Re: [PATCH] do not attempt to close cifs files which are already closed due to session reconnect

["Steve French" <smfrench@xxxxxxxxx>]

Slightly updated




-- 
Thanks,

Steve

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index f1ae1f5..c57c056 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -606,7 +606,15 @@ GLOBAL_EXTERN struct list_head		cifs_tcp_ses_list;
  * changes to the tcon->tidStatus should be done while holding this lock.
  */
 GLOBAL_EXTERN rwlock_t		cifs_tcp_ses_lock;
-GLOBAL_EXTERN rwlock_t GlobalSMBSeslock;  /* protects list inserts on 3 above */
+
+/*
+ * This lock protects the cifs_file->llist and cifs_file->flist
+ * list operations, and updates to some flags (cifs_file->invalidHandle)
+ * It will be moved to either use the tcon->stat_lock or equivalent later.
+ * If cifs_tcp_ses_lock and the lock below are both needed to be held, then
+ * the cifs_tcp_ses_lock must be grabbed first and released last.
+ */
+GLOBAL_EXTERN rwlock_t GlobalSMBSeslock;
 
 GLOBAL_EXTERN struct list_head GlobalOplock_Q;
 
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 6449e1a..b691b89 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -488,12 +488,13 @@ int cifs_close(struct inode *inode, struct file *file)
 	pTcon = cifs_sb->tcon;
 	if (pSMBFile) {
 		struct cifsLockInfo *li, *tmp;
-
+		write_lock(&GlobalSMBSeslock);
 		pSMBFile->closePend = true;
 		if (pTcon) {
 			/* no sense reconnecting to close a file that is
 			   already closed */
 			if (!pTcon->need_reconnect) {
+				write_unlock(&GlobalSMBSeslock);
 				timeout = 2;
 				while ((atomic_read(&pSMBFile->wrtPending) != 0)
 					&& (timeout <= 2048)) {
@@ -510,12 +511,15 @@ int cifs_close(struct inode *inode, struct file *file)
 					timeout *= 4;
 				}
 				if (atomic_read(&pSMBFile->wrtPending))
-					cERROR(1,
-						("close with pending writes"));
-				rc = CIFSSMBClose(xid, pTcon,
+					cERROR(1, ("close with pending write"));
+				if (!pTcon->need_reconnect &&
+				    !pSMBFile->invalidHandle)
+					rc = CIFSSMBClose(xid, pTcon,
 						  pSMBFile->netfid);
-			}
-		}
+			} else
+				write_unlock(&GlobalSMBSeslock);
+		} else
+			write_unlock(&GlobalSMBSeslock);
 
 		/* Delete any outstanding lock records.
 		   We'll lose them when the file is closed anyway. */
@@ -587,15 +591,18 @@ int cifs_closedir(struct inode *inode, struct file *file)
 		pTcon = cifs_sb->tcon;
 
 		cFYI(1, ("Freeing private data in close dir"));
+		write_lock(&GlobalSMBSeslock);
 		if (!pCFileStruct->srch_inf.endOfSearch &&
 		    !pCFileStruct->invalidHandle) {
 			pCFileStruct->invalidHandle = true;
+			write_unlock(&GlobalSMBSeslock);
 			rc = CIFSFindClose(xid, pTcon, pCFileStruct->netfid);
 			cFYI(1, ("Closing uncompleted readdir with rc %d",
 				 rc));
 			/* not much we can do if it fails anyway, ignore rc */
 			rc = 0;
-		}
+		} else
+			write_unlock(&GlobalSMBSeslock);
 		ptmp = pCFileStruct->srch_inf.ntwrk_buf_start;
 		if (ptmp) {
 			cFYI(1, ("closedir free smb buf in srch struct"));
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index addd1dc..9ee3f68 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -555,12 +555,14 @@ is_valid_oplock_break(struct smb_hdr *buf, struct TCP_Server_Info *srv)
 				continue;
 
 			cifs_stats_inc(&tcon->num_oplock_brks);
+			write_lock(&GlobalSMBSeslock);
 			list_for_each(tmp2, &tcon->openFileList) {
 				netfile = list_entry(tmp2, struct cifsFileInfo,
 						     tlist);
 				if (pSMB->Fid != netfile->netfid)
 					continue;
 
+				write_unlock(&GlobalSMBSeslock);
 				read_unlock(&cifs_tcp_ses_lock);
 				cFYI(1, ("file id match, oplock break"));
 				pCifsInode = CIFS_I(netfile->pInode);
@@ -576,6 +578,7 @@ is_valid_oplock_break(struct smb_hdr *buf, struct TCP_Server_Info *srv)
 
 				return true;
 			}
+			write_unlock(&GlobalSMBSeslock);
 			read_unlock(&cifs_tcp_ses_lock);
 			cFYI(1, ("No matching file for oplock break"));
 			return true;
diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index 58d5729..9f51f9b 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -741,11 +741,14 @@ static int find_cifs_entry(const int xid, struct cifsTconInfo *pTcon,
 	   (index_to_find < first_entry_in_buffer)) {
 		/* close and restart search */
 		cFYI(1, ("search backing up - close and restart search"));
+		write_lock(&GlobalSMBSeslock);
 		if (!cifsFile->srch_inf.endOfSearch &&
 		    !cifsFile->invalidHandle) {
 			cifsFile->invalidHandle = true;
+			write_unlock(&GlobalSMBSeslock);
 			CIFSFindClose(xid, pTcon, cifsFile->netfid);
-		}
+		} else
+			write_unlock(&GlobalSMBSeslock);
 		if (cifsFile->srch_inf.ntwrk_buf_start) {
 			cFYI(1, ("freeing SMB ff cache buf on search rewind"));
 			if (cifsFile->srch_inf.smallBuf)