From: Darrick J. Wong <djwong@xxxxxxxxxx>
Support FALLOC_FL_MAP_FREE_SPACE as a fallocate mode. This is
experimental code to see if we can build a free space defragmenter out
of this.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
io/prealloc.c | 37 +++++++++++++++++++++++++++++++++++++
man/man8/xfs_io.8 | 8 +++++++-
2 files changed, 44 insertions(+), 1 deletion(-)
diff --git a/io/prealloc.c b/io/prealloc.c
index 5805897a4a0..02de16651c1 100644
--- a/io/prealloc.c
+++ b/io/prealloc.c
@@ -32,6 +32,10 @@
#define FALLOC_FL_UNSHARE_RANGE 0x40
#endif
+#ifndef FALLOC_FL_MAP_FREE_SPACE
+#define FALLOC_FL_MAP_FREE_SPACE (1U << 30)
+#endif
+
static cmdinfo_t allocsp_cmd;
static cmdinfo_t freesp_cmd;
static cmdinfo_t resvsp_cmd;
@@ -44,6 +48,7 @@ static cmdinfo_t fcollapse_cmd;
static cmdinfo_t finsert_cmd;
static cmdinfo_t fzero_cmd;
static cmdinfo_t funshare_cmd;
+static cmdinfo_t fmapfree_cmd;
#endif
static int
@@ -381,6 +386,28 @@ funshare_f(
}
return 0;
}
+
+static int
+fmapfree_f(
+ int argc,
+ char **argv)
+{
+ xfs_flock64_t segment;
+ int mode = FALLOC_FL_MAP_FREE_SPACE;
+ int index = 1;
+
+ if (!offset_length(argv[index], argv[index + 1], &segment)) {
+ exitcode = 1;
+ return 0;
+ }
+
+ if (fallocate(file->fd, mode, segment.l_start, segment.l_len)) {
+ perror("fallocate");
+ exitcode = 1;
+ return 0;
+ }
+ return 0;
+}
#endif /* HAVE_FALLOCATE */
void
@@ -496,5 +523,15 @@ prealloc_init(void)
funshare_cmd.oneline =
_("unshares shared blocks within the range");
add_command(&funshare_cmd);
+
+ fmapfree_cmd.name = "fmapfree";
+ fmapfree_cmd.cfunc = fmapfree_f;
+ fmapfree_cmd.argmin = 2;
+ fmapfree_cmd.argmax = 2;
+ fmapfree_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK;
+ fmapfree_cmd.args = _("off len");
+ fmapfree_cmd.oneline =
+ _("maps free space into a file");
+ add_command(&fmapfree_cmd);
#endif /* HAVE_FALLOCATE */
}
diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8
index ece778fc76c..b10523325ee 100644
--- a/man/man8/xfs_io.8
+++ b/man/man8/xfs_io.8
@@ -513,8 +513,14 @@ Call fallocate with FALLOC_FL_INSERT_RANGE flag as described in the
.BR fallocate (2)
manual page to create the hole by shifting data blocks.
.TP
+.BI fmapfree " offset length"
+Maps free physical space into the file by calling fallocate with
+the FALLOC_FL_MAP_FREE_SPACE flag as described in the
+.BR fallocate (2)
+manual page.
+.TP
.BI fpunch " offset length"
-Punches (de-allocates) blocks in the file by calling fallocate with
+Punches (de-allocates) blocks in the file by calling fallocate with
the FALLOC_FL_PUNCH_HOLE flag as described in the
.BR fallocate (2)
manual page.
