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xfs_io: [v4] add the lseek() SEEK_DATA/SEEK_HOLE support

PATCH New Mark Tinguely 1 participant 1 message Nov 6, 2012 1 message not in the archive

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Mark Tinguely

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PATCH 1/1 xfs_io: [v4] add the lseek() SEEK_DATA/SEEK_HOLE support

Add the lseek SEEK_DATA/SEEK_HOLE support into xfs_io. The result from the lseek() call will be printed to the output. For example:

xfs_io> lseek -h 609k
Type Offset
hole 630784

Signed-off-by Mark Tinguely <[email protected]>

---
v1 -> v2 Add "-a" and "-r" options.
Simplify the output.
v2 -> v3 Refactor for configure.in -> configure.ac change.
SEEK_DATA with -1 offset behaves badly on older Linux. Display error message as "ERR <errno>".
v3 -> v4 Change command name to "seek"
Modified detection of first data/hole. Separate output routine.
Single loop to handle each data/hole item.

 configure.ac          |    1 
 include/builddefs.in  |    1 
 io/Makefile           |    5 +
 io/init.c             |    1 
 io/io.h               |    6 +
 io/seek.c             |  164 ++++++++++++++++++++++++++++++++++++++++++++++++++
 m4/package_libcdev.m4 |   15 ++++
 man/man8/xfs_io.8     |   35 ++++++++++
 8 files changed, 228 insertions(+)
configure.ac +1 -0
Index: seek_xfsprogs/configure.ac
===================================================================
@@ -110,6 +110,7 @@ AC_HAVE_GETMNTINFO
 AC_HAVE_FALLOCATE
 AC_HAVE_FIEMAP
 AC_HAVE_PREADV
+AC_HAVE_SEEK_DATA
 AC_HAVE_SYNC_FILE_RANGE
 AC_HAVE_BLKID_TOPO($enable_blkid)
include/builddefs.in +1 -0
Index: seek_xfsprogs/include/builddefs.in
===================================================================
@@ -102,6 +102,7 @@ HAVE_GETMNTINFO = @have_getmntinfo@
 HAVE_FALLOCATE = @have_fallocate@
 HAVE_FIEMAP = @have_fiemap@
 HAVE_PREADV = @have_preadv@
+HAVE_SEEK_DATA = @have_seek_data@
 HAVE_SYNC_FILE_RANGE = @have_sync_file_range@
 
 GCCFLAGS = -funsigned-char -fno-strict-aliasing -Wall
io/Makefile +5 -0
Index: seek_xfsprogs/io/Makefile
===================================================================
@@ -80,6 +80,11 @@ ifeq ($(HAVE_PREADV),yes)
 LCFLAGS += -DHAVE_PREADV -DHAVE_PWRITEV
 endif
 
+ifeq ($(HAVE_SEEK_DATA),yes)
+LCFLAGS += -DHAVE_SEEK_DATA
+CFILES += seek.c
+endif
+
 default: depend $(LTCOMMAND)
 
 include $(BUILDRULES)
io/init.c +1 -0
Index: seek_xfsprogs/io/init.c
===================================================================
@@ -64,6 +64,7 @@ init_commands(void)
 	help_init();
 	imap_init();
 	inject_init();
+	seek_init();
 	madvise_init();
 	mincore_init();
 	mmap_init();
io/io.h +6 -0
Index: seek_xfsprogs/io/io.h
===================================================================
@@ -108,6 +108,12 @@ extern void		quit_init(void);
 extern void		shutdown_init(void);
 extern void		truncate_init(void);
 
+#ifdef HAVE_SEEK_DATA
+extern void		seek_init(void);
+#else
+#define seek_init()	do { } while (0)
+#endif
+
 #ifdef HAVE_FADVISE
 extern void		fadvise_init(void);
 #else
io/seek.c new file +174 -0

174 lines not on this page · raw message

m4/package_libcdev.m4 +15 -0
Index: seek_xfsprogs/m4/package_libcdev.m4
===================================================================
@@ -153,6 +153,21 @@ AC_DEFUN([AC_HAVE_PREADV],
     AC_SUBST(have_preadv)
   ])
 
+# 
+# Check if we have a working fadvise system call
+# 
+AC_DEFUN([AC_HAVE_SEEK_DATA],
+  [ AC_MSG_CHECKING([for lseek SEEK_DATA])
+    AC_TRY_COMPILE([
+#include <linux/fs.h>
+    ], [
+	lseek(0, 0, SEEK_DATA);
+    ],	have_seek_data=yes
+	AC_MSG_RESULT(yes),
+	AC_MSG_RESULT(no))
+    AC_SUBST(have_seek_data)
+  ])
+
 #
 # Check if we have a sync_file_range libc call (Linux)
 #
man/man8/xfs_io.8 +35 -0
Index: seek_xfsprogs/man/man8/xfs_io.8
===================================================================
@@ -377,6 +377,41 @@ must be specified as another open file
 .RB ( \-f )
 or by path
 .RB ( \-i ).
+.TP
+.BI "seek  \-a | \-d | \-h [ \-r ] offset"
+On platforms that support the
+.BR lseek (2)
+.B SEEK_DATA
+and
+.B SEEK_HOLE
+options, display the offsets of the specified segments.
+.RS 1.0i
+.PD 0
+.TP 0.4i
+.B \-a
+Display both
+.B data
+and
+.B hole
+segments starting at the specified
+.B offset.
+.TP
+.B \-d
+Display the 
+.B data
+segment starting at the specified
+.B offset.
+.TP
+.B \-h
+Display the 
+.B hole
+segment starting at the specified
+.B offset.
+.TP
+.B \-r
+Recursively display all the specified segments starting at the specified
+.B offset.
+.TP
 
 .SH MEMORY MAPPED I/O COMMANDS
 .TP

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