ext4: fix extent sanity checking code with AGGRESSIVE_TEST

The extents sanity-checking code depends on the ext4_ext_space_*()
functions returning the maximum alloable size for eh_max; however,
when the debugging #ifdef AGGRESSIVE_TEST is enabled to test the
extent tree handling code, this prevents a normally created ext4
filesystem from being mounted with the errors:

Aug 26 15:43:50 bsd086 kernel: [   96.070277] EXT4-fs error (device sda8): ext4_ext_check_inode: bad header/extent in inode #8: too large eh_max - magic f30a, entries 1, max 4(3), depth 0(0)
Aug 26 15:43:50 bsd086 kernel: [   96.070526] EXT4-fs (sda8): no journal found

Bug reported by Akira Fujita.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 34 insertions, 26 deletions

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 8c20caf4aa5c..7a3832577923 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -229,57 +229,65 @@ ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
         return newblock;
 }
 
-static int ext4_ext_space_block(struct inode *inode)
+static inline int ext4_ext_space_block(struct inode *inode, int check)
 {
         int size;
 
         size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
                         / sizeof(struct ext4_extent);
+        if (!check) {
 #ifdef AGGRESSIVE_TEST
-        if (size > 6)
-                size = 6;
+                if (size > 6)
+                        size = 6;
 #endif
+        }
         return size;
 }
 
-static int ext4_ext_space_block_idx(struct inode *inode)
+static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
 {
         int size;
 
         size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
                         / sizeof(struct ext4_extent_idx);
+        if (!check) {
 #ifdef AGGRESSIVE_TEST
-        if (size > 5)
-                size = 5;
+                if (size > 5)
+                        size = 5;
 #endif
+        }
         return size;
 }
 
-static int ext4_ext_space_root(struct inode *inode)
+static inline int ext4_ext_space_root(struct inode *inode, int check)
 {
         int size;
 
         size = sizeof(EXT4_I(inode)->i_data);
         size -= sizeof(struct ext4_extent_header);
         size /= sizeof(struct ext4_extent);
+        if (!check) {
 #ifdef AGGRESSIVE_TEST
-        if (size > 3)
-                size = 3;
+                if (size > 3)
+                        size = 3;
 #endif
+        }
         return size;
 }
 
-static int ext4_ext_space_root_idx(struct inode *inode)
+static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
 {
         int size;
 
         size = sizeof(EXT4_I(inode)->i_data);
         size -= sizeof(struct ext4_extent_header);
         size /= sizeof(struct ext4_extent_idx);
+        if (!check) {
 #ifdef AGGRESSIVE_TEST
-        if (size > 4)
-                size = 4;
+                if (size > 4)
+                        size = 4;
 #endif
+        }
         return size;
 }
 
@@ -293,9 +301,9 @@ int ext4_ext_calc_metadata_amount(struct inode *inode, int blocks)
         int lcap, icap, rcap, leafs, idxs, num;
         int newextents = blocks;
 
-        rcap = ext4_ext_space_root_idx(inode);
-        lcap = ext4_ext_space_block(inode);
-        icap = ext4_ext_space_block_idx(inode);
+        rcap = ext4_ext_space_root_idx(inode, 0);
+        lcap = ext4_ext_space_block(inode, 0);
+        icap = ext4_ext_space_block_idx(inode, 0);
 
         /* number of new leaf blocks needed */
         num = leafs = (newextents + lcap - 1) / lcap;
@@ -320,14 +328,14 @@ ext4_ext_max_entries(struct inode *inode, int depth)
 
         if (depth == ext_depth(inode)) {
                 if (depth == 0)
-                        max = ext4_ext_space_root(inode);
+                        max = ext4_ext_space_root(inode, 1);
                 else
-                        max = ext4_ext_space_root_idx(inode);
+                        max = ext4_ext_space_root_idx(inode, 1);
         } else {
                 if (depth == 0)
-                        max = ext4_ext_space_block(inode);
+                        max = ext4_ext_space_block(inode, 1);
                 else
-                        max = ext4_ext_space_block_idx(inode);
+                        max = ext4_ext_space_block_idx(inode, 1);
         }
 
         return max;
@@ -626,7 +634,7 @@ int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
         eh->eh_depth = 0;
         eh->eh_entries = 0;
         eh->eh_magic = EXT4_EXT_MAGIC;
-        eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode));
+        eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
         ext4_mark_inode_dirty(handle, inode);
         ext4_ext_invalidate_cache(inode);
         return 0;
@@ -851,7 +859,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 
         neh = ext_block_hdr(bh);
         neh->eh_entries = 0;
-        neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode));
+        neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
         neh->eh_magic = EXT4_EXT_MAGIC;
         neh->eh_depth = 0;
         ex = EXT_FIRST_EXTENT(neh);
@@ -927,7 +935,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
                 neh = ext_block_hdr(bh);
                 neh->eh_entries = cpu_to_le16(1);
                 neh->eh_magic = EXT4_EXT_MAGIC;
-                neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode));
+                neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
                 neh->eh_depth = cpu_to_le16(depth - i);
                 fidx = EXT_FIRST_INDEX(neh);
                 fidx->ei_block = border;
@@ -1052,9 +1060,9 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
         /* old root could have indexes or leaves
          * so calculate e_max right way */
         if (ext_depth(inode))
-          neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode));
+                neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
         else
-          neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode));
+                neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
         neh->eh_magic = EXT4_EXT_MAGIC;
         set_buffer_uptodate(bh);
         unlock_buffer(bh);
@@ -1069,7 +1077,7 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
                 goto out;
 
         curp->p_hdr->eh_magic = EXT4_EXT_MAGIC;
-        curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode));
+        curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
         curp->p_hdr->eh_entries = cpu_to_le16(1);
         curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr);
 
@@ -2348,7 +2356,7 @@ static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start)
                 if (err == 0) {
                         ext_inode_hdr(inode)->eh_depth = 0;
                         ext_inode_hdr(inode)->eh_max =
-                                cpu_to_le16(ext4_ext_space_root(inode));
+                                cpu_to_le16(ext4_ext_space_root(inode, 0));
                         err = ext4_ext_dirty(handle, inode, path);
                 }
         }