On Sun, 2008-08-17 at 15:17 +0100, David Woodhouse wrote:
> Subject: [PATCH] Remove special cases for "." and ".."
>
> We never get asked by the VFS to lookup either of them, and we can
> handle the readdir() case a lot more simply, too.
And a few other minor cleanups... some cosmetic, but note the WARN_ON().
From: David Woodhouse <David.Woodhouse@xxxxxxxxx>
Date: Sun, 17 Aug 2008 17:08:36 +0100
Subject: [PATCH] Minor cleanup of btrfs_real_readdir()
Signed-off-by: David Woodhouse <David.Woodhouse@xxxxxxxxx>
---
inode.c | 42 +++++++++++++++++++++++++++---------------
1 files changed, 27 insertions(+), 15 deletions(-)
diff --git a/inode.c b/inode.c
index 411dfc4..187e1f8 100644
--- a/inode.c
+++ b/inode.c
@@ -1960,34 +1960,34 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
return 0;
filp->f_pos = 1;
}
-
- key.objectid = inode->i_ino;
- path = btrfs_alloc_path();
- path->reada = 2;
-
/* special case for .., just use the back ref */
if (filp->f_pos == 1) {
u64 pino = parent_ino(filp->f_path.dentry);
over = filldir(dirent, "..", 2,
2, pino, DT_DIR);
if (over)
- goto nopos;
+ return 0;
filp->f_pos = 2;
}
+ path = btrfs_alloc_path();
+ path->reada = 2;
+
btrfs_set_key_type(&key, key_type);
key.offset = filp->f_pos;
+ key.objectid = inode->i_ino;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto err;
advance = 0;
- while(1) {
+
+ while (1) {
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
slot = path->slots[0];
if (advance || slot >= nritems) {
- if (slot >= nritems -1) {
+ if (slot >= nritems - 1) {
ret = btrfs_next_leaf(root, path);
if (ret)
break;
@@ -2011,19 +2011,23 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
continue;
filp->f_pos = found_key.offset;
- advance = 1;
+
di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
di_cur = 0;
di_total = btrfs_item_size(leaf, item);
- while(di_cur < di_total) {
+
+ while (di_cur < di_total) {
struct btrfs_key location;
name_len = btrfs_dir_name_len(leaf, di);
- if (name_len < 32) {
+ if (name_len <= sizeof(tmp_name)) {
name_ptr = tmp_name;
} else {
name_ptr = kmalloc(name_len, GFP_NOFS);
- BUG_ON(!name_ptr);
+ if (!name_ptr) {
+ ret = -ENOMEM;
+ goto err;
+ }
}
read_extent_buffer(leaf, name_ptr,
(unsigned long)(di + 1), name_len);
@@ -2031,8 +2035,7 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
btrfs_dir_item_key_to_cpu(leaf, di, &location);
over = filldir(dirent, name_ptr, name_len,
- found_key.offset,
- location.objectid,
+ found_key.offset, location.objectid,
d_type);
if (name_ptr != tmp_name)
@@ -2040,12 +2043,21 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
if (over)
goto nopos;
+
di_len = btrfs_dir_name_len(leaf, di) +
- btrfs_dir_data_len(leaf, di) +sizeof(*di);
+ btrfs_dir_data_len(leaf, di) + sizeof(*di);
di_cur += di_len;
di = (struct btrfs_dir_item *)((char *)di + di_len);
+
+ /* If there's more than one directory entry in each
+ item, then the offset isn't unique. Seeking in
+ directories will be broken. Can this ever actually
+ happen? */
+ WARN_ON(di_cur != di_total);
}
}
+
+ /* Reached end of directory/root. Bump pos past the last item. */
if (key_type == BTRFS_DIR_INDEX_KEY)
filp->f_pos = INT_LIMIT(typeof(filp->f_pos));
else
--
1.5.5.1
--
David Woodhouse Open Source Technology Centre
David.Woodhouse@xxxxxxxxx Intel Corporation
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