ext4: Add support for 48 bit inode i_blocks.
Use the __le16 l_i_reserved1 field of the linux2 struct of ext4_inode
to represet the higher 16 bits for i_blocks. With this change max_file
size becomes (2**48 -1 )* 512 bytes.
We add a RO_COMPAT feature to the super block to indicate that inode
have i_blocks represented as a split 48 bits. Super block with this
feature set cannot be mounted read write on a kernel with CONFIG_LSF
disabled.
Super block flag EXT4_FEATURE_RO_COMPAT_HUGE_FILE
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index e663455..bb89fe7 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2667,6 +2667,22 @@
if (flags & S_DIRSYNC)
ei->i_flags |= EXT4_DIRSYNC_FL;
}
+static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,
+ struct ext4_inode_info *ei)
+{
+ blkcnt_t i_blocks ;
+ struct super_block *sb = ei->vfs_inode.i_sb;
+
+ if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
+ /* we are using combined 48 bit field */
+ i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 |
+ le32_to_cpu(raw_inode->i_blocks_lo);
+ return i_blocks;
+ } else {
+ return le32_to_cpu(raw_inode->i_blocks_lo);
+ }
+}
void ext4_read_inode(struct inode * inode)
{
@@ -2715,8 +2731,8 @@
* recovery code: that's fine, we're about to complete
* the process of deleting those. */
}
- inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
ei->i_flags = le32_to_cpu(raw_inode->i_flags);
+ inode->i_blocks = ext4_inode_blocks(raw_inode, ei);
ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo);
if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
cpu_to_le32(EXT4_OS_HURD)) {
@@ -2799,6 +2815,43 @@
return;
}
+static int ext4_inode_blocks_set(handle_t *handle,
+ struct ext4_inode *raw_inode,
+ struct ext4_inode_info *ei)
+{
+ struct inode *inode = &(ei->vfs_inode);
+ u64 i_blocks = inode->i_blocks;
+ struct super_block *sb = inode->i_sb;
+ int err = 0;
+
+ if (i_blocks <= ~0U) {
+ /*
+ * i_blocks can be represnted in a 32 bit variable
+ * as multiple of 512 bytes
+ */
+ raw_inode->i_blocks_lo = cpu_to_le32((u32)i_blocks);
+ raw_inode->i_blocks_high = 0;
+ } else if (i_blocks <= 0xffffffffffffULL) {
+ /*
+ * i_blocks can be represented in a 48 bit variable
+ * as multiple of 512 bytes
+ */
+ err = ext4_update_rocompat_feature(handle, sb,
+ EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
+ if (err)
+ goto err_out;
+ /* i_block is stored in the split 48 bit fields */
+ raw_inode->i_blocks_lo = cpu_to_le32((u32)i_blocks);
+ raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
+ } else {
+ ext4_error(sb, __FUNCTION__,
+ "Wrong inode i_blocks count %llu\n",
+ (unsigned long long)inode->i_blocks);
+ }
+err_out:
+ return err;
+}
+
/*
* Post the struct inode info into an on-disk inode location in the
* buffer-cache. This gobbles the caller's reference to the
@@ -2853,7 +2906,8 @@
EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode);
EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode);
- raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
+ if (ext4_inode_blocks_set(handle, raw_inode, ei))
+ goto out_brelse;
raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
raw_inode->i_flags = cpu_to_le32(ei->i_flags);
if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=