From d83dc950b3ec1fbde33b23d42c5154091a74f4d9 Mon Sep 17 00:00:00 2001 From: Robert Yang Date: Mon, 23 Dec 2013 03:44:03 -0500 Subject: [PATCH 09/11] misc/create_inode.c: handle hardlinks Create the inode and save the native inode number when we meet the hard link (st_nlink > 1) at the first time, use ext2fs_link() to link the name to the target inode number when we meet the same native inode number again. This algorithm is referred from the genext2fs. Upstream-Status: Backport Signed-off-by: Robert Yang Reviewed-by: Darren Hart --- misc/create_inode.c | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++ misc/create_inode.h | 18 +++++++++++ misc/mke2fs.c | 12 +++++++ 3 files changed, 118 insertions(+) diff --git a/misc/create_inode.c b/misc/create_inode.c index aad7354..763504d 100644 --- a/misc/create_inode.c +++ b/misc/create_inode.c @@ -18,6 +18,44 @@ #define S_BLKSIZE 512 #endif +/* For saving the hard links */ +int hdlink_cnt = HDLINK_CNT; + +/* 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; + + retval = ext2fs_read_inode(current_fs, ino, &inode); + if (retval) { + com_err(__func__, 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__, retval, "while expanding directory"); + return retval; + } + retval = ext2fs_link(current_fs, parent_ino, name, ino, inode.i_flags); + } + if (retval) { + com_err(__func__, retval, "while linking %s", name); + return retval; + } + + inode.i_links_count++; + + retval = ext2fs_write_inode(current_fs, ino, &inode); + if (retval) + com_err(__func__, 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) { @@ -278,6 +316,17 @@ fail: return retval; } +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) { @@ -388,9 +437,11 @@ 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; ext2_ino_t ino; errcode_t retval; int read_cnt; + int hdlink; root = EXT2_ROOT_INO; @@ -412,6 +463,22 @@ 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 */ + save_inode = 0; + 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__, retval, "while linking %s", name); + return retval; + } + continue; + } else + save_inode = 1; + } + switch(st.st_mode & S_IFMT) { case S_IFCHR: case S_IFBLK: @@ -480,6 +547,27 @@ 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; diff --git a/misc/create_inode.h b/misc/create_inode.h index 9fc97fa..2b6d429 100644 --- a/misc/create_inode.h +++ b/misc/create_inode.h @@ -6,9 +6,27 @@ #include "ext2fs/ext2fs.h" #include "nls-enable.h" +struct hdlink_s +{ + ext2_ino_t src_ino; + ext2_ino_t dst_ino; +}; + +struct hdlinks_s +{ + int count; + struct hdlink_s *hdl; +}; + +struct hdlinks_s hdlinks; + ext2_filsys current_fs; ext2_ino_t root; +/* For saving the hard links */ +#define HDLINK_CNT 4 +extern int hdlink_cnt; + /* For populating the filesystem */ extern errcode_t populate_fs(ext2_ino_t parent_ino, const char *source_dir); extern errcode_t do_mknod_internal(ext2_ino_t cwd, const char *name, struct stat *st); diff --git a/misc/mke2fs.c b/misc/mke2fs.c index 578b62d..a63f0b7 100644 --- a/misc/mke2fs.c +++ b/misc/mke2fs.c @@ -2730,6 +2730,18 @@ no_journal: if (!quiet) printf("%s", _("Copying files into the device: ")); + /* + * Allocate memory for the hardlinks, we don't need free() + * since the lifespan will be over after the fs populated. + */ + if ((hdlinks.hdl = (struct hdlink_s *) + malloc(hdlink_cnt * sizeof(struct hdlink_s))) == NULL) { + fprintf(stderr, "%s", _("\nNot enough memory\n")); + retval = ext2fs_close(fs); + return retval; + } + + hdlinks.count = 0; current_fs = fs; root = EXT2_ROOT_INO; retval = populate_fs(root, root_dir); -- 1.7.10.4