
+ * thread, so we do not need any special locks, however we have to prevent
+ * inode allocation from the current group, so we take alloc_sem lock, to
+ * block ext4_claim_inode until we are finished.
+ */
+extern int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
+ int barrier)
+{
+ struct ext4_group_info *grp = ext4_get_group_info(sb, group);
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_group_desc *gdp = NULL;
+ struct buffer_head *group_desc_bh;
+ handle_t *handle;
+ ext4_fsblk_t blk;
+ int num, ret = 0, used_blks = 0;
+ unsigned long flags = BLKDEV_IFL_WAIT;
+
+ /* This should not happen, but just to be sure check this */
+ if (sb->s_flags & MS_RDONLY) {
+ ret = 1;
+ goto out;
+ }
+
+ gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
+ if (!gdp)
+ goto out;
+
+ /*
+ * We do not need to lock this, because we are the only one
+ * handling this flag.
+ */
+ if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
+ goto out;
+
+ handle = ext4_journal_start_sb(sb, 1);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ goto out;
+ }
+
+ down_write(&grp->alloc_sem);
+ /*
+ * If inode bitmap was already initialized there may be some
+ * used inodes so we need to skip blocks with used inodes in
+ * inode table.
+ */
+ if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)))
+ used_blks = DIV_ROUND_UP((EXT4_INODES_PER_GROUP(sb) -
+ ext4_itable_unused_count(sb, gdp)),
+ sbi->s_inodes_per_block);
+
+ blk = ext4_inode_table(sb, gdp) + used_blks;
+ num = sbi->s_itb_per_group - used_blks;
+
+ BUFFER_TRACE(group_desc_bh, "get_write_access");
+ ret = ext4_journal_get_write_access(handle,
+ group_desc_bh);
+ if (ret)
+ goto err_out;
+
+ if (unlikely(num > EXT4_INODES_PER_GROUP(sb))) {
+ ext4_error(sb, "Something is wrong with group %u\n"
+ "Used itable blocks: %d"
+ "Itable blocks per group: %lu\n",
+ group, used_blks, sbi->s_itb_per_group);
+ ret = 1;
+ goto err_out;
+ }
+
+ /*
+ * Skip zeroout if the inode table is full. But we set the ZEROED
+ * flag anyway, because obviously, when it is full it does not need
+ * further zeroing.
+ */
+ if (unlikely(num == 0))
+ goto skip_zeroout;
+
+ ext4_debug("going to zero out inode table in group %d\n",
+ group);
+ if (barrier)
+ flags |= BLKDEV_IFL_BARRIER;
+ ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS, flags);
+ if (ret < 0)
+ goto err_out;
+
+skip_zeroout:
+ ext4_lock_group(sb, group);
+ gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
+ gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
+ ext4_unlock_group(sb, group);
+
+ BUFFER_TRACE(group_desc_bh,
+ "call ext4_handle_dirty_metadata");
+ ret = ext4_handle_dirty_metadata(handle, NULL,
+ group_desc_bh);
+
+err_out:
+ up_write(&grp->alloc_sem);
+ ext4_journal_stop(handle);
+out:
+ return ret;
+}
projects / mv-sheeva.git / blobdiff