From 24c19ef40474c3930597f31ae233dc06319bd881 Mon Sep 17 00:00:00 2001 From: Mark Fasheh Date: Fri, 22 Sep 2006 17:28:19 -0700 Subject: [PATCH] ocfs2: Remove i_generation from inode lock names OCFS2 puts inode meta data in the "lock value block" provided by the DLM. Typically, i_generation is encoded in the lock name so that a deleted inode on and a new one in the same block don't share the same lvb. Unfortunately, that scheme means that the read in ocfs2_read_locked_inode() is potentially thrown away as soon as the meta data lock is taken - we cannot encode the lock name without first knowing i_generation, which requires a disk read. This patch encodes i_generation in the inode meta data lvb, and removes the value from the inode meta data lock name. This way, the read can be covered by a lock, and at the same time we can distinguish between an up to date and a stale LVB. This will help cold-cache stat(2) performance in particular. Since this patch changes the protocol version, we take the opportunity to do a minor re-organization of two of the LVB fields. Signed-off-by: Mark Fasheh --- fs/ocfs2/cluster/tcp_internal.h | 5 +- fs/ocfs2/dlmglue.c | 42 +++++++-- fs/ocfs2/dlmglue.h | 7 +- fs/ocfs2/export.c | 4 +- fs/ocfs2/inode.c | 146 ++++++++++++++++++++++++-------- fs/ocfs2/inode.h | 8 +- fs/ocfs2/journal.c | 3 +- fs/ocfs2/namei.c | 2 +- fs/ocfs2/super.c | 4 +- fs/ocfs2/sysfile.c | 2 +- 10 files changed, 170 insertions(+), 53 deletions(-) diff --git a/fs/ocfs2/cluster/tcp_internal.h b/fs/ocfs2/cluster/tcp_internal.h index da42b515cd..4b46aac7d2 100644 --- a/fs/ocfs2/cluster/tcp_internal.h +++ b/fs/ocfs2/cluster/tcp_internal.h @@ -44,6 +44,9 @@ * locking semantics of the file system using the protocol. It should * be somewhere else, I'm sure, but right now it isn't. * + * New in version 4: + * - Remove i_generation from lock names for better stat performance. + * * New in version 3: * - Replace dentry votes with a cluster lock * @@ -51,7 +54,7 @@ * - full 64 bit i_size in the metadata lock lvbs * - introduction of "rw" lock and pushing meta/data locking down */ -#define O2NET_PROTOCOL_VERSION 3ULL +#define O2NET_PROTOCOL_VERSION 4ULL struct o2net_handshake { __be64 protocol_version; __be64 connector_id; diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c index 6cd84dffbb..ecb3cba228 100644 --- a/fs/ocfs2/dlmglue.c +++ b/fs/ocfs2/dlmglue.c @@ -320,6 +320,7 @@ void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res) void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res, enum ocfs2_lock_type type, + unsigned int generation, struct inode *inode) { struct ocfs2_lock_res_ops *ops; @@ -341,7 +342,7 @@ void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res, }; ocfs2_build_lock_name(type, OCFS2_I(inode)->ip_blkno, - inode->i_generation, res->l_name); + generation, res->l_name); ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res, type, ops, inode); } @@ -1173,17 +1174,19 @@ static void ocfs2_cluster_unlock(struct ocfs2_super *osb, int ocfs2_create_new_lock(struct ocfs2_super *osb, struct ocfs2_lock_res *lockres, - int ex) + int ex, + int local) { int level = ex ? LKM_EXMODE : LKM_PRMODE; unsigned long flags; + int lkm_flags = local ? LKM_LOCAL : 0; spin_lock_irqsave(&lockres->l_lock, flags); BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED); lockres_or_flags(lockres, OCFS2_LOCK_LOCAL); spin_unlock_irqrestore(&lockres->l_lock, flags); - return ocfs2_lock_create(osb, lockres, level, LKM_LOCAL); + return ocfs2_lock_create(osb, lockres, level, lkm_flags); } /* Grants us an EX lock on the data and metadata resources, skipping @@ -1212,19 +1215,23 @@ int ocfs2_create_new_inode_locks(struct inode *inode) * on a resource which has an invalid one -- we'll set it * valid when we release the EX. */ - ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_rw_lockres, 1); + ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_rw_lockres, 1, 1); if (ret) { mlog_errno(ret); goto bail; } - ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_meta_lockres, 1); + /* + * We don't want to use LKM_LOCAL on a meta data lock as they + * don't use a generation in their lock names. + */ + ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_meta_lockres, 1, 0); if (ret) { mlog_errno(ret); goto bail; } - ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_data_lockres, 1); + ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_data_lockres, 1, 1); if (ret) { mlog_errno(ret); goto bail; @@ -1413,6 +1420,16 @@ static void __ocfs2_stuff_meta_lvb(struct inode *inode) lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb; + /* + * Invalidate the LVB of a deleted inode - this way other + * nodes are forced to go to disk and discover the new inode + * status. + */ + if (oi->ip_flags & OCFS2_INODE_DELETED) { + lvb->lvb_version = 0; + goto out; + } + lvb->lvb_version = OCFS2_LVB_VERSION; lvb->lvb_isize = cpu_to_be64(i_size_read(inode)); lvb->lvb_iclusters = cpu_to_be32(oi->ip_clusters); @@ -1429,6 +1446,7 @@ static void __ocfs2_stuff_meta_lvb(struct inode *inode) lvb->lvb_iattr = cpu_to_be32(oi->ip_attr); lvb->lvb_igeneration = cpu_to_be32(inode->i_generation); +out: mlog_meta_lvb(0, lockres); mlog_exit_void(); @@ -1727,6 +1745,18 @@ int ocfs2_meta_lock_full(struct inode *inode, wait_event(osb->recovery_event, ocfs2_node_map_is_empty(osb, &osb->recovery_map)); + /* + * We only see this flag if we're being called from + * ocfs2_read_locked_inode(). It means we're locking an inode + * which hasn't been populated yet, so clear the refresh flag + * and let the caller handle it. + */ + if (inode->i_state & I_NEW) { + status = 0; + ocfs2_complete_lock_res_refresh(lockres, 0); + goto bail; + } + /* This is fun. The caller may want a bh back, or it may * not. ocfs2_meta_lock_update definitely wants one in, but * may or may not read one, depending on what's in the diff --git a/fs/ocfs2/dlmglue.h b/fs/ocfs2/dlmglue.h index 45a74f44b6..4a27693872 100644 --- a/fs/ocfs2/dlmglue.h +++ b/fs/ocfs2/dlmglue.h @@ -32,9 +32,9 @@ #define OCFS2_LVB_VERSION 4 struct ocfs2_meta_lvb { - __be16 lvb_reserved0; - __u8 lvb_reserved1; __u8 lvb_version; + __u8 lvb_reserved0; + __be16 lvb_reserved1; __be32 lvb_iclusters; __be32 lvb_iuid; __be32 lvb_igid; @@ -62,13 +62,14 @@ void ocfs2_dlm_shutdown(struct ocfs2_super *osb); void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res); void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res, enum ocfs2_lock_type type, + unsigned int generation, struct inode *inode); void ocfs2_dentry_lock_res_init(struct ocfs2_dentry_lock *dl, u64 parent, struct inode *inode); void ocfs2_lock_res_free(struct ocfs2_lock_res *res); int ocfs2_create_new_inode_locks(struct inode *inode); int ocfs2_create_new_lock(struct ocfs2_super *osb, - struct ocfs2_lock_res *lockres, int ex); + struct ocfs2_lock_res *lockres, int ex, int local); int ocfs2_drop_inode_locks(struct inode *inode); int ocfs2_data_lock_full(struct inode *inode, int write, diff --git a/fs/ocfs2/export.c b/fs/ocfs2/export.c index ffcd79749e..fb91089a60 100644 --- a/fs/ocfs2/export.c +++ b/fs/ocfs2/export.c @@ -58,7 +58,7 @@ static struct dentry *ocfs2_get_dentry(struct super_block *sb, void *vobjp) return ERR_PTR(-ESTALE); } - inode = ocfs2_iget(OCFS2_SB(sb), handle->ih_blkno); + inode = ocfs2_iget(OCFS2_SB(sb), handle->ih_blkno, 0); if (IS_ERR(inode)) { mlog_errno(PTR_ERR(inode)); @@ -115,7 +115,7 @@ static struct dentry *ocfs2_get_parent(struct dentry *child) goto bail_unlock; } - inode = ocfs2_iget(OCFS2_SB(dir->i_sb), blkno); + inode = ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0); if (IS_ERR(inode)) { mlog(ML_ERROR, "Unable to create inode %llu\n", (unsigned long long)blkno); diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c index 66ca7a82b6..69d3db5691 100644 --- a/fs/ocfs2/inode.c +++ b/fs/ocfs2/inode.c @@ -54,8 +54,6 @@ #include "buffer_head_io.h" -#define OCFS2_FI_FLAG_NOWAIT 0x1 -#define OCFS2_FI_FLAG_DELETE 0x2 struct ocfs2_find_inode_args { u64 fi_blkno; @@ -109,7 +107,7 @@ struct inode *ocfs2_ilookup_for_vote(struct ocfs2_super *osb, return ilookup5(osb->sb, args.fi_ino, ocfs2_find_actor, &args); } -struct inode *ocfs2_iget(struct ocfs2_super *osb, u64 blkno) +struct inode *ocfs2_iget(struct ocfs2_super *osb, u64 blkno, int flags) { struct inode *inode = NULL; struct super_block *sb = osb->sb; @@ -127,7 +125,7 @@ struct inode *ocfs2_iget(struct ocfs2_super *osb, u64 blkno) } args.fi_blkno = blkno; - args.fi_flags = 0; + args.fi_flags = flags; args.fi_ino = ino_from_blkno(sb, blkno); inode = iget5_locked(sb, args.fi_ino, ocfs2_find_actor, @@ -297,15 +295,11 @@ int ocfs2_populate_inode(struct inode *inode, struct ocfs2_dinode *fe, OCFS2_I(inode)->ip_orphaned_slot = OCFS2_INVALID_SLOT; OCFS2_I(inode)->ip_attr = le32_to_cpu(fe->i_attr); - if (create_ino) - inode->i_ino = ino_from_blkno(inode->i_sb, - le64_to_cpu(fe->i_blkno)); - - mlog(0, "blkno = %llu, ino = %lu, create_ino = %s\n", - (unsigned long long)fe->i_blkno, inode->i_ino, create_ino ? "true" : "false"); - inode->i_nlink = le16_to_cpu(fe->i_links_count); + if (fe->i_flags & cpu_to_le32(OCFS2_SYSTEM_FL)) + OCFS2_I(inode)->ip_flags |= OCFS2_INODE_SYSTEM_FILE; + if (fe->i_flags & cpu_to_le32(OCFS2_LOCAL_ALLOC_FL)) { OCFS2_I(inode)->ip_flags |= OCFS2_INODE_BITMAP; mlog(0, "local alloc inode: i_ino=%lu\n", inode->i_ino); @@ -343,12 +337,28 @@ int ocfs2_populate_inode(struct inode *inode, struct ocfs2_dinode *fe, break; } + if (create_ino) { + inode->i_ino = ino_from_blkno(inode->i_sb, + le64_to_cpu(fe->i_blkno)); + + /* + * If we ever want to create system files from kernel, + * the generation argument to + * ocfs2_inode_lock_res_init() will have to change. + */ + BUG_ON(fe->i_flags & cpu_to_le32(OCFS2_SYSTEM_FL)); + + ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_meta_lockres, + OCFS2_LOCK_TYPE_META, 0, inode); + } + ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_rw_lockres, - OCFS2_LOCK_TYPE_RW, inode); - ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_meta_lockres, - OCFS2_LOCK_TYPE_META, inode); + OCFS2_LOCK_TYPE_RW, inode->i_generation, + inode); + ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_data_lockres, - OCFS2_LOCK_TYPE_DATA, inode); + OCFS2_LOCK_TYPE_DATA, inode->i_generation, + inode); ocfs2_set_inode_flags(inode); inode->i_flags |= S_NOATIME; @@ -366,15 +376,15 @@ static int ocfs2_read_locked_inode(struct inode *inode, struct ocfs2_super *osb; struct ocfs2_dinode *fe; struct buffer_head *bh = NULL; - int status; - int sysfile = 0; + int status, can_lock; + u32 generation = 0; mlog_entry("(0x%p, 0x%p)\n", inode, args); status = -EINVAL; if (inode == NULL || inode->i_sb == NULL) { mlog(ML_ERROR, "bad inode\n"); - goto bail; + return status; } sb = inode->i_sb; osb = OCFS2_SB(sb); @@ -382,50 +392,110 @@ static int ocfs2_read_locked_inode(struct inode *inode, if (!args) { mlog(ML_ERROR, "bad inode args\n"); make_bad_inode(inode); - goto bail; + return status; } - /* Read the FE off disk. This is safe because the kernel only - * does one read_inode2 for a new inode, and if it doesn't - * exist yet then nobody can be working on it! */ - status = ocfs2_read_block(osb, args->fi_blkno, &bh, 0, NULL); + /* + * To improve performance of cold-cache inode stats, we take + * the cluster lock here if possible. + * + * Generally, OCFS2 never trusts the contents of an inode + * unless it's holding a cluster lock, so taking it here isn't + * a correctness issue as much as it is a performance + * improvement. + * + * There are three times when taking the lock is not a good idea: + * + * 1) During startup, before we have initialized the DLM. + * + * 2) If we are reading certain system files which never get + * cluster locks (local alloc, truncate log). + * + * 3) If the process doing the iget() is responsible for + * orphan dir recovery. We're holding the orphan dir lock and + * can get into a deadlock with another process on another + * node in ->delete_inode(). + * + * #1 and #2 can be simply solved by never taking the lock + * here for system files (which are the only type we read + * during mount). It's a heavier approach, but our main + * concern is user-accesible files anyway. + * + * #3 works itself out because we'll eventually take the + * cluster lock before trusting anything anyway. + */ + can_lock = !(args->fi_flags & OCFS2_FI_FLAG_SYSFILE) + && !(args->fi_flags & OCFS2_FI_FLAG_NOLOCK); + + /* + * To maintain backwards compatibility with older versions of + * ocfs2-tools, we still store the generation value for system + * files. The only ones that actually matter to userspace are + * the journals, but it's easier and inexpensive to just flag + * all system files similarly. + */ + if (args->fi_flags & OCFS2_FI_FLAG_SYSFILE) + generation = osb->fs_generation; + + ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_meta_lockres, + OCFS2_LOCK_TYPE_META, + generation, inode); + + if (can_lock) { + status = ocfs2_meta_lock(inode, NULL, NULL, 0); + if (status) { + make_bad_inode(inode); + mlog_errno(status); + return status; + } + } + + status = ocfs2_read_block(osb, args->fi_blkno, &bh, 0, + can_lock ? inode : NULL); if (status < 0) { mlog_errno(status); - make_bad_inode(inode); goto bail; } + status = -EINVAL; fe = (struct ocfs2_dinode *) bh->b_data; if (!OCFS2_IS_VALID_DINODE(fe)) { mlog(ML_ERROR, "Invalid dinode #%llu: signature = %.*s\n", (unsigned long long)fe->i_blkno, 7, fe->i_signature); - make_bad_inode(inode); goto bail; } - if (fe->i_flags & cpu_to_le32(OCFS2_SYSTEM_FL)) - sysfile = 1; + /* + * This is a code bug. Right now the caller needs to + * understand whether it is asking for a system file inode or + * not so the proper lock names can be built. + */ + mlog_bug_on_msg(!!(fe->i_flags & cpu_to_le32(OCFS2_SYSTEM_FL)) != + !!(args->fi_flags & OCFS2_FI_FLAG_SYSFILE), + "Inode %llu: system file state is ambigous\n", + (unsigned long long)args->fi_blkno); if (S_ISCHR(le16_to_cpu(fe->i_mode)) || S_ISBLK(le16_to_cpu(fe->i_mode))) inode->i_rdev = huge_decode_dev(le64_to_cpu(fe->id1.dev1.i_rdev)); - status = -EINVAL; if (ocfs2_populate_inode(inode, fe, 0) < 0) { mlog(ML_ERROR, "populate failed! i_blkno=%llu, i_ino=%lu\n", (unsigned long long)fe->i_blkno, inode->i_ino); - make_bad_inode(inode); goto bail; } BUG_ON(args->fi_blkno != le64_to_cpu(fe->i_blkno)); - if (sysfile) - OCFS2_I(inode)->ip_flags |= OCFS2_INODE_SYSTEM_FILE; - status = 0; bail: + if (can_lock) + ocfs2_meta_unlock(inode, 0); + + if (status < 0) + make_bad_inode(inode); + if (args && bh) brelse(bh); @@ -898,9 +968,15 @@ void ocfs2_delete_inode(struct inode *inode) goto bail_unlock_inode; } - /* Mark the inode as successfully deleted. This is important - * for ocfs2_clear_inode as it will check this flag and skip - * any checkpointing work */ + /* + * Mark the inode as successfully deleted. + * + * This is important for ocfs2_clear_inode() as it will check + * this flag and skip any checkpointing work + * + * ocfs2_stuff_meta_lvb() also uses this flag to invalidate + * the LVB for other nodes. + */ OCFS2_I(inode)->ip_flags |= OCFS2_INODE_DELETED; bail_unlock_inode: diff --git a/fs/ocfs2/inode.h b/fs/ocfs2/inode.h index 4d1e539925..9957810fdf 100644 --- a/fs/ocfs2/inode.h +++ b/fs/ocfs2/inode.h @@ -122,7 +122,13 @@ struct buffer_head *ocfs2_bread(struct inode *inode, int block, void ocfs2_clear_inode(struct inode *inode); void ocfs2_delete_inode(struct inode *inode); void ocfs2_drop_inode(struct inode *inode); -struct inode *ocfs2_iget(struct ocfs2_super *osb, u64 feoff); + +/* Flags for ocfs2_iget() */ +#define OCFS2_FI_FLAG_NOWAIT 0x1 +#define OCFS2_FI_FLAG_DELETE 0x2 +#define OCFS2_FI_FLAG_SYSFILE 0x4 +#define OCFS2_FI_FLAG_NOLOCK 0x8 +struct inode *ocfs2_iget(struct ocfs2_super *osb, u64 feoff, int flags); struct inode *ocfs2_ilookup_for_vote(struct ocfs2_super *osb, u64 blkno, int delete_vote); diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c index f92bf1dd37..fd9734def5 100644 --- a/fs/ocfs2/journal.c +++ b/fs/ocfs2/journal.c @@ -1493,7 +1493,8 @@ static int ocfs2_queue_orphans(struct ocfs2_super *osb, if (de->name_len == 2 && !strncmp("..", de->name, 2)) continue; - iter = ocfs2_iget(osb, le64_to_cpu(de->inode)); + iter = ocfs2_iget(osb, le64_to_cpu(de->inode), + OCFS2_FI_FLAG_NOLOCK); if (IS_ERR(iter)) continue; diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c index 6fa978874c..849c3b4bb9 100644 --- a/fs/ocfs2/namei.c +++ b/fs/ocfs2/namei.c @@ -179,7 +179,7 @@ static struct dentry *ocfs2_lookup(struct inode *dir, struct dentry *dentry, if (status < 0) goto bail_add; - inode = ocfs2_iget(OCFS2_SB(dir->i_sb), blkno); + inode = ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0); if (IS_ERR(inode)) { mlog(ML_ERROR, "Unable to create inode %llu\n", (unsigned long long)blkno); diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c index 33a6de6fc6..4c29cd7cc8 100644 --- a/fs/ocfs2/super.c +++ b/fs/ocfs2/super.c @@ -202,7 +202,7 @@ static int ocfs2_init_global_system_inodes(struct ocfs2_super *osb) mlog_entry_void(); - new = ocfs2_iget(osb, osb->root_blkno); + new = ocfs2_iget(osb, osb->root_blkno, OCFS2_FI_FLAG_SYSFILE); if (IS_ERR(new)) { status = PTR_ERR(new); mlog_errno(status); @@ -210,7 +210,7 @@ static int ocfs2_init_global_system_inodes(struct ocfs2_super *osb) } osb->root_inode = new; - new = ocfs2_iget(osb, osb->system_dir_blkno); + new = ocfs2_iget(osb, osb->system_dir_blkno, OCFS2_FI_FLAG_SYSFILE); if (IS_ERR(new)) { status = PTR_ERR(new); mlog_errno(status); diff --git a/fs/ocfs2/sysfile.c b/fs/ocfs2/sysfile.c index 98435002ac..5df6e35d09 100644 --- a/fs/ocfs2/sysfile.c +++ b/fs/ocfs2/sysfile.c @@ -115,7 +115,7 @@ static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb, goto bail; } - inode = ocfs2_iget(osb, blkno); + inode = ocfs2_iget(osb, blkno, OCFS2_FI_FLAG_SYSFILE); if (IS_ERR(inode)) { mlog_errno(PTR_ERR(inode)); inode = NULL; -- 2.39.5