ceph: use ihold when we already have an inode ref

We should use ihold whenever we already have a stable inode ref, even
when we aren't holding i_lock.  This avoids adding new and unnecessary
locking dependencies.

Signed-off-by: Sage Weil <sage@newdream.net>

10 files changed, 37 insertions, 28 deletions

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 33da49dc3cc6..5a3953db8118 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -453,7 +453,7 @@ static int ceph_writepage(struct page *page, struct writeback_control *wbc)
         int err;
         struct inode *inode = page->mapping->host;
         BUG_ON(!inode);
-        igrab(inode);
+        ihold(inode);
         err = writepage_nounlock(page, wbc);
         unlock_page(page);
         iput(inode);
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 1f72b00447c4..f605753c8fe9 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -2940,14 +2940,12 @@ void ceph_flush_dirty_caps(struct ceph_mds_client *mdsc)
         while (!list_empty(&mdsc->cap_dirty)) {
                 ci = list_first_entry(&mdsc->cap_dirty, struct ceph_inode_info,
                                       i_dirty_item);
-                inode = igrab(&ci->vfs_inode);
+                inode = &ci->vfs_inode;
+                ihold(inode);
                 dout("flush_dirty_caps %p\n", inode);
                 spin_unlock(&mdsc->cap_dirty_lock);
-                if (inode) {
-                        ceph_check_caps(ci, CHECK_CAPS_NODELAY|CHECK_CAPS_FLUSH,
-                                        NULL);
-                        iput(inode);
-                }
+                ceph_check_caps(ci, CHECK_CAPS_NODELAY|CHECK_CAPS_FLUSH, NULL);
+                iput(inode);
                 spin_lock(&mdsc->cap_dirty_lock);
         }
         spin_unlock(&mdsc->cap_dirty_lock);
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 33729e822bb9..ef8f08c343e8 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -308,7 +308,8 @@ more:
                 req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
                 if (IS_ERR(req))
                         return PTR_ERR(req);
-                req->r_inode = igrab(inode);
+                req->r_inode = inode;
+                ihold(inode);
                 req->r_dentry = dget(filp->f_dentry);
                 /* hints to request -> mds selection code */
                 req->r_direct_mode = USE_AUTH_MDS;
@@ -787,10 +788,12 @@ static int ceph_link(struct dentry *old_dentry, struct inode *dir,
         req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
         err = ceph_mdsc_do_request(mdsc, dir, req);
-        if (err)
+        if (err) {
                 d_drop(dentry);
-        else if (!req->r_reply_info.head->is_dentry)
-                d_instantiate(dentry, igrab(old_dentry->d_inode));
+        } else if (!req->r_reply_info.head->is_dentry) {
+                ihold(old_dentry->d_inode);
+                d_instantiate(dentry, old_dentry->d_inode);
+        }
         ceph_mdsc_put_request(req);
         return err;
 }
diff --git a/fs/ceph/export.c b/fs/ceph/export.c
index a610d3d67488..f67b687550de 100644
--- a/fs/ceph/export.c
+++ b/fs/ceph/export.c
@@ -109,7 +109,7 @@ static struct dentry *__fh_to_dentry(struct super_block *sb,
                 err = ceph_mdsc_do_request(mdsc, NULL, req);
                 inode = req->r_target_inode;
                 if (inode)
-                        igrab(inode);
+                        ihold(inode);
                 ceph_mdsc_put_request(req);
                 if (!inode)
                         return ERR_PTR(-ESTALE);
@@ -167,7 +167,7 @@ static struct dentry *__cfh_to_dentry(struct super_block *sb,
                 err = ceph_mdsc_do_request(mdsc, NULL, req);
                 inode = req->r_target_inode;
                 if (inode)
-                        igrab(inode);
+                        ihold(inode);
                 ceph_mdsc_put_request(req);
                 if (!inode)
                         return ERR_PTR(err ? err : -ESTALE);
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 203252d88d9f..8c5ac4e72832 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -191,7 +191,8 @@ int ceph_open(struct inode *inode, struct file *file)
                 err = PTR_ERR(req);
                 goto out;
         }
-        req->r_inode = igrab(inode);
+        req->r_inode = inode;
+        ihold(inode);
         req->r_num_caps = 1;
         err = ceph_mdsc_do_request(mdsc, parent_inode, req);
         if (!err)
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 70b6a4839c38..d8858e96ab18 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -1101,10 +1101,10 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
                                 goto done;
                         }
                         req->r_dentry = dn;  /* may have spliced */
-                        igrab(in);
+                        ihold(in);
                 } else if (ceph_ino(in) == vino.ino &&
                            ceph_snap(in) == vino.snap) {
-                        igrab(in);
+                        ihold(in);
                 } else {
                         dout(" %p links to %p %llx.%llx, not %llx.%llx\n",
                              dn, in, ceph_ino(in), ceph_snap(in),
@@ -1144,7 +1144,7 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
                         goto done;
                 }
                 req->r_dentry = dn;  /* may have spliced */
-                igrab(in);
+                ihold(in);
                 rinfo->head->is_dentry = 1;  /* fool notrace handlers */
         }
 
@@ -1328,7 +1328,7 @@ void ceph_queue_writeback(struct inode *inode)
         if (queue_work(ceph_inode_to_client(inode)->wb_wq,
                        &ceph_inode(inode)->i_wb_work)) {
                 dout("ceph_queue_writeback %p\n", inode);
-                igrab(inode);
+                ihold(inode);
         } else {
                 dout("ceph_queue_writeback %p failed\n", inode);
         }
@@ -1353,7 +1353,7 @@ void ceph_queue_invalidate(struct inode *inode)
         if (queue_work(ceph_inode_to_client(inode)->pg_inv_wq,
                        &ceph_inode(inode)->i_pg_inv_work)) {
                 dout("ceph_queue_invalidate %p\n", inode);
-                igrab(inode);
+                ihold(inode);
         } else {
                 dout("ceph_queue_invalidate %p failed\n", inode);
         }
@@ -1477,7 +1477,7 @@ void ceph_queue_vmtruncate(struct inode *inode)
         if (queue_work(ceph_sb_to_client(inode->i_sb)->trunc_wq,
                        &ci->i_vmtruncate_work)) {
                 dout("ceph_queue_vmtruncate %p\n", inode);
-                igrab(inode);
+                ihold(inode);
         } else {
                 dout("ceph_queue_vmtruncate %p failed, pending=%d\n",
                      inode, ci->i_truncate_pending);
@@ -1738,7 +1738,8 @@ int ceph_setattr(struct dentry *dentry, struct iattr *attr)
                 __mark_inode_dirty(inode, inode_dirty_flags);
 
         if (mask) {
-                req->r_inode = igrab(inode);
+                req->r_inode = inode;
+                ihold(inode);
                 req->r_inode_drop = release;
                 req->r_args.setattr.mask = cpu_to_le32(mask);
                 req->r_num_caps = 1;
@@ -1779,7 +1780,8 @@ int ceph_do_getattr(struct inode *inode, int mask)
         req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_GETATTR, USE_ANY_MDS);
         if (IS_ERR(req))
                 return PTR_ERR(req);
-        req->r_inode = igrab(inode);
+        req->r_inode = inode;
+        ihold(inode);
         req->r_num_caps = 1;
         req->r_args.getattr.mask = cpu_to_le32(mask);
         err = ceph_mdsc_do_request(mdsc, NULL, req);
diff --git a/fs/ceph/ioctl.c b/fs/ceph/ioctl.c
index 8888c9ba68db..ef0b5f48e13a 100644
--- a/fs/ceph/ioctl.c
+++ b/fs/ceph/ioctl.c
@@ -73,7 +73,8 @@ static long ceph_ioctl_set_layout(struct file *file, void __user *arg)
                                        USE_AUTH_MDS);
         if (IS_ERR(req))
                 return PTR_ERR(req);
-        req->r_inode = igrab(inode);
+        req->r_inode = inode;
+        ihold(inode);
         req->r_inode_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_FILE_EXCL;
 
         req->r_args.setlayout.layout.fl_stripe_unit =
@@ -135,7 +136,8 @@ static long ceph_ioctl_set_layout_policy (struct file *file, void __user *arg)
 
         if (IS_ERR(req))
                 return PTR_ERR(req);
-        req->r_inode = igrab(inode);
+        req->r_inode = inode;
+        ihold(inode);
 
         req->r_args.setlayout.layout.fl_stripe_unit =
                         cpu_to_le32(l.stripe_unit);
diff --git a/fs/ceph/locks.c b/fs/ceph/locks.c
index 476b329867d4..7f0f72c53f7e 100644
--- a/fs/ceph/locks.c
+++ b/fs/ceph/locks.c
@@ -23,7 +23,8 @@ static int ceph_lock_message(u8 lock_type, u16 operation, struct file *file,
         req = ceph_mdsc_create_request(mdsc, operation, USE_AUTH_MDS);
         if (IS_ERR(req))
                 return PTR_ERR(req);
-        req->r_inode = igrab(inode);
+        req->r_inode = inode;
+        ihold(inode);
 
         /* mds requires start and length rather than start and end */
         if (LLONG_MAX == fl->fl_end)
diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c
index 24067d68a554..54b14de2e729 100644
--- a/fs/ceph/snap.c
+++ b/fs/ceph/snap.c
@@ -722,7 +722,7 @@ static void flush_snaps(struct ceph_mds_client *mdsc)
                 ci = list_first_entry(&mdsc->snap_flush_list,
                                 struct ceph_inode_info, i_snap_flush_item);
                 inode = &ci->vfs_inode;
-                igrab(inode);
+                ihold(inode);
                 spin_unlock(&mdsc->snap_flush_lock);
                 spin_lock(&inode->i_lock);
                 __ceph_flush_snaps(ci, &session, 0);
diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index f2b628696180..f42d730f1b66 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -665,7 +665,8 @@ static int ceph_sync_setxattr(struct dentry *dentry, const char *name,
                 err = PTR_ERR(req);
                 goto out;
         }
-        req->r_inode = igrab(inode);
+        req->r_inode = inode;
+        ihold(inode);
         req->r_inode_drop = CEPH_CAP_XATTR_SHARED;
         req->r_num_caps = 1;
         req->r_args.setxattr.flags = cpu_to_le32(flags);
@@ -795,7 +796,8 @@ static int ceph_send_removexattr(struct dentry *dentry, const char *name)
                                        USE_AUTH_MDS);
         if (IS_ERR(req))
                 return PTR_ERR(req);
-        req->r_inode = igrab(inode);
+        req->r_inode = inode;
+        ihold(inode);
         req->r_inode_drop = CEPH_CAP_XATTR_SHARED;
         req->r_num_caps = 1;
         req->r_path2 = kstrdup(name, GFP_NOFS);