From 24c19ef40474c3930597f31ae233dc06319bd881 Mon Sep 17 00:00:00 2001 From: Mark Fasheh Date: Fri, 22 Sep 2006 17:28:19 -0700 Subject: 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/inode.c | 146 ++++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 111 insertions(+), 35 deletions(-) (limited to 'fs/ocfs2/inode.c') diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c index 66ca7a82b68..69d3db56916 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: -- cgit v1.2.3