Btrfs: Always use 64bit inode number

There's a potential problem in 32bit system when we exhaust 32bit inode
numbers and start to allocate big inode numbers, because btrfs uses
inode->i_ino in many places.

So here we always use BTRFS_I(inode)->location.objectid, which is an
u64 variable.

There are 2 exceptions that BTRFS_I(inode)->location.objectid !=
inode->i_ino: the btree inode (0 vs 1) and empty subvol dirs (256 vs 2),
and inode->i_ino will be used in those cases.

Another reason to make this change is I'm going to use a special inode
to save free ino cache, and the inode number must be > (u64)-256.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>

1 files changed, 14 insertions, 13 deletions

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 75899a01dded..bef020451525 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -298,6 +298,7 @@ int btrfs_drop_extents(struct btrfs_trans_handle *trans, struct inode *inode,
         struct btrfs_path *path;
         struct btrfs_key key;
         struct btrfs_key new_key;
+        u64 ino = btrfs_ino(inode);
         u64 search_start = start;
         u64 disk_bytenr = 0;
         u64 num_bytes = 0;
@@ -318,14 +319,14 @@ int btrfs_drop_extents(struct btrfs_trans_handle *trans, struct inode *inode,
 
         while (1) {
                 recow = 0;
-                ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
+                ret = btrfs_lookup_file_extent(trans, root, path, ino,
                                                search_start, -1);
                 if (ret < 0)
                         break;
                 if (ret > 0 && path->slots[0] > 0 && search_start == start) {
                         leaf = path->nodes[0];
                         btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
-                        if (key.objectid == inode->i_ino &&
+                        if (key.objectid == ino &&
                             key.type == BTRFS_EXTENT_DATA_KEY)
                                 path->slots[0]--;
                 }
@@ -346,7 +347,7 @@ next_slot:
                 }
 
                 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
-                if (key.objectid > inode->i_ino ||
+                if (key.objectid > ino ||
                     key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
                         break;
 
@@ -592,6 +593,7 @@ int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
         int del_slot = 0;
         int recow;
         int ret;
+        u64 ino = btrfs_ino(inode);
 
         btrfs_drop_extent_cache(inode, start, end - 1, 0);
 
@@ -600,7 +602,7 @@ int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
 again:
         recow = 0;
         split = start;
-        key.objectid = inode->i_ino;
+        key.objectid = ino;
         key.type = BTRFS_EXTENT_DATA_KEY;
         key.offset = split;
 
@@ -612,8 +614,7 @@ again:
 
         leaf = path->nodes[0];
         btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
-        BUG_ON(key.objectid != inode->i_ino ||
-               key.type != BTRFS_EXTENT_DATA_KEY);
+        BUG_ON(key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY);
         fi = btrfs_item_ptr(leaf, path->slots[0],
                             struct btrfs_file_extent_item);
         BUG_ON(btrfs_file_extent_type(leaf, fi) !=
@@ -630,7 +631,7 @@ again:
                 other_start = 0;
                 other_end = start;
                 if (extent_mergeable(leaf, path->slots[0] - 1,
-                                     inode->i_ino, bytenr, orig_offset,
+                                     ino, bytenr, orig_offset,
                                      &other_start, &other_end)) {
                         new_key.offset = end;
                         btrfs_set_item_key_safe(trans, root, path, &new_key);
@@ -653,7 +654,7 @@ again:
                 other_start = end;
                 other_end = 0;
                 if (extent_mergeable(leaf, path->slots[0] + 1,
-                                     inode->i_ino, bytenr, orig_offset,
+                                     ino, bytenr, orig_offset,
                                      &other_start, &other_end)) {
                         fi = btrfs_item_ptr(leaf, path->slots[0],
                                             struct btrfs_file_extent_item);
@@ -702,7 +703,7 @@ again:
 
                 ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, 0,
                                            root->root_key.objectid,
-                                           inode->i_ino, orig_offset);
+                                           ino, orig_offset);
                 BUG_ON(ret);
 
                 if (split == start) {
@@ -718,7 +719,7 @@ again:
         other_start = end;
         other_end = 0;
         if (extent_mergeable(leaf, path->slots[0] + 1,
-                             inode->i_ino, bytenr, orig_offset,
+                             ino, bytenr, orig_offset,
                              &other_start, &other_end)) {
                 if (recow) {
                         btrfs_release_path(root, path);
@@ -729,13 +730,13 @@ again:
                 del_nr++;
                 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
                                         0, root->root_key.objectid,
-                                        inode->i_ino, orig_offset);
+                                        ino, orig_offset);
                 BUG_ON(ret);
         }
         other_start = 0;
         other_end = start;
         if (extent_mergeable(leaf, path->slots[0] - 1,
-                             inode->i_ino, bytenr, orig_offset,
+                             ino, bytenr, orig_offset,
                              &other_start, &other_end)) {
                 if (recow) {
                         btrfs_release_path(root, path);
@@ -746,7 +747,7 @@ again:
                 del_nr++;
                 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
                                         0, root->root_key.objectid,
-                                        inode->i_ino, orig_offset);
+                                        ino, orig_offset);
                 BUG_ON(ret);
         }
         if (del_nr == 0) {