| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Wed, 28 Aug 2013 13:25:58 +0800
From: Robert Yang <liezhi.yang@...driver.com>
To: <linux-ext4@...r.kernel.org>
CC: <tytso@....edu>, <dvhart@...ux.intel.com>
Subject: [RFC 08/10] misc/util.c: handle hardlinks
Create the file and save the source inode number when we meet the hard
link at the first time, use ext2fs_link() to link the name to the target
inode number when we meet the same source inode number again.
Signed-off-by: Robert Yang <liezhi.yang@...driver.com>
---
misc/util.c | 85 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 85 insertions(+)
diff --git a/misc/util.c b/misc/util.c
index 1a0a58c..11134db 100644
--- a/misc/util.c
+++ b/misc/util.c
@@ -314,6 +314,42 @@ void dump_mmp_msg(struct mmp_struct *mmp, const char *msg)
}
}
+/* Link an inode number to a directory */
+static errcode_t add_link(ext2_ino_t parent_ino, ext2_ino_t ino, const char *name)
+{
+ struct ext2_inode inode;
+ errcode_t retval;
+ char *func_name = "add_to_dir";
+
+ retval = ext2fs_read_inode(current_fs, ino, &inode);
+ if (retval) {
+ com_err(func_name, retval, "while reading inode %u", ino);
+ return retval;
+ }
+
+ retval = ext2fs_link(current_fs, parent_ino, name, ino, inode.i_flags);
+ if (retval == EXT2_ET_DIR_NO_SPACE) {
+ retval = ext2fs_expand_dir(current_fs, parent_ino);
+ if (retval) {
+ com_err(func_name, retval, "while expanding directory");
+ return retval;
+ }
+ retval = ext2fs_link(current_fs, parent_ino, name, ino, inode.i_flags);
+ }
+ if (retval) {
+ com_err(func_name, retval, "while linking %s", name);
+ return retval;
+ }
+
+ inode.i_links_count++;
+
+ retval = ext2fs_write_inode(current_fs, ino, &inode);
+ if (retval)
+ com_err(func_name, retval, "while writing inode %u", ino);
+
+ return retval;
+}
+
/* Fill the uid, gid, mode and time for the inode */
static void fill_inode(struct ext2_inode *inode, struct stat *st)
{
@@ -542,6 +578,17 @@ try_again:
}
}
+int is_hardlink(ext2_ino_t ino)
+{
+ int i;
+
+ for(i = 0; i < hdlinks.count; i++) {
+ if(hdlinks.hdl[i].src_ino == ino)
+ return i;
+ }
+ return -1;
+}
+
/* Copy the native file to the fs */
errcode_t do_write_internal(ext2_ino_t cwd, const char *src, const char *dest)
{
@@ -640,10 +687,12 @@ errcode_t populate_fs(ext2_ino_t parent_ino, const char *source_dir)
struct dirent *dent;
struct stat st;
char ln_target[PATH_MAX];
+ unsigned int save_inode = 0;
char *func_name = "populate_fs";
ext2_ino_t ino;
errcode_t retval;
int read_cnt;
+ int hdlink;
root = EXT2_ROOT_INO;
@@ -665,6 +714,21 @@ errcode_t populate_fs(ext2_ino_t parent_ino, const char *source_dir)
lstat(dent->d_name, &st);
name = dent->d_name;
+ /* Check for hardlinks */
+ if (!S_ISDIR(st.st_mode) && !S_ISLNK(st.st_mode) && st.st_nlink > 1) {
+ hdlink = is_hardlink(st.st_ino);
+ if (hdlink >= 0) {
+ retval = add_link(parent_ino,
+ hdlinks.hdl[hdlink].dst_ino, name);
+ if (retval) {
+ com_err(func_name, retval, "while linking %s", name);
+ return retval;
+ }
+ continue;
+ } else
+ save_inode = 1;
+ }
+
switch(st.st_mode & S_IFMT) {
case S_IFCHR:
case S_IFBLK:
@@ -733,6 +797,27 @@ errcode_t populate_fs(ext2_ino_t parent_ino, const char *source_dir)
_("while setting inode for \"%s\""), name);
return retval;
}
+
+ /* Save the hardlink ino */
+ if (save_inode) {
+ /*
+ * Check whether need more memory, and we don't need
+ * free() since the lifespan will be over after the fs
+ * populated.
+ */
+ if (hdlinks.count == hdlink_cnt) {
+ if ((hdlinks.hdl = realloc (hdlinks.hdl,
+ (hdlink_cnt + HDLINK_CNT) *
+ sizeof (struct hdlink_s))) == NULL) {
+ com_err(name, errno, "Not enough memory");
+ return errno;
+ }
+ hdlink_cnt += HDLINK_CNT;
+ }
+ hdlinks.hdl[hdlinks.count].src_ino = st.st_ino;
+ hdlinks.hdl[hdlinks.count].dst_ino = ino;
+ hdlinks.count++;
+ }
}
closedir(dh);
return retval;
--
1.8.1.2
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists