From 2f276c511137d97e56b19e29865e1e6569315ccb Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Wed, 13 Mar 2013 19:44:32 +0800 Subject: [PATCH] ceph: use i_release_count to indicate dir's completeness Current ceph code tracks directory's completeness in two places. ceph_readdir() checks i_release_count to decide if it can set the I_COMPLETE flag in i_ceph_flags. All other places check the I_COMPLETE flag. This indirection introduces locking complexity. This patch adds a new variable i_complete_count to ceph_inode_info. Set i_release_count's value to it when marking a directory complete. By comparing the two variables, we know if a directory is complete Signed-off-by: Yan, Zheng --- fs/ceph/caps.c | 4 ++-- fs/ceph/dir.c | 25 +++++++++++++------------ fs/ceph/inode.c | 13 +++++++------ fs/ceph/mds_client.c | 10 +++------- fs/ceph/super.h | 42 ++++++++++++++++++++---------------------- 5 files changed, 45 insertions(+), 49 deletions(-) diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index bc575a4a813e..f9563108d189 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -490,7 +490,7 @@ static void __check_cap_issue(struct ceph_inode_info *ci, struct ceph_cap *cap, ci->i_rdcache_gen++; /* - * if we are newly issued FILE_SHARED, clear I_COMPLETE; we + * if we are newly issued FILE_SHARED, mark dir not complete; we * don't know what happened to this directory while we didn't * have the cap. */ @@ -499,7 +499,7 @@ static void __check_cap_issue(struct ceph_inode_info *ci, struct ceph_cap *cap, ci->i_shared_gen++; if (S_ISDIR(ci->vfs_inode.i_mode)) { dout(" marking %p NOT complete\n", &ci->vfs_inode); - ci->i_ceph_flags &= ~CEPH_I_COMPLETE; + __ceph_dir_clear_complete(ci); } } } diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c index 0c369ac62c07..f02d82b7933e 100644 --- a/fs/ceph/dir.c +++ b/fs/ceph/dir.c @@ -107,7 +107,7 @@ static unsigned fpos_off(loff_t p) * falling back to a "normal" sync readdir if any dentries in the dir * are dropped. * - * I_COMPLETE tells indicates we have all dentries in the dir. It is + * Complete dir indicates that we have all dentries in the dir. It is * defined IFF we hold CEPH_CAP_FILE_SHARED (which will be revoked by * the MDS if/when the directory is modified). */ @@ -198,8 +198,8 @@ more: filp->f_pos++; /* make sure a dentry wasn't dropped while we didn't have parent lock */ - if (!ceph_i_test(dir, CEPH_I_COMPLETE)) { - dout(" lost I_COMPLETE on %p; falling back to mds\n", dir); + if (!ceph_dir_is_complete(dir)) { + dout(" lost dir complete on %p; falling back to mds\n", dir); err = -EAGAIN; goto out; } @@ -258,7 +258,7 @@ static int ceph_readdir(struct file *filp, void *dirent, filldir_t filldir) if (filp->f_pos == 0) { /* note dir version at start of readdir so we can tell * if any dentries get dropped */ - fi->dir_release_count = ci->i_release_count; + fi->dir_release_count = atomic_read(&ci->i_release_count); dout("readdir off 0 -> '.'\n"); if (filldir(dirent, ".", 1, ceph_make_fpos(0, 0), @@ -284,7 +284,7 @@ static int ceph_readdir(struct file *filp, void *dirent, filldir_t filldir) if ((filp->f_pos == 2 || fi->dentry) && !ceph_test_mount_opt(fsc, NOASYNCREADDIR) && ceph_snap(inode) != CEPH_SNAPDIR && - (ci->i_ceph_flags & CEPH_I_COMPLETE) && + __ceph_dir_is_complete(ci) && __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1)) { spin_unlock(&ci->i_ceph_lock); err = __dcache_readdir(filp, dirent, filldir); @@ -350,7 +350,8 @@ more: if (!req->r_did_prepopulate) { dout("readdir !did_prepopulate"); - fi->dir_release_count--; /* preclude I_COMPLETE */ + /* preclude from marking dir complete */ + fi->dir_release_count--; } /* note next offset and last dentry name */ @@ -428,9 +429,9 @@ more: * the complete dir contents in our cache. */ spin_lock(&ci->i_ceph_lock); - if (ci->i_release_count == fi->dir_release_count) { + if (atomic_read(&ci->i_release_count) == fi->dir_release_count) { dout(" marking %p complete\n", inode); - ci->i_ceph_flags |= CEPH_I_COMPLETE; + __ceph_dir_set_complete(ci, fi->dir_release_count); ci->i_max_offset = filp->f_pos; } spin_unlock(&ci->i_ceph_lock); @@ -605,7 +606,7 @@ static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry, fsc->mount_options->snapdir_name, dentry->d_name.len) && !is_root_ceph_dentry(dir, dentry) && - (ci->i_ceph_flags & CEPH_I_COMPLETE) && + __ceph_dir_is_complete(ci) && (__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1))) { spin_unlock(&ci->i_ceph_lock); dout(" dir %p complete, -ENOENT\n", dir); @@ -909,7 +910,7 @@ static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry, */ /* d_move screws up d_subdirs order */ - ceph_i_clear(new_dir, CEPH_I_COMPLETE); + ceph_dir_clear_complete(new_dir); d_move(old_dentry, new_dentry); @@ -1079,7 +1080,7 @@ static void ceph_d_prune(struct dentry *dentry) if (IS_ROOT(dentry)) return; - /* if we are not hashed, we don't affect I_COMPLETE */ + /* if we are not hashed, we don't affect dir's completeness */ if (d_unhashed(dentry)) return; @@ -1087,7 +1088,7 @@ static void ceph_d_prune(struct dentry *dentry) * we hold d_lock, so d_parent is stable, and d_fsdata is never * cleared until d_release */ - ceph_i_clear(dentry->d_parent->d_inode, CEPH_I_COMPLETE); + ceph_dir_clear_complete(dentry->d_parent->d_inode); } /* diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index eeac43dd04eb..1b173edc8083 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -302,7 +302,8 @@ struct inode *ceph_alloc_inode(struct super_block *sb) ci->i_version = 0; ci->i_time_warp_seq = 0; ci->i_ceph_flags = 0; - ci->i_release_count = 0; + atomic_set(&ci->i_release_count, 1); + atomic_set(&ci->i_complete_count, 0); ci->i_symlink = NULL; memset(&ci->i_dir_layout, 0, sizeof(ci->i_dir_layout)); @@ -721,9 +722,9 @@ static int fill_inode(struct inode *inode, ceph_snap(inode) == CEPH_NOSNAP && (le32_to_cpu(info->cap.caps) & CEPH_CAP_FILE_SHARED) && (issued & CEPH_CAP_FILE_EXCL) == 0 && - (ci->i_ceph_flags & CEPH_I_COMPLETE) == 0) { + !__ceph_dir_is_complete(ci)) { dout(" marking %p complete (empty)\n", inode); - ci->i_ceph_flags |= CEPH_I_COMPLETE; + __ceph_dir_set_complete(ci, atomic_read(&ci->i_release_count)); ci->i_max_offset = 2; } no_change: @@ -857,7 +858,7 @@ static void ceph_set_dentry_offset(struct dentry *dn) di = ceph_dentry(dn); spin_lock(&ci->i_ceph_lock); - if ((ceph_inode(inode)->i_ceph_flags & CEPH_I_COMPLETE) == 0) { + if (!__ceph_dir_is_complete(ci)) { spin_unlock(&ci->i_ceph_lock); return; } @@ -1061,8 +1062,8 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req, /* * d_move() puts the renamed dentry at the end of * d_subdirs. We need to assign it an appropriate - * directory offset so we can behave when holding - * I_COMPLETE. + * directory offset so we can behave when dir is + * complete. */ ceph_set_dentry_offset(req->r_old_dentry); dout("dn %p gets new offset %lld\n", req->r_old_dentry, diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 600d770d70f7..0db6f5206d11 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -2034,20 +2034,16 @@ out: } /* - * Invalidate dir I_COMPLETE, dentry lease state on an aborted MDS + * Invalidate dir's completeness, dentry lease state on an aborted MDS * namespace request. */ void ceph_invalidate_dir_request(struct ceph_mds_request *req) { struct inode *inode = req->r_locked_dir; - struct ceph_inode_info *ci = ceph_inode(inode); - dout("invalidate_dir_request %p (I_COMPLETE, lease(s))\n", inode); - spin_lock(&ci->i_ceph_lock); - ci->i_ceph_flags &= ~CEPH_I_COMPLETE; - ci->i_release_count++; - spin_unlock(&ci->i_ceph_lock); + dout("invalidate_dir_request %p (complete, lease(s))\n", inode); + ceph_dir_clear_complete(inode); if (req->r_dentry) ceph_invalidate_dentry_lease(req->r_dentry); if (req->r_old_dentry) diff --git a/fs/ceph/super.h b/fs/ceph/super.h index a04eda714df4..8696be2ff679 100644 --- a/fs/ceph/super.h +++ b/fs/ceph/super.h @@ -244,7 +244,8 @@ struct ceph_inode_info { u32 i_time_warp_seq; unsigned i_ceph_flags; - unsigned long i_release_count; + atomic_t i_release_count; + atomic_t i_complete_count; struct ceph_dir_layout i_dir_layout; struct ceph_file_layout i_layout; @@ -254,7 +255,7 @@ struct ceph_inode_info { struct timespec i_rctime; u64 i_rbytes, i_rfiles, i_rsubdirs; u64 i_files, i_subdirs; - u64 i_max_offset; /* largest readdir offset, set with I_COMPLETE */ + u64 i_max_offset; /* largest readdir offset, set with complete dir */ struct rb_root i_fragtree; struct mutex i_fragtree_mutex; @@ -419,38 +420,35 @@ static inline struct inode *ceph_find_inode(struct super_block *sb, /* * Ceph inode. */ -#define CEPH_I_COMPLETE 1 /* we have complete directory cached */ #define CEPH_I_NODELAY 4 /* do not delay cap release */ #define CEPH_I_FLUSH 8 /* do not delay flush of dirty metadata */ #define CEPH_I_NOFLUSH 16 /* do not flush dirty caps */ -static inline void ceph_i_clear(struct inode *inode, unsigned mask) +static inline void __ceph_dir_set_complete(struct ceph_inode_info *ci, + int release_count) { - struct ceph_inode_info *ci = ceph_inode(inode); - - spin_lock(&ci->i_ceph_lock); - ci->i_ceph_flags &= ~mask; - spin_unlock(&ci->i_ceph_lock); + atomic_set(&ci->i_complete_count, release_count); } -static inline void ceph_i_set(struct inode *inode, unsigned mask) +static inline void __ceph_dir_clear_complete(struct ceph_inode_info *ci) { - struct ceph_inode_info *ci = ceph_inode(inode); + atomic_inc(&ci->i_release_count); +} - spin_lock(&ci->i_ceph_lock); - ci->i_ceph_flags |= mask; - spin_unlock(&ci->i_ceph_lock); +static inline bool __ceph_dir_is_complete(struct ceph_inode_info *ci) +{ + return atomic_read(&ci->i_complete_count) == + atomic_read(&ci->i_release_count); } -static inline bool ceph_i_test(struct inode *inode, unsigned mask) +static inline void ceph_dir_clear_complete(struct inode *inode) { - struct ceph_inode_info *ci = ceph_inode(inode); - bool r; + __ceph_dir_clear_complete(ceph_inode(inode)); +} - spin_lock(&ci->i_ceph_lock); - r = (ci->i_ceph_flags & mask) == mask; - spin_unlock(&ci->i_ceph_lock); - return r; +static inline bool ceph_dir_is_complete(struct inode *inode) +{ + return __ceph_dir_is_complete(ceph_inode(inode)); } @@ -565,7 +563,7 @@ struct ceph_file_info { u64 next_offset; /* offset of next chunk (last_name's + 1) */ char *last_name; /* last entry in previous chunk */ struct dentry *dentry; /* next dentry (for dcache readdir) */ - unsigned long dir_release_count; + int dir_release_count; /* used for -o dirstat read() on directory thing */ char *dir_info; -- 2.20.1