diff options
| -rw-r--r-- | fs/dcache.c | 27 |
1 files changed, 18 insertions, 9 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index 7599d35b4ae5..cb25a1a5e307 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -2372,7 +2372,8 @@ void dentry_update_name_case(struct dentry *dentry, struct qstr *name) } EXPORT_SYMBOL(dentry_update_name_case); -static void switch_names(struct dentry *dentry, struct dentry *target) +static void switch_names(struct dentry *dentry, struct dentry *target, + bool exchange) { if (dname_external(target)) { if (dname_external(dentry)) { @@ -2406,6 +2407,12 @@ static void switch_names(struct dentry *dentry, struct dentry *target) */ unsigned int i; BUILD_BUG_ON(!IS_ALIGNED(DNAME_INLINE_LEN, sizeof(long))); + if (!exchange) { + memcpy(dentry->d_iname, target->d_name.name, + target->d_name.len + 1); + dentry->d_name.hash_len = target->d_name.hash_len; + return; + } for (i = 0; i < DNAME_INLINE_LEN / sizeof(long); i++) { swap(((long *) &dentry->d_iname)[i], ((long *) &target->d_iname)[i]); @@ -2456,12 +2463,15 @@ static void dentry_unlock_for_move(struct dentry *dentry, struct dentry *target) * When switching names, the actual string doesn't strictly have to * be preserved in the target - because we're dropping the target * anyway. As such, we can just do a simple memcpy() to copy over - * the new name before we switch. - * - * Note that we have to be a lot more careful about getting the hash - * switched - we have to switch the hash value properly even if it - * then no longer matches the actual (corrupted) string of the target. - * The hash value has to match the hash queue that the dentry is on.. + * the new name before we switch, unless we are going to rehash + * it. Note that if we *do* unhash the target, we are not allowed + * to rehash it without giving it a new name/hash key - whether + * we swap or overwrite the names here, resulting name won't match + * the reality in filesystem; it's only there for d_path() purposes. + * Note that all of this is happening under rename_lock, so the + * any hash lookup seeing it in the middle of manipulations will + * be discarded anyway. So we do not care what happens to the hash + * key in that case. */ /* * __d_move - move a dentry @@ -2507,9 +2517,8 @@ static void __d_move(struct dentry *dentry, struct dentry *target, d_hash(dentry->d_parent, dentry->d_name.hash)); } - /* Switch the names.. */ - switch_names(dentry, target); + switch_names(dentry, target, exchange); /* ... and switch them in the tree */ if (IS_ROOT(dentry)) { |