Introduce a new ioctl that uses the reverse mapping btree to return
information about the physical layout of the filesystem.
v2: shorten the device field to u32 since that's all we need for
dev_t. Support reporting reverse mapping information for all the
devices that XFS supports (data, log).
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
libxfs/xfs_fs.h | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 65 insertions(+)
diff --git a/libxfs/xfs_fs.h b/libxfs/xfs_fs.h
index df58c1c..11149fa 100644
--- a/libxfs/xfs_fs.h
+++ b/libxfs/xfs_fs.h
@@ -117,6 +117,70 @@ struct getbmapx {
#define BMV_OF_SHARED 0x8 /* segment shared with another file */
/*
+ * Structure for XFS_IOC_GETFSMAP.
+ *
+ * Similar to XFS_IOC_GETBMAPX, the first two elements in the array are
+ * used to constrain the output. The first element in the array should
+ * represent the lowest disk address that the user wants to learn about.
+ * The second element in the array should represent the highest disk
+ * address to query. Subsequent array elements will be filled out by the
+ * command.
+ *
+ * The fmv_iflags field is only used in the first structure. The
+ * fmv_oflags field is filled in for each returned structure after the
+ * second structure. The fmv_unused1 fields in the first two array
+ * elements must be zero.
+ *
+ * The fmv_count, fmv_entries, and fmv_iflags fields in the second array
+ * element must be zero.
+ *
+ * fmv_block, fmv_offset, and fmv_length are expressed in units of 512
+ * byte sectors.
+ */
+#ifndef HAVE_GETFSMAP
+struct getfsmap {
+ __u32 fmv_device; /* device id */
+ __u32 fmv_unused1; /* future use, must be zero */
+ __u64 fmv_block; /* starting block */
+ __u64 fmv_owner; /* owner id */
+ __u64 fmv_offset; /* file offset of segment */
+ __u64 fmv_length; /* length of segment, blocks */
+ __u32 fmv_oflags; /* mapping flags */
+ __u32 fmv_iflags; /* control flags (1st structure) */
+ __u32 fmv_count; /* # of entries in array incl. input */
+ __u32 fmv_entries; /* # of entries filled in (output). */
+ __u64 fmv_unused2; /* future use, must be zero */
+};
+#endif
+
+/* fmv_iflags values - set by XFS_IOC_GETFSMAP caller in the header. */
+/* no flags defined yet */
+#define FMV_HIF_VALID 0
+
+/* fmv_oflags values - returned in the header segment only. */
+#define FMV_HOF_DEV_T 0x1 /* fmv_device values will be dev_t */
+
+/* fmv_flags values - returned for each non-header segment */
+#define FMV_OF_PREALLOC 0x1 /* segment = unwritten pre-allocation */
+#define FMV_OF_ATTR_FORK 0x2 /* segment = attribute fork */
+#define FMV_OF_EXTENT_MAP 0x4 /* segment = extent map */
+#define FMV_OF_SHARED 0x8 /* segment = shared with another file */
+#define FMV_OF_SPECIAL_OWNER 0x10 /* owner is a special value */
+#define FMV_OF_LAST 0x20 /* segment is the last in the FS */
+
+/* fmv_owner special values */
+#define FMV_OWN_FREE (-1ULL) /* free space */
+#define FMV_OWN_UNKNOWN (-2ULL) /* unknown owner */
+#define FMV_OWN_FS (-3ULL) /* static fs metadata */
+#define FMV_OWN_LOG (-4ULL) /* journalling log */
+#define FMV_OWN_AG (-5ULL) /* per-AG metadata */
+#define FMV_OWN_INOBT (-6ULL) /* inode btree blocks */
+#define FMV_OWN_INODES (-7ULL) /* inodes */
+#define FMV_OWN_REFC (-8ULL) /* refcount tree */
+#define FMV_OWN_COW (-9ULL) /* cow staging */
+#define FMV_OWN_DEFECTIVE (-10ULL) /* bad blocks */
+
+/*
* Structure for XFS_IOC_FSSETDM.
* For use by backup and restore programs to set the XFS on-disk inode
* fields di_dmevmask and di_dmstate. These must be set to exactly and
@@ -523,6 +587,7 @@ typedef struct xfs_swapext
#define XFS_IOC_GETBMAPX _IOWR('X', 56, struct getbmap)
#define XFS_IOC_ZERO_RANGE _IOW ('X', 57, struct xfs_flock64)
#define XFS_IOC_FREE_EOFBLOCKS _IOR ('X', 58, struct xfs_fs_eofblocks)
+#define XFS_IOC_GETFSMAP _IOWR('X', 59, struct getfsmap)
/*
* ioctl commands that replace IRIX syssgi()'s
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