--- /dev/null
+Index: linux-2.6.9/fs/ext3/super.c
+===================================================================
+--- linux-2.6.9.orig/fs/ext3/super.c
++++ linux-2.6.9/fs/ext3/super.c
+@@ -35,6 +35,8 @@
+ #include <linux/mount.h>
+ #include <linux/namei.h>
+ #include <linux/quotaops.h>
++#include <linux/kthread.h>
++#include <linux/utsname.h>
+ #include <asm/uaccess.h>
+ #include "xattr.h"
+ #include "acl.h"
+@@ -440,6 +442,9 @@ void ext3_put_super (struct super_block
+ invalidate_bdev(sbi->journal_bdev, 0);
+ ext3_blkdev_remove(sbi);
+ }
++ if (sbi->s_mmp_tsk)
++ kthread_stop(sbi->s_mmp_tsk);
++
+ sb->s_fs_info = NULL;
+ kfree(sbi);
+ return;
+@@ -1431,6 +1436,314 @@ static unsigned long descriptor_loc(stru
+ return (first_data_block + has_super + (bg * sbi->s_blocks_per_group));
+ }
+
++/*
++ * Write the MMP block using WRITE_SYNC to try to get the block on-disk
++ * faster.
++ */
++static int write_mmp_block(struct buffer_head *bh)
++{
++ mark_buffer_dirty(bh);
++ lock_buffer(bh);
++ bh->b_end_io = end_buffer_write_sync;
++ get_bh(bh);
++ submit_bh(WRITE_SYNC, bh);
++ wait_on_buffer(bh);
++ if (unlikely(!buffer_uptodate(bh)))
++ return 1;
++
++ return 0;
++}
++
++/*
++ * Read the MMP block. It _must_ be read from disk and hence we clear the
++ * uptodate flag on the buffer.
++ */
++static int read_mmp_block(struct super_block *sb, struct buffer_head **bh,
++ unsigned long mmp_block)
++{
++ struct mmp_struct *mmp;
++
++ if (*bh)
++ clear_buffer_uptodate(*bh);
++
++ brelse(*bh);
++
++ *bh = sb_bread(sb, mmp_block);
++ if (!*bh) {
++ ext3_warning(sb, __FUNCTION__,
++ "Error while reading MMP block %lu", mmp_block);
++ return -EIO;
++ }
++
++ mmp = (struct mmp_struct *)((*bh)->b_data);
++ if (le32_to_cpu(mmp->mmp_magic) != EXT3_MMP_MAGIC)
++ return -EINVAL;
++
++ return 0;
++}
++
++/*
++ * Dump as much information as possible to help the admin.
++ */
++static void dump_mmp_msg(struct super_block *sb, struct mmp_struct *mmp,
++ const char *function, const char *msg)
++{
++ ext3_warning(sb, function, msg);
++ ext3_warning(sb, function, "MMP failure info: last update time: %llu, "
++ "last update node: %s, last update device: %s\n",
++ le64_to_cpu(mmp->mmp_time), mmp->mmp_nodename,
++ mmp->mmp_bdevname);
++}
++
++/*
++ * kmmpd will update the MMP sequence every s_mmp_update_interval seconds
++ */
++static int kmmpd(void *data)
++{
++ struct super_block *sb = (struct super_block *) data;
++ struct ext3_super_block *es = EXT3_SB(sb)->s_es;
++ struct buffer_head *bh = NULL;
++ struct mmp_struct *mmp;
++ unsigned long mmp_block;
++ u32 seq = 0;
++ unsigned long failed_writes = 0;
++ int mmp_update_interval = le16_to_cpu(es->s_mmp_update_interval);
++ unsigned mmp_check_interval;
++ unsigned long last_update_time;
++ unsigned long diff;
++ int retval;
++
++ mmp_block = le64_to_cpu(es->s_mmp_block);
++ retval = read_mmp_block(sb, &bh, mmp_block);
++ if (retval)
++ goto failed;
++
++ mmp = (struct mmp_struct *)(bh->b_data);
++ mmp->mmp_time = cpu_to_le64(get_seconds());
++ /*
++ * Start with the higher mmp_check_interval and reduce it if
++ * the MMP block is being updated on time.
++ */
++ mmp_check_interval = max(5 * mmp_update_interval,
++ EXT3_MMP_MIN_CHECK_INTERVAL);
++ mmp->mmp_check_interval = cpu_to_le16(mmp_check_interval);
++ bdevname(bh->b_bdev, mmp->mmp_bdevname);
++
++ down_read(&uts_sem);
++ memcpy(mmp->mmp_nodename, system_utsname.nodename,
++ sizeof(mmp->mmp_nodename));
++ up_read(&uts_sem);
++
++ while (!kthread_should_stop()) {
++ if (++seq > EXT3_MMP_SEQ_MAX)
++ seq = 1;
++
++ mmp->mmp_seq = cpu_to_le32(seq);
++ mmp->mmp_time = cpu_to_le64(get_seconds());
++ last_update_time = jiffies;
++
++ retval = write_mmp_block(bh);
++ /*
++ * Don't spew too many error messages. Print one every
++ * (s_mmp_update_interval * 60) seconds.
++ */
++ if (retval && (failed_writes % 60) == 0) {
++ ext3_error(sb, __FUNCTION__,
++ "Error writing to MMP block");
++ failed_writes++;
++ }
++
++ if (!(le32_to_cpu(es->s_feature_incompat) &
++ EXT3_FEATURE_INCOMPAT_MMP)) {
++ ext3_warning(sb, __FUNCTION__, "kmmpd being stopped "
++ "since MMP feature has been disabled.");
++ EXT3_SB(sb)->s_mmp_tsk = 0;
++ goto failed;
++ }
++
++ if (sb->s_flags & MS_RDONLY) {
++ ext3_warning(sb, __FUNCTION__, "kmmpd being stopped "
++ "since filesystem has been remounted as "
++ "readonly.");
++ EXT3_SB(sb)->s_mmp_tsk = 0;
++ goto failed;
++ }
++
++ diff = jiffies - last_update_time;
++ if (diff < mmp_update_interval * HZ) {
++ set_current_state(TASK_INTERRUPTIBLE);
++ schedule_timeout(EXT3_MMP_UPDATE_INTERVAL * HZ - diff);
++ }
++
++ /*
++ * We need to make sure that more than mmp_check_interval
++ * seconds have not passed since writing. If that has happened
++ * we need to check if the MMP block is as we left it.
++ */
++ diff = jiffies - last_update_time;
++ if (diff > mmp_check_interval * HZ) {
++ struct buffer_head *bh_check = NULL;
++ struct mmp_struct *mmp_check;
++
++ retval = read_mmp_block(sb, &bh_check, mmp_block);
++ if (retval) {
++ EXT3_SB(sb)->s_mmp_tsk = 0;
++ goto failed;
++ }
++
++ mmp_check = (struct mmp_struct *)(bh_check->b_data);
++ if (mmp->mmp_time != mmp_check->mmp_time ||
++ memcmp(mmp->mmp_nodename, mmp_check->mmp_nodename,
++ sizeof(mmp->mmp_nodename)))
++ dump_mmp_msg(sb, mmp_check, __FUNCTION__,
++ "Error while updating MMP info. "
++ "The filesystem seems to have "
++ "been multiply mounted.");
++
++ put_bh(bh_check);
++ }
++
++ /*
++ * Adjust the mmp_check_interval depending on how much time
++ * it took for the MMP block to be written.
++ */
++ mmp_check_interval = max(5 * diff / HZ,
++ (unsigned long) EXT3_MMP_MIN_CHECK_INTERVAL);
++ mmp->mmp_check_interval = cpu_to_le16(mmp_check_interval);
++ }
++
++ /*
++ * Unmount seems to be clean.
++ */
++ mmp->mmp_seq = cpu_to_le32(EXT3_MMP_SEQ_CLEAN);
++ mmp->mmp_time = cpu_to_le64(get_seconds());
++
++ retval = write_mmp_block(bh);
++
++failed:
++ brelse(bh);
++ return retval;
++}
++
++/*
++ * Get a random new sequence number but make sure it is not greater than
++ * EXT3_MMP_SEQ_MAX.
++ */
++static unsigned int mmp_new_seq(void)
++{
++ u32 new_seq;
++
++ do {
++ get_random_bytes(&new_seq, sizeof(u32));
++ } while (new_seq > EXT3_MMP_SEQ_MAX);
++
++ return new_seq;
++}
++
++/*
++ * Protect the filesystem from being mounted more than once.
++ */
++static int ext3_multi_mount_protect(struct super_block *sb,
++ unsigned long mmp_block)
++{
++ struct ext3_super_block *es = EXT3_SB(sb)->s_es;
++ struct buffer_head *bh = NULL;
++ struct mmp_struct *mmp = NULL;
++ u32 seq;
++ unsigned int mmp_check_interval = le16_to_cpu(es->s_mmp_update_interval);
++ int retval;
++
++ if (mmp_block < le32_to_cpu(es->s_first_data_block) ||
++ mmp_block >= le32_to_cpu(es->s_blocks_count)) {
++ ext3_warning(sb, __FUNCTION__,
++ "Invalid MMP block in superblock");
++ goto failed;
++ }
++
++ retval = read_mmp_block(sb, &bh, mmp_block);
++ if (retval)
++ goto failed;
++
++ mmp = (struct mmp_struct *)(bh->b_data);
++
++ if (mmp_check_interval < EXT3_MMP_MIN_CHECK_INTERVAL)
++ mmp_check_interval = EXT3_MMP_MIN_CHECK_INTERVAL;
++
++ /*
++ * If check_interval in MMP block is larger, use that instead of
++ * update_interval from the superblock.
++ */
++ if (mmp->mmp_check_interval > mmp_check_interval)
++ mmp_check_interval = mmp->mmp_check_interval;
++
++ seq = le32_to_cpu(mmp->mmp_seq);
++ if (seq == EXT3_MMP_SEQ_CLEAN)
++ goto skip;
++
++ if (seq == EXT3_MMP_SEQ_FSCK) {
++ dump_mmp_msg(sb, mmp, __FUNCTION__,
++ "fsck is running on the filesystem");
++ goto failed;
++ }
++
++ schedule_timeout_uninterruptible(HZ * (2 * mmp_check_interval + 1));
++
++ retval = read_mmp_block(sb, &bh, mmp_block);
++ if (retval)
++ goto failed;
++ mmp = (struct mmp_struct *)(bh->b_data);
++ if (seq != le32_to_cpu(mmp->mmp_seq)) {
++ dump_mmp_msg(sb, mmp, __FUNCTION__,
++ "Device is already active on another node.");
++ goto failed;
++ }
++
++skip:
++ /*
++ * write a new random sequence number.
++ */
++ mmp->mmp_seq = seq = cpu_to_le32(mmp_new_seq());
++
++ retval = write_mmp_block(bh);
++ if (retval)
++ goto failed;
++
++ /*
++ * wait for MMP interval and check mmp_seq.
++ */
++ schedule_timeout_uninterruptible(HZ * (2 * mmp_check_interval + 1));
++
++ retval = read_mmp_block(sb, &bh, mmp_block);
++ if (retval)
++ goto failed;
++ mmp = (struct mmp_struct *)(bh->b_data);
++ if (seq != le32_to_cpu(mmp->mmp_seq)) {
++ dump_mmp_msg(sb, mmp, __FUNCTION__,
++ "Device is already active on another node.");
++ goto failed;
++ }
++
++ /*
++ * Start a kernel thread to update the MMP block periodically.
++ */
++ EXT3_SB(sb)->s_mmp_tsk = kthread_run(kmmpd, sb, "kmmpd-%02x:%02x",
++ MAJOR(sb->s_dev),
++ MINOR(sb->s_dev));
++ if (IS_ERR(EXT3_SB(sb)->s_mmp_tsk)) {
++ EXT3_SB(sb)->s_mmp_tsk = 0;
++ ext3_warning(sb, __FUNCTION__, "Unable to create kmmpd thread "
++ "for %s.", sb->s_id);
++ goto failed;
++ }
++
++ brelse(bh);
++ return 0;
++
++failed:
++ brelse(bh);
++ return 1;
++}
++
+
+ static int ext3_fill_super (struct super_block *sb, void *data, int silent)
+ {
+@@ -1738,6 +2051,11 @@ static int ext3_fill_super (struct super
+ EXT3_HAS_INCOMPAT_FEATURE(sb,
+ EXT3_FEATURE_INCOMPAT_RECOVER));
+
++ if (EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_MMP) &&
++ !(sb->s_flags & MS_RDONLY))
++ if (ext3_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
++ goto failed_mount3;
++
+ /*
+ * The first inode we look at is the journal inode. Don't try
+ * root first: it may be modified in the journal!
+@@ -2371,6 +2689,11 @@ int ext3_remount (struct super_block * s
+ return ret;
+ if (!ext3_setup_super (sb, es, 0))
+ sb->s_flags &= ~MS_RDONLY;
++ if (EXT3_HAS_INCOMPAT_FEATURE(sb,
++ EXT3_FEATURE_INCOMPAT_MMP))
++ if (ext3_multi_mount_protect(sb,
++ le64_to_cpu(es->s_mmp_block)))
++ return -EROFS;
+ }
+ }
+ return 0;
+Index: linux-2.6.9/include/linux/ext3_fs.h
+===================================================================
+--- linux-2.6.9.orig/include/linux/ext3_fs.h
++++ linux-2.6.9/include/linux/ext3_fs.h
+@@ -577,13 +577,17 @@ struct ext3_super_block {
+ __le32 s_first_meta_bg; /* First metablock block group */
+ __le32 s_mkfs_time; /* When the filesystem was created */
+ __le32 s_jnl_blocks[17]; /* Backup of the journal inode */
+- __le32 s_blocks_count_hi; /* Blocks count high 32 bits */
++/*150*/ __le32 s_blocks_count_hi; /* Blocks count high 32 bits */
+ __le32 s_r_blocks_count_hi; /* Reserved blocks count high 32 bits*/
+ __le32 s_free_blocks_hi; /* Free blocks count high 32 bits */
+ __le16 s_min_extra_isize; /* All inodes have at least # bytes */
+ __le16 s_want_extra_isize; /* New inodes should reserve # bytes */
+- __le32 s_flags; /* Miscellaneous flags */
+- __u32 s_reserved[167]; /* Padding to the end of the block */
++/*160*/ __le32 s_flags; /* Miscellaneous flags */
++ __le16 s_raid_stride; /* RAID stride */
++ __le16 s_mmp_update_interval; /* # seconds to wait in MMP checking */
++ __le64 s_mmp_block; /* Block for multi-mount protection */
++/*170*/ __le32 s_raid_stripe_width; /* blocks on all data disks (N*stride)*/
++ __le32 s_reserved[163]; /* Padding to the end of the block */
+ };
+
+ #ifdef __KERNEL__
+@@ -667,12 +671,14 @@ static inline struct ext3_inode_info *EX
+ #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008 /* Journal device */
+ #define EXT3_FEATURE_INCOMPAT_META_BG 0x0010
+ #define EXT3_FEATURE_INCOMPAT_EXTENTS 0x0040 /* extents support */
++#define EXT3_FEATURE_INCOMPAT_MMP 0x0100
+
+ #define EXT3_FEATURE_COMPAT_SUPP EXT2_FEATURE_COMPAT_EXT_ATTR
+ #define EXT3_FEATURE_INCOMPAT_SUPP (EXT3_FEATURE_INCOMPAT_FILETYPE| \
+ EXT3_FEATURE_INCOMPAT_RECOVER| \
+ EXT3_FEATURE_INCOMPAT_META_BG| \
+- EXT3_FEATURE_INCOMPAT_EXTENTS)
++ EXT3_FEATURE_INCOMPAT_EXTENTS| \
++ EXT3_FEATURE_INCOMPAT_MMP)
+ #define EXT3_FEATURE_RO_COMPAT_SUPP (EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER| \
+ EXT3_FEATURE_RO_COMPAT_LARGE_FILE| \
+ EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
+@@ -832,6 +838,39 @@ struct dir_private_info {
+ #define ERR_BAD_DX_DIR -75000
+
+ /*
++ * This structure will be used for multiple mount protection. It will be
++ * written into the block number saved in the s_mmp_block field in the
++ * superblock. Programs that check MMP should assume that if
++ * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
++ * to use the filesystem, regardless of how old the timestamp is.
++ */
++#define EXT3_MMP_MAGIC 0x004D4D50U /* ASCII for MMP */
++#define EXT3_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
++#define EXT3_MMP_SEQ_FSCK 0xE24D4D50U /* mmp_seq value when being fscked */
++#define EXT3_MMP_SEQ_MAX 0xE24D4D4FU /* maximum valid mmp_seq value */
++
++struct mmp_struct {
++ __le32 mmp_magic;
++ __le32 mmp_seq;
++ __le64 mmp_time;
++ char mmp_nodename[64];
++ char mmp_bdevname[32];
++ __le16 mmp_check_interval;
++ __le16 mmp_pad1;
++ __le32 mmp_pad2[227];
++};
++
++/*
++ * Default interval in seconds to update the MMP sequence number.
++ */
++#define EXT3_MMP_UPDATE_INTERVAL 1
++
++/*
++ * Minimum interval for MMP checking in seconds.
++ */
++#define EXT3_MMP_MIN_CHECK_INTERVAL 5
++
++/*
+ * Function prototypes
+ */
+
+Index: linux-2.6.9/include/linux/ext3_fs_sb.h
+===================================================================
+--- linux-2.6.9.orig/include/linux/ext3_fs_sb.h
++++ linux-2.6.9/include/linux/ext3_fs_sb.h
+@@ -143,6 +143,7 @@ struct ext3_sb_info {
+ /* locality groups */
+ struct ext3_locality_group *s_locality_groups;
+
++ struct task_struct *s_mmp_tsk; /* Kernel thread for multiple mount protection */
+ };
+
+ #define EXT3_GROUP_INFO(sb, group) \
--- /dev/null
+Index: linux-2.6.16.46-0.14/fs/ext3/super.c
+===================================================================
+--- linux-2.6.16.46-0.14.orig/fs/ext3/super.c
++++ linux-2.6.16.46-0.14/fs/ext3/super.c
+@@ -36,6 +36,8 @@
+ #include <linux/namei.h>
+ #include <linux/quotaops.h>
+ #include <linux/seq_file.h>
++#include <linux/kthread.h>
++#include <linux/utsname.h>
+
+ #include <asm/uaccess.h>
+
+@@ -436,6 +438,9 @@ static void ext3_put_super (struct super
+ invalidate_bdev(sbi->journal_bdev, 0);
+ ext3_blkdev_remove(sbi);
+ }
++ if (sbi->s_mmp_tsk)
++ kthread_stop(sbi->s_mmp_tsk);
++
+ sb->s_fs_info = NULL;
+ kfree(sbi);
+ return;
+@@ -1521,6 +1526,313 @@ static unsigned long descriptor_loc(stru
+ return (first_data_block + has_super + (bg * sbi->s_blocks_per_group));
+ }
+
++/*
++ * Write the MMP block using WRITE_SYNC to try to get the block on-disk
++ * faster.
++ */
++static int write_mmp_block(struct buffer_head *bh)
++{
++ mark_buffer_dirty(bh);
++ lock_buffer(bh);
++ bh->b_end_io = end_buffer_write_sync;
++ get_bh(bh);
++ submit_bh(WRITE_SYNC, bh);
++ wait_on_buffer(bh);
++ if (unlikely(!buffer_uptodate(bh)))
++ return 1;
++
++ return 0;
++}
++
++/*
++ * Read the MMP block. It _must_ be read from disk and hence we clear the
++ * uptodate flag on the buffer.
++ */
++static int read_mmp_block(struct super_block *sb, struct buffer_head **bh,
++ unsigned long mmp_block)
++{
++ struct mmp_struct *mmp;
++
++ if (*bh)
++ clear_buffer_uptodate(*bh);
++
++ brelse(*bh);
++
++ *bh = sb_bread(sb, mmp_block);
++ if (!*bh) {
++ ext3_warning(sb, __FUNCTION__,
++ "Error while reading MMP block %lu", mmp_block);
++ return -EIO;
++ }
++
++ mmp = (struct mmp_struct *)((*bh)->b_data);
++ if (le32_to_cpu(mmp->mmp_magic) != EXT3_MMP_MAGIC)
++ return -EINVAL;
++
++ return 0;
++}
++
++/*
++ * Dump as much information as possible to help the admin.
++ */
++static void dump_mmp_msg(struct super_block *sb, struct mmp_struct *mmp,
++ const char *function, const char *msg)
++{
++ ext3_warning(sb, function, msg);
++ ext3_warning(sb, function, "MMP failure info: last update time: %llu, "
++ "last update node: %s, last update device: %s\n",
++ le64_to_cpu(mmp->mmp_time), mmp->mmp_nodename,
++ mmp->mmp_bdevname);
++}
++
++/*
++ * kmmpd will update the MMP sequence every s_mmp_update_interval seconds
++ */
++static int kmmpd(void *data)
++{
++ struct super_block *sb = (struct super_block *) data;
++ struct ext3_super_block *es = EXT3_SB(sb)->s_es;
++ struct buffer_head *bh = NULL;
++ struct mmp_struct *mmp;
++ unsigned long mmp_block;
++ u32 seq = 0;
++ unsigned long failed_writes = 0;
++ int mmp_update_interval = le16_to_cpu(es->s_mmp_update_interval);
++ unsigned mmp_check_interval;
++ unsigned long last_update_time;
++ unsigned long diff;
++ int retval;
++
++ mmp_block = le64_to_cpu(es->s_mmp_block);
++ retval = read_mmp_block(sb, &bh, mmp_block);
++ if (retval)
++ goto failed;
++
++ mmp = (struct mmp_struct *)(bh->b_data);
++ mmp->mmp_time = cpu_to_le64(get_seconds());
++ /*
++ * Start with the higher mmp_check_interval and reduce it if
++ * the MMP block is being updated on time.
++ */
++ mmp_check_interval = max(5 * mmp_update_interval,
++ EXT3_MMP_MIN_CHECK_INTERVAL);
++ mmp->mmp_check_interval = cpu_to_le16(mmp_check_interval);
++ bdevname(bh->b_bdev, mmp->mmp_bdevname);
++
++ down_read(&uts_sem);
++ memcpy(mmp->mmp_nodename, system_utsname.nodename,
++ sizeof(mmp->mmp_nodename));
++ up_read(&uts_sem);
++
++ while (!kthread_should_stop()) {
++ if (++seq > EXT3_MMP_SEQ_MAX)
++ seq = 1;
++
++ mmp->mmp_seq = cpu_to_le32(seq);
++ mmp->mmp_time = cpu_to_le64(get_seconds());
++ last_update_time = jiffies;
++
++ retval = write_mmp_block(bh);
++ /*
++ * Don't spew too many error messages. Print one every
++ * (s_mmp_update_interval * 60) seconds.
++ */
++ if (retval && (failed_writes % 60) == 0) {
++ ext3_error(sb, __FUNCTION__,
++ "Error writing to MMP block");
++ failed_writes++;
++ }
++
++ if (!(le32_to_cpu(es->s_feature_incompat) &
++ EXT3_FEATURE_INCOMPAT_MMP)) {
++ ext3_warning(sb, __FUNCTION__, "kmmpd being stopped "
++ "since MMP feature has been disabled.");
++ EXT3_SB(sb)->s_mmp_tsk = 0;
++ goto failed;
++ }
++
++ if (sb->s_flags & MS_RDONLY) {
++ ext3_warning(sb, __FUNCTION__, "kmmpd being stopped "
++ "since filesystem has been remounted as "
++ "readonly.");
++ EXT3_SB(sb)->s_mmp_tsk = 0;
++ goto failed;
++ }
++
++ diff = jiffies - last_update_time;
++ if (diff < mmp_update_interval * HZ)
++ schedule_timeout_interruptible(EXT3_MMP_UPDATE_INTERVAL*
++ HZ - diff);
++
++ /*
++ * We need to make sure that more than mmp_check_interval
++ * seconds have not passed since writing. If that has happened
++ * we need to check if the MMP block is as we left it.
++ */
++ diff = jiffies - last_update_time;
++ if (diff > mmp_check_interval * HZ) {
++ struct buffer_head *bh_check = NULL;
++ struct mmp_struct *mmp_check;
++
++ retval = read_mmp_block(sb, &bh_check, mmp_block);
++ if (retval) {
++ EXT3_SB(sb)->s_mmp_tsk = 0;
++ goto failed;
++ }
++
++ mmp_check = (struct mmp_struct *)(bh_check->b_data);
++ if (mmp->mmp_time != mmp_check->mmp_time ||
++ memcmp(mmp->mmp_nodename, mmp_check->mmp_nodename,
++ sizeof(mmp->mmp_nodename)))
++ dump_mmp_msg(sb, mmp_check, __FUNCTION__,
++ "Error while updating MMP info. "
++ "The filesystem seems to have "
++ "been multiply mounted.");
++
++ put_bh(bh_check);
++ }
++
++ /*
++ * Adjust the mmp_check_interval depending on how much time
++ * it took for the MMP block to be written.
++ */
++ mmp_check_interval = max(5 * diff / HZ,
++ (unsigned long) EXT3_MMP_MIN_CHECK_INTERVAL);
++ mmp->mmp_check_interval = cpu_to_le16(mmp_check_interval);
++ }
++
++ /*
++ * Unmount seems to be clean.
++ */
++ mmp->mmp_seq = cpu_to_le32(EXT3_MMP_SEQ_CLEAN);
++ mmp->mmp_time = cpu_to_le64(get_seconds());
++
++ retval = write_mmp_block(bh);
++
++failed:
++ brelse(bh);
++ return retval;
++}
++
++/*
++ * Get a random new sequence number but make sure it is not greater than
++ * EXT3_MMP_SEQ_MAX.
++ */
++static unsigned int mmp_new_seq(void)
++{
++ u32 new_seq;
++
++ do {
++ get_random_bytes(&new_seq, sizeof(u32));
++ } while (new_seq > EXT3_MMP_SEQ_MAX);
++
++ return new_seq;
++}
++
++/*
++ * Protect the filesystem from being mounted more than once.
++ */
++static int ext3_multi_mount_protect(struct super_block *sb,
++ unsigned long mmp_block)
++{
++ struct ext3_super_block *es = EXT3_SB(sb)->s_es;
++ struct buffer_head *bh = NULL;
++ struct mmp_struct *mmp = NULL;
++ u32 seq;
++ unsigned int mmp_check_interval = le16_to_cpu(es->s_mmp_update_interval);
++ int retval;
++
++ if (mmp_block < le32_to_cpu(es->s_first_data_block) ||
++ mmp_block >= le32_to_cpu(es->s_blocks_count)) {
++ ext3_warning(sb, __FUNCTION__,
++ "Invalid MMP block in superblock");
++ goto failed;
++ }
++
++ retval = read_mmp_block(sb, &bh, mmp_block);
++ if (retval)
++ goto failed;
++
++ mmp = (struct mmp_struct *)(bh->b_data);
++
++ if (mmp_check_interval < EXT3_MMP_MIN_CHECK_INTERVAL)
++ mmp_check_interval = EXT3_MMP_MIN_CHECK_INTERVAL;
++
++ /*
++ * If check_interval in MMP block is larger, use that instead of
++ * update_interval from the superblock.
++ */
++ if (mmp->mmp_check_interval > mmp_check_interval)
++ mmp_check_interval = mmp->mmp_check_interval;
++
++ seq = le32_to_cpu(mmp->mmp_seq);
++ if (seq == EXT3_MMP_SEQ_CLEAN)
++ goto skip;
++
++ if (seq == EXT3_MMP_SEQ_FSCK) {
++ dump_mmp_msg(sb, mmp, __FUNCTION__,
++ "fsck is running on the filesystem");
++ goto failed;
++ }
++
++ schedule_timeout_uninterruptible(HZ * (2 * mmp_check_interval + 1));
++
++ retval = read_mmp_block(sb, &bh, mmp_block);
++ if (retval)
++ goto failed;
++ mmp = (struct mmp_struct *)(bh->b_data);
++ if (seq != le32_to_cpu(mmp->mmp_seq)) {
++ dump_mmp_msg(sb, mmp, __FUNCTION__,
++ "Device is already active on another node.");
++ goto failed;
++ }
++
++skip:
++ /*
++ * write a new random sequence number.
++ */
++ mmp->mmp_seq = seq = cpu_to_le32(mmp_new_seq());
++
++ retval = write_mmp_block(bh);
++ if (retval)
++ goto failed;
++
++ /*
++ * wait for MMP interval and check mmp_seq.
++ */
++ schedule_timeout_uninterruptible(HZ * (2 * mmp_check_interval + 1));
++
++ retval = read_mmp_block(sb, &bh, mmp_block);
++ if (retval)
++ goto failed;
++ mmp = (struct mmp_struct *)(bh->b_data);
++ if (seq != le32_to_cpu(mmp->mmp_seq)) {
++ dump_mmp_msg(sb, mmp, __FUNCTION__,
++ "Device is already active on another node.");
++ goto failed;
++ }
++
++ /*
++ * Start a kernel thread to update the MMP block periodically.
++ */
++ EXT3_SB(sb)->s_mmp_tsk = kthread_run(kmmpd, sb, "kmmpd-%02x:%02x",
++ MAJOR(sb->s_dev),
++ MINOR(sb->s_dev));
++ if (IS_ERR(EXT3_SB(sb)->s_mmp_tsk)) {
++ EXT3_SB(sb)->s_mmp_tsk = 0;
++ ext3_warning(sb, __FUNCTION__, "Unable to create kmmpd thread "
++ "for %s.", sb->s_id);
++ goto failed;
++ }
++
++ brelse(bh);
++ return 0;
++
++failed:
++ brelse(bh);
++ return 1;
++}
++
+
+ static int ext3_fill_super (struct super_block *sb, void *data, int silent)
+ {
+@@ -1828,6 +2140,11 @@ static int ext3_fill_super (struct super
+ EXT3_HAS_INCOMPAT_FEATURE(sb,
+ EXT3_FEATURE_INCOMPAT_RECOVER));
+
++ if (EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_MMP) &&
++ !(sb->s_flags & MS_RDONLY))
++ if (ext3_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
++ goto failed_mount3;
++
+ /*
+ * The first inode we look at is the journal inode. Don't try
+ * root first: it may be modified in the journal!
+@@ -2438,7 +2755,7 @@ static int ext3_remount (struct super_bl
+ unsigned long n_blocks_count = 0;
+ unsigned long old_sb_flags;
+ struct ext3_mount_options old_opts;
+- int err;
++ int err = 0;
+ #ifdef CONFIG_QUOTA
+ int i;
+ #endif
+@@ -2522,6 +2839,11 @@ static int ext3_remount (struct super_bl
+ }
+ if (!ext3_setup_super (sb, es, 0))
+ sb->s_flags &= ~MS_RDONLY;
++ if (EXT3_HAS_INCOMPAT_FEATURE(sb,
++ EXT3_FEATURE_INCOMPAT_MMP))
++ if (ext3_multi_mount_protect(sb,
++ le64_to_cpu(es->s_mmp_block)))
++ goto restore_opts;
+ }
+ }
+ #ifdef CONFIG_QUOTA
+Index: linux-2.6.16.46-0.14/include/linux/ext3_fs.h
+===================================================================
+--- linux-2.6.16.46-0.14.orig/include/linux/ext3_fs.h
++++ linux-2.6.16.46-0.14/include/linux/ext3_fs.h
+@@ -599,13 +599,17 @@ struct ext3_super_block {
+ __le32 s_first_meta_bg; /* First metablock block group */
+ __le32 s_mkfs_time; /* When the filesystem was created */
+ __le32 s_jnl_blocks[17]; /* Backup of the journal inode */
+- __le32 s_blocks_count_hi; /* Blocks count high 32 bits */
++/*150*/ __le32 s_blocks_count_hi; /* Blocks count high 32 bits */
+ __le32 s_r_blocks_count_hi; /* Reserved blocks count high 32 bits*/
+ __le32 s_free_blocks_hi; /* Free blocks count high 32 bits */
+ __le16 s_min_extra_isize; /* All inodes have at least # bytes */
+ __le16 s_want_extra_isize; /* New inodes should reserve # bytes */
+- __le32 s_flags; /* Miscellaneous flags */
+- __u32 s_reserved[167]; /* Padding to the end of the block */
++/*160*/ __le32 s_flags; /* Miscellaneous flags */
++ __le16 s_raid_stride; /* RAID stride */
++ __le16 s_mmp_update_interval; /* # seconds to wait in MMP checking */
++ __le64 s_mmp_block; /* Block for multi-mount protection */
++/*170*/ __le32 s_raid_stripe_width; /* blocks on all data disks (N*stride)*/
++ __le32 s_reserved[163]; /* Padding to the end of the block */
+ };
+
+ #ifdef __KERNEL__
+@@ -699,12 +703,14 @@ static inline int ext3_valid_inum(struct
+ #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008 /* Journal device */
+ #define EXT3_FEATURE_INCOMPAT_META_BG 0x0010
+ #define EXT3_FEATURE_INCOMPAT_EXTENTS 0x0040 /* extents support */
++#define EXT3_FEATURE_INCOMPAT_MMP 0x0100
+
+ #define EXT3_FEATURE_COMPAT_SUPP EXT2_FEATURE_COMPAT_EXT_ATTR
+ #define EXT3_FEATURE_INCOMPAT_SUPP (EXT3_FEATURE_INCOMPAT_FILETYPE| \
+ EXT3_FEATURE_INCOMPAT_RECOVER| \
+ EXT3_FEATURE_INCOMPAT_META_BG| \
+- EXT3_FEATURE_INCOMPAT_EXTENTS)
++ EXT3_FEATURE_INCOMPAT_EXTENTS| \
++ EXT3_FEATURE_INCOMPAT_MMP)
+ #define EXT3_FEATURE_RO_COMPAT_SUPP (EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER| \
+ EXT3_FEATURE_RO_COMPAT_LARGE_FILE| \
+ EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
+@@ -864,6 +870,39 @@ struct dir_private_info {
+ #define ERR_BAD_DX_DIR -75000
+
+ /*
++ * This structure will be used for multiple mount protection. It will be
++ * written into the block number saved in the s_mmp_block field in the
++ * superblock. Programs that check MMP should assume that if
++ * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
++ * to use the filesystem, regardless of how old the timestamp is.
++ */
++#define EXT3_MMP_MAGIC 0x004D4D50U /* ASCII for MMP */
++#define EXT3_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
++#define EXT3_MMP_SEQ_FSCK 0xE24D4D50U /* mmp_seq value when being fscked */
++#define EXT3_MMP_SEQ_MAX 0xE24D4D4FU /* maximum valid mmp_seq value */
++
++struct mmp_struct {
++ __le32 mmp_magic;
++ __le32 mmp_seq;
++ __le64 mmp_time;
++ char mmp_nodename[64];
++ char mmp_bdevname[32];
++ __le16 mmp_check_interval;
++ __le16 mmp_pad1;
++ __le32 mmp_pad2[227];
++};
++
++/*
++ * Default interval in seconds to update the MMP sequence number.
++ */
++#define EXT3_MMP_UPDATE_INTERVAL 1
++
++/*
++ * Minimum interval for MMP checking in seconds.
++ */
++#define EXT3_MMP_MIN_CHECK_INTERVAL 5
++
++/*
+ * Function prototypes
+ */
+
+Index: linux-2.6.16.46-0.14/include/linux/ext3_fs_sb.h
+===================================================================
+--- linux-2.6.16.46-0.14.orig/include/linux/ext3_fs_sb.h
++++ linux-2.6.16.46-0.14/include/linux/ext3_fs_sb.h
+@@ -140,6 +140,7 @@ struct ext3_sb_info {
+ /* locality groups */
+ struct ext3_locality_group *s_locality_groups;
+
++ struct task_struct *s_mmp_tsk; /* Kernel thread for multiple mount protection */
+ };
+
+ #define EXT3_GROUP_INFO(sb, group) \
--- /dev/null
+Index: linux-2.6.18/fs/ext3/super.c
+===================================================================
+--- linux-2.6.18.orig/fs/ext3/super.c
++++ linux-2.6.18/fs/ext3/super.c
+@@ -35,6 +35,8 @@
+ #include <linux/namei.h>
+ #include <linux/quotaops.h>
+ #include <linux/seq_file.h>
++#include <linux/kthread.h>
++#include <linux/utsname.h>
+
+ #include <asm/uaccess.h>
+
+@@ -435,6 +437,9 @@ static void ext3_put_super (struct super
+ invalidate_bdev(sbi->journal_bdev, 0);
+ ext3_blkdev_remove(sbi);
+ }
++ if (sbi->s_mmp_tsk)
++ kthread_stop(sbi->s_mmp_tsk);
++
+ sb->s_fs_info = NULL;
+ kfree(sbi);
+ return;
+@@ -1528,6 +1533,313 @@ static ext3_fsblk_t descriptor_loc(struc
+ return (has_super + ext3_group_first_block_no(sb, bg));
+ }
+
++/*
++ * Write the MMP block using WRITE_SYNC to try to get the block on-disk
++ * faster.
++ */
++static int write_mmp_block(struct buffer_head *bh)
++{
++ mark_buffer_dirty(bh);
++ lock_buffer(bh);
++ bh->b_end_io = end_buffer_write_sync;
++ get_bh(bh);
++ submit_bh(WRITE_SYNC, bh);
++ wait_on_buffer(bh);
++ if (unlikely(!buffer_uptodate(bh)))
++ return 1;
++
++ return 0;
++}
++
++/*
++ * Read the MMP block. It _must_ be read from disk and hence we clear the
++ * uptodate flag on the buffer.
++ */
++static int read_mmp_block(struct super_block *sb, struct buffer_head **bh,
++ unsigned long mmp_block)
++{
++ struct mmp_struct *mmp;
++
++ if (*bh)
++ clear_buffer_uptodate(*bh);
++
++ brelse(*bh);
++
++ *bh = sb_bread(sb, mmp_block);
++ if (!*bh) {
++ ext3_warning(sb, __FUNCTION__,
++ "Error while reading MMP block %lu", mmp_block);
++ return -EIO;
++ }
++
++ mmp = (struct mmp_struct *)((*bh)->b_data);
++ if (le32_to_cpu(mmp->mmp_magic) != EXT3_MMP_MAGIC)
++ return -EINVAL;
++
++ return 0;
++}
++
++/*
++ * Dump as much information as possible to help the admin.
++ */
++static void dump_mmp_msg(struct super_block *sb, struct mmp_struct *mmp,
++ const char *function, const char *msg)
++{
++ ext3_warning(sb, function, msg);
++ ext3_warning(sb, function, "MMP failure info: last update time: %llu, "
++ "last update node: %s, last update device: %s\n",
++ le64_to_cpu(mmp->mmp_time), mmp->mmp_nodename,
++ mmp->mmp_bdevname);
++}
++
++/*
++ * kmmpd will update the MMP sequence every s_mmp_update_interval seconds
++ */
++static int kmmpd(void *data)
++{
++ struct super_block *sb = (struct super_block *) data;
++ struct ext3_super_block *es = EXT3_SB(sb)->s_es;
++ struct buffer_head *bh = NULL;
++ struct mmp_struct *mmp;
++ unsigned long mmp_block;
++ u32 seq = 0;
++ unsigned long failed_writes = 0;
++ int mmp_update_interval = le16_to_cpu(es->s_mmp_update_interval);
++ unsigned mmp_check_interval;
++ unsigned long last_update_time;
++ unsigned long diff;
++ int retval;
++
++ mmp_block = le64_to_cpu(es->s_mmp_block);
++ retval = read_mmp_block(sb, &bh, mmp_block);
++ if (retval)
++ goto failed;
++
++ mmp = (struct mmp_struct *)(bh->b_data);
++ mmp->mmp_time = cpu_to_le64(get_seconds());
++ /*
++ * Start with the higher mmp_check_interval and reduce it if
++ * the MMP block is being updated on time.
++ */
++ mmp_check_interval = max(5 * mmp_update_interval,
++ EXT3_MMP_MIN_CHECK_INTERVAL);
++ mmp->mmp_check_interval = cpu_to_le16(mmp_check_interval);
++ bdevname(bh->b_bdev, mmp->mmp_bdevname);
++
++ down_read(&uts_sem);
++ memcpy(mmp->mmp_nodename, system_utsname.nodename,
++ sizeof(mmp->mmp_nodename));
++ up_read(&uts_sem);
++
++ while (!kthread_should_stop()) {
++ if (++seq > EXT3_MMP_SEQ_MAX)
++ seq = 1;
++
++ mmp->mmp_seq = cpu_to_le32(seq);
++ mmp->mmp_time = cpu_to_le64(get_seconds());
++ last_update_time = jiffies;
++
++ retval = write_mmp_block(bh);
++ /*
++ * Don't spew too many error messages. Print one every
++ * (s_mmp_update_interval * 60) seconds.
++ */
++ if (retval && (failed_writes % 60) == 0) {
++ ext3_error(sb, __FUNCTION__,
++ "Error writing to MMP block");
++ failed_writes++;
++ }
++
++ if (!(le32_to_cpu(es->s_feature_incompat) &
++ EXT3_FEATURE_INCOMPAT_MMP)) {
++ ext3_warning(sb, __FUNCTION__, "kmmpd being stopped "
++ "since MMP feature has been disabled.");
++ EXT3_SB(sb)->s_mmp_tsk = 0;
++ goto failed;
++ }
++
++ if (sb->s_flags & MS_RDONLY) {
++ ext3_warning(sb, __FUNCTION__, "kmmpd being stopped "
++ "since filesystem has been remounted as "
++ "readonly.");
++ EXT3_SB(sb)->s_mmp_tsk = 0;
++ goto failed;
++ }
++
++ diff = jiffies - last_update_time;
++ if (diff < mmp_update_interval * HZ)
++ schedule_timeout_interruptible(EXT3_MMP_UPDATE_INTERVAL*
++ HZ - diff);
++
++ /*
++ * We need to make sure that more than mmp_check_interval
++ * seconds have not passed since writing. If that has happened
++ * we need to check if the MMP block is as we left it.
++ */
++ diff = jiffies - last_update_time;
++ if (diff > mmp_check_interval * HZ) {
++ struct buffer_head *bh_check = NULL;
++ struct mmp_struct *mmp_check;
++
++ retval = read_mmp_block(sb, &bh_check, mmp_block);
++ if (retval) {
++ EXT3_SB(sb)->s_mmp_tsk = 0;
++ goto failed;
++ }
++
++ mmp_check = (struct mmp_struct *)(bh_check->b_data);
++ if (mmp->mmp_time != mmp_check->mmp_time ||
++ memcmp(mmp->mmp_nodename, mmp_check->mmp_nodename,
++ sizeof(mmp->mmp_nodename)))
++ dump_mmp_msg(sb, mmp_check, __FUNCTION__,
++ "Error while updating MMP info. "
++ "The filesystem seems to have "
++ "been multiply mounted.");
++
++ put_bh(bh_check);
++ }
++
++ /*
++ * Adjust the mmp_check_interval depending on how much time
++ * it took for the MMP block to be written.
++ */
++ mmp_check_interval = max(5 * diff / HZ,
++ (unsigned long) EXT3_MMP_MIN_CHECK_INTERVAL);
++ mmp->mmp_check_interval = cpu_to_le16(mmp_check_interval);
++ }
++
++ /*
++ * Unmount seems to be clean.
++ */
++ mmp->mmp_seq = cpu_to_le32(EXT3_MMP_SEQ_CLEAN);
++ mmp->mmp_time = cpu_to_le64(get_seconds());
++
++ retval = write_mmp_block(bh);
++
++failed:
++ brelse(bh);
++ return retval;
++}
++
++/*
++ * Get a random new sequence number but make sure it is not greater than
++ * EXT3_MMP_SEQ_MAX.
++ */
++static unsigned int mmp_new_seq(void)
++{
++ u32 new_seq;
++
++ do {
++ get_random_bytes(&new_seq, sizeof(u32));
++ } while (new_seq > EXT3_MMP_SEQ_MAX);
++
++ return new_seq;
++}
++
++/*
++ * Protect the filesystem from being mounted more than once.
++ */
++static int ext3_multi_mount_protect(struct super_block *sb,
++ unsigned long mmp_block)
++{
++ struct ext3_super_block *es = EXT3_SB(sb)->s_es;
++ struct buffer_head *bh = NULL;
++ struct mmp_struct *mmp = NULL;
++ u32 seq;
++ unsigned int mmp_check_interval = le16_to_cpu(es->s_mmp_update_interval);
++ int retval;
++
++ if (mmp_block < le32_to_cpu(es->s_first_data_block) ||
++ mmp_block >= le32_to_cpu(es->s_blocks_count)) {
++ ext3_warning(sb, __FUNCTION__,
++ "Invalid MMP block in superblock");
++ goto failed;
++ }
++
++ retval = read_mmp_block(sb, &bh, mmp_block);
++ if (retval)
++ goto failed;
++
++ mmp = (struct mmp_struct *)(bh->b_data);
++
++ if (mmp_check_interval < EXT3_MMP_MIN_CHECK_INTERVAL)
++ mmp_check_interval = EXT3_MMP_MIN_CHECK_INTERVAL;
++
++ /*
++ * If check_interval in MMP block is larger, use that instead of
++ * update_interval from the superblock.
++ */
++ if (mmp->mmp_check_interval > mmp_check_interval)
++ mmp_check_interval = mmp->mmp_check_interval;
++
++ seq = le32_to_cpu(mmp->mmp_seq);
++ if (seq == EXT3_MMP_SEQ_CLEAN)
++ goto skip;
++
++ if (seq == EXT3_MMP_SEQ_FSCK) {
++ dump_mmp_msg(sb, mmp, __FUNCTION__,
++ "fsck is running on the filesystem");
++ goto failed;
++ }
++
++ schedule_timeout_uninterruptible(HZ * (2 * mmp_check_interval + 1));
++
++ retval = read_mmp_block(sb, &bh, mmp_block);
++ if (retval)
++ goto failed;
++ mmp = (struct mmp_struct *)(bh->b_data);
++ if (seq != le32_to_cpu(mmp->mmp_seq)) {
++ dump_mmp_msg(sb, mmp, __FUNCTION__,
++ "Device is already active on another node.");
++ goto failed;
++ }
++
++skip:
++ /*
++ * write a new random sequence number.
++ */
++ mmp->mmp_seq = seq = cpu_to_le32(mmp_new_seq());
++
++ retval = write_mmp_block(bh);
++ if (retval)
++ goto failed;
++
++ /*
++ * wait for MMP interval and check mmp_seq.
++ */
++ schedule_timeout_uninterruptible(HZ * (2 * mmp_check_interval + 1));
++
++ retval = read_mmp_block(sb, &bh, mmp_block);
++ if (retval)
++ goto failed;
++ mmp = (struct mmp_struct *)(bh->b_data);
++ if (seq != le32_to_cpu(mmp->mmp_seq)) {
++ dump_mmp_msg(sb, mmp, __FUNCTION__,
++ "Device is already active on another node.");
++ goto failed;
++ }
++
++ /*
++ * Start a kernel thread to update the MMP block periodically.
++ */
++ EXT3_SB(sb)->s_mmp_tsk = kthread_run(kmmpd, sb, "kmmpd-%02x:%02x",
++ MAJOR(sb->s_dev),
++ MINOR(sb->s_dev));
++ if (IS_ERR(EXT3_SB(sb)->s_mmp_tsk)) {
++ EXT3_SB(sb)->s_mmp_tsk = 0;
++ ext3_warning(sb, __FUNCTION__, "Unable to create kmmpd thread "
++ "for %s.", sb->s_id);
++ goto failed;
++ }
++
++ brelse(bh);
++ return 0;
++
++failed:
++ brelse(bh);
++ return 1;
++}
++
+
+ static int ext3_fill_super (struct super_block *sb, void *data, int silent)
+ {
+@@ -1844,6 +2156,11 @@ static int ext3_fill_super (struct super
+ EXT3_HAS_INCOMPAT_FEATURE(sb,
+ EXT3_FEATURE_INCOMPAT_RECOVER));
+
++ if (EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_MMP) &&
++ !(sb->s_flags & MS_RDONLY))
++ if (ext3_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
++ goto failed_mount3;
++
+ /*
+ * The first inode we look at is the journal inode. Don't try
+ * root first: it may be modified in the journal!
+@@ -2446,7 +2763,7 @@ static int ext3_remount (struct super_bl
+ ext3_fsblk_t n_blocks_count = 0;
+ unsigned long old_sb_flags;
+ struct ext3_mount_options old_opts;
+- int err;
++ int err = 0;
+ #ifdef CONFIG_QUOTA
+ int i;
+ #endif
+@@ -2530,6 +2847,11 @@ static int ext3_remount (struct super_bl
+ }
+ if (!ext3_setup_super (sb, es, 0))
+ sb->s_flags &= ~MS_RDONLY;
++ if (EXT3_HAS_INCOMPAT_FEATURE(sb,
++ EXT3_FEATURE_INCOMPAT_MMP))
++ if (ext3_multi_mount_protect(sb,
++ le64_to_cpu(es->s_mmp_block)))
++ goto restore_opts;
+ }
+ }
+ #ifdef CONFIG_QUOTA
+Index: linux-2.6.18/include/linux/ext3_fs.h
+===================================================================
+--- linux-2.6.18.orig/include/linux/ext3_fs.h
++++ linux-2.6.18/include/linux/ext3_fs.h
+@@ -593,13 +593,17 @@ struct ext3_super_block {
+ __le32 s_first_meta_bg; /* First metablock block group */
+ __le32 s_mkfs_time; /* When the filesystem was created */
+ __le32 s_jnl_blocks[17]; /* Backup of the journal inode */
+- __le32 s_blocks_count_hi; /* Blocks count high 32 bits */
++/*150*/ __le32 s_blocks_count_hi; /* Blocks count high 32 bits */
+ __le32 s_r_blocks_count_hi; /* Reserved blocks count high 32 bits*/
+ __le32 s_free_blocks_count_hi; /* Free blocks count high 32 bits */
+ __le16 s_min_extra_isize; /* All inodes have at least # bytes */
+ __le16 s_want_extra_isize; /* New inodes should reserve # bytes */
+- __le32 s_flags; /* Miscellaneous flags */
+- __u32 s_reserved[167]; /* Padding to the end of the block */
++/*160*/ __le32 s_flags; /* Miscellaneous flags */
++ __le16 s_raid_stride; /* RAID stride */
++ __le16 s_mmp_update_interval; /* # seconds to wait in MMP checking */
++ __le64 s_mmp_block; /* Block for multi-mount protection */
++/*170*/ __le32 s_raid_stripe_width; /* blocks on all data disks (N*stride)*/
++ __le32 s_reserved[163]; /* Padding to the end of the block */
+ };
+
+ #ifdef __KERNEL__
+@@ -702,12 +706,14 @@ static inline int ext3_valid_inum(struct
+ #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008 /* Journal device */
+ #define EXT3_FEATURE_INCOMPAT_META_BG 0x0010
+ #define EXT3_FEATURE_INCOMPAT_EXTENTS 0x0040 /* extents support */
++#define EXT3_FEATURE_INCOMPAT_MMP 0x0100
+
+ #define EXT3_FEATURE_COMPAT_SUPP EXT2_FEATURE_COMPAT_EXT_ATTR
+ #define EXT3_FEATURE_INCOMPAT_SUPP (EXT3_FEATURE_INCOMPAT_FILETYPE| \
+ EXT3_FEATURE_INCOMPAT_RECOVER| \
+ EXT3_FEATURE_INCOMPAT_META_BG| \
+- EXT3_FEATURE_INCOMPAT_EXTENTS)
++ EXT3_FEATURE_INCOMPAT_EXTENTS| \
++ EXT3_FEATURE_INCOMPAT_MMP)
+ #define EXT3_FEATURE_RO_COMPAT_SUPP (EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER| \
+ EXT3_FEATURE_RO_COMPAT_LARGE_FILE| \
+ EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
+@@ -870,6 +876,39 @@ ext3_group_first_block_no(struct super_b
+ #define ERR_BAD_DX_DIR -75000
+
+ /*
++ * This structure will be used for multiple mount protection. It will be
++ * written into the block number saved in the s_mmp_block field in the
++ * superblock. Programs that check MMP should assume that if
++ * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
++ * to use the filesystem, regardless of how old the timestamp is.
++ */
++#define EXT3_MMP_MAGIC 0x004D4D50U /* ASCII for MMP */
++#define EXT3_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
++#define EXT3_MMP_SEQ_FSCK 0xE24D4D50U /* mmp_seq value when being fscked */
++#define EXT3_MMP_SEQ_MAX 0xE24D4D4FU /* maximum valid mmp_seq value */
++
++struct mmp_struct {
++ __le32 mmp_magic;
++ __le32 mmp_seq;
++ __le64 mmp_time;
++ char mmp_nodename[64];
++ char mmp_bdevname[32];
++ __le16 mmp_check_interval;
++ __le16 mmp_pad1;
++ __le32 mmp_pad2[227];
++};
++
++/*
++ * Default interval in seconds to update the MMP sequence number.
++ */
++#define EXT3_MMP_UPDATE_INTERVAL 1
++
++/*
++ * Minimum interval for MMP checking in seconds.
++ */
++#define EXT3_MMP_MIN_CHECK_INTERVAL 5
++
++/*
+ * Function prototypes
+ */
+
+Index: linux-2.6.18/include/linux/ext3_fs_sb.h
+===================================================================
+--- linux-2.6.18.orig/include/linux/ext3_fs_sb.h
++++ linux-2.6.18/include/linux/ext3_fs_sb.h
+@@ -151,6 +151,7 @@ struct ext3_sb_info {
+ /* locality groups */
+ struct ext3_locality_group *s_locality_groups;
+
++ struct task_struct *s_mmp_tsk; /* Kernel thread for multiple mount protection */
+ };
+
+ #define EXT3_GROUP_INFO(sb, group) \
ext3-uninit-2.6.9.patch
ext3-nanosecond-2.6-rhel4.patch
ext3-unlink-race.patch
+ext3-mmp-2.6-rhel4.patch
ext3-uninit-2.6-sles10.patch
ext3-nanosecond-2.6-sles10.patch
ext3-inode-version-2.6-sles10.patch
+ext3-mmp-2.6-sles10.patch
ext3-uninit-2.6.18.patch
ext3-nanosecond-2.6.18-vanilla.patch
ext3-inode-version-2.6.18-vanilla.patch
+ext3-mmp-2.6.18-vanilla.patch
git://git.whamcloud.com / fs / lustre-release.git / commitdiff