* [PATCH 2/2] Make Multi Mount Protection (MMP) optional at configure time.
2012-06-26 1:42 [PATCH 1/2] ext2fs.h: Chnage the way EXT2_LIB_FEATURE_INCOMPAT_SUPP deals with optional features Tony Breeds
@ 2012-06-26 1:42 ` Tony Breeds
2012-07-30 19:40 ` Theodore Ts'o
2012-07-30 19:40 ` [PATCH 1/2] ext2fs.h: Chnage the way EXT2_LIB_FEATURE_INCOMPAT_SUPP deals with optional features Theodore Ts'o
1 sibling, 1 reply; 4+ messages in thread
From: Tony Breeds @ 2012-06-26 1:42 UTC (permalink / raw)
To: linux-ext4, Ted Ts'o, Andreas Dilger
Add --{en,dis}able-mmp options for configure, default to enabled.
Also make tools fail gracefully in the event of encoutering a filesystem
with MMP enabled when the tools were compiled with --disable-mmp
Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
---
configure.in | 17 +++++++++++++++++
debugfs/debugfs.c | 5 +++++
debugfs/set_fields.c | 5 +++++
lib/config.h.in | 3 +++
lib/ext2fs/ext2fs.h | 8 +++++++-
lib/ext2fs/mmp.c | 32 ++++++++++++++++++++++++++++++++
6 files changed, 69 insertions(+), 1 deletions(-)
diff --git a/configure.in b/configure.in
index 7373e8e..a02234d 100644
--- a/configure.in
+++ b/configure.in
@@ -746,6 +746,23 @@ AC_MSG_RESULT([Building uuidd by default])
)
AC_SUBST(UUIDD_CMT)
dnl
+dnl handle --disable-mmp
+dnl
+AH_TEMPLATE([CONFIG_MMP], [Define to 1 to enable mmp support])
+AC_ARG_ENABLE([mmp],
+[ --disable-mmp disable support mmp, Multi Mount Protection],
+if test "$enableval" = "no"
+then
+ AC_MSG_RESULT([Disabling mmp support])
+else
+ AC_MSG_RESULT([Enabling mmp support])
+ AC_DEFINE(CONFIG_MMP, 1)
+fi
+,
+AC_MSG_RESULT([Enabling mmp support by default])
+AC_DEFINE(CONFIG_MMP, 1)
+)
+dnl
dnl
dnl
MAKEFILE_LIBRARY=$srcdir/lib/Makefile.library
diff --git a/debugfs/debugfs.c b/debugfs/debugfs.c
index cf80bd0..0c27b1e 100644
--- a/debugfs/debugfs.c
+++ b/debugfs/debugfs.c
@@ -2194,6 +2194,7 @@ void do_punch(int argc, char *argv[])
void do_dump_mmp(int argc EXT2FS_ATTR((unused)), char *argv[])
{
+#if CONFIG_MMP
struct ext2_super_block *sb;
struct mmp_struct *mmp_s;
time_t t;
@@ -2237,6 +2238,10 @@ void do_dump_mmp(int argc EXT2FS_ATTR((unused)), char *argv[])
fprintf(stdout, "node_name: %s\n", mmp_s->mmp_nodename);
fprintf(stdout, "device_name: %s\n", mmp_s->mmp_bdevname);
fprintf(stdout, "magic: 0x%x\n", mmp_s->mmp_magic);
+#else
+ fprintf(stdout, "MMP is unsupported, please recompile with "
+ "--enable-mmp\n");
+#endif
}
static int source_file(const char *cmd_file, int sci_idx)
diff --git a/debugfs/set_fields.c b/debugfs/set_fields.c
index 08bfd8d..a42faa2 100644
--- a/debugfs/set_fields.c
+++ b/debugfs/set_fields.c
@@ -765,6 +765,7 @@ static errcode_t parse_mmp_clear(struct field_set_info *info,
void do_set_mmp_value(int argc, char *argv[])
{
+#ifdef CONFIG_MMP
const char *usage = "<field> <value>\n"
"\t\"set_mmp_value -l\" will list the names of "
"MMP fields\n\twhich can be set.";
@@ -819,5 +820,9 @@ void do_set_mmp_value(int argc, char *argv[])
&set_mmp);
*mmp_s = set_mmp;
}
+#else
+ fprintf(stdout, "MMP is unsupported, please recompile with "
+ "--enable-mmp\n");
+#endif
}
diff --git a/lib/config.h.in b/lib/config.h.in
index 90e9743..52c3897 100644
--- a/lib/config.h.in
+++ b/lib/config.h.in
@@ -12,6 +12,9 @@
/* Define to 1 if debugging ext3/4 journal code */
#undef CONFIG_JBD_DEBUG
+/* Define to 1 to enable mmp support */
+#undef CONFIG_MMP
+
/* Define to 1 to enable quota support */
#undef CONFIG_QUOTA
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index 7be148e..542b20f 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -559,6 +559,12 @@ typedef struct ext2_icount *ext2_icount_t;
#define EXT2_LIB_INCOMPAT_COMPRESSION (0)
#endif
+#ifdef CONFIG_MMP
+#define EXT4_LIB_INCOMPAT_MMP EXT4_FEATURE_INCOMPAT_MMP
+#else
+#define EXT4_LIB_INCOMPAT_MMP (0)
+#endif
+
#define EXT2_LIB_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE|\
EXT2_LIB_INCOMPAT_COMPRESSION|\
EXT3_FEATURE_INCOMPAT_JOURNAL_DEV|\
@@ -566,7 +572,7 @@ typedef struct ext2_icount *ext2_icount_t;
EXT3_FEATURE_INCOMPAT_RECOVER|\
EXT3_FEATURE_INCOMPAT_EXTENTS|\
EXT4_FEATURE_INCOMPAT_FLEX_BG|\
- EXT4_FEATURE_INCOMPAT_MMP|\
+ EXT4_LIB_INCOMPAT_MMP|\
EXT4_FEATURE_INCOMPAT_64BIT)
#ifdef CONFIG_QUOTA
#define EXT2_LIB_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER|\
diff --git a/lib/ext2fs/mmp.c b/lib/ext2fs/mmp.c
index bb3772d..c76aefa 100644
--- a/lib/ext2fs/mmp.c
+++ b/lib/ext2fs/mmp.c
@@ -33,6 +33,7 @@
errcode_t ext2fs_mmp_read(ext2_filsys fs, blk64_t mmp_blk, void *buf)
{
+#ifdef CONFIG_MMP
struct mmp_struct *mmp_cmp;
errcode_t retval = 0;
@@ -88,10 +89,14 @@ errcode_t ext2fs_mmp_read(ext2_filsys fs, blk64_t mmp_blk, void *buf)
out:
return retval;
+#else
+ return EXT2_ET_OP_NOT_SUPPORTED;
+#endif
}
errcode_t ext2fs_mmp_write(ext2_filsys fs, blk64_t mmp_blk, void *buf)
{
+#ifdef CONFIG_MMP
struct mmp_struct *mmp_s = buf;
struct timeval tv;
errcode_t retval = 0;
@@ -119,6 +124,9 @@ errcode_t ext2fs_mmp_write(ext2_filsys fs, blk64_t mmp_blk, void *buf)
/* Make sure the block gets to disk quickly */
io_channel_flush(fs->io);
return retval;
+#else
+ return EXT2_ET_OP_NOT_SUPPORTED;
+#endif
}
#ifdef HAVE_SRANDOM
@@ -128,6 +136,7 @@ errcode_t ext2fs_mmp_write(ext2_filsys fs, blk64_t mmp_blk, void *buf)
unsigned ext2fs_mmp_new_seq()
{
+#ifdef CONFIG_MMP
unsigned new_seq;
struct timeval tv;
@@ -144,6 +153,9 @@ unsigned ext2fs_mmp_new_seq()
} while (new_seq > EXT4_MMP_SEQ_MAX);
return new_seq;
+#else
+ return EXT2_ET_OP_NOT_SUPPORTED;
+#endif
}
static errcode_t ext2fs_mmp_reset(ext2_filsys fs)
@@ -182,6 +194,7 @@ out:
errcode_t ext2fs_mmp_clear(ext2_filsys fs)
{
+#ifdef CONFIG_MMP
errcode_t retval = 0;
if (!(fs->flags & EXT2_FLAG_RW))
@@ -190,10 +203,14 @@ errcode_t ext2fs_mmp_clear(ext2_filsys fs)
retval = ext2fs_mmp_reset(fs);
return retval;
+#else
+ return EXT2_ET_OP_NOT_SUPPORTED;
+#endif
}
errcode_t ext2fs_mmp_init(ext2_filsys fs)
{
+#ifdef CONFIG_MMP
struct ext2_super_block *sb = fs->super;
blk64_t mmp_block;
errcode_t retval;
@@ -222,6 +239,9 @@ errcode_t ext2fs_mmp_init(ext2_filsys fs)
out:
return retval;
+#else
+ return EXT2_ET_OP_NOT_SUPPORTED;
+#endif
}
/*
@@ -229,6 +249,7 @@ out:
*/
errcode_t ext2fs_mmp_start(ext2_filsys fs)
{
+#ifdef CONFIG_MMP
struct mmp_struct *mmp_s;
unsigned seq;
unsigned int mmp_check_interval;
@@ -318,6 +339,9 @@ clean_seq:
mmp_error:
return retval;
+#else
+ return EXT2_ET_OP_NOT_SUPPORTED;
+#endif
}
/*
@@ -328,6 +352,7 @@ mmp_error:
*/
errcode_t ext2fs_mmp_stop(ext2_filsys fs)
{
+#ifdef CONFIG_MMP
struct mmp_struct *mmp, *mmp_cmp;
errcode_t retval = 0;
@@ -357,6 +382,9 @@ mmp_error:
}
return retval;
+#else
+ return EXT2_ET_OP_NOT_SUPPORTED;
+#endif
}
#define EXT2_MIN_MMP_UPDATE_INTERVAL 60
@@ -366,6 +394,7 @@ mmp_error:
*/
errcode_t ext2fs_mmp_update(ext2_filsys fs)
{
+#ifdef CONFIG_MMP
struct mmp_struct *mmp, *mmp_cmp;
struct timeval tv;
errcode_t retval = 0;
@@ -394,4 +423,7 @@ errcode_t ext2fs_mmp_update(ext2_filsys fs)
mmp_error:
return retval;
+#else
+ return EXT2_ET_OP_NOT_SUPPORTED;
+#endif
}
--
1.7.7.6
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