On 03/13/2013 09:24 AM, Greg Farnum wrote: > On Monday, March 11, 2013 at 5:42 AM, Yan, Zheng wrote: >> From: "Yan, Zheng" <zheng.z....@intel.com> >> >> 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 <zheng.z....@intel.com >> (mailto:zheng.z....@intel.com)> >> --- >> 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 | 41 +++++++++++++++++++---------------------- >> 5 files changed, 44 insertions(+), 49 deletions(-) >> >> diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c >> index 76634f4..124e8a1 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 76821be..11966c4 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 2b3fee7..d8db2df 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; >> + ci->i_complete_count = 0; >> + atomic_set(&ci->i_release_count, 1); >> ci->i_symlink = NULL; >> >> memset(&ci->i_dir_layout, 0, sizeof(ci->i_dir_layout)); >> @@ -720,9 +721,9 @@ 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: >> @@ -856,7 +857,7 @@ 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; >> } >> @@ -1060,8 +1061,8 @@ 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 ab899c8..edf90a5 100644 >> --- a/fs/ceph/mds_client.c >> +++ b/fs/ceph/mds_client.c >> @@ -2030,20 +2030,16 @@ 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 e5f1875..dde77ac 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; >> + int i_complete_count; >> + atomic_t i_release_count; > > What makes it safe to treat i_complete_count as an int instead of an atomic? > As far as I can tell it's not consistently used under any locks, but maybe > I'm missing something that the VFS is giving me. :/ > -Greg
The code only assigns value to i_complete_count, the instruction is inherent atomic. Regards Yan, Zheng -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
