[PATCH 10/26] xfs: allow bulkstat to return metadata directories

Darrick J. Wong
2024-08-23T00:04:46Z

From: Darrick J. Wong <djwong@kernel.org>

Allow the V5 bulkstat ioctl to return information about metadata
directory files so that xfs_scrub can find and scrub them, since they
are otherwise ordinary directories.

(Metadata files of course require per-file scrub code and hence do not
need exposure.)

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/libxfs/xfs_fs.h | 10 +++++++++-
fs/xfs/xfs_ioctl.c | 7 +++++++
fs/xfs/xfs_itable.c | 33 +++++++++++++++++++++++++++++----
fs/xfs/xfs_itable.h | 3 +++
4 files changed, 48 insertions(+), 5 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
index aba7fb0389bab..cb7563d330d0f 100644
--- a/fs/xfs/libxfs/xfs_fs.h
+++ b/fs/xfs/libxfs/xfs_fs.h
@@ -490,9 +490,17 @@ struct xfs_bulk_ireq {
*/
#define XFS_BULK_IREQ_NREXT64 (1U << 2)

+/*
+ * Allow bulkstat to return information about metadata directories. This
+ * enables xfs_scrub to find them for scanning, as they are otherwise ordinary
+ * directories.
+ */
+#define XFS_BULK_IREQ_METADIR (1U << 31)
+
#define XFS_BULK_IREQ_FLAGS_ALL (XFS_BULK_IREQ_AGNO | \
XFS_BULK_IREQ_SPECIAL | \
- XFS_BULK_IREQ_NREXT64)
+ XFS_BULK_IREQ_NREXT64 | \
+ XFS_BULK_IREQ_METADIR)

/* Operate on the root directory inode. */
#define XFS_BULK_IREQ_SPECIAL_ROOT (1)
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 90b3ee21e7fe6..b53af3e674912 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -233,6 +233,10 @@ xfs_bulk_ireq_setup(
if (hdr->flags & XFS_BULK_IREQ_NREXT64)
breq->flags |= XFS_IBULK_NREXT64;

+ /* Caller wants to see metadata directories in bulkstat output. */
+ if (hdr->flags & XFS_BULK_IREQ_METADIR)
+ breq->flags |= XFS_IBULK_METADIR;
+
return 0;
}

@@ -323,6 +327,9 @@ xfs_ioc_inumbers(
if (copy_from_user(&hdr, &arg->hdr, sizeof(hdr)))
return -EFAULT;

+ if (hdr.flags & XFS_BULK_IREQ_METADIR)
+ return -EINVAL;
+
error = xfs_bulk_ireq_setup(mp, &hdr, &breq, arg->inumbers);
if (error == -ECANCELED)
goto out_teardown;
diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
index c0757ab994957..198d52e9f81f6 100644
--- a/fs/xfs/xfs_itable.c
+++ b/fs/xfs/xfs_itable.c
@@ -36,6 +36,14 @@ struct xfs_bstat_chunk {
struct xfs_bulkstat *buf;
};

+static inline bool
+want_metadir_file(
+ struct xfs_inode *ip,
+ struct xfs_ibulk *breq)
+{
+ return xfs_is_metadir_inode(ip) && (breq->flags & XFS_IBULK_METADIR);
+}
+
/*
* Fill out the bulkstat info for a single inode and report it somewhere.
*
@@ -69,9 +77,6 @@ xfs_bulkstat_one_int(
vfsuid_t vfsuid;
vfsgid_t vfsgid;

- if (xfs_internal_inum(mp, ino))
- goto out_advance;
-
error = xfs_iget(mp, tp, ino,
(XFS_IGET_DONTCACHE | XFS_IGET_UNTRUSTED),
XFS_ILOCK_SHARED, &ip);
@@ -97,8 +102,28 @@ xfs_bulkstat_one_int(
vfsuid = i_uid_into_vfsuid(idmap, inode);
vfsgid = i_gid_into_vfsgid(idmap, inode);

+ /*
+ * If caller wants files from the metadata directories, push out the
+ * bare minimum information for enabling scrub.
+ */
+ if (want_metadir_file(ip, bc->breq)) {
+ memset(buf, 0, sizeof(*buf));
+ buf->bs_ino = ino;
+ buf->bs_gen = inode->i_generation;
+ buf->bs_mode = inode->i_mode & S_IFMT;
+ xfs_bulkstat_health(ip, buf);
+ buf->bs_version = XFS_BULKSTAT_VERSION_V5;
+ xfs_iunlock(ip, XFS_ILOCK_SHARED);
+ xfs_irele(ip);
+
+ error = bc->formatter(bc->breq, buf);
+ if (!error || error == -ECANCELED)
+ goto out_advance;
+ goto out;
+ }
+
/* If this is a private inode, don't leak its details to userspace. */
- if (IS_PRIVATE(inode)) {
+ if (IS_PRIVATE(inode) || xfs_internal_inum(mp, ino)) {
xfs_iunlock(ip, XFS_ILOCK_SHARED);
xfs_irele(ip);
error = -EINVAL;
diff --git a/fs/xfs/xfs_itable.h b/fs/xfs/xfs_itable.h
index 1659f13f17a89..f10e8f8f23351 100644
--- a/fs/xfs/xfs_itable.h
+++ b/fs/xfs/xfs_itable.h
@@ -22,6 +22,9 @@ struct xfs_ibulk {
/* Fill out the bs_extents64 field if set. */
#define XFS_IBULK_NREXT64 (1U << 1)

+/* Signal that we can return metadata directories. */
+#define XFS_IBULK_METADIR (1U << 2)
+
/*
* Advance the user buffer pointer by one record of the given size. If the
* buffer is now full, return the appropriate error code.