From c4ce867fdad200dfd8aa8cbe1eabc26c14c51635 Mon Sep 17 00:00:00 2001 From: Goldwyn Rodrigues Date: Sat, 29 Mar 2014 10:20:02 -0500 Subject: [PATCH] Introduce md_cluster_info md_cluster_info stores the cluster information in the MD device. The join() is called when mddev detects it is a clustered device. The main responsibilities are: 1. Setup a DLM lockspace 2. Setup all initial locks such as super block locks and bitmap lock (will come later) The leave() clears up the lockspace and all the locks held. Signed-off-by: Goldwyn Rodrigues --- drivers/md/bitmap.c | 9 ++++++- drivers/md/md-cluster.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++--- drivers/md/md.c | 2 ++ drivers/md/md.h | 8 ++++++ 4 files changed, 80 insertions(+), 4 deletions(-) diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c index 3a57679..e2aacca 100644 --- a/drivers/md/bitmap.c +++ b/drivers/md/bitmap.c @@ -433,6 +433,7 @@ void bitmap_update_sb(struct bitmap *bitmap) /* This might have been changed by a reshape */ sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors); sb->chunksize = cpu_to_le32(bitmap->mddev->bitmap_info.chunksize); + sb->nodes = cpu_to_le32(bitmap->mddev->bitmap_info.nodes); sb->sectors_reserved = cpu_to_le32(bitmap->mddev-> bitmap_info.space); kunmap_atomic(sb); @@ -544,6 +545,7 @@ static int bitmap_read_sb(struct bitmap *bitmap) bitmap_super_t *sb; unsigned long chunksize, daemon_sleep, write_behind; unsigned long long events; + int nodes = 0; unsigned long sectors_reserved = 0; int err = -EINVAL; struct page *sb_page; @@ -583,6 +585,7 @@ static int bitmap_read_sb(struct bitmap *bitmap) daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ; write_behind = le32_to_cpu(sb->write_behind); sectors_reserved = le32_to_cpu(sb->sectors_reserved); + nodes = le32_to_cpu(sb->nodes); /* verify that the bitmap-specific fields are valid */ if (sb->magic != cpu_to_le32(BITMAP_MAGIC)) @@ -643,6 +646,7 @@ out_no_sb: bitmap->mddev->bitmap_info.chunksize = chunksize; bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep; bitmap->mddev->bitmap_info.max_write_behind = write_behind; + bitmap->mddev->bitmap_info.nodes = nodes; if (bitmap->mddev->bitmap_info.space == 0 || bitmap->mddev->bitmap_info.space > sectors_reserved) bitmap->mddev->bitmap_info.space = sectors_reserved; @@ -2186,6 +2190,8 @@ __ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store); static ssize_t metadata_show(struct mddev *mddev, char *page) { + if (mddev_is_clustered(mddev)) + return sprintf(page, "clustered\n"); return sprintf(page, "%s\n", (mddev->bitmap_info.external ? "external" : "internal")); } @@ -2198,7 +2204,8 @@ static ssize_t metadata_store(struct mddev *mddev, const char *buf, size_t len) return -EBUSY; if (strncmp(buf, "external", 8) == 0) mddev->bitmap_info.external = 1; - else if (strncmp(buf, "internal", 8) == 0) + else if ((strncmp(buf, "internal", 8) == 0) || + (strncmp(buf, "clustered", 9) == 0)) mddev->bitmap_info.external = 0; else return -EINVAL; diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c index e223560..d141d48 100644 --- a/drivers/md/md-cluster.c +++ b/drivers/md/md-cluster.c @@ -22,8 +22,16 @@ struct dlm_lock_resource { struct dlm_lksb lksb; char *name; /* lock name. */ uint32_t flags; /* flags to pass to dlm_lock() */ - void (*bast)(void *arg, int mode); /* blocking AST function pointer*/ struct completion completion; /* completion for synchronized locking */ + void (*bast)(void *arg, int mode); /* blocking AST function pointer*/ + struct mddev *mddev; /* pointing back to mddev. */ +}; + +struct md_cluster_info { + /* dlm lock space and resources for clustered raid. */ + dlm_lockspace_t *lockspace; + struct dlm_lock_resource *sb_lock; + struct mutex sb_mutex; }; static void sync_ast(void *arg) @@ -53,16 +61,18 @@ static int dlm_unlock_sync(struct dlm_lock_resource *res) return dlm_lock_sync(res, DLM_LOCK_NL); } -static struct dlm_lock_resource *lockres_init(dlm_lockspace_t *lockspace, +static struct dlm_lock_resource *lockres_init(struct mddev *mddev, char *name, void (*bastfn)(void *arg, int mode), int with_lvb) { struct dlm_lock_resource *res = NULL; int ret, namelen; + struct md_cluster_info *cinfo = mddev->cluster_info; res = kzalloc(sizeof(struct dlm_lock_resource), GFP_KERNEL); if (!res) return NULL; - res->ls = lockspace; + res->ls = cinfo->lockspace; + res->mddev = mddev; namelen = strlen(name); res->name = kzalloc(namelen + 1, GFP_KERNEL); if (!res->name) { @@ -114,13 +124,62 @@ static void lockres_free(struct dlm_lock_resource *res) kfree(res); } +static char *pretty_uuid(char *dest, char *src) +{ + int i, len = 0; + + for (i = 0; i < 16; i++) { + if (i == 4 || i == 6 || i == 8 || i == 10) + len += sprintf(dest + len, "-"); + len += sprintf(dest + len, "%02x", (__u8)src[i]); + } + return dest; +} + static int join(struct mddev *mddev, int nodes) { + struct md_cluster_info *cinfo; + int ret; + char str[64]; + + if (!try_module_get(THIS_MODULE)) + return -ENOENT; + + cinfo = kzalloc(sizeof(struct md_cluster_info), GFP_KERNEL); + if (!cinfo) + return -ENOMEM; + + memset(str, 0, 64); + pretty_uuid(str, mddev->uuid); + ret = dlm_new_lockspace(str, NULL, DLM_LSFL_FS, LVB_SIZE, + NULL, NULL, NULL, &cinfo->lockspace); + if (ret) + goto err; + cinfo->sb_lock = lockres_init(mddev, "cmd-super", + NULL, 0); + if (!cinfo->sb_lock) { + ret = -ENOMEM; + goto err; + } + mutex_init(&cinfo->sb_mutex); + mddev->cluster_info = cinfo; return 0; +err: + if (cinfo->lockspace) + dlm_release_lockspace(cinfo->lockspace, 2); + kfree(cinfo); + module_put(THIS_MODULE); + return ret; } static int leave(struct mddev *mddev) { + struct md_cluster_info *cinfo = mddev->cluster_info; + + if (!cinfo) + return 0; + lockres_free(cinfo->sb_lock); + dlm_release_lockspace(cinfo->lockspace, 2); return 0; } diff --git a/drivers/md/md.c b/drivers/md/md.c index 57ecb51..3387f94 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -7279,6 +7279,8 @@ int md_setup_cluster(struct mddev *mddev, int nodes) void md_cluster_stop(struct mddev *mddev) { + if (!md_cluster_ops) + return; md_cluster_ops->leave(mddev); module_put(md_cluster_mod); } diff --git a/drivers/md/md.h b/drivers/md/md.h index 0185931..80fc899 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -203,6 +203,8 @@ extern int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors, int is_new); extern void md_ack_all_badblocks(struct badblocks *bb); +struct md_cluster_info; + struct mddev { void *private; struct md_personality *pers; @@ -431,6 +433,7 @@ struct mddev { unsigned long daemon_sleep; /* how many jiffies between updates? */ unsigned long max_write_behind; /* write-behind mode */ int external; + int nodes; /* Maximum number of nodes in the cluster */ } bitmap_info; atomic_t max_corr_read_errors; /* max read retries */ @@ -449,6 +452,7 @@ struct mddev { struct work_struct flush_work; struct work_struct event_work; /* used by dm to report failure event */ void (*sync_super)(struct mddev *mddev, struct md_rdev *rdev); + struct md_cluster_info *cluster_info; }; static inline int __must_check mddev_lock(struct mddev *mddev) @@ -676,4 +680,8 @@ static inline void rdev_dec_pending(struct md_rdev *rdev, struct mddev *mddev) } extern struct md_cluster_operations *md_cluster_ops; +static inline int mddev_is_clustered(struct mddev *mddev) +{ + return mddev->cluster_info && mddev->bitmap_info.nodes > 1; +} #endif /* _MD_MD_H */ -- 2.7.4