[PATCH 116/145] xfs_io: get and set the CoW extent size hint
Darrick J. Wong
darrick.wong at oracle.com
Thu Jun 16 20:42:57 CDT 2016
Enable administrators to get or set the CoW extent size hint.
Signed-off-by: Darrick J. Wong <darrick.wong at oracle.com>
---
io/attr.c | 8 ++-
io/open.c | 166 +++++++++++++++++++++++++++++++++++++++++++++++++++++
man/man8/xfs_io.8 | 16 +++++
3 files changed, 189 insertions(+), 1 deletion(-)
diff --git a/io/attr.c b/io/attr.c
index 0186b1d..13bec73 100644
--- a/io/attr.c
+++ b/io/attr.c
@@ -48,9 +48,11 @@ static struct xflags {
{ FS_XFLAG_NODEFRAG, "f", "no-defrag" },
{ FS_XFLAG_FILESTREAM, "S", "filestream" },
{ FS_XFLAG_DAX, "x", "dax" },
+ { FS_XFLAG_REFLINK, "R", "reflink" },
+ { FS_XFLAG_COWEXTSIZE, "C", "cowextsize" },
{ 0, NULL, NULL }
};
-#define CHATTR_XFLAG_LIST "r"/*p*/"iasAdtPneEfSx"
+#define CHATTR_XFLAG_LIST "r"/*p*/"iasAdtPneEfSxRC"
static void
lsattr_help(void)
@@ -75,6 +77,8 @@ 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"
+" R -- file data blocks may be shared with another 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 +115,8 @@ 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"
+" +/-R -- set/clear the reflink 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/open.c b/io/open.c
index 2303527..1e682a4 100644
--- a/io/open.c
+++ b/io/open.c
@@ -46,8 +46,10 @@ static cmdinfo_t chproj_cmd;
static cmdinfo_t lsproj_cmd;
static cmdinfo_t extsize_cmd;
static cmdinfo_t inode_cmd;
+static cmdinfo_t cowextsize_cmd;
static prid_t prid;
static long extsize;
+static long cowextsize;
off64_t
filesize(void)
@@ -125,6 +127,7 @@ 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);
+ printf(_("fsxattr.cowextsize = %u\n"), fsx.fsx_cowextsize);
printf(_("fsxattr.nextents = %u\n"), fsx.fsx_nextents);
printf(_("fsxattr.naextents = %u\n"), fsxa.fsx_nextents);
}
@@ -696,6 +699,158 @@ extsize_f(
return 0;
}
+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, (extsize >= 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;
+}
+
static int
statfs_f(
int argc,
@@ -964,6 +1119,16 @@ open_init(void)
_("Query inode number usage in the filesystem");
inode_cmd.help = inode_help;
+ 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(&open_cmd);
add_command(&stat_cmd);
add_command(&close_cmd);
@@ -972,4 +1137,5 @@ open_init(void)
add_command(&lsproj_cmd);
add_command(&extsize_cmd);
add_command(&inode_cmd);
+ add_command(&cowextsize_cmd);
}
diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8
index 6c45c37..cc70b7c 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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