diff options
| -rw-r--r-- | fs/xfs/libxfs/xfs_format.h | 7 | ||||
| -rw-r--r-- | fs/xfs/libxfs/xfs_sb.c | 30 | ||||
| -rw-r--r-- | fs/xfs/libxfs/xfs_sb.h | 1 | ||||
| -rw-r--r-- | fs/xfs/xfs_ioctl.c | 86 |
4 files changed, 122 insertions, 2 deletions
diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h index 42956d8d95ed..c1cb29a5f4f6 100644 --- a/fs/xfs/libxfs/xfs_format.h +++ b/fs/xfs/libxfs/xfs_format.h @@ -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 */ diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c index a35344ae4951..ea6c85a4c27c 100644 --- a/fs/xfs/libxfs/xfs_sb.c +++ b/fs/xfs/libxfs/xfs_sb.c @@ -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, diff --git a/fs/xfs/libxfs/xfs_sb.h b/fs/xfs/libxfs/xfs_sb.h index fc65d4e1433a..03e0cc6bf3a6 100644 --- a/fs/xfs/libxfs/xfs_sb.h +++ b/fs/xfs/libxfs/xfs_sb.h @@ -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); diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c index 89fb1eb80aae..f9c97ea52961 100644 --- a/fs/xfs/xfs_ioctl.c +++ b/fs/xfs/xfs_ioctl.c @@ -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: |