Sometimes, it's not true that the root directory is always
the first result from calling bulkstat with lastino == 0
assumed by xfsdump.
Recently XFS_BULK_IREQ_SPECIAL_ROOT was introduced last year,
yet that doesn't exist in old kernels.
Alternatively, we can also use bulkstat to walk through
all dirs and find the exact dir whose ino # of ".." is
itself by getdents, and that should be considered as the
root dir.
Fixes: 25195ebf107d ("xfsdump: handle bind mount targets")
Cc: Eric Sandeen <sandeen@xxxxxxxxxx>
Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxx>
---
preliminary test with the original testcase is done...
dump/content.c | 168 ++++++++++++++++++++++++++++++++++++++++---------
1 file changed, 140 insertions(+), 28 deletions(-)
diff --git a/dump/content.c b/dump/content.c
index 30232d4..653d4eb 100644
--- a/dump/content.c
+++ b/dump/content.c
@@ -511,6 +511,132 @@ static bool_t create_inv_session(
ix_t subtreecnt,
size_t strmix);
+struct fixrootino_context {
+ xfs_ino_t rootino;
+ struct dirent *gdp;
+ size_t gdsz;
+};
+
+static bool_t
+scan_rootinode(int fd,
+ xfs_ino_t ino,
+ struct dirent *gdp,
+ size_t gdsz)
+{
+ while (1) {
+ struct dirent *p;
+ int nread;
+
+ nread = getdents_wrap(fd, (char *)gdp, gdsz);
+ /*
+ * negative count indicates something very bad happened;
+ * try to gracefully end this dir.
+ */
+ if (nread < 0) {
+ mlog(MLOG_NORMAL | MLOG_WARNING,
+_("unable to read dirents for directory ino %llu: %s\n"),
+ ino, strerror(errno));
+ /* !!! curtis looked at this, and pointed out that
+ * we could take some recovery action here. if the
+ * errno is appropriate, lseek64 to the value of
+ * doff field of the last dirent successfully
+ * obtained, and contiue the loop.
+ */
+ nread = 0; /* pretend we are done */
+ }
+
+ /* no more directory entries: break; */
+ if (!nread)
+ break;
+
+ for (p = gdp; nread > 0;
+ nread -= (int)p->d_reclen,
+ assert(nread >= 0),
+ p = (struct dirent *)((char *)p + p->d_reclen)) {
+ if (!strcmp(p->d_name, "..") && p->d_ino == ino) {
+ mlog(MLOG_NITTY, "FOUND: name %s d_ino %llu\n",
+ p->d_name, ino);
+ return BOOL_TRUE;
+ }
+ }
+ }
+ return BOOL_FALSE;
+}
+
+/* ARGSUSED */
+static int
+cb_find_root_inode(void *arg1,
+ jdm_fshandle_t *fshandlep,
+ int fsfd,
+ struct xfs_bstat *statp)
+{
+ int fd;
+ struct fixrootino_context *ctx = arg1;
+
+ /* open the directory named by statp*/
+ fd = jdm_open(fshandlep, statp, O_RDONLY);
+ if (fd < 0) {
+ mlog(MLOG_NORMAL | MLOG_WARNING, _(
+ "unable to open directory: ino %llu: %s\n"),
+ statp->bs_ino, strerror(errno));
+ return RV_OK; /* continue anyway */
+ }
+
+ if (scan_rootinode(fd, statp->bs_ino, ctx->gdp, ctx->gdsz)) {
+ ctx->rootino = statp->bs_ino;
+ return RV_NOMORE;
+ }
+ return RV_OK;
+}
+
+static bool_t
+fix_root_inode(
+ stat64_t *rootstat,
+ struct xfs_bstat *sc_rootxfsstatp)
+{
+ struct xfs_bstat *bstatbufp;
+ int rval;
+ struct fixrootino_context ctx;
+ rv_t rv = RV_OK;
+
+ ctx.gdsz = sizeof(struct dirent) + NAME_MAX + 1;
+ if (ctx.gdsz < GETDENTSBUF_SZ_MIN)
+ ctx.gdsz = GETDENTSBUF_SZ_MIN;
+
+ ctx.gdp = (struct dirent *)calloc(1, ctx.gdsz);
+ assert(ctx.gdp);
+
+ /* already a root dir */
+ if (scan_rootinode(sc_fsfd, rootstat->st_ino, ctx.gdp, ctx.gdsz))
+ goto out;
+
+ /* allocate a buffer for use by bigstat_iter */
+ bstatbufp = (struct xfs_bstat *)calloc(BSTATBUFLEN,
+ sizeof(struct xfs_bstat));
+ assert(bstatbufp);
+
+ rval = bigstat_iter(sc_fshandlep, sc_fsfd, BIGSTAT_ITER_DIR,
+ (xfs_ino_t)0, cb_find_root_inode,
+ &ctx, NULL, NULL, (int *)&rv, preemptchk,
+ bstatbufp, BSTATBUFLEN);
+ if (rval)
+ return BOOL_FALSE;
+
+ if (rv != RV_NOMORE && rv != RV_OK)
+ return BOOL_FALSE;
+
+ mlog(MLOG_NORMAL | MLOG_NOTE,
+ "fix up rootino %lld, bind mount?\n", ctx.rootino);
+ rootstat->st_ino = ctx.rootino;
+out:
+ if (bigstat_one(sc_fsfd, rootstat->st_ino, sc_rootxfsstatp) < 0) {
+ mlog( MLOG_ERROR,
+ _("failed to get bulkstat information for root inode\n"));
+ return BOOL_FALSE;
+ }
+ return BOOL_TRUE;
+}
+
bool_t
content_init(int argc,
char *argv[],
@@ -1381,6 +1507,18 @@ baseuuidbypass:
return BOOL_FALSE;
}
+ /* alloc a file system handle, to be used with the jdm_open()
+ * functions.
+ */
+ sc_fshandlep = jdm_getfshandle(mntpnt);
+ if (!sc_fshandlep) {
+ mlog(MLOG_NORMAL, _(
+ "unable to construct a file system handle for %s: %s\n"),
+ mntpnt,
+ strerror(errno));
+ return BOOL_FALSE;
+ }
+
/* figure out the ino for the root directory of the fs
* and get its struct xfs_bstat for inomap_build(). This could
* be a bind mount; don't ask for the mount point inode,
@@ -1388,9 +1526,6 @@ baseuuidbypass:
*/
{
stat64_t rootstat;
- xfs_ino_t lastino = 0;
- int ocount = 0;
- struct xfs_fsop_bulkreq bulkreq;
/* Get the inode of the mount point */
rval = fstat64(sc_fsfd, &rootstat);
@@ -1404,33 +1539,10 @@ baseuuidbypass:
(struct xfs_bstat *)calloc(1, sizeof(struct xfs_bstat));
assert(sc_rootxfsstatp);
- /* Get the first valid (i.e. root) inode in this fs */
- bulkreq.lastip = (__u64 *)&lastino;
- bulkreq.icount = 1;
- bulkreq.ubuffer = sc_rootxfsstatp;
- bulkreq.ocount = &ocount;
- if (ioctl(sc_fsfd, XFS_IOC_FSBULKSTAT, &bulkreq) < 0) {
- mlog(MLOG_ERROR,
- _("failed to get bulkstat information for root inode\n"));
+ if (!fix_root_inode(&rootstat, sc_rootxfsstatp)) {
+ mlog(MLOG_ERROR, _("failed to fix root inode\n"));
return BOOL_FALSE;
}
-
- if (sc_rootxfsstatp->bs_ino != rootstat.st_ino)
- mlog (MLOG_NORMAL | MLOG_NOTE,
- _("root ino %lld differs from mount dir ino %lld, bind mount?\n"),
- sc_rootxfsstatp->bs_ino, rootstat.st_ino);
- }
-
- /* alloc a file system handle, to be used with the jdm_open()
- * functions.
- */
- sc_fshandlep = jdm_getfshandle(mntpnt);
- if (!sc_fshandlep) {
- mlog(MLOG_NORMAL, _(
- "unable to construct a file system handle for %s: %s\n"),
- mntpnt,
- strerror(errno));
- return BOOL_FALSE;
}
if (preemptchk(PREEMPT_FULL)) {
--
2.18.1
