Move the handling of duplicate names into its own function. As a
result, all names other than "lost+found" files (not just those that
get obfuscated) will be checked to avoid duplication.
This makes the local buffer newname[] in generate_obfuscated_name()
unnecessary, so just drop it and use the passed-in name.
Signed-off-by: Alex Elder <aelder@xxxxxxx>
Updates:
- A comment about handling of a leading '/' character is now modified
to match the updated code, rather than being deleted altogether.
- Renamed handle_duplicates() to be handle_duplicate_name().
---
db/metadump.c | 78
++++++++++++++++++++++++++++++++++------------------------
1 file changed, 47 insertions(+), 31 deletions(-)
Index: b/db/metadump.c
===================================================================
--- a/db/metadump.c
+++ b/db/metadump.c
@@ -552,6 +552,37 @@ obfuscate_name(
ASSERT(libxfs_da_hashname(name, name_len) == hash);
}
+/*
+ * Look up the given name in the name table. If it is already
+ * present, find an alternate and attempt to use that name instead.
+ *
+ * Returns 1 if the (possibly modified) name is not present in the
+ * name table. Returns 0 otherwise.
+ */
+static int
+handle_duplicate_name(xfs_dahash_t hash, size_t name_len, uchar_t
*name)
+{
+ int dup = 0;
+
+ if (!nametable_find(hash, name_len, name))
+ return 1; /* Not already in table */
+
+ /* Name is already in use. Need to find an alternate. */
+
+ do {
+ obfuscate_name(hash, name_len, name);
+
+ /*
+ * Search the name table to be sure we don't produce
+ * a name that's already been used.
+ */
+ if (!nametable_find(hash, name_len, name))
+ break;
+ } while (++dup < DUP_MAX);
+
+ return dup < DUP_MAX ? 1 : 0;
+}
+
static void
generate_obfuscated_name(
xfs_ino_t ino,
@@ -559,8 +590,6 @@ generate_obfuscated_name(
uchar_t *name)
{
xfs_dahash_t hash;
- int dup = 0;
- uchar_t newname[NAME_MAX];
/*
* We don't obfuscate "lost+found" or any orphan files
@@ -572,48 +601,35 @@ generate_obfuscated_name(
return;
/*
- * If the name starts with a slash, just skip over it. We
- * will copy our obfuscated name back into space following
- * the slash when we're done. Our new name will not have
- * the '/', and that's the version we'll keep in our
- * duplicates table. Note that the namelen value passed in
- * does not include the leading slash (if any).
+ * If the name starts with a slash, just skip over it. It
+ * isn't included in the hash and we don't record it in the
+ * name table. Note that the namelen value passed in does
+ * not count the leading slash (if one is present).
*/
if (*name == '/')
name++;
- hash = libxfs_da_hashname(name, namelen);
- do {
- obfuscate_name(hash, namelen, newname);
+ /* Obfuscate the name (if possible) */
- /*
- * Search the name table to be sure we don't produce
- * a name that's already been used.
- */
- if (!nametable_find(hash, namelen, newname))
- break;
- } while (++dup < DUP_MAX);
+ hash = libxfs_da_hashname(name, namelen);
+ obfuscate_name(hash, namelen, name);
/*
- * Update the caller's copy with the obfuscated name.
- *
- * If we couldn't come up with one, just use the original
- * name without obfuscation. Issue a warning if we managed
- * to previously create an obfuscated name that matches the
- * one we're working on now.
+ * Make sure the name is not something already seen. If we
+ * fail to find a suitable alternate, we're dealing with a
+ * very pathological situation, and we may end up creating
+ * a duplicate name in the metadump, so issue a warning.
*/
- if (dup < DUP_MAX)
- memcpy(name, newname, namelen);
- else if (nametable_find(hash, namelen, name))
+ if (!handle_duplicate_name(hash, namelen, name)) {
print_warning("duplicate name for inode %llu "
"in dir inode %llu\n",
(unsigned long long) ino,
(unsigned long long) cur_ino);
+ return;
+ }
+
+ /* Create an entry for the new name in the name table. */
- /*
- * Create an entry for the name in the name table. Use the
- * original name if we got too many dups.
- */
if (!nametable_add(hash, namelen, name))
print_warning("unable to record name for inode %llu "
"in dir inode %llu\n",
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