Enable administrators to get or set the CoW extent size hint.
Report the hint when we run stat. This also requires some
autoconf magic to detect whether or not fsx_cowextsize exists.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
configure.ac | 1
include/builddefs.in | 4 +
io/Makefile | 5 +
io/attr.c | 5 +
io/cowextsize.c | 202 +++++++++++++++++++++++++++++++++++++++++++++++++
io/init.c | 1
io/io.h | 6 +
io/open.c | 3 +
m4/package_libcdev.m4 | 26 ++++++
man/man8/xfs_io.8 | 16 ++++
10 files changed, 268 insertions(+), 1 deletion(-)
create mode 100644 io/cowextsize.c
diff --git a/configure.ac b/configure.ac
index 8a39e75..539966d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -134,6 +134,7 @@ AC_HAVE_FLS
AC_HAVE_READDIR
AC_HAVE_FSETXATTR
AC_HAVE_MREMAP
+AC_HAVE_FSXATTR_COWEXTSIZE
if test "$enable_blkid" = yes; then
AC_HAVE_BLKID_TOPO
diff --git a/include/builddefs.in b/include/builddefs.in
index fd7eb74..165fa78 100644
--- a/include/builddefs.in
+++ b/include/builddefs.in
@@ -109,6 +109,7 @@ HAVE_MNTENT = @have_mntent@
HAVE_FLS = @have_fls@
HAVE_FSETXATTR = @have_fsetxattr@
HAVE_MREMAP = @have_mremap@
+HAVE_FSXATTR_COWEXTSIZE = @have_fsxattr_cowextsize@
ENABLE_INTERNAL_FSXATTR = @enable_internal_fsxattr@
GCCFLAGS = -funsigned-char -fno-strict-aliasing -Wall
@@ -149,6 +150,9 @@ endif
ifeq ($(ENABLE_BLKID),yes)
PCFLAGS+= -DENABLE_BLKID
endif
+ifeq ($(HAVE_FSXATTR_COWEXTSIZE),yes)
+PCFLAGS+= -DHAVE_FSXATTR_COWEXTSIZE
+endif
ifeq ($(ENABLE_INTERNAL_FSXATTR),yes)
PCFLAGS+= -DOVERRIDE_SYSTEM_FSXATTR
endif
diff --git a/io/Makefile b/io/Makefile
index 62bc03b..1997ca9 100644
--- a/io/Makefile
+++ b/io/Makefile
@@ -99,6 +99,11 @@ ifeq ($(HAVE_MREMAP),yes)
LCFLAGS += -DHAVE_MREMAP
endif
+ifeq ($(HAVE_FSXATTR_COWEXTSIZE),yes)
+CFILES += cowextsize.c
+# -DHAVE_FSXATTR_COWEXTSIZE already set in PCFLAGS
+endif
+
default: depend $(LTCOMMAND)
include $(BUILDRULES)
diff --git a/io/attr.c b/io/attr.c
index d1962f3..b8eec1b 100644
--- a/io/attr.c
+++ b/io/attr.c
@@ -48,9 +48,10 @@ static struct xflags {
{ FS_XFLAG_NODEFRAG, "f", "no-defrag" },
{ FS_XFLAG_FILESTREAM, "S", "filestream" },
{ FS_XFLAG_DAX, "x", "dax" },
+ { FS_XFLAG_COWEXTSIZE, "C", "cowextsize" },
{ 0, NULL, NULL }
};
-#define CHATTR_XFLAG_LIST "r"/*p*/"iasAdtPneEfSx"
+#define CHATTR_XFLAG_LIST "r"/*p*/"iasAdtPneEfSxC"
static void
lsattr_help(void)
@@ -75,6 +76,7 @@ lsattr_help(void)
" f -- do not include this file when defragmenting the filesystem\n"
" S -- enable filestreams allocator for this directory\n"
" x -- Use direct access (DAX) for data in this file\n"
+" C -- for files with shared blocks, observe the inode CoW extent size value\n"
"\n"
" Options:\n"
" -R -- recursively descend (useful when current file is a directory)\n"
@@ -111,6 +113,7 @@ chattr_help(void)
" +/-f -- set/clear the no-defrag flag\n"
" +/-S -- set/clear the filestreams allocator flag\n"
" +/-x -- set/clear the direct access (DAX) flag\n"
+" +/-C -- set/clear the CoW extent-size flag\n"
" Note1: user must have certain capabilities to modify immutable/append-only.\n"
" Note2: immutable/append-only files cannot be deleted; removing these files\n"
" requires the immutable/append-only flag to be cleared first.\n"
diff --git a/io/cowextsize.c b/io/cowextsize.c
new file mode 100644
index 0000000..b4a1c2e
--- /dev/null
+++ b/io/cowextsize.c
@@ -0,0 +1,202 @@
+/*
+ * Copyright (C) 2016 Oracle. All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+/*
+ * If configure didn't find a struct fsxattr with fsx_cowextsize,
+ * disable the only other source (so far) of struct fsxattr. Thus,
+ * build with the internal definition of struct fsxattr, which has
+ * fsx_cowextsize.
+ */
+#include "platform_defs.h"
+#include "command.h"
+#include "init.h"
+#include "io.h"
+#include "input.h"
+#include "path.h"
+
+static cmdinfo_t cowextsize_cmd;
+static long cowextsize;
+
+static void
+cowextsize_help(void)
+{
+ printf(_(
+"\n"
+" report or modify preferred CoW extent size (in bytes) for the current path\n"
+"\n"
+" -R -- recursively descend (useful when current path is a directory)\n"
+" -D -- recursively descend, only modifying cowextsize on directories\n"
+"\n"));
+}
+
+static int
+get_cowextsize(const char *path, int fd)
+{
+ struct fsxattr fsx;
+
+ if ((xfsctl(path, fd, XFS_IOC_FSGETXATTR, &fsx)) < 0) {
+ printf("%s: XFS_IOC_FSGETXATTR %s: %s\n",
+ progname, path, strerror(errno));
+ return 0;
+ }
+ printf("[%u] %s\n", fsx.fsx_cowextsize, path);
+ return 0;
+}
+
+static int
+set_cowextsize(const char *path, int fd, long extsz)
+{
+ struct fsxattr fsx;
+ struct stat64 stat;
+
+ if (fstat64(fd, &stat) < 0) {
+ perror("fstat64");
+ return 0;
+ }
+ if ((xfsctl(path, fd, XFS_IOC_FSGETXATTR, &fsx)) < 0) {
+ printf("%s: XFS_IOC_FSGETXATTR %s: %s\n",
+ progname, path, strerror(errno));
+ return 0;
+ }
+
+ if (S_ISREG(stat.st_mode) || S_ISDIR(stat.st_mode)) {
+ fsx.fsx_xflags |= FS_XFLAG_COWEXTSIZE;
+ } else {
+ printf(_("invalid target file type - file %s\n"), path);
+ return 0;
+ }
+ fsx.fsx_cowextsize = extsz;
+
+ if ((xfsctl(path, fd, XFS_IOC_FSSETXATTR, &fsx)) < 0) {
+ printf("%s: XFS_IOC_FSSETXATTR %s: %s\n",
+ progname, path, strerror(errno));
+ return 0;
+ }
+
+ return 0;
+}
+
+static int
+get_cowextsize_callback(
+ const char *path,
+ const struct stat *stat,
+ int status,
+ struct FTW *data)
+{
+ int fd;
+
+ if (recurse_dir && !S_ISDIR(stat->st_mode))
+ return 0;
+
+ fd = open(path, O_RDONLY);
+ if (fd < 0) {
+ fprintf(stderr, _("%s: cannot open %s: %s\n"),
+ progname, path, strerror(errno));
+ } else {
+ get_cowextsize(path, fd);
+ close(fd);
+ }
+ return 0;
+}
+
+static int
+set_cowextsize_callback(
+ const char *path,
+ const struct stat *stat,
+ int status,
+ struct FTW *data)
+{
+ int fd;
+
+ if (recurse_dir && !S_ISDIR(stat->st_mode))
+ return 0;
+
+ fd = open(path, O_RDONLY);
+ if (fd < 0) {
+ fprintf(stderr, _("%s: cannot open %s: %s\n"),
+ progname, path, strerror(errno));
+ } else {
+ set_cowextsize(path, fd, cowextsize);
+ close(fd);
+ }
+ return 0;
+}
+
+static int
+cowextsize_f(
+ int argc,
+ char **argv)
+{
+ size_t blocksize, sectsize;
+ int c;
+
+ recurse_all = recurse_dir = 0;
+ init_cvtnum(&blocksize, §size);
+ while ((c = getopt(argc, argv, "DR")) != EOF) {
+ switch (c) {
+ case 'D':
+ recurse_all = 0;
+ recurse_dir = 1;
+ break;
+ case 'R':
+ recurse_all = 1;
+ recurse_dir = 0;
+ break;
+ default:
+ return command_usage(&cowextsize_cmd);
+ }
+ }
+
+ if (optind < argc) {
+ cowextsize = (long)cvtnum(blocksize, sectsize, argv[optind]);
+ if (cowextsize < 0) {
+ printf(_("non-numeric cowextsize argument -- %s\n"),
+ argv[optind]);
+ return 0;
+ }
+ } else {
+ cowextsize = -1;
+ }
+
+ if (recurse_all || recurse_dir)
+ nftw(file->name, (cowextsize >= 0) ?
+ set_cowextsize_callback : get_cowextsize_callback,
+ 100, FTW_PHYS | FTW_MOUNT | FTW_DEPTH);
+ else if (cowextsize >= 0)
+ set_cowextsize(file->name, file->fd, cowextsize);
+ else
+ get_cowextsize(file->name, file->fd);
+ return 0;
+}
+
+void
+cowextsize_init(void)
+{
+ cowextsize_cmd.name = "cowextsize";
+ cowextsize_cmd.cfunc = cowextsize_f;
+ cowextsize_cmd.args = _("[-D | -R] [cowextsize]");
+ cowextsize_cmd.argmin = 0;
+ cowextsize_cmd.argmax = -1;
+ cowextsize_cmd.flags = CMD_NOMAP_OK;
+ cowextsize_cmd.oneline =
+ _("get/set preferred CoW extent size (in bytes) for the open file");
+ cowextsize_cmd.help = cowextsize_help;
+
+ add_command(&cowextsize_cmd);
+}
diff --git a/io/init.c b/io/init.c
index efe7390..6b88cc6 100644
--- a/io/init.c
+++ b/io/init.c
@@ -85,6 +85,7 @@ init_commands(void)
sync_range_init();
truncate_init();
reflink_init();
+ cowextsize_init();
}
static int
diff --git a/io/io.h b/io/io.h
index 2bc7ac4..4264e4d 100644
--- a/io/io.h
+++ b/io/io.h
@@ -169,3 +169,9 @@ extern void readdir_init(void);
#endif
extern void reflink_init(void);
+
+#ifdef HAVE_FSXATTR_COWEXTSIZE
+extern void cowextsize_init(void);
+#else
+#define cowextsize_init() do { } while (0)
+#endif
diff --git a/io/open.c b/io/open.c
index 8f934ee..27943c7 100644
--- a/io/open.c
+++ b/io/open.c
@@ -125,6 +125,9 @@ stat_f(
printxattr(fsx.fsx_xflags, verbose, 0, file->name, 1, 1);
printf(_("fsxattr.projid = %u\n"), fsx.fsx_projid);
printf(_("fsxattr.extsize = %u\n"), fsx.fsx_extsize);
+#if defined HAVE_FSXATTR_COWEXTSIZE
+ printf(_("fsxattr.cowextsize = %u\n"), fsx.fsx_cowextsize);
+#endif
printf(_("fsxattr.nextents = %u\n"), fsx.fsx_nextents);
printf(_("fsxattr.naextents = %u\n"), fsxa.fsx_nextents);
}
diff --git a/m4/package_libcdev.m4 b/m4/package_libcdev.m4
index 7a847e9..45954c2 100644
--- a/m4/package_libcdev.m4
+++ b/m4/package_libcdev.m4
@@ -265,3 +265,29 @@ AC_DEFUN([AC_HAVE_MREMAP],
)
AC_SUBST(have_mremap)
])
+
+#
+# Check if we have a struct fsxattr with a fsx_cowextsize field.
+# If linux/fs.h has a struct with that field, then we're ok.
+# If we can't find fsxattr in linux/fs.h at all, the internal
+# definitions provide it, and we're ok.
+#
+# The only way we won't have this is if the kernel headers don't
+# have the field.
+#
+AC_DEFUN([AC_HAVE_FSXATTR_COWEXTSIZE],
+ [ AM_CONDITIONAL([INTERNAL_FSXATTR], [test "x$enable_internal_fsxattr" = xyes])
+ AM_COND_IF([INTERNAL_FSXATTR],
+ [have_fsxattr_cowextsize=yes],
+ [ AC_CHECK_TYPE(struct fsxattr,
+ [AC_CHECK_MEMBER(struct fsxattr.fsx_cowextsize,
+ have_fsxattr_cowextsize=yes,
+ have_fsxattr_cowextsize=no,
+ [#include <linux/fs.h>]
+ )],
+ have_fsxattr_cowextsize=yes,
+ [#include <linux/fs.h>]
+ )
+ ])
+ AC_SUBST(have_fsxattr_cowextsize)
+ ])
diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8
index d089524..2365550 100644
--- a/man/man8/xfs_io.8
+++ b/man/man8/xfs_io.8
@@ -283,6 +283,22 @@ The
should be specified in bytes, or using one of the usual units suffixes
(k, m, g, b, etc). The extent size is always reported in units of bytes.
.TP
+.BI "cowextsize [ \-R | \-D ] [ " value " ]"
+Display and/or modify the preferred copy-on-write extent size used
+when allocating space for the currently open file. If the
+.B \-R
+option is specified, a recursive descent is performed
+for all directory entries below the currently open file
+.RB ( \-D
+can be used to restrict the output to directories only).
+If the target file is a directory, then the inherited CoW extent size
+is set for that directory (new files created in that directory
+inherit that CoW extent size).
+The
+.I value
+should be specified in bytes, or using one of the usual units suffixes
+(k, m, g, b, etc). The extent size is always reported in units of bytes.
+.TP
.BI "allocsp " size " 0"
Sets the size of the file to
.I size
--
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