diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt
index 4917cf24a5e0885518cf06a12e53d4057f5c91fa..10ec4639f1522dad34d66eea61443750435fe3ae 100644
--- a/Documentation/filesystems/ext4.txt
+++ b/Documentation/filesystems/ext4.txt
@@ -581,6 +581,13 @@ Table of Ext4 specific ioctls
behaviour may change in the future as it is
not necessary and has been done this way only
for sake of simplicity.
+
+ EXT4_IOC_RESIZE_FS Resize the filesystem to a new size. The number
+ of blocks of resized filesystem is passed in via
+ 64 bit integer argument. The kernel allocates
+ bitmaps and inode table, the userspace tool thus
+ just passes the new number of blocks.
+
..............................................................................
References
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 05058e2b7f4fb7279558ebdc68afee36de276e06..4bc0e82a9054b45aff2b9112d343442fcd1db4b4 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -583,6 +583,7 @@ enum {
/* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
#define EXT4_IOC_ALLOC_DA_BLKS _IO('f', 12)
#define EXT4_IOC_MOVE_EXT _IOWR('f', 15, struct move_extent)
+#define EXT4_IOC_RESIZE_FS _IOW('f', 16, __u64)
#if defined(__KERNEL__) && defined(CONFIG_COMPAT)
/*
@@ -1929,6 +1930,7 @@ extern int ext4_group_add(struct super_block *sb,
extern int ext4_group_extend(struct super_block *sb,
struct ext4_super_block *es,
ext4_fsblk_t n_blocks_count);
+extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
/* super.c */
extern void *ext4_kvmalloc(size_t size, gfp_t flags);
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index ff1aab7cd6e839dace648a74fdf6b04882a9b273..c1a98804a3831503620215fa72fc665d2454410d 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -18,6 +18,8 @@
#include "ext4_jbd2.h"
#include "ext4.h"
+#define MAX_32_NUM ((((unsigned long long) 1) << 32) - 1)
+
long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct inode *inode = filp->f_dentry->d_inode;
@@ -329,6 +331,60 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
return err;
}
+ case EXT4_IOC_RESIZE_FS: {
+ ext4_fsblk_t n_blocks_count;
+ struct super_block *sb = inode->i_sb;
+ int err = 0, err2 = 0;
+
+ if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
+ ext4_msg(sb, KERN_ERR,
+ "Online resizing not (yet) supported with bigalloc");
+ return -EOPNOTSUPP;
+ }
+
+ if (EXT4_HAS_INCOMPAT_FEATURE(sb,
+ EXT4_FEATURE_INCOMPAT_META_BG)) {
+ ext4_msg(sb, KERN_ERR,
+ "Online resizing not (yet) supported with meta_bg");
+ return -EOPNOTSUPP;
+ }
+
+ if (copy_from_user(&n_blocks_count, (__u64 __user *)arg,
+ sizeof(__u64))) {
+ return -EFAULT;
+ }
+
+ if (n_blocks_count > MAX_32_NUM &&
+ !EXT4_HAS_INCOMPAT_FEATURE(sb,
+ EXT4_FEATURE_INCOMPAT_64BIT)) {
+ ext4_msg(sb, KERN_ERR,
+ "File system only supports 32-bit block numbers");
+ return -EOPNOTSUPP;
+ }
+
+ err = ext4_resize_begin(sb);
+ if (err)
+ return err;
+
+ err = mnt_want_write(filp->f_path.mnt);
+ if (err)
+ goto resizefs_out;
+
+ err = ext4_resize_fs(sb, n_blocks_count);
+ if (EXT4_SB(sb)->s_journal) {
+ jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
+ err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
+ jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
+ }
+ if (err == 0)
+ err = err2;
+ mnt_drop_write(filp->f_path.mnt);
+resizefs_out:
+ ext4_resize_end(sb);
+ return err;
+ }
+
case FITRIM:
{
struct request_queue *q = bdev_get_queue(sb->s_bdev);
@@ -427,6 +483,7 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
}
case EXT4_IOC_MOVE_EXT:
case FITRIM:
+ case EXT4_IOC_RESIZE_FS:
break;
default:
return -ENOIOCTLCMD;
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index dac23561f3eb8e171843150579bd82f2e397a780..5fe2a013ee65f8e748729a17a8a49430c859f134 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -1430,6 +1430,70 @@ static int ext4_flex_group_add(struct super_block *sb,
return err;
}
+static int ext4_setup_next_flex_gd(struct super_block *sb,
+ struct ext4_new_flex_group_data *flex_gd,
+ ext4_fsblk_t n_blocks_count,
+ unsigned long flexbg_size)
+{
+ struct ext4_super_block *es = EXT4_SB(sb)->s_es;
+ struct ext4_new_group_data *group_data = flex_gd->groups;
+ ext4_fsblk_t o_blocks_count;
+ ext4_group_t n_group;
+ ext4_group_t group;
+ ext4_group_t last_group;
+ ext4_grpblk_t last;
+ ext4_grpblk_t blocks_per_group;
+ unsigned long i;
+
+ blocks_per_group = EXT4_BLOCKS_PER_GROUP(sb);
+
+ o_blocks_count = ext4_blocks_count(es);
+
+ if (o_blocks_count == n_blocks_count)
+ return 0;
+
+ ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
+ BUG_ON(last);
+ ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &last);
+
+ last_group = group | (flexbg_size - 1);
+ if (last_group > n_group)
+ last_group = n_group;
+
+ flex_gd->count = last_group - group + 1;
+
+ for (i = 0; i < flex_gd->count; i++) {
+ int overhead;
+
+ group_data[i].group = group + i;
+ group_data[i].blocks_count = blocks_per_group;
+ overhead = ext4_bg_has_super(sb, group + i) ?
+ (1 + ext4_bg_num_gdb(sb, group + i) +
+ le16_to_cpu(es->s_reserved_gdt_blocks)) : 0;
+ group_data[i].free_blocks_count = blocks_per_group - overhead;
+ if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
+ flex_gd->bg_flags[i] = EXT4_BG_BLOCK_UNINIT |
+ EXT4_BG_INODE_UNINIT;
+ else
+ flex_gd->bg_flags[i] = EXT4_BG_INODE_ZEROED;
+ }
+
+ if (last_group == n_group &&
+ EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
+ /* We need to initialize block bitmap of last group. */
+ flex_gd->bg_flags[i - 1] &= ~EXT4_BG_BLOCK_UNINIT;
+
+ if ((last_group == n_group) && (last != blocks_per_group - 1)) {
+ group_data[i - 1].blocks_count = last + 1;
+ group_data[i - 1].free_blocks_count -= blocks_per_group-
+ last - 1;
+ }
+
+ return 1;
+}
+
/* Add group descriptor data to an existing or new group descriptor block.
* Ensure we handle all possible error conditions _before_ we start modifying
* the filesystem, because we cannot abort the transaction and not have it
@@ -1827,3 +1891,116 @@ int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
exit_put:
return err;
} /* ext4_group_extend */
+
+/*
+ * ext4_resize_fs() resizes a fs to new size specified by @n_blocks_count
+ *
+ * @sb: super block of the fs to be resized
+ * @n_blocks_count: the number of blocks resides in the resized fs
+ */
+int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count)
+{
+ struct ext4_new_flex_group_data *flex_gd = NULL;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_super_block *es = sbi->s_es;
+ struct buffer_head *bh;
+ struct inode *resize_inode;
+ ext4_fsblk_t o_blocks_count;
+ ext4_group_t o_group;
+ ext4_group_t n_group;
+ ext4_grpblk_t offset;
+ unsigned long n_desc_blocks;
+ unsigned long o_desc_blocks;
+ unsigned long desc_blocks;
+ int err = 0, flexbg_size = 1;
+
+ o_blocks_count = ext4_blocks_count(es);
+
+ if (test_opt(sb, DEBUG))
+ printk(KERN_DEBUG "EXT4-fs: resizing filesystem from %llu "
+ "upto %llu blocks\n", o_blocks_count, n_blocks_count);
+
+ if (n_blocks_count < o_blocks_count) {
+ /* On-line shrinking not supported */
+ ext4_warning(sb, "can't shrink FS - resize aborted");
+ return -EINVAL;
+ }
+
+ if (n_blocks_count == o_blocks_count)
+ /* Nothing need to do */
+ return 0;
+
+ ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &offset);
+ ext4_get_group_no_and_offset(sb, o_blocks_count, &o_group, &offset);
+
+ n_desc_blocks = (n_group + EXT4_DESC_PER_BLOCK(sb)) /
+ EXT4_DESC_PER_BLOCK(sb);
+ o_desc_blocks = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
+ EXT4_DESC_PER_BLOCK(sb);
+ desc_blocks = n_desc_blocks - o_desc_blocks;
+
+ if (desc_blocks &&
+ (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_RESIZE_INODE) ||
+ le16_to_cpu(es->s_reserved_gdt_blocks) < desc_blocks)) {
+ ext4_warning(sb, "No reserved GDT blocks, can't resize");
+ return -EPERM;
+ }
+
+ resize_inode = ext4_iget(sb, EXT4_RESIZE_INO);
+ if (IS_ERR(resize_inode)) {
+ ext4_warning(sb, "Error opening resize inode");
+ return PTR_ERR(resize_inode);
+ }
+
+ /* See if the device is actually as big as what was requested */
+ bh = sb_bread(sb, n_blocks_count - 1);
+ if (!bh) {
+ ext4_warning(sb, "can't read last block, resize aborted");
+ return -ENOSPC;
+ }
+ brelse(bh);
+
+ if (offset != 0) {
+ /* extend the last group */
+ ext4_grpblk_t add;
+ add = EXT4_BLOCKS_PER_GROUP(sb) - offset;
+ err = ext4_group_extend_no_check(sb, o_blocks_count, add);
+ if (err)
+ goto out;
+ }
+
+ if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
+ es->s_log_groups_per_flex)
+ flexbg_size = 1 << es->s_log_groups_per_flex;
+
+ o_blocks_count = ext4_blocks_count(es);
+ if (o_blocks_count == n_blocks_count)
+ goto out;
+
+ flex_gd = alloc_flex_gd(flexbg_size);
+ if (flex_gd == NULL) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ /* Add flex groups. Note that a regular group is a
+ * flex group with 1 group.
+ */
+ while (ext4_setup_next_flex_gd(sb, flex_gd, n_blocks_count,
+ flexbg_size)) {
+ ext4_alloc_group_tables(sb, flex_gd, flexbg_size);
+ err = ext4_flex_group_add(sb, resize_inode, flex_gd);
+ if (unlikely(err))
+ break;
+ }
+
+out:
+ if (flex_gd)
+ free_flex_gd(flex_gd);
+
+ iput(resize_inode);
+ if (test_opt(sb, DEBUG))
+ printk(KERN_DEBUG "EXT4-fs: resized filesystem from %llu "
+ "upto %llu blocks\n", o_blocks_count, n_blocks_count);
+ return err;
+}