xfs: implement online get/set fs label (f7664b31) · Commits · 戴 / test

fs/xfs/libxfs/xfs_format.h

+5 −2

Original line number	Diff line number	Diff line
		@@ -98,6 +98,9 @@ struct xfs_ifork;
		XFS_SB_VERSION2_PROJID32BIT \| \
		XFS_SB_VERSION2_FTYPE)

		/* Maximum size of the xfs filesystem label, no terminating NULL */
		#define XFSLABEL_MAX 12

		/*
		* Superblock - in core version. Must match the ondisk version below.
		* Must be padded to 64 bit alignment.
		@@ -122,7 +125,7 @@ typedef struct xfs_sb {
		uint16_t sb_sectsize; /* volume sector size, bytes */
		uint16_t sb_inodesize; /* inode size, bytes */
		uint16_t sb_inopblock; /* inodes per block */
		char sb_fname[12]; /* file system name */
		char sb_fname[XFSLABEL_MAX]; /* file system name */
		uint8_t sb_blocklog; /* log2 of sb_blocksize */
		uint8_t sb_sectlog; /* log2 of sb_sectsize */
		uint8_t sb_inodelog; /* log2 of sb_inodesize */
		@@ -213,7 +216,7 @@ typedef struct xfs_dsb {
		__be16 sb_sectsize; /* volume sector size, bytes */
		__be16 sb_inodesize; /* inode size, bytes */
		__be16 sb_inopblock; /* inodes per block */
		char sb_fname[12]; /* file system name */
		char sb_fname[XFSLABEL_MAX]; /* file system name */
		__u8 sb_blocklog; /* log2 of sb_blocksize */
		__u8 sb_sectlog; /* log2 of sb_sectsize */
		__u8 sb_inodelog; /* log2 of sb_inodesize */

fs/xfs/libxfs/xfs_sb.c

+30 −0

Original line number	Diff line number	Diff line
		@@ -961,6 +961,36 @@ xfs_update_secondary_sbs(
		return saved_error ? saved_error : error;
		}

		/*
		* Same behavior as xfs_sync_sb, except that it is always synchronous and it
		* also writes the superblock buffer to disk sector 0 immediately.
		*/
		int
		xfs_sync_sb_buf(
		struct xfs_mount *mp)
		{
		struct xfs_trans *tp;
		int error;

		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_sb, 0, 0, 0, &tp);
		if (error)
		return error;

		xfs_log_sb(tp);
		xfs_trans_bhold(tp, mp->m_sb_bp);
		xfs_trans_set_sync(tp);
		error = xfs_trans_commit(tp);
		if (error)
		goto out;
		/*
		* write out the sb buffer to get the changes to disk
		*/
		error = xfs_bwrite(mp->m_sb_bp);
		out:
		xfs_buf_relse(mp->m_sb_bp);
		return error;
		}

		int
		xfs_fs_geometry(
		struct xfs_sb *sbp,

fs/xfs/libxfs/xfs_sb.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -36,6 +36,7 @@ extern int xfs_initialize_perag_data(struct xfs_mount *, xfs_agnumber_t);

		extern void xfs_log_sb(struct xfs_trans *tp);
		extern int xfs_sync_sb(struct xfs_mount *mp, bool wait);
		extern int xfs_sync_sb_buf(struct xfs_mount *mp);
		extern void xfs_sb_mount_common(struct xfs_mount mp, struct xfs_sb sbp);
		extern void xfs_sb_from_disk(struct xfs_sb to, struct xfs_dsb from);
		extern void xfs_sb_to_disk(struct xfs_dsb to, struct xfs_sb from);

fs/xfs/xfs_ioctl.c

+86 −0

Original line number	Diff line number	Diff line
		@@ -1811,6 +1811,88 @@ xfs_ioc_swapext(
		return error;
		}

		static int
		xfs_ioc_getlabel(
		struct xfs_mount *mp,
		char __user *user_label)
		{
		struct xfs_sb *sbp = &mp->m_sb;
		char label[XFSLABEL_MAX + 1];

		/* Paranoia */
		BUILD_BUG_ON(sizeof(sbp->sb_fname) > FSLABEL_MAX);

		spin_lock(&mp->m_sb_lock);
		strncpy(label, sbp->sb_fname, sizeof(sbp->sb_fname));
		spin_unlock(&mp->m_sb_lock);

		/* xfs on-disk label is 12 chars, be sure we send a null to user */
		label[XFSLABEL_MAX] = '\0';
		if (copy_to_user(user_label, label, sizeof(sbp->sb_fname)))
		return -EFAULT;
		return 0;
		}

		static int
		xfs_ioc_setlabel(
		struct file *filp,
		struct xfs_mount *mp,
		char __user *newlabel)
		{
		struct xfs_sb *sbp = &mp->m_sb;
		char label[XFSLABEL_MAX + 1];
		size_t len;
		int error;

		if (!capable(CAP_SYS_ADMIN))
		return -EPERM;
		/*
		* The generic ioctl allows up to FSLABEL_MAX chars, but XFS is much
		* smaller, at 12 bytes. We copy one more to be sure we find the
		* (required) NULL character to test the incoming label length.
		* NB: The on disk label doesn't need to be null terminated.
		*/
		if (copy_from_user(label, newlabel, XFSLABEL_MAX + 1))
		return -EFAULT;
		len = strnlen(label, XFSLABEL_MAX + 1);
		if (len > sizeof(sbp->sb_fname))
		return -EINVAL;

		error = mnt_want_write_file(filp);
		if (error)
		return error;

		spin_lock(&mp->m_sb_lock);
		memset(sbp->sb_fname, 0, sizeof(sbp->sb_fname));
		strncpy(sbp->sb_fname, label, sizeof(sbp->sb_fname));
		spin_unlock(&mp->m_sb_lock);

		/*
		* Now we do several things to satisfy userspace.
		* In addition to normal logging of the primary superblock, we also
		* immediately write these changes to sector zero for the primary, then
		* update all backup supers (as xfs_db does for a label change), then
		* invalidate the block device page cache. This is so that any prior
		* buffered reads from userspace (i.e. from blkid) are invalidated,
		* and userspace will see the newly-written label.
		*/
		error = xfs_sync_sb_buf(mp);
		if (error)
		goto out;
		/*
		* growfs also updates backup supers so lock against that.
		*/
		mutex_lock(&mp->m_growlock);
		error = xfs_update_secondary_sbs(mp);
		mutex_unlock(&mp->m_growlock);

		invalidate_bdev(mp->m_ddev_targp->bt_bdev);

		out:
		mnt_drop_write_file(filp);
		return error;
		}

		/*
		* Note: some of the ioctl's return positive numbers as a
		* byte count indicating success, such as readlink_by_handle.
		@@ -1834,6 +1916,10 @@ xfs_file_ioctl(
		switch (cmd) {
		case FITRIM:
		return xfs_ioc_trim(mp, arg);
		case FS_IOC_GETFSLABEL:
		return xfs_ioc_getlabel(mp, arg);
		case FS_IOC_SETFSLABEL:
		return xfs_ioc_setlabel(filp, mp, arg);
		case XFS_IOC_ALLOCSP:
		case XFS_IOC_FREESP:
		case XFS_IOC_RESVSP:

Admin message