diff options
author | Ross Zwisler <ross.zwisler@linux.intel.com> | 2018-01-04 13:58:29 -0600 |
---|---|---|
committer | Eric Sandeen <sandeen@redhat.com> | 2018-01-04 13:58:29 -0600 |
commit | dad796834cb930832a4de53cbd26fafcd01cd888 (patch) | |
tree | e1695b8aa8e5e76fe71469b03dbb0e32c5692f34 | |
parent | 9502da215bb8affebc968586c2d7b79693b04fb6 (diff) | |
download | xfsprogs-dev-dad796834cb930832a4de53cbd26fafcd01cd888.tar.gz |
xfs_io: add MAP_SYNC support to mmap()
Add support for a new -S flag to xfs_io's mmap command. This opens the
mapping with the (MAP_SYNC | MAP_SHARED_VALIDATE) flags instead of the
standard MAP_SHARED flag.
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Suggested-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
-rw-r--r-- | configure.ac | 1 | ||||
-rw-r--r-- | include/builddefs.in | 1 | ||||
-rw-r--r-- | include/linux.h | 8 | ||||
-rw-r--r-- | io/Makefile | 4 | ||||
-rw-r--r-- | io/io.h | 1 | ||||
-rw-r--r-- | io/mmap.c | 29 | ||||
-rw-r--r-- | m4/package_libcdev.m4 | 16 | ||||
-rw-r--r-- | man/man8/xfs_io.8 | 6 |
8 files changed, 60 insertions, 6 deletions
diff --git a/configure.ac b/configure.ac index e5d0309f80..f3325aa044 100644 --- a/configure.ac +++ b/configure.ac @@ -163,6 +163,7 @@ AC_HAVE_MREMAP AC_NEED_INTERNAL_FSXATTR AC_HAVE_GETFSMAP AC_HAVE_STATFS_FLAGS +AC_HAVE_MAP_SYNC if test "$enable_blkid" = yes; then AC_HAVE_BLKID_TOPO diff --git a/include/builddefs.in b/include/builddefs.in index f4448c62df..1f33022321 100644 --- a/include/builddefs.in +++ b/include/builddefs.in @@ -116,6 +116,7 @@ HAVE_MREMAP = @have_mremap@ NEED_INTERNAL_FSXATTR = @need_internal_fsxattr@ HAVE_GETFSMAP = @have_getfsmap@ HAVE_STATFS_FLAGS = @have_statfs_flags@ +HAVE_MAP_SYNC = @have_map_sync@ GCCFLAGS = -funsigned-char -fno-strict-aliasing -Wall # -Wbitwise -Wno-transparent-union -Wno-old-initializer -Wno-decl diff --git a/include/linux.h b/include/linux.h index 6ce344c5ec..1998941a6d 100644 --- a/include/linux.h +++ b/include/linux.h @@ -327,4 +327,12 @@ fsmap_advance( #define HAVE_GETFSMAP #endif /* HAVE_GETFSMAP */ +#ifndef HAVE_MAP_SYNC +#define MAP_SYNC 0 +#define MAP_SHARED_VALIDATE 0 +#else +#include <asm-generic/mman.h> +#include <asm-generic/mman-common.h> +#endif /* HAVE_MAP_SYNC */ + #endif /* __XFS_LINUX_H__ */ diff --git a/io/Makefile b/io/Makefile index aa0ab7de7c..979434a2a1 100644 --- a/io/Makefile +++ b/io/Makefile @@ -104,6 +104,10 @@ ifeq ($(HAVE_MREMAP),yes) LCFLAGS += -DHAVE_MREMAP endif +ifeq ($(HAVE_MAP_SYNC),yes) +LCFLAGS += -DHAVE_MAP_SYNC +endif + # On linux we get fsmap from the system or define it ourselves # so include this based on platform type. If this reverts to only # the autoconf check w/o local definition, change to testing HAVE_GETFSMAP @@ -65,6 +65,7 @@ typedef struct mmap_region { size_t length; /* length of mapping */ off64_t offset; /* start offset into backing file */ int prot; /* protection mode of the mapping */ + bool map_sync; /* is this a MAP_SYNC mapping? */ char *name; /* name of backing file */ } mmap_region_t; @@ -42,7 +42,7 @@ print_mapping( int index, int braces) { - unsigned char buffer[8] = { 0 }; + char buffer[8] = { 0 }; int i; static struct { @@ -57,6 +57,10 @@ print_mapping( for (i = 0, p = pflags; p->prot != PROT_NONE; i++, p++) buffer[i] = (map->prot & p->prot) ? p->mode : '-'; + + if (map->map_sync) + sprintf(&buffer[i], " S"); + printf("%c%03d%c 0x%lx - 0x%lx %s %14s (%lld : %ld)\n", braces? '[' : ' ', index, braces? ']' : ' ', (unsigned long)map->addr, @@ -146,6 +150,7 @@ mmap_help(void) " -r -- map with PROT_READ protection\n" " -w -- map with PROT_WRITE protection\n" " -x -- map with PROT_EXEC protection\n" +" -S -- map with MAP_SYNC and MAP_SHARED_VALIDATE flags\n" " -s <size> -- first do mmap(size)/munmap(size), try to reserve some free space\n" " If no protection mode is specified, all are used by default.\n" "\n")); @@ -161,7 +166,7 @@ mmap_f( void *address = NULL; char *filename; size_t blocksize, sectsize; - int c, prot = 0; + int c, prot = 0, flags = MAP_SHARED; if (argc == 1) { if (mapping) @@ -184,7 +189,7 @@ mmap_f( init_cvtnum(&blocksize, §size); - while ((c = getopt(argc, argv, "rwxs:")) != EOF) { + while ((c = getopt(argc, argv, "rwxSs:")) != EOF) { switch (c) { case 'r': prot |= PROT_READ; @@ -195,6 +200,19 @@ mmap_f( case 'x': prot |= PROT_EXEC; break; + case 'S': + flags = MAP_SYNC | MAP_SHARED_VALIDATE; + + /* + * If MAP_SYNC and MAP_SHARED_VALIDATE aren't defined + * in the system headers we will have defined them + * both as 0. + */ + if (!flags) { + printf("MAP_SYNC not supported\n"); + return 0; + } + break; case 's': length2 = cvtnum(blocksize, sectsize, optarg); break; @@ -238,7 +256,7 @@ mmap_f( MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); munmap(address, length2); } - address = mmap(address, length, prot, MAP_SHARED, file->fd, offset); + address = mmap(address, length, prot, flags, file->fd, offset); if (address == MAP_FAILED) { perror("mmap"); free(filename); @@ -263,6 +281,7 @@ mmap_f( mapping->offset = offset; mapping->name = filename; mapping->prot = prot; + mapping->map_sync = (flags == (MAP_SYNC | MAP_SHARED_VALIDATE)); return 0; } @@ -676,7 +695,7 @@ mmap_init(void) mmap_cmd.argmax = -1; mmap_cmd.flags = CMD_NOMAP_OK | CMD_NOFILE_OK | CMD_FOREIGN_OK | CMD_FLAG_ONESHOT; - mmap_cmd.args = _("[N] | [-rwx] [-s size] [off len]"); + mmap_cmd.args = _("[N] | [-rwxS] [-s size] [off len]"); mmap_cmd.oneline = _("mmap a range in the current file, show mappings"); mmap_cmd.help = mmap_help; diff --git a/m4/package_libcdev.m4 b/m4/package_libcdev.m4 index 7b4dfc8553..71cedc5cab 100644 --- a/m4/package_libcdev.m4 +++ b/m4/package_libcdev.m4 @@ -328,3 +328,19 @@ AC_DEFUN([AC_HAVE_STATFS_FLAGS], ) AC_SUBST(have_statfs_flags) ]) + +# +# Check if we have MAP_SYNC defines (Linux) +# +AC_DEFUN([AC_HAVE_MAP_SYNC], + [ AC_MSG_CHECKING([for MAP_SYNC]) + AC_TRY_COMPILE([ +#include <asm-generic/mman.h> +#include <asm-generic/mman-common.h> + ], [ + int flags = MAP_SYNC | MAP_SHARED_VALIDATE; + ], have_map_sync=yes + AC_MSG_RESULT(yes), + AC_MSG_RESULT(no)) + AC_SUBST(have_map_sync) + ]) diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8 index a9bcc29dcd..3f77781f33 100644 --- a/man/man8/xfs_io.8 +++ b/man/man8/xfs_io.8 @@ -776,7 +776,7 @@ Each (sec, nsec) pair constitutes a single timestamp value. .SH MEMORY MAPPED I/O COMMANDS .TP -.BI "mmap [ " N " | [[ \-rwx ] [\-s " size " ] " "offset length " ]] +.BI "mmap [ " N " | [[ \-rwxS ] [\-s " size " ] " "offset length " ]] With no arguments, .B mmap shows the current mappings. Specifying a single numeric argument @@ -792,6 +792,10 @@ PROT_WRITE .RB ( \-w ), and PROT_EXEC .RB ( \-x ). +The mapping will be created with the MAP_SHARED flag by default, or with the +Linux specific (MAP_SYNC | MAP_SHARED_VALIDATE) flags if +.B -S +is given. .BI \-s " size" is used to do a mmap(size) && munmap(size) operation at first, try to reserve some extendible free memory space, if |