From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Introduce a new ioctl that uses the reverse mapping btree to return
information about the physical layout of the filesystem.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
configure.ac | 1
include/builddefs.in | 7 +++
include/linux.h | 109 +++++++++++++++++++++++++++++++++++++++++++++++++
libxfs/xfs_fs.h | 13 ++++++
libxfs/xfs_rmap.c | 28 +++++++++++++
libxfs/xfs_rmap.h | 2 +
m4/package_libcdev.m4 | 19 +++++++++
7 files changed, 178 insertions(+), 1 deletion(-)
diff --git a/configure.ac b/configure.ac
index aa102e4..794a804 100644
--- a/configure.ac
+++ b/configure.ac
@@ -142,6 +142,7 @@ AC_HAVE_READDIR
AC_HAVE_FSETXATTR
AC_HAVE_MREMAP
AC_NEED_INTERNAL_FSXATTR
+AC_HAVE_SYS_GETFSMAP
if test "$enable_blkid" = yes; then
AC_HAVE_BLKID_TOPO
diff --git a/include/builddefs.in b/include/builddefs.in
index 4d6bb2d..e285731 100644
--- a/include/builddefs.in
+++ b/include/builddefs.in
@@ -112,16 +112,18 @@ HAVE_FLS = @have_fls@
HAVE_FSETXATTR = @have_fsetxattr@
HAVE_MREMAP = @have_mremap@
NEED_INTERNAL_FSXATTR = @need_internal_fsxattr@
+HAVE_SYS_GETFSMAP = @have_sys_getfsmap@
GCCFLAGS = -funsigned-char -fno-strict-aliasing -Wall
# -Wbitwise -Wno-transparent-union -Wno-old-initializer -Wno-decl
ifeq ($(PKG_PLATFORM),linux)
-PCFLAGS = -D_GNU_SOURCE $(GCCFLAGS)
+PCFLAGS = -D_GNU_SOURCE $(GCCFLAGS) -DHAVE_GETFSMAP
ifeq ($(HAVE_UMODE_T),yes)
PCFLAGS += -DHAVE_UMODE_T
endif
DEPENDFLAGS = -D__linux__
+HAVE_GETFSMAP = yes
endif
ifeq ($(PKG_PLATFORM),gnukfreebsd)
PCFLAGS = -D_GNU_SOURCE $(GCCFLAGS)
@@ -150,6 +152,9 @@ endif
ifeq ($(NEED_INTERNAL_FSXATTR),yes)
PCFLAGS+= -DOVERRIDE_SYSTEM_FSXATTR
endif
+ifeq ($(PKG_PLATFORM)_$(HAVE_SYS_GETFSMAP),linux_)
+PCFLAGS+= -DOVERRIDE_GETFSMAP
+endif
GCFLAGS = $(DEBUG) \
diff --git a/include/linux.h b/include/linux.h
index 6a676ca..181d25c 100644
--- a/include/linux.h
+++ b/include/linux.h
@@ -35,7 +35,15 @@
#ifdef OVERRIDE_SYSTEM_FSXATTR
# define fsxattr sys_fsxattr
#endif
+#ifdef OVERRIDE_GETFSMAP
+# define fsmap sys_fsmap
+# define fsmap_head sys_fsmap_head
+#endif
#include <linux/fs.h> /* fsxattr defintion for new kernels */
+#ifdef OVERRIDE_GETFSMAP
+# undef fsmap
+# undef fsmap_head
+#endif
#ifdef OVERRIDE_SYSTEM_FSXATTR
# undef fsxattr
#endif
@@ -222,4 +230,105 @@ struct fsxattr {
#define FS_XFLAG_COWEXTSIZE 0x00010000 /* CoW extent size allocator hint */
#endif
+#ifdef OVERRIDE_GETFSMAP
+/*
+ * Structure for FS_IOC_GETFSMAP.
+ *
+ * The memory layout for this call are the scalar values defined in
+ * struct fsmap_head, followed by two struct fsmap that describe
+ * the lower and upper bound of mappings to return, followed by an
+ * array of struct fsmap mappings.
+ *
+ * fmh_iflags control the output of the call, whereas fmh_oflags report
+ * on the overall record output. fmh_count should be set to the
+ * length of the fmh_recs array, and fmh_entries will be set to the
+ * number of entries filled out during each call. If fmh_count is
+ * zero, the number of reverse mappings will be returned in
+ * fmh_entries, though no mappings will be returned. fmh_reserved
+ * must be set to zero.
+ *
+ * The two elements in the fmh_keys array are used to constrain the
+ * output. The first element in the array should represent the
+ * lowest disk mapping ("low key") that the user wants to learn
+ * about. If this value is all zeroes, the filesystem will return
+ * the first entry it knows about. For a subsequent call, the
+ * contents of fsmap_head.fmh_recs[fsmap_head.fmh_count - 1] should be
+ * copied into fmh_keys[0] to have the kernel start where it left off.
+ *
+ * The second element in the fmh_keys array should represent the
+ * highest disk mapping ("high key") that the user wants to learn
+ * about. If this value is all ones, the filesystem will not stop
+ * until it runs out of mapping to return or runs out of space in
+ * fmh_recs.
+ *
+ * fmr_device can be either a 32-bit cookie representing a device, or
+ * a 32-bit dev_t if the FMH_OF_DEV_T flag is set. fmr_physical,
+ * fmr_offset, and fmr_length are expressed in units of bytes.
+ * fmr_owner is either an inode number, or a special value if
+ * FMR_OF_SPECIAL_OWNER is set in fmr_flags.
+ */
+struct fsmap {
+ __u32 fmr_device; /* device id */
+ __u32 fmr_flags; /* mapping flags */
+ __u64 fmr_physical; /* device offset of segment */
+ __u64 fmr_owner; /* owner id */
+ __u64 fmr_offset; /* file offset of segment */
+ __u64 fmr_length; /* length of segment */
+ __u64 fmr_reserved[3]; /* must be zero */
+};
+
+struct fsmap_head {
+ __u32 fmh_iflags; /* control flags */
+ __u32 fmh_oflags; /* output flags */
+ __u32 fmh_count; /* # of entries in array incl. input */
+ __u32 fmh_entries; /* # of entries filled in (output). */
+ __u64 fmh_reserved[6]; /* must be zero */
+
+ struct fsmap fmh_keys[2]; /* low and high keys for the mapping search */
+ struct fsmap fmh_recs[]; /* returned records */
+};
+
+/* Size of an fsmap_head with room for nr records. */
+static inline size_t
+fsmap_sizeof(
+ unsigned int nr)
+{
+ return sizeof(struct fsmap_head) + nr * sizeof(struct fsmap);
+}
+
+/* Start the next fsmap query at the end of the current query results. */
+static inline void
+fsmap_advance(
+ struct fsmap_head *head)
+{
+ head->fmh_keys[0] = head->fmh_recs[head->fmh_entries - 1];
+}
+
+/* fmh_iflags values - set by XFS_IOC_GETFSMAP caller in the header. */
+/* no flags defined yet */
+#define FMH_IF_VALID 0
+
+/* fmh_oflags values - returned in the header segment only. */
+#define FMH_OF_DEV_T 0x1 /* fmr_device values will be dev_t */
+
+/* fmr_flags values - returned for each non-header segment */
+#define FMR_OF_PREALLOC 0x1 /* segment = unwritten pre-allocation */
+#define FMR_OF_ATTR_FORK 0x2 /* segment = attribute fork */
+#define FMR_OF_EXTENT_MAP 0x4 /* segment = extent map */
+#define FMR_OF_SHARED 0x8 /* segment = shared with another file */
+#define FMR_OF_SPECIAL_OWNER 0x10 /* owner is a special value */
+#define FMR_OF_LAST 0x20 /* segment is the last in the FS */
+
+/* Each FS gets to define its own special owner codes. */
+#define FMR_OWNER(type, code) (((__u64)type << 32) | \
+ ((__u64)code & 0xFFFFFFFFULL))
+#define FMR_OWNER_TYPE(owner) ((__u32)((__u64)owner >> 32))
+#define FMR_OWNER_CODE(owner) ((__u32)(((__u64)owner & 0xFFFFFFFFULL)))
+#define FMR_OWN_FREE FMR_OWNER(0, 1) /* free space */
+#define FMR_OWN_UNKNOWN FMR_OWNER(0, 2) /* unknown owner */
+#define FMR_OWN_METADATA FMR_OWNER(0, 3) /* metadata */
+
+#define FS_IOC_GETFSMAP _IOWR('X', 59, struct fsmap_head)
+#endif /* OVERRIDE_GETFSMAP */
+
#endif /* __XFS_LINUX_H__ */
diff --git a/libxfs/xfs_fs.h b/libxfs/xfs_fs.h
index 11fe42a..1831cff 100644
--- a/libxfs/xfs_fs.h
+++ b/libxfs/xfs_fs.h
@@ -113,6 +113,18 @@ struct getbmapx {
#define BMV_OF_LAST 0x4 /* segment is the last in the file */
#define BMV_OF_SHARED 0x8 /* segment shared with another file */
+/* fmr_owner special values for FS_IOC_GETFSMAP */
+#define XFS_FMR_OWN_FREE FMR_OWN_FREE /* free space */
+#define XFS_FMR_OWN_UNKNOWN FMR_OWN_UNKNOWN /* unknown owner */
+#define XFS_FMR_OWN_FS FMR_OWNER('X', 1) /* static fs metadata */
+#define XFS_FMR_OWN_LOG FMR_OWNER('X', 2) /* journalling log */
+#define XFS_FMR_OWN_AG FMR_OWNER('X', 3) /* per-AG metadata */
+#define XFS_FMR_OWN_INOBT FMR_OWNER('X', 4) /* inode btree blocks */
+#define XFS_FMR_OWN_INODES FMR_OWNER('X', 5) /* inodes */
+#define XFS_FMR_OWN_REFC FMR_OWNER('X', 6) /* refcount tree */
+#define XFS_FMR_OWN_COW FMR_OWNER('X', 7) /* cow staging */
+#define XFS_FMR_OWN_DEFECTIVE FMR_OWNER('X', 8) /* bad blocks */
+
/*
* Structure for XFS_IOC_FSSETDM.
* For use by backup and restore programs to set the XFS on-disk inode
@@ -522,6 +534,7 @@ 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)
+/* XFS_IOC_GETFSMAP ------ hoisted 59 */
/*
* ioctl commands that replace IRIX syssgi()'s
diff --git a/libxfs/xfs_rmap.c b/libxfs/xfs_rmap.c
index 7738f50..f78771d 100644
--- a/libxfs/xfs_rmap.c
+++ b/libxfs/xfs_rmap.c
@@ -2303,3 +2303,31 @@ xfs_rmap_free_extent(
return __xfs_rmap_add(mp, dfops, XFS_RMAP_FREE, owner,
XFS_DATA_FORK, &bmap);
}
+
+/* Compare rmap records. Returns -1 if a < b, 1 if a > b, and 0 if equal. */
+int
+xfs_rmap_compare(
+ const struct xfs_rmap_irec *a,
+ const struct xfs_rmap_irec *b)
+{
+ __u64 oa;
+ __u64 ob;
+
+ oa = xfs_rmap_irec_offset_pack(a);
+ ob = xfs_rmap_irec_offset_pack(b);
+
+ if (a->rm_startblock < b->rm_startblock)
+ return -1;
+ else if (a->rm_startblock > b->rm_startblock)
+ return 1;
+ else if (a->rm_owner < b->rm_owner)
+ return -1;
+ else if (a->rm_owner > b->rm_owner)
+ return 1;
+ else if (oa < ob)
+ return -1;
+ else if (oa > ob)
+ return 1;
+ else
+ return 0;
+}
diff --git a/libxfs/xfs_rmap.h b/libxfs/xfs_rmap.h
index faf2c1a..98f908f 100644
--- a/libxfs/xfs_rmap.h
+++ b/libxfs/xfs_rmap.h
@@ -214,5 +214,7 @@ int xfs_rmap_find_left_neighbor(struct xfs_btree_cur *cur, xfs_agblock_t bno,
int xfs_rmap_lookup_le_range(struct xfs_btree_cur *cur, xfs_agblock_t bno,
uint64_t owner, uint64_t offset, unsigned int flags,
struct xfs_rmap_irec *irec, int *stat);
+int xfs_rmap_compare(const struct xfs_rmap_irec *a,
+ const struct xfs_rmap_irec *b);
#endif /* __XFS_RMAP_H__ */
diff --git a/m4/package_libcdev.m4 b/m4/package_libcdev.m4
index bc3b4ce..f9b0945 100644
--- a/m4/package_libcdev.m4
+++ b/m4/package_libcdev.m4
@@ -277,3 +277,22 @@ AC_DEFUN([AC_NEED_INTERNAL_FSXATTR],
)
AC_SUBST(need_internal_fsxattr)
])
+
+#
+# Check if we have a FS_IOC_GETFSMAP ioctl (Linux)
+#
+AC_DEFUN([AC_HAVE_SYS_GETFSMAP],
+ [ AC_MSG_CHECKING([for GETFSMAP])
+ AC_TRY_LINK([
+#define _GNU_SOURCE
+#include <sys/syscall.h>
+#include <unistd.h>
+#include <linux/fsmap.h>
+ ], [
+ unsigned long x = FS_IOC_GETFSMAP;
+ struct fsmap_head fh;
+ ], have_sys_getfsmap=yes
+ AC_MSG_RESULT(yes),
+ AC_MSG_RESULT(no))
+ AC_SUBST(have_sys_getfsmap)
+ ])
--
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