From: Darrick J. Wong <djwong@xxxxxxxxxx>
Create a pair of commands to create and remove directory entries to
support functional testing of directory tree corruption.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
---
db/namei.c | 378 ++++++++++++++++++++++++++++++++++++++++++++++
include/xfs_inode.h | 4
libxfs/libxfs_api_defs.h | 8 +
man/man8/xfs_db.8 | 20 ++
4 files changed, 409 insertions(+), 1 deletion(-)
diff --git a/db/namei.c b/db/namei.c
index 46b4cacb5..d57ead4f1 100644
--- a/db/namei.c
+++ b/db/namei.c
@@ -916,6 +916,376 @@ static struct cmdinfo parent_cmd = {
.help = parent_help,
};
+static void
+link_help(void)
+{
+ dbprintf(_(
+"\n"
+" Create a directory entry in the current directory that points to the\n"
+" specified file.\n"
+"\n"
+" Options:\n"
+" -i -- Point to this specific inode number.\n"
+" -p -- Point to the inode given by this path.\n"
+" -t -- Set the file type to this value.\n"
+" name -- Create this directory entry with this name.\n"
+ ));
+}
+
+static int
+create_child(
+ struct xfs_mount *mp,
+ xfs_ino_t parent_ino,
+ const char *name,
+ unsigned int ftype,
+ xfs_ino_t child_ino)
+{
+ struct xfs_name xname = {
+ .name = (const unsigned char *)name,
+ .len = strlen(name),
+ .type = ftype,
+ };
+ struct xfs_parent_args *ppargs = NULL;
+ struct xfs_trans *tp;
+ struct xfs_inode *dp, *ip;
+ unsigned int resblks;
+ bool isdir;
+ int error;
+
+ error = -libxfs_iget(mp, NULL, parent_ino, 0, &dp);
+ if (error)
+ return error;
+
+ if (!S_ISDIR(VFS_I(dp)->i_mode)) {
+ error = -ENOTDIR;
+ goto out_dp;
+ }
+
+ error = -libxfs_iget(mp, NULL, child_ino, 0, &ip);
+ if (error)
+ goto out_dp;
+ isdir = S_ISDIR(VFS_I(ip)->i_mode);
+
+ if (xname.type == XFS_DIR3_FT_UNKNOWN)
+ xname.type = libxfs_mode_to_ftype(VFS_I(ip)->i_mode);
+
+ error = -libxfs_parent_start(mp, &ppargs);
+ if (error)
+ goto out_ip;
+
+ resblks = libxfs_link_space_res(mp, MAXNAMELEN);
+ error = -libxfs_trans_alloc(mp, &M_RES(mp)->tr_link, resblks, 0, 0,
+ &tp);
+ if (error)
+ goto out_parent;
+
+ libxfs_trans_ijoin(tp, dp, 0);
+ libxfs_trans_ijoin(tp, ip, 0);
+
+ error = -libxfs_dir_createname(tp, dp, &xname, ip->i_ino, resblks);
+ if (error)
+ goto out_trans;
+
+ /* bump dp's link to ip */
+ libxfs_bumplink(tp, ip);
+
+ /* bump ip's dotdot link to dp */
+ if (isdir)
+ libxfs_bumplink(tp, dp);
+
+ /* Replace the dotdot entry in the child directory. */
+ if (isdir) {
+ error = -libxfs_dir_replace(tp, ip, &xfs_name_dotdot,
+ dp->i_ino, resblks);
+ if (error)
+ goto out_trans;
+ }
+
+ if (ppargs) {
+ error = -libxfs_parent_addname(tp, ppargs, dp, &xname, ip);
+ if (error)
+ goto out_trans;
+ }
+
+ error = -libxfs_trans_commit(tp);
+ goto out_parent;
+
+out_trans:
+ libxfs_trans_cancel(tp);
+out_parent:
+ libxfs_parent_finish(mp, ppargs);
+out_ip:
+ libxfs_irele(ip);
+out_dp:
+ libxfs_irele(dp);
+ return error;
+}
+
+static const char *ftype_map[] = {
+ [XFS_DIR3_FT_REG_FILE] = "reg",
+ [XFS_DIR3_FT_DIR] = "dir",
+ [XFS_DIR3_FT_CHRDEV] = "cdev",
+ [XFS_DIR3_FT_BLKDEV] = "bdev",
+ [XFS_DIR3_FT_FIFO] = "fifo",
+ [XFS_DIR3_FT_SOCK] = "sock",
+ [XFS_DIR3_FT_SYMLINK] = "symlink",
+ [XFS_DIR3_FT_WHT] = "whiteout",
+};
+
+static int
+link_f(
+ int argc,
+ char **argv)
+{
+ xfs_ino_t child_ino = NULLFSINO;
+ int ftype = XFS_DIR3_FT_UNKNOWN;
+ unsigned int i;
+ int c;
+ int error = 0;
+
+ while ((c = getopt(argc, argv, "i:p:t:")) != -1) {
+ switch (c) {
+ case 'i':
+ errno = 0;
+ child_ino = strtoull(optarg, NULL, 0);
+ if (errno == ERANGE) {
+ printf("%s: unknown inode number\n", optarg);
+ exitcode = 1;
+ return 0;
+ }
+ break;
+ case 'p':
+ push_cur();
+ error = path_walk(optarg);
+ if (error) {
+ printf("%s: %s\n", optarg, strerror(error));
+ exitcode = 1;
+ return 0;
+ } else if (iocur_top->typ != &typtab[TYP_INODE]) {
+ printf("%s: does not point to an inode\n",
+ optarg);
+ exitcode = 1;
+ return 0;
+ } else {
+ child_ino = iocur_top->ino;
+ }
+ pop_cur();
+ break;
+ case 't':
+ for (i = 0; i < ARRAY_SIZE(ftype_map); i++) {
+ if (ftype_map[i] &&
+ !strcmp(ftype_map[i], optarg)) {
+ ftype = i;
+ break;
+ }
+ }
+ if (i == ARRAY_SIZE(ftype_map)) {
+ printf("%s: unknown file type\n", optarg);
+ exitcode = 1;
+ return 0;
+ }
+ break;
+ default:
+ link_help();
+ return 0;
+ }
+ }
+
+ if (child_ino == NULLFSINO) {
+ printf("link: need to specify child via -i or -p\n");
+ exitcode = 1;
+ return 0;
+ }
+
+ if (iocur_top->typ != &typtab[TYP_INODE]) {
+ printf("io cursor does not point to an inode.\n");
+ exitcode = 1;
+ return 0;
+ }
+
+ if (optind + 1 != argc) {
+ printf("link: need directory entry name");
+ exitcode = 1;
+ return 0;
+ }
+
+ error = create_child(mp, iocur_top->ino, argv[optind], ftype,
+ child_ino);
+ if (error) {
+ printf("link failed: %s\n", strerror(error));
+ exitcode = 1;
+ return 0;
+ }
+
+ return 0;
+}
+
+static struct cmdinfo link_cmd = {
+ .name = "link",
+ .cfunc = link_f,
+ .argmin = 0,
+ .argmax = -1,
+ .canpush = 0,
+ .args = "[-i ino] [-p path] [-t ftype] name",
+ .help = link_help,
+};
+
+static void
+unlink_help(void)
+{
+ dbprintf(_(
+"\n"
+" Remove a directory entry from the current directory.\n"
+"\n"
+" Options:\n"
+" name -- Remove the directory entry with this name.\n"
+ ));
+}
+
+static void
+droplink(
+ struct xfs_trans *tp,
+ struct xfs_inode *ip)
+{
+ struct inode *inode = VFS_I(ip);
+
+ libxfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
+
+ if (inode->i_nlink != XFS_NLINK_PINNED)
+ drop_nlink(VFS_I(ip));
+
+ libxfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+}
+
+static int
+remove_child(
+ struct xfs_mount *mp,
+ xfs_ino_t parent_ino,
+ const char *name)
+{
+ struct xfs_name xname = {
+ .name = (const unsigned char *)name,
+ .len = strlen(name),
+ };
+ struct xfs_parent_args *ppargs;
+ struct xfs_trans *tp;
+ struct xfs_inode *dp, *ip;
+ xfs_ino_t child_ino;
+ unsigned int resblks;
+ int error;
+
+ error = -libxfs_iget(mp, NULL, parent_ino, 0, &dp);
+ if (error)
+ return error;
+
+ if (!S_ISDIR(VFS_I(dp)->i_mode)) {
+ error = -ENOTDIR;
+ goto out_dp;
+ }
+
+ error = -libxfs_dir_lookup(NULL, dp, &xname, &child_ino, NULL);
+ if (error)
+ goto out_dp;
+
+ error = -libxfs_iget(mp, NULL, child_ino, 0, &ip);
+ if (error)
+ goto out_dp;
+
+ error = -libxfs_parent_start(mp, &ppargs);
+ if (error)
+ goto out_ip;
+
+ resblks = libxfs_remove_space_res(mp, MAXNAMELEN);
+ error = -libxfs_trans_alloc(mp, &M_RES(mp)->tr_remove, resblks, 0, 0,
+ &tp);
+ if (error)
+ goto out_parent;
+
+ libxfs_trans_ijoin(tp, dp, 0);
+ libxfs_trans_ijoin(tp, ip, 0);
+
+ if (S_ISDIR(VFS_I(ip)->i_mode)) {
+ /* drop ip's dotdot link to dp */
+ droplink(tp, dp);
+ } else {
+ libxfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
+ }
+
+ /* drop dp's link to ip */
+ droplink(tp, ip);
+
+ error = -libxfs_dir_removename(tp, dp, &xname, ip->i_ino, resblks);
+ if (error)
+ goto out_trans;
+
+ if (ppargs) {
+ error = -libxfs_parent_removename(tp, ppargs, dp, &xname, ip);
+ if (error)
+ goto out_trans;
+ }
+
+ error = -libxfs_trans_commit(tp);
+ goto out_parent;
+
+out_trans:
+ libxfs_trans_cancel(tp);
+out_parent:
+ libxfs_parent_finish(mp, ppargs);
+out_ip:
+ libxfs_irele(ip);
+out_dp:
+ libxfs_irele(dp);
+ return error;
+}
+
+static int
+unlink_f(
+ int argc,
+ char **argv)
+{
+ int c;
+ int error = 0;
+
+ while ((c = getopt(argc, argv, "")) != -1) {
+ switch (c) {
+ default:
+ unlink_help();
+ return 0;
+ }
+ }
+
+ if (iocur_top->typ != &typtab[TYP_INODE]) {
+ printf("io cursor does not point to an inode.\n");
+ exitcode = 1;
+ return 0;
+ }
+
+ if (optind + 1 != argc) {
+ printf("unlink: need directory entry name");
+ exitcode = 1;
+ return 0;
+ }
+
+ error = remove_child(mp, iocur_top->ino, argv[optind]);
+ if (error) {
+ printf("unlink failed: %s\n", strerror(error));
+ exitcode = 1;
+ return 0;
+ }
+
+ return 0;
+}
+
+static struct cmdinfo unlink_cmd = {
+ .name = "unlink",
+ .cfunc = unlink_f,
+ .argmin = 0,
+ .argmax = -1,
+ .canpush = 0,
+ .args = "name",
+ .help = unlink_help,
+};
+
void
namei_init(void)
{
@@ -927,4 +1297,12 @@ namei_init(void)
parent_cmd.oneline = _("list parent pointers");
add_command(&parent_cmd);
+
+ if (expert_mode) {
+ link_cmd.oneline = _("create directory link");
+ add_command(&link_cmd);
+
+ unlink_cmd.oneline = _("remove directory link");
+ add_command(&unlink_cmd);
+ }
}
diff --git a/include/xfs_inode.h b/include/xfs_inode.h
index 45339b426..9bbf37225 100644
--- a/include/xfs_inode.h
+++ b/include/xfs_inode.h
@@ -315,6 +315,10 @@ static inline void inc_nlink(struct inode *inode)
{
inode->i_nlink++;
}
+static inline void drop_nlink(struct inode *inode)
+{
+ inode->i_nlink--;
+}
static inline bool xfs_is_reflink_inode(struct xfs_inode *ip)
{
diff --git a/libxfs/libxfs_api_defs.h b/libxfs/libxfs_api_defs.h
index bceaab8ba..b7edaf788 100644
--- a/libxfs/libxfs_api_defs.h
+++ b/libxfs/libxfs_api_defs.h
@@ -147,12 +147,16 @@
#define xfs_dir_init libxfs_dir_init
#define xfs_dir_ino_validate libxfs_dir_ino_validate
#define xfs_dir_lookup libxfs_dir_lookup
+#define xfs_dir_removename libxfs_dir_removename
#define xfs_dir_replace libxfs_dir_replace
#define xfs_dqblk_repair libxfs_dqblk_repair
#define xfs_dquot_from_disk_ts libxfs_dquot_from_disk_ts
#define xfs_dquot_verify libxfs_dquot_verify
+#define xfs_bumplink libxfs_bumplink
+#define xfs_droplink libxfs_droplink
+
#define xfs_finobt_calc_reserves libxfs_finobt_calc_reserves
#define xfs_finobt_init_cursor libxfs_finobt_init_cursor
#define xfs_free_extent libxfs_free_extent
@@ -191,13 +195,15 @@
#define xfs_iread_extents libxfs_iread_extents
#define xfs_irele libxfs_irele
+#define xfs_link_space_res libxfs_link_space_res
#define xfs_log_calc_minimum_size libxfs_log_calc_minimum_size
#define xfs_log_get_max_trans_res libxfs_log_get_max_trans_res
#define xfs_log_sb libxfs_log_sb
#define xfs_mode_to_ftype libxfs_mode_to_ftype
#define xfs_mkdir_space_res libxfs_mkdir_space_res
-#define xfs_parent_add libxfs_parent_add
+#define xfs_parent_addname libxfs_parent_addname
#define xfs_parent_finish libxfs_parent_finish
+#define xfs_parent_removename libxfs_parent_removename
#define xfs_parent_start libxfs_parent_start
#define xfs_parent_from_attr libxfs_parent_from_attr
#define xfs_perag_get libxfs_perag_get
diff --git a/man/man8/xfs_db.8 b/man/man8/xfs_db.8
index a561bdc49..f8db6c36f 100644
--- a/man/man8/xfs_db.8
+++ b/man/man8/xfs_db.8
@@ -901,6 +901,21 @@ will result in truncation and a warning will be issued. If no
.I label
is given, the current filesystem label is printed.
.TP
+.BI "link [-i " ino "] [-p " path "] [-t " ftype "] name"
+In the current directory, create a directory entry with the given
+.I name
+pointing to a file.
+The file must be specified either as a directory tree path as given by the
+.I path
+option; or directly as an inode number as given by the
+.I ino
+option.
+The file type in the directory entry will be determined from the mode of the
+child file unless the
+.I ftype
+option is given.
+The file being targetted must not be on the iunlink list.
+.TP
.BI "log [stop | start " filename ]
Start logging output to
.IR filename ,
@@ -1052,6 +1067,11 @@ Print the timestamps in the current locale's date and time format instead of
raw seconds since the Unix epoch.
.RE
.TP
+.BI "unlink name"
+In the current directory, remove a directory entry with the given
+.IR name .
+The file being targetted will not be put on the iunlink list.
+.TP
.BI "uuid [" uuid " | " generate " | " rewrite " | " restore ]
Set the filesystem universally unique identifier (UUID).
The filesystem UUID can be used by
