ceph: pre-allocate data structure that tracks caps flushing

Signed-off-by: Yan, Zheng <zyan@redhat.com>

8 files changed, 102 insertions, 16 deletions

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 5f53ac0d9d7c..7edf3c49e661 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -1308,12 +1308,17 @@ static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
         struct inode *inode = file_inode(vma->vm_file);
         struct ceph_inode_info *ci = ceph_inode(inode);
         struct ceph_file_info *fi = vma->vm_file->private_data;
+        struct ceph_cap_flush *prealloc_cf;
         struct page *page = vmf->page;
         loff_t off = page_offset(page);
         loff_t size = i_size_read(inode);
         size_t len;
         int want, got, ret;
 
+        prealloc_cf = ceph_alloc_cap_flush();
+        if (!prealloc_cf)
+                return VM_FAULT_SIGBUS;
+
         if (ci->i_inline_version != CEPH_INLINE_NONE) {
                 struct page *locked_page = NULL;
                 if (off == 0) {
@@ -1323,8 +1328,10 @@ static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
                 ret = ceph_uninline_data(vma->vm_file, locked_page);
                 if (locked_page)
                         unlock_page(locked_page);
-                if (ret < 0)
-                        return VM_FAULT_SIGBUS;
+                if (ret < 0) {
+                        ret = VM_FAULT_SIGBUS;
+                        goto out_free;
+                }
         }
 
         if (off + PAGE_CACHE_SIZE <= size)
@@ -1346,7 +1353,8 @@ static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
                         break;
                 if (ret != -ERESTARTSYS) {
                         WARN_ON(1);
-                        return VM_FAULT_SIGBUS;
+                        ret = VM_FAULT_SIGBUS;
+                        goto out_free;
                 }
         }
         dout("page_mkwrite %p %llu~%zd got cap refs on %s\n",
@@ -1381,7 +1389,8 @@ out:
                 int dirty;
                 spin_lock(&ci->i_ceph_lock);
                 ci->i_inline_version = CEPH_INLINE_NONE;
-                dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR);
+                dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR,
+                                               &prealloc_cf);
                 spin_unlock(&ci->i_ceph_lock);
                 if (dirty)
                         __mark_inode_dirty(inode, dirty);
@@ -1390,6 +1399,8 @@ out:
         dout("page_mkwrite %p %llu~%zd dropping cap refs on %s ret %d\n",
              inode, off, len, ceph_cap_string(got), ret);
         ceph_put_cap_refs(ci, got);
+out_free:
+        ceph_free_cap_flush(prealloc_cf);
 
         return ret;
 }
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 69a16044ec41..dd7b20adf1d4 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -1356,7 +1356,8 @@ static void ceph_flush_snaps(struct ceph_inode_info *ci)
  * Caller is then responsible for calling __mark_inode_dirty with the
  * returned flags value.
  */
-int __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask)
+int __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask,
+                           struct ceph_cap_flush **pcf)
 {
         struct ceph_mds_client *mdsc =
                 ceph_sb_to_client(ci->vfs_inode.i_sb)->mdsc;
@@ -1376,6 +1377,9 @@ int __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask)
              ceph_cap_string(was | mask));
         ci->i_dirty_caps |= mask;
         if (was == 0) {
+                WARN_ON_ONCE(ci->i_prealloc_cap_flush);
+                swap(ci->i_prealloc_cap_flush, *pcf);
+
                 if (!ci->i_head_snapc) {
                         WARN_ON_ONCE(!rwsem_is_locked(&mdsc->snap_rwsem));
                         ci->i_head_snapc = ceph_get_snap_context(
@@ -1391,6 +1395,8 @@ int __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask)
                         ihold(inode);
                         dirty |= I_DIRTY_SYNC;
                 }
+        } else {
+                WARN_ON_ONCE(!ci->i_prealloc_cap_flush);
         }
         BUG_ON(list_empty(&ci->i_dirty_item));
         if (((was | ci->i_flushing_caps) & CEPH_CAP_FILE_BUFFER) &&
@@ -1446,6 +1452,17 @@ static void __add_cap_flushing_to_mdsc(struct ceph_mds_client *mdsc,
         rb_insert_color(&cf->g_node, &mdsc->cap_flush_tree);
 }
 
+struct ceph_cap_flush *ceph_alloc_cap_flush(void)
+{
+        return kmem_cache_alloc(ceph_cap_flush_cachep, GFP_KERNEL);
+}
+
+void ceph_free_cap_flush(struct ceph_cap_flush *cf)
+{
+        if (cf)
+                kmem_cache_free(ceph_cap_flush_cachep, cf);
+}
+
 static u64 __get_oldest_flush_tid(struct ceph_mds_client *mdsc)
 {
         struct rb_node *n = rb_first(&mdsc->cap_flush_tree);
@@ -1469,11 +1486,12 @@ static int __mark_caps_flushing(struct inode *inode,
 {
         struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;
         struct ceph_inode_info *ci = ceph_inode(inode);
-        struct ceph_cap_flush *cf;
+        struct ceph_cap_flush *cf = NULL;
         int flushing;
 
         BUG_ON(ci->i_dirty_caps == 0);
         BUG_ON(list_empty(&ci->i_dirty_item));
+        BUG_ON(!ci->i_prealloc_cap_flush);
 
         flushing = ci->i_dirty_caps;
         dout("__mark_caps_flushing flushing %s, flushing_caps %s -> %s\n",
@@ -1484,7 +1502,7 @@ static int __mark_caps_flushing(struct inode *inode,
         ci->i_dirty_caps = 0;
         dout(" inode %p now !dirty\n", inode);
 
-        cf = kmalloc(sizeof(*cf), GFP_ATOMIC);
+        swap(cf, ci->i_prealloc_cap_flush);
         cf->caps = flushing;
         cf->kick = false;
 
@@ -3075,7 +3093,7 @@ out:
                 cf = list_first_entry(&to_remove,
                                       struct ceph_cap_flush, list);
                 list_del(&cf->list);
-                kfree(cf);
+                ceph_free_cap_flush(cf);
         }
         if (drop)
                 iput(inode);
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 0a76a370d798..8a4eb4d21d3c 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -939,6 +939,7 @@ static ssize_t ceph_write_iter(struct kiocb *iocb, struct iov_iter *from)
         struct ceph_inode_info *ci = ceph_inode(inode);
         struct ceph_osd_client *osdc =
                 &ceph_sb_to_client(inode->i_sb)->client->osdc;
+        struct ceph_cap_flush *prealloc_cf;
         ssize_t count, written = 0;
         int err, want, got;
         loff_t pos;
@@ -946,6 +947,10 @@ static ssize_t ceph_write_iter(struct kiocb *iocb, struct iov_iter *from)
         if (ceph_snap(inode) != CEPH_NOSNAP)
                 return -EROFS;
 
+        prealloc_cf = ceph_alloc_cap_flush();
+        if (!prealloc_cf)
+                return -ENOMEM;
+
         mutex_lock(&inode->i_mutex);
 
         /* We can write back this queue in page reclaim */
@@ -1050,7 +1055,8 @@ retry_snap:
                 int dirty;
                 spin_lock(&ci->i_ceph_lock);
                 ci->i_inline_version = CEPH_INLINE_NONE;
-                dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR);
+                dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR,
+                                               &prealloc_cf);
                 spin_unlock(&ci->i_ceph_lock);
                 if (dirty)
                         __mark_inode_dirty(inode, dirty);
@@ -1074,6 +1080,7 @@ retry_snap:
 out:
         mutex_unlock(&inode->i_mutex);
 out_unlocked:
+        ceph_free_cap_flush(prealloc_cf);
         current->backing_dev_info = NULL;
         return written ? written : err;
 }
@@ -1270,6 +1277,7 @@ static long ceph_fallocate(struct file *file, int mode,
         struct ceph_inode_info *ci = ceph_inode(inode);
         struct ceph_osd_client *osdc =
                 &ceph_inode_to_client(inode)->client->osdc;
+        struct ceph_cap_flush *prealloc_cf;
         int want, got = 0;
         int dirty;
         int ret = 0;
@@ -1282,6 +1290,10 @@ static long ceph_fallocate(struct file *file, int mode,
         if (!S_ISREG(inode->i_mode))
                 return -EOPNOTSUPP;
 
+        prealloc_cf = ceph_alloc_cap_flush();
+        if (!prealloc_cf)
+                return -ENOMEM;
+
         mutex_lock(&inode->i_mutex);
 
         if (ceph_snap(inode) != CEPH_NOSNAP) {
@@ -1328,7 +1340,8 @@ static long ceph_fallocate(struct file *file, int mode,
         if (!ret) {
                 spin_lock(&ci->i_ceph_lock);
                 ci->i_inline_version = CEPH_INLINE_NONE;
-                dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR);
+                dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR,
+                                               &prealloc_cf);
                 spin_unlock(&ci->i_ceph_lock);
                 if (dirty)
                         __mark_inode_dirty(inode, dirty);
@@ -1337,6 +1350,7 @@ static long ceph_fallocate(struct file *file, int mode,
         ceph_put_cap_refs(ci, got);
 unlock:
         mutex_unlock(&inode->i_mutex);
+        ceph_free_cap_flush(prealloc_cf);
         return ret;
 }
 
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 3326302f5884..e86d1a4efc46 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -416,6 +416,7 @@ struct inode *ceph_alloc_inode(struct super_block *sb)
         ci->i_flushing_caps = 0;
         INIT_LIST_HEAD(&ci->i_dirty_item);
         INIT_LIST_HEAD(&ci->i_flushing_item);
+        ci->i_prealloc_cap_flush = NULL;
         ci->i_cap_flush_tree = RB_ROOT;
         init_waitqueue_head(&ci->i_cap_wq);
         ci->i_hold_caps_min = 0;
@@ -1720,6 +1721,7 @@ int ceph_setattr(struct dentry *dentry, struct iattr *attr)
         const unsigned int ia_valid = attr->ia_valid;
         struct ceph_mds_request *req;
         struct ceph_mds_client *mdsc = ceph_sb_to_client(dentry->d_sb)->mdsc;
+        struct ceph_cap_flush *prealloc_cf;
         int issued;
         int release = 0, dirtied = 0;
         int mask = 0;
@@ -1734,10 +1736,16 @@ int ceph_setattr(struct dentry *dentry, struct iattr *attr)
         if (err != 0)
                 return err;
 
+        prealloc_cf = ceph_alloc_cap_flush();
+        if (!prealloc_cf)
+                return -ENOMEM;
+
         req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SETATTR,
                                        USE_AUTH_MDS);
-        if (IS_ERR(req))
+        if (IS_ERR(req)) {
+                ceph_free_cap_flush(prealloc_cf);
                 return PTR_ERR(req);
+        }
 
         spin_lock(&ci->i_ceph_lock);
         issued = __ceph_caps_issued(ci, NULL);
@@ -1895,7 +1903,8 @@ int ceph_setattr(struct dentry *dentry, struct iattr *attr)
                 dout("setattr %p ATTR_FILE ... hrm!\n", inode);
 
         if (dirtied) {
-                inode_dirty_flags = __ceph_mark_dirty_caps(ci, dirtied);
+                inode_dirty_flags = __ceph_mark_dirty_caps(ci, dirtied,
+                                                           &prealloc_cf);
                 inode->i_ctime = CURRENT_TIME;
         }
 
@@ -1927,9 +1936,11 @@ int ceph_setattr(struct dentry *dentry, struct iattr *attr)
         ceph_mdsc_put_request(req);
         if (mask & CEPH_SETATTR_SIZE)
                 __ceph_do_pending_vmtruncate(inode);
+        ceph_free_cap_flush(prealloc_cf);
         return err;
 out_put:
         ceph_mdsc_put_request(req);
+        ceph_free_cap_flush(prealloc_cf);
         return err;
 }
 
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 89e4305a94d4..8d73fe9d488b 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -1189,6 +1189,10 @@ static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
                 }
                 spin_unlock(&mdsc->cap_dirty_lock);
 
+                if (!ci->i_dirty_caps && ci->i_prealloc_cap_flush) {
+                        list_add(&ci->i_prealloc_cap_flush->list, &to_remove);
+                        ci->i_prealloc_cap_flush = NULL;
+                }
         }
         spin_unlock(&ci->i_ceph_lock);
         while (!list_empty(&to_remove)) {
@@ -1196,7 +1200,7 @@ static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
                 cf = list_first_entry(&to_remove,
                                       struct ceph_cap_flush, list);
                 list_del(&cf->list);
-                kfree(cf);
+                ceph_free_cap_flush(cf);
         }
         while (drop--)
                 iput(inode);
diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index edeb83c43112..d1c833c321b9 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -622,6 +622,7 @@ static void destroy_fs_client(struct ceph_fs_client *fsc)
  */
 struct kmem_cache *ceph_inode_cachep;
 struct kmem_cache *ceph_cap_cachep;
+struct kmem_cache *ceph_cap_flush_cachep;
 struct kmem_cache *ceph_dentry_cachep;
 struct kmem_cache *ceph_file_cachep;
 
@@ -647,6 +648,10 @@ static int __init init_caches(void)
                                      SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
         if (ceph_cap_cachep == NULL)
                 goto bad_cap;
+        ceph_cap_flush_cachep = KMEM_CACHE(ceph_cap_flush,
+                                           SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
+        if (ceph_cap_flush_cachep == NULL)
+                goto bad_cap_flush;
 
         ceph_dentry_cachep = KMEM_CACHE(ceph_dentry_info,
                                         SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
@@ -665,6 +670,8 @@ static int __init init_caches(void)
 bad_file:
         kmem_cache_destroy(ceph_dentry_cachep);
 bad_dentry:
+        kmem_cache_destroy(ceph_cap_flush_cachep);
+bad_cap_flush:
         kmem_cache_destroy(ceph_cap_cachep);
 bad_cap:
         kmem_cache_destroy(ceph_inode_cachep);
@@ -681,6 +688,7 @@ static void destroy_caches(void)
 
         kmem_cache_destroy(ceph_inode_cachep);
         kmem_cache_destroy(ceph_cap_cachep);
+        kmem_cache_destroy(ceph_cap_flush_cachep);
         kmem_cache_destroy(ceph_dentry_cachep);
         kmem_cache_destroy(ceph_file_cachep);
 
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index e7f13f742357..4415e977d72b 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -309,6 +309,7 @@ struct ceph_inode_info {
         /* we need to track cap writeback on a per-cap-bit basis, to allow
          * overlapping, pipelined cap flushes to the mds.  we can probably
          * reduce the tid to 8 bits if we're concerned about inode size. */
+        struct ceph_cap_flush *i_prealloc_cap_flush;
         struct rb_root i_cap_flush_tree;
         wait_queue_head_t i_cap_wq;      /* threads waiting on a capability */
         unsigned long i_hold_caps_min; /* jiffies */
@@ -578,7 +579,10 @@ static inline int __ceph_caps_dirty(struct ceph_inode_info *ci)
 {
         return ci->i_dirty_caps | ci->i_flushing_caps;
 }
-extern int __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask);
+extern struct ceph_cap_flush *ceph_alloc_cap_flush(void);
+extern void ceph_free_cap_flush(struct ceph_cap_flush *cf);
+extern int __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask,
+                                  struct ceph_cap_flush **pcf);
 
 extern int __ceph_caps_revoking_other(struct ceph_inode_info *ci,
                                       struct ceph_cap *ocap, int mask);
diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index c6f7d9b82085..819163d8313b 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -912,6 +912,7 @@ int __ceph_setxattr(struct dentry *dentry, const char *name,
         struct ceph_vxattr *vxattr;
         struct ceph_inode_info *ci = ceph_inode(inode);
         struct ceph_mds_client *mdsc = ceph_sb_to_client(dentry->d_sb)->mdsc;
+        struct ceph_cap_flush *prealloc_cf = NULL;
         int issued;
         int err;
         int dirty = 0;
@@ -950,6 +951,10 @@ int __ceph_setxattr(struct dentry *dentry, const char *name,
         if (!xattr)
                 goto out;
 
+        prealloc_cf = ceph_alloc_cap_flush();
+        if (!prealloc_cf)
+                goto out;
+
         spin_lock(&ci->i_ceph_lock);
 retry:
         issued = __ceph_caps_issued(ci, NULL);
@@ -991,7 +996,8 @@ retry:
                           flags, value ? 1 : -1, &xattr);
 
         if (!err) {
-                dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_XATTR_EXCL);
+                dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_XATTR_EXCL,
+                                               &prealloc_cf);
                 ci->i_xattrs.dirty = true;
                 inode->i_ctime = CURRENT_TIME;
         }
@@ -1001,6 +1007,7 @@ retry:
                 up_read(&mdsc->snap_rwsem);
         if (dirty)
                 __mark_inode_dirty(inode, dirty);
+        ceph_free_cap_flush(prealloc_cf);
         return err;
 
 do_sync:
@@ -1010,6 +1017,7 @@ do_sync_unlocked:
                 up_read(&mdsc->snap_rwsem);
         err = ceph_sync_setxattr(dentry, name, value, size, flags);
 out:
+        ceph_free_cap_flush(prealloc_cf);
         kfree(newname);
         kfree(newval);
         kfree(xattr);
@@ -1062,6 +1070,7 @@ int __ceph_removexattr(struct dentry *dentry, const char *name)
         struct ceph_vxattr *vxattr;
         struct ceph_inode_info *ci = ceph_inode(inode);
         struct ceph_mds_client *mdsc = ceph_sb_to_client(dentry->d_sb)->mdsc;
+        struct ceph_cap_flush *prealloc_cf = NULL;
         int issued;
         int err;
         int required_blob_size;
@@ -1079,6 +1088,10 @@ int __ceph_removexattr(struct dentry *dentry, const char *name)
         if (!strncmp(name, XATTR_CEPH_PREFIX, XATTR_CEPH_PREFIX_LEN))
                 goto do_sync_unlocked;
 
+        prealloc_cf = ceph_alloc_cap_flush();
+        if (!prealloc_cf)
+                return -ENOMEM;
+
         err = -ENOMEM;
         spin_lock(&ci->i_ceph_lock);
 retry:
@@ -1120,7 +1133,8 @@ retry:
 
         err = __remove_xattr_by_name(ceph_inode(inode), name);
 
-        dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_XATTR_EXCL);
+        dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_XATTR_EXCL,
+                                       &prealloc_cf);
         ci->i_xattrs.dirty = true;
         inode->i_ctime = CURRENT_TIME;
         spin_unlock(&ci->i_ceph_lock);
@@ -1128,12 +1142,14 @@ retry:
                 up_read(&mdsc->snap_rwsem);
         if (dirty)
                 __mark_inode_dirty(inode, dirty);
+        ceph_free_cap_flush(prealloc_cf);
         return err;
 do_sync:
         spin_unlock(&ci->i_ceph_lock);
 do_sync_unlocked:
         if (lock_snap_rwsem)
                 up_read(&mdsc->snap_rwsem);
+        ceph_free_cap_flush(prealloc_cf);
         err = ceph_send_removexattr(dentry, name);
         return err;
 }