4 files changed, 39 insertions, 27 deletions

diff --git a/fs/ext4/ext4_extents.h b/fs/ext4/ext4_extents.h
index 2e29abb30f76..476414644387 100644
--- a/fs/ext4/ext4_extents.h
+++ b/fs/ext4/ext4_extents.h
@@ -133,8 +133,11 @@ typedef int (*ext_prepare_callback)(struct inode *, struct ext4_ext_path *,
 #define EXT_BREAK      1
 #define EXT_REPEAT     2
 
-/* Maximum logical block in a file; ext4_extent's ee_block is __le32 */
-#define EXT_MAX_BLOCK   0xffffffff
+/*
+ * Maximum number of logical blocks in a file; ext4_extent's ee_block is
+ * __le32.
+ */
+#define EXT_MAX_BLOCKS  0xffffffff
 
 /*
  * EXT_INIT_MAX_LEN is the maximum number of blocks we can have in an
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 5199bac7fc62..41575704600a 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -1408,7 +1408,7 @@ got_index:
 
 /*
  * ext4_ext_next_allocated_block:
- * returns allocated block in subsequent extent or EXT_MAX_BLOCK.
+ * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
  * NOTE: it considers block number from index entry as
  * allocated block. Thus, index entries have to be consistent
  * with leaves.
@@ -1422,7 +1422,7 @@ ext4_ext_next_allocated_block(struct ext4_ext_path *path)
         depth = path->p_depth;
 
         if (depth == 0 && path->p_ext == NULL)
-                return EXT_MAX_BLOCK;
+                return EXT_MAX_BLOCKS;
 
         while (depth >= 0) {
                 if (depth == path->p_depth) {
@@ -1439,12 +1439,12 @@ ext4_ext_next_allocated_block(struct ext4_ext_path *path)
                 depth--;
         }
 
-        return EXT_MAX_BLOCK;
+        return EXT_MAX_BLOCKS;
 }
 
 /*
  * ext4_ext_next_leaf_block:
- * returns first allocated block from next leaf or EXT_MAX_BLOCK
+ * returns first allocated block from next leaf or EXT_MAX_BLOCKS
  */
 static ext4_lblk_t ext4_ext_next_leaf_block(struct inode *inode,
                                         struct ext4_ext_path *path)
@@ -1456,7 +1456,7 @@ static ext4_lblk_t ext4_ext_next_leaf_block(struct inode *inode,
 
         /* zero-tree has no leaf blocks at all */
         if (depth == 0)
-                return EXT_MAX_BLOCK;
+                return EXT_MAX_BLOCKS;
 
         /* go to index block */
         depth--;
@@ -1469,7 +1469,7 @@ static ext4_lblk_t ext4_ext_next_leaf_block(struct inode *inode,
                 depth--;
         }
 
-        return EXT_MAX_BLOCK;
+        return EXT_MAX_BLOCKS;
 }
 
 /*
@@ -1677,13 +1677,13 @@ static unsigned int ext4_ext_check_overlap(struct inode *inode,
          */
         if (b2 < b1) {
                 b2 = ext4_ext_next_allocated_block(path);
-                if (b2 == EXT_MAX_BLOCK)
+                if (b2 == EXT_MAX_BLOCKS)
                         goto out;
         }
 
         /* check for wrap through zero on extent logical start block*/
         if (b1 + len1 < b1) {
-                len1 = EXT_MAX_BLOCK - b1;
+                len1 = EXT_MAX_BLOCKS - b1;
                 newext->ee_len = cpu_to_le16(len1);
                 ret = 1;
         }
@@ -1767,7 +1767,7 @@ repeat:
         fex = EXT_LAST_EXTENT(eh);
         next = ext4_ext_next_leaf_block(inode, path);
         if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block)
-            && next != EXT_MAX_BLOCK) {
+            && next != EXT_MAX_BLOCKS) {
                 ext_debug("next leaf block - %d\n", next);
                 BUG_ON(npath != NULL);
                 npath = ext4_ext_find_extent(inode, next, NULL);
@@ -1887,7 +1887,7 @@ static int ext4_ext_walk_space(struct inode *inode, ext4_lblk_t block,
         BUG_ON(func == NULL);
         BUG_ON(inode == NULL);
 
-        while (block < last && block != EXT_MAX_BLOCK) {
+        while (block < last && block != EXT_MAX_BLOCKS) {
                 num = last - block;
                 /* find extent for this block */
                 down_read(&EXT4_I(inode)->i_data_sem);
@@ -2020,7 +2020,7 @@ ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
         if (ex == NULL) {
                 /* there is no extent yet, so gap is [0;-] */
                 lblock = 0;
-                len = EXT_MAX_BLOCK;
+                len = EXT_MAX_BLOCKS;
                 ext_debug("cache gap(whole file):");
         } else if (block < le32_to_cpu(ex->ee_block)) {
                 lblock = block;
@@ -2350,7 +2350,7 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
                          * never happen because at least one of the end points
                          * needs to be on the edge of the extent.
                          */
-                        if (end == EXT_MAX_BLOCK) {
+                        if (end == EXT_MAX_BLOCKS - 1) {
                                 ext_debug("  bad truncate %u:%u\n",
                                                 start, end);
                                 block = 0;
@@ -2398,7 +2398,7 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
                          * If this is a truncate, this condition
                          * should never happen
                          */
-                        if (end == EXT_MAX_BLOCK) {
+                        if (end == EXT_MAX_BLOCKS - 1) {
                                 ext_debug("  bad truncate %u:%u\n",
                                         start, end);
                                 err = -EIO;
@@ -2478,7 +2478,7 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
                  * we need to remove it from the leaf
                  */
                 if (num == 0) {
-                        if (end != EXT_MAX_BLOCK) {
+                        if (end != EXT_MAX_BLOCKS - 1) {
                                 /*
                                  * For hole punching, we need to scoot all the
                                  * extents up when an extent is removed so that
@@ -3699,7 +3699,7 @@ void ext4_ext_truncate(struct inode *inode)
 
         last_block = (inode->i_size + sb->s_blocksize - 1)
                         >> EXT4_BLOCK_SIZE_BITS(sb);
-        err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCK);
+        err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
 
         /* In a multi-transaction truncate, we only make the final
          * transaction synchronous.
@@ -4347,8 +4347,8 @@ int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 
                 start_blk = start >> inode->i_sb->s_blocksize_bits;
                 last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
-                if (last_blk >= EXT_MAX_BLOCK)
-                        last_blk = EXT_MAX_BLOCK-1;
+                if (last_blk >= EXT_MAX_BLOCKS)
+                        last_blk = EXT_MAX_BLOCKS-1;
                 len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
 
                 /*
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index 2b8304bf3c50..f57455a1b1b2 100644
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -1002,12 +1002,12 @@ mext_check_arguments(struct inode *orig_inode,
                 return -EINVAL;
         }
 
-        if ((orig_start > EXT_MAX_BLOCK) ||
-            (donor_start > EXT_MAX_BLOCK) ||
-            (*len > EXT_MAX_BLOCK) ||
-            (orig_start + *len > EXT_MAX_BLOCK))  {
+        if ((orig_start >= EXT_MAX_BLOCKS) ||
+            (donor_start >= EXT_MAX_BLOCKS) ||
+            (*len > EXT_MAX_BLOCKS) ||
+            (orig_start + *len >= EXT_MAX_BLOCKS))  {
                 ext4_debug("ext4 move extent: Can't handle over [%u] blocks "
-                        "[ino:orig %lu, donor %lu]\n", EXT_MAX_BLOCK,
+                        "[ino:orig %lu, donor %lu]\n", EXT_MAX_BLOCKS,
                         orig_inode->i_ino, donor_inode->i_ino);
                 return -EINVAL;
         }
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index cc5c157aa11d..9ea71aa864b3 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2243,6 +2243,12 @@ static void ext4_orphan_cleanup(struct super_block *sb,
  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
  * so that won't be a limiting factor.
  *
+ * However there is other limiting factor. We do store extents in the form
+ * of starting block and length, hence the resulting length of the extent
+ * covering maximum file size must fit into on-disk format containers as
+ * well. Given that length is always by 1 unit bigger than max unit (because
+ * we count 0 as well) we have to lower the s_maxbytes by one fs block.
+ *
  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
  */
 static loff_t ext4_max_size(int blkbits, int has_huge_files)
@@ -2264,10 +2270,13 @@ static loff_t ext4_max_size(int blkbits, int has_huge_files)
                 upper_limit <<= blkbits;
         }
 
-        /* 32-bit extent-start container, ee_block */
-        res = 1LL << 32;
+        /*
+         * 32-bit extent-start container, ee_block. We lower the maxbytes
+         * by one fs block, so ee_len can cover the extent of maximum file
+         * size
+         */
+        res = (1LL << 32) - 1;
         res <<= blkbits;
-        res -= 1;
 
         /* Sanity check against vm- & vfs- imposed limits */
         if (res > upper_limit)