btrfs: add debug check for extent_io range alignment

The 'end' value must exactly cover the end of the interval, which means
one byte less than the expected block alignment, or in case of a file
smaller than one block, one byte less than the inode size.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index b306b3a88fc7512248aa5a29e93ec57a2fca1d0f..03ca3ab958981475909780a46537c9f6d2b1c532 100644 (file)
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -77,10 +77,29 @@ void btrfs_leak_debug_check(void)
                kmem_cache_free(extent_buffer_cache, eb);
        }
 }
+
+#define btrfs_debug_check_extent_io_range(inode, start, end)           \
+       __btrfs_debug_check_extent_io_range(__func__, (inode), (start), (end))
+static inline void __btrfs_debug_check_extent_io_range(const char *caller,
+               struct inode *inode, u64 start, u64 end)
+{
+       u64 isize = i_size_read(inode);
+
+       if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) {
+               printk_ratelimited(KERN_DEBUG
+                   "btrfs: %s: ino %llu isize %llu odd range [%llu,%llu]\n",
+                               caller,
+                               (unsigned long long)btrfs_ino(inode),
+                               (unsigned long long)isize,
+                               (unsigned long long)start,
+                               (unsigned long long)end);
+       }
+}
 #else
 #define btrfs_leak_debug_add(new, head)        do {} while (0)
 #define btrfs_leak_debug_del(entry)    do {} while (0)
 #define btrfs_leak_debug_check()       do {} while (0)
+#define btrfs_debug_check_extent_io_range(c, s, e)     do {} while (0)
 #endif
 
 #define BUFFER_LRU_MAX 64
@@ -522,6 +541,8 @@ int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
        int err;
        int clear = 0;
 
+       btrfs_debug_check_extent_io_range(tree->mapping->host, start, end);
+
        if (delete)
                bits |= ~EXTENT_CTLBITS;
        bits |= EXTENT_FIRST_DELALLOC;
@@ -677,6 +698,8 @@ static void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
        struct extent_state *state;
        struct rb_node *node;
 
+       btrfs_debug_check_extent_io_range(tree->mapping->host, start, end);
+
        spin_lock(&tree->lock);
 again:
        while (1) {
@@ -769,6 +792,8 @@ __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
        u64 last_start;
        u64 last_end;
 
+       btrfs_debug_check_extent_io_range(tree->mapping->host, start, end);
+
        bits |= EXTENT_FIRST_DELALLOC;
 again:
        if (!prealloc && (mask & __GFP_WAIT)) {
@@ -989,6 +1014,8 @@ int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
        u64 last_start;
        u64 last_end;
 
+       btrfs_debug_check_extent_io_range(tree->mapping->host, start, end);
+
 again:
        if (!prealloc && (mask & __GFP_WAIT)) {
                prealloc = alloc_extent_state(mask);