+++ /dev/null
-Index: linux-stage/fs/ext4/super.c
-===================================================================
---- linux-stage.orig/fs/ext4/super.c
-+++ linux-stage/fs/ext4/super.c
-@@ -39,6 +39,8 @@
- #include <linux/log2.h>
- #include <linux/crc16.h>
- #include <asm/uaccess.h>
-+#include <linux/kthread.h>
-+#include <linux/utsname.h>
-
- #include "ext4.h"
- #include "ext4_jbd2.h"
-@@ -600,6 +602,8 @@ static void ext4_put_super(struct super_
- invalidate_bdev(sbi->journal_bdev);
- ext4_blkdev_remove(sbi);
- }
-+ if (sbi->s_mmp_tsk)
-+ kthread_stop(sbi->s_mmp_tsk);
- sb->s_fs_info = NULL;
- kfree(sbi);
- return;
-@@ -808,7 +812,6 @@ static int ext4_show_options(struct seq_
- if (!test_opt(sb, DELALLOC))
- seq_puts(seq, ",nodelalloc");
-
--
- if (sbi->s_stripe)
- seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
- /*
-@@ -831,6 +834,340 @@ static int ext4_show_options(struct seq_
- }
-
-
-+
-+/*
-+ * 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);
-+
-+ /* This would be sb_bread(sb, mmp_block), except we need to be sure
-+ * that the MD RAID device cache has been bypassed, and that the read
-+ * is not blocked in the elevator. */
-+ if (!*bh)
-+ *bh = sb_getblk(sb, mmp_block);
-+ if (*bh) {
-+ get_bh(*bh);
-+ lock_buffer(*bh);
-+ (*bh)->b_end_io = end_buffer_read_sync;
-+ submit_bh(READ_SYNC, *bh);
-+ wait_on_buffer(*bh);
-+ if (!buffer_uptodate(*bh)) {
-+ brelse(*bh);
-+ *bh = NULL;
-+ }
-+ }
-+ if (!*bh) {
-+ ext4_warning(sb, __func__,
-+ "Error while reading MMP block %lu", mmp_block);
-+ return -EIO;
-+ }
-+
-+ mmp = (struct mmp_struct *)((*bh)->b_data);
-+ if (le32_to_cpu(mmp->mmp_magic) != EXT4_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)
-+{
-+ ext4_warning(sb, function, "%s", msg);
-+ ext4_warning(sb, function, "MMP failure info: last update time: %llu, "
-+ "last update node: %s, last update device: %s\n",
-+ (long long unsigned int)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 ext4_super_block *es = EXT4_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,
-+ EXT4_MMP_MIN_CHECK_INTERVAL);
-+ mmp->mmp_check_interval = cpu_to_le16(mmp_check_interval);
-+ bdevname(bh->b_bdev, mmp->mmp_bdevname);
-+
-+ memcpy(mmp->mmp_nodename, init_utsname()->nodename,
-+ sizeof(mmp->mmp_nodename));
-+
-+ while (!kthread_should_stop()) {
-+ if (++seq > EXT4_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) {
-+ ext4_error(sb, __func__,
-+ "Error writing to MMP block");
-+ failed_writes++;
-+ }
-+
-+ if (!(le32_to_cpu(es->s_feature_incompat) &
-+ EXT4_FEATURE_INCOMPAT_MMP)) {
-+ ext4_warning(sb, __func__, "kmmpd being stopped "
-+ "since MMP feature has been disabled.");
-+ EXT4_SB(sb)->s_mmp_tsk = 0;
-+ goto failed;
-+ }
-+
-+ if (sb->s_flags & MS_RDONLY) {
-+ ext4_warning(sb, __func__, "kmmpd being stopped "
-+ "since filesystem has been remounted as "
-+ "readonly.");
-+ EXT4_SB(sb)->s_mmp_tsk = 0;
-+ goto failed;
-+ }
-+
-+ diff = jiffies - last_update_time;
-+ if (diff < mmp_update_interval * HZ)
-+ schedule_timeout_interruptible(EXT4_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) {
-+ EXT4_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, __func__,
-+ "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) EXT4_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(EXT4_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
-+ * EXT4_MMP_SEQ_MAX.
-+ */
-+static unsigned int mmp_new_seq(void)
-+{
-+ u32 new_seq;
-+
-+ do {
-+ get_random_bytes(&new_seq, sizeof(u32));
-+ } while (new_seq > EXT4_MMP_SEQ_MAX);
-+
-+ return new_seq;
-+}
-+
-+/*
-+ * Protect the filesystem from being mounted more than once.
-+ */
-+static int ext4_multi_mount_protect(struct super_block *sb,
-+ unsigned long mmp_block)
-+{
-+ struct ext4_super_block *es = EXT4_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);
-+ unsigned int wait_time = 0;
-+ int retval;
-+
-+ if (mmp_block < le32_to_cpu(es->s_first_data_block) ||
-+ mmp_block >= ext4_blocks_count(es)) {
-+ ext4_warning(sb, __func__,
-+ "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 < EXT4_MMP_MIN_CHECK_INTERVAL)
-+ mmp_check_interval = EXT4_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 == EXT4_MMP_SEQ_CLEAN)
-+ goto skip;
-+
-+ if (seq == EXT4_MMP_SEQ_FSCK) {
-+ dump_mmp_msg(sb, mmp, __func__,
-+ "fsck is running on the filesystem");
-+ goto failed;
-+ }
-+
-+ wait_time = min(mmp_check_interval * 2 + 1,
-+ mmp_check_interval + 60);
-+
-+ /* Print MMP interval if more than 20 secs. */
-+ if (wait_time > EXT4_MMP_MIN_CHECK_INTERVAL * 4)
-+ ext4_warning(sb, __func__, "MMP interval %u higher than "
-+ "expected, please wait.\n", wait_time * 2);
-+
-+ if (schedule_timeout_interruptible(HZ * wait_time) != 0) {
-+ ext4_warning(sb, __func__, "MMP startup interrupted, failing mount\n");
-+ goto failed;
-+ }
-+
-+ 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, __func__,
-+ "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.
-+ */
-+ if (schedule_timeout_interruptible(HZ * wait_time) != 0) {
-+ ext4_warning(sb, __func__, "MMP startup interrupted, failing mount\n");
-+ goto failed;
-+ }
-+
-+ 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, __func__,
-+ "Device is already active on another node.");
-+ goto failed;
-+ }
-+
-+ /*
-+ * Start a kernel thread to update the MMP block periodically.
-+ */
-+ EXT4_SB(sb)->s_mmp_tsk = kthread_run(kmmpd, sb, "kmmpd-%02x:%02x",
-+ MAJOR(sb->s_dev),
-+ MINOR(sb->s_dev));
-+ if (IS_ERR(EXT4_SB(sb)->s_mmp_tsk)) {
-+ EXT4_SB(sb)->s_mmp_tsk = 0;
-+ ext4_warning(sb, __func__, "Unable to create kmmpd thread "
-+ "for %s.", sb->s_id);
-+ goto failed;
-+ }
-+
-+ brelse(bh);
-+ return 0;
-+
-+failed:
-+ brelse(bh);
-+ return 1;
-+}
-+
- static struct inode *ext4_nfs_get_inode(struct super_block *sb,
- u64 ino, u32 generation)
- {
-@@ -2371,6 +2708,11 @@ static int ext4_fill_super(struct super_
- EXT4_HAS_INCOMPAT_FEATURE(sb,
- EXT4_FEATURE_INCOMPAT_RECOVER));
-
-+ if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
-+ !(sb->s_flags & MS_RDONLY))
-+ if (ext4_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!
-@@ -2571,6 +2913,8 @@ failed_mount3:
- percpu_counter_destroy(&sbi->s_freeinodes_counter);
- percpu_counter_destroy(&sbi->s_dirs_counter);
- percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
-+ if (sbi->s_mmp_tsk)
-+ kthread_stop(sbi->s_mmp_tsk);
- failed_mount2:
- for (i = 0; i < db_count; i++)
- brelse(sbi->s_group_desc[i]);
-@@ -3086,7 +3430,7 @@ static int ext4_remount(struct super_blo
- unsigned long old_sb_flags;
- struct ext4_mount_options old_opts;
- ext4_group_t g;
-- int err;
-+ int err = 0;
- #ifdef CONFIG_QUOTA
- int i;
- #endif
-@@ -3211,6 +3555,13 @@ static int ext4_remount(struct super_blo
- goto restore_opts;
- if (!ext4_setup_super(sb, es, 0))
- sb->s_flags &= ~MS_RDONLY;
-+ if (EXT4_HAS_INCOMPAT_FEATURE(sb,
-+ EXT4_FEATURE_INCOMPAT_MMP))
-+ if (ext4_multi_mount_protect(sb,
-+ le64_to_cpu(es->s_mmp_block))) {
-+ err = -EROFS;
-+ goto restore_opts;
-+ }
- }
- }
- #ifdef CONFIG_QUOTA
-Index: linux-stage/fs/ext4/ext4.h
-===================================================================
---- linux-stage.orig/fs/ext4/ext4.h
-+++ linux-stage/fs/ext4/ext4.h
-@@ -660,7 +660,7 @@ struct ext4_super_block {
- __le16 s_want_extra_isize; /* New inodes should reserve # bytes */
- __le32 s_flags; /* Miscellaneous flags */
- __le16 s_raid_stride; /* RAID stride */
-- __le16 s_mmp_interval; /* # seconds to wait in MMP checking */
-+ __le16 s_mmp_update_interval; /* # seconds to wait in MMP checking */
- __le64 s_mmp_block; /* Block for multi-mount protection */
- __le32 s_raid_stripe_width; /* blocks on all data disks (N*stride)*/
- __u8 s_log_groups_per_flex; /* FLEX_BG group size */
-@@ -777,7 +777,8 @@ static inline int ext4_valid_inum(struct
- EXT4_FEATURE_INCOMPAT_META_BG| \
- EXT4_FEATURE_INCOMPAT_EXTENTS| \
- EXT4_FEATURE_INCOMPAT_64BIT| \
-- EXT4_FEATURE_INCOMPAT_FLEX_BG)
-+ EXT4_FEATURE_INCOMPAT_FLEX_BG| \
-+ EXT4_FEATURE_INCOMPAT_MMP)
- #define EXT4_FEATURE_RO_COMPAT_SUPP (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
- EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
- EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
-@@ -981,6 +982,39 @@ do { \
- #endif
-
- /*
-+ * 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 EXT4_MMP_MAGIC 0x004D4D50U /* ASCII for MMP */
-+#define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
-+#define EXT4_MMP_SEQ_FSCK 0xE24D4D50U /* mmp_seq value when being fscked */
-+#define EXT4_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 EXT4_MMP_UPDATE_INTERVAL 1
-+
-+/*
-+ * Minimum interval for MMP checking in seconds.
-+ */
-+#define EXT4_MMP_MIN_CHECK_INTERVAL 5
-+
-+/*
- * Function prototypes
- */
-
-Index: linux-stage/fs/ext4/ext4_sb.h
-===================================================================
---- linux-stage.orig/fs/ext4/ext4_sb.h
-+++ linux-stage/fs/ext4/ext4_sb.h
-@@ -149,6 +149,8 @@ struct ext4_sb_info {
-
- unsigned int s_log_groups_per_flex;
- struct flex_groups *s_flex_groups;
-+
-+ struct task_struct *s_mmp_tsk; /* Kernel thread for multiple mount protection */
- };
-
- #endif /* _EXT4_SB */
git://git.whamcloud.com / fs / lustre-release.git / blobdiff