sdcard: Remove lower case squashing of file names

sdcard daemon will now create new files and directories using
the actual name passed in by the client.
For existing files, sdcard will do case insensitive matching
when case sensitive lookup fails.

Change-Id: I89f995ea01beb2c63a9b36943dbcfaa16e7cd972
Signed-off-by: Mike Lockwood <lockwood@android.com>

1 files changed, 106 insertions, 110 deletions

diff --git a/sdcard/sdcard.c b/sdcard/sdcard.c
index cc2cce7..9bb9d4b 100644
--- a/sdcard/sdcard.c
+++ b/sdcard/sdcard.c
@@ -95,6 +95,12 @@ struct node {
     __u32 namelen;
 
     char *name;
+    /* If non-null, this is the real name of the file in the underlying storage.
+     * This may differ from the field "name" only by case.
+     * strlen(actual_name) will always equal strlen(name), so it is safe to use
+     * namelen for both fields.
+     */
+    char *actual_name;
 };
 
 struct fuse {
@@ -109,21 +115,13 @@ struct fuse {
     char rootpath[1024];
 };
 
-/* true if file names should be squashed to lower case */
-static int force_lower_case = 0;
 static unsigned uid = -1;
 static unsigned gid = -1;
 
 #define PATH_BUFFER_SIZE 1024
 
-static void normalize_name(char *name)
-{
-    if (force_lower_case) {
-        char ch;
-        while ((ch = *name) != 0)
-            *name++ = tolower(ch);
-    }
-}
+#define NO_CASE_SENSITIVE_MATCH 0
+#define CASE_SENSITIVE_MATCH 1
 
 /*
  * Get the real-life absolute path to a node.
@@ -131,8 +129,10 @@ static void normalize_name(char *name)
  *   buf: storage for returned string
  *   name: append this string to path if set
  */
-char *node_get_path(struct node *node, char *buf, const char *name)
+char *do_node_get_path(struct node *node, char *buf, const char *name, int match_case_insensitive)
 {
+    struct node *in_node = node;
+    const char *in_name = name;
     char *out = buf + PATH_BUFFER_SIZE - 1;
     int len;
     out[0] = 0;
@@ -143,7 +143,7 @@ char *node_get_path(struct node *node, char *buf, const char *name)
     }
 
     while (node) {
-        name = node->name;
+        name = (node->actual_name ? node->actual_name : node->name);
         len = node->namelen;
         node = node->parent;
     start:
@@ -151,12 +151,45 @@ char *node_get_path(struct node *node, char *buf, const char *name)
             return 0;
         out -= len;
         memcpy(out, name, len);
-        out --;
-        out[0] = '/';
+        /* avoid double slash at beginning of path */
+        if (out[0] != '/') {
+            out --;
+            out[0] = '/';
+        }
     }
 
-    normalize_name(out);
-    return out;
+    /* If we are searching for a file within node (rather than computing node's path)
+     * and fail, then we need to look for a case insensitive match.
+     */
+    if (in_name && match_case_insensitive && access(out, F_OK) != 0) {
+        char *path, buffer[PATH_BUFFER_SIZE];
+        DIR* dir;
+        struct dirent* entry;
+        path = do_node_get_path(in_node, buffer, NULL, NO_CASE_SENSITIVE_MATCH);
+        dir = opendir(path);
+        if (!dir) {
+            ERROR("opendir %s failed: %s", path, strerror(errno));
+            return out;
+        }
+
+        while ((entry = readdir(dir))) {
+            if (!strcasecmp(entry->d_name, in_name)) {
+                /* we have a match - replace the name */
+                len = strlen(in_name);
+                memcpy(buf + PATH_BUFFER_SIZE - len - 1, entry->d_name, len);
+                break;
+            }
+        }
+        closedir(dir);
+    }
+
+   return out;
+}
+
+char *node_get_path(struct node *node, char *buf, const char *name)
+{
+    /* We look for case insensitive matches by default */
+    return do_node_get_path(node, buf, name, CASE_SENSITIVE_MATCH);
 }
 
 void attr_from_stat(struct fuse_attr *attr, struct stat *s)
@@ -214,6 +247,41 @@ static void add_node_to_parent(struct node *node, struct node *parent) {
     parent->refcount++;
 }
 
+/* Check to see if our parent directory already has a file with a name
+ * that differs only by case.  If we find one, store it in the actual_name
+ * field so node_get_path will map it to this file in the underlying storage.
+ */
+static void node_find_actual_name(struct node *node)
+{
+    char *path, buffer[PATH_BUFFER_SIZE];
+    const char *node_name = node->name;
+    DIR* dir;
+    struct dirent* entry;
+
+    if (!node->parent) return;
+
+    path = node_get_path(node->parent, buffer, 0);
+    dir = opendir(path);
+    if (!dir) {
+        ERROR("opendir %s failed: %s", path, strerror(errno));
+        return;
+    }
+
+    while ((entry = readdir(dir))) {
+        const char *test_name = entry->d_name;
+        if (strcmp(test_name, node_name) && !strcasecmp(test_name, node_name)) {
+            /* we have a match - differs but only by case */
+            node->actual_name = strdup(test_name);
+            if (!node->actual_name) {
+                ERROR("strdup failed - out of memory\n");
+                exit(1);
+            }
+            break;
+        }
+    }
+    closedir(dir);
+}
+
 struct node *node_create(struct node *parent, const char *name, __u64 nid, __u64 gen)
 {
     struct node *node;
@@ -234,7 +302,7 @@ struct node *node_create(struct node *parent, const char *name, __u64 nid, __u64
     add_node_to_parent(node, parent);
     memcpy(node->name, name, namelen + 1);
     node->namelen = namelen;
-
+    node_find_actual_name(node);
     return node;
 }
 
@@ -246,6 +314,7 @@ static char *rename_node(struct node *node, const char *name)
         return 0;
     node->name = newname;
     memcpy(node->name, name, node->namelen + 1);
+    node_find_actual_name(node);
     return node->name;
 }
 
@@ -397,6 +466,7 @@ void node_release(struct node *node)
             /* TODO: remove debugging - poison memory */
         memset(node->name, 0xef, node->namelen);
         free(node->name);
+        free(node->actual_name);
         memset(node, 0xfc, sizeof(*node));
         free(node);
     }
@@ -458,75 +528,6 @@ void lookup_entry(struct fuse *fuse, struct node *node,
     fuse_reply(fuse, unique, &out, sizeof(out));
 }
 
-static int name_needs_normalizing(const char* name) {
-    char ch;
-    while ((ch = *name++) != 0) {
-        if (ch != tolower(ch))
-            return 1;
-    }
-    return 0;
-}
-
-static void recursive_fix_files(const char* path) {
-    DIR* dir;
-    struct dirent* entry;
-    char pathbuf[PATH_MAX];
-    char oldpath[PATH_MAX];
-    int pathLength = strlen(path);
-    int pathRemaining;
-    char* fileSpot;
-
-    if (pathLength >= sizeof(pathbuf) - 1) {
-        ERROR("path too long: %s\n", path);
-        return;
-    }
-    strcpy(pathbuf, path);
-    if (pathbuf[pathLength - 1] != '/') {
-        pathbuf[pathLength++] = '/';
-    }
-    fileSpot = pathbuf + pathLength;
-    pathRemaining = sizeof(pathbuf) - pathLength - 1;
-
-    dir = opendir(path);
-    if (!dir) {
-        ERROR("opendir %s failed: %s", path, strerror(errno));
-        return;
-    }
-
-    while ((entry = readdir(dir))) {
-        const char* name = entry->d_name;
-        int nameLength;
-
-        // ignore "." and ".."
-        if (name[0] == '.' && (name[1] == 0 || (name[1] == '.' && name[2] == 0))) {
-            continue;
-        }
-
-       nameLength = strlen(name);
-       if (nameLength > pathRemaining) {
-            ERROR("path %s/%s too long\n", path, name);
-            continue;
-        }
-        strcpy(fileSpot, name);
-
-        // make sure owner and group are correct
-        chown(pathbuf, uid, gid);
-
-        if (name_needs_normalizing(name)) {
-            /* rename file to lower case file name */
-            strlcpy(oldpath, pathbuf, sizeof(oldpath));
-            normalize_name(pathbuf);
-            rename(oldpath, pathbuf);
-        }
-
-        if (entry->d_type == DT_DIR) {
-            /* recurse to subdirectories */
-            recursive_fix_files(pathbuf);
-        }
-    }
-    closedir(dir);
-}
-
 void handle_fuse_request(struct fuse *fuse, struct fuse_in_header *hdr, void *data, unsigned len)
 {
     struct node *node;
@@ -682,7 +683,16 @@ void handle_fuse_request(struct fuse *fuse, struct fuse_in_header *hdr, void *da
             fuse_status(fuse, hdr->unique, -ENOENT);
             return;
         }
-        newpath = node_get_path(newparent, newbuffer, newname);
+        if (newparent == node) {
+            /* Special case for renaming a file where destination
+             * is same path differing only by case.
+             * In this case we don't want to look for a case insensitive match.
+             * This allows commands like "mv foo FOO" to work as expected.
+             */
+            newpath = do_node_get_path(newparent, newbuffer, newname, NO_CASE_SENSITIVE_MATCH);
+        } else {
+            newpath = node_get_path(newparent, newbuffer, newname);
+        }
 
         if (!remove_child(node, target->nid)) {
             ERROR("RENAME remove_child not found");
@@ -922,30 +932,19 @@ int main(int argc, char **argv)
     int fd;
     int res;
     const char *path = NULL;
-    int fix_files = 0;
     int i;
 
     for (i = 1; i < argc; i++) {
         char* arg = argv[i];
-        if (arg[0] == '-') {
-            if (!strcmp(arg, "-l")) {
-                force_lower_case = 1;
-            } else if (!strcmp(arg, "-f")) {
-                fix_files = 1;
-            } else {
-                return usage();
-            }
-        } else {
-            if (!path)
-                path = arg;
-            else if (uid == -1)
-                uid = strtoul(arg, 0, 10);
-            else if (gid == -1)
-                gid = strtoul(arg, 0, 10);
-            else {
-                ERROR("too many arguments\n");
-                return usage();
-            }
+        if (!path)
+            path = arg;
+        else if (uid == -1)
+            uid = strtoul(arg, 0, 10);
+        else if (gid == -1)
+            gid = strtoul(arg, 0, 10);
+        else {
+            ERROR("too many arguments\n");
+            return usage();
         }
     }
 
@@ -976,9 +975,6 @@ int main(int argc, char **argv)
         return -1;
     }
 
-    if (fix_files)
-        recursive_fix_files(path);
-
     if (setgid(gid) < 0) {
         ERROR("cannot setgid!\n");
         return -1;