cifs: eliminate cifsInodeInfo->write_behind_rc (try #6)

write_behind_rc is redundant and just adds complexity to the code. What
we really want to do instead is to use mapping_set_error to reset the
flags on the mapping when we find a writeback error and can't report it
to userspace yet.

For cifs_flush and cifs_fsync, we shouldn't reset the flags since errors
returned there do get reported to userspace.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Suresh Jayaraman <sjayaraman@suse.de>
Reviewed-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

4 files changed, 15 insertions, 39 deletions

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 34371637f210..e8b9523c9f39 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -318,7 +318,6 @@ cifs_alloc_inode(struct super_block *sb)
                 return NULL;
         cifs_inode->cifsAttrs = 0x20;   /* default */
         cifs_inode->time = 0;
-        cifs_inode->write_behind_rc = 0;
         /* Until the file is open and we have gotten oplock
         info back from the server, can not assume caching of
         file data or metadata */
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 7128c291cec8..ef5709b250e6 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -420,7 +420,6 @@ struct cifsInodeInfo {
         struct list_head lockList;
         /* BB add in lists for dirty pages i.e. write caching info for oplock */
         struct list_head openFileList;
-        int write_behind_rc;
         __u32 cifsAttrs; /* e.g. DOS archive bit, sparse, compressed, system */
         unsigned long time;     /* jiffies of last update/check of inode */
         bool clientCanCacheRead:1;      /* read oplock */
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 128e07b85d6c..ad47820655d9 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -131,8 +131,7 @@ static inline int cifs_open_inode_helper(struct inode *inode,
                         /* BB no need to lock inode until after invalidate
                         since namei code should already have it locked? */
                         rc = filemap_write_and_wait(inode->i_mapping);
-                        if (rc != 0)
-                                pCifsInode->write_behind_rc = rc;
+                        mapping_set_error(inode->i_mapping, rc);
                 }
                 cFYI(1, "invalidating remote inode since open detected it "
                          "changed");
@@ -606,8 +605,7 @@ reopen_success:
 
         if (can_flush) {
                 rc = filemap_write_and_wait(inode->i_mapping);
-                if (rc != 0)
-                        CIFS_I(inode)->write_behind_rc = rc;
+                mapping_set_error(inode->i_mapping, rc);
 
                 pCifsInode->clientCanCacheAll = false;
                 pCifsInode->clientCanCacheRead = false;
@@ -1489,12 +1487,7 @@ retry:
                         if (rc || bytes_written < bytes_to_write) {
                                 cERROR(1, "Write2 ret %d, wrote %d",
                                           rc, bytes_written);
-                                /* BB what if continued retry is
-                                   requested via mount flags? */
-                                if (rc == -ENOSPC)
-                                        set_bit(AS_ENOSPC, &mapping->flags);
-                                else
-                                        set_bit(AS_EIO, &mapping->flags);
+                                mapping_set_error(mapping, rc);
                         } else {
                                 cifs_stats_bytes_written(tcon, bytes_written);
                         }
@@ -1639,11 +1632,10 @@ int cifs_fsync(struct file *file, int datasync)
 
         rc = filemap_write_and_wait(inode->i_mapping);
         if (rc == 0) {
-                rc = CIFS_I(inode)->write_behind_rc;
-                CIFS_I(inode)->write_behind_rc = 0;
+                struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
+
                 tcon = tlink_tcon(smbfile->tlink);
-                if (!rc && tcon && smbfile &&
-                   !(CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC))
+                if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC))
                         rc = CIFSSMBFlush(xid, tcon, smbfile->netfid);
         }
 
@@ -1688,14 +1680,8 @@ int cifs_flush(struct file *file, fl_owner_t id)
         struct inode *inode = file->f_path.dentry->d_inode;
         int rc = 0;
 
-        if (file->f_mode & FMODE_WRITE) {
+        if (file->f_mode & FMODE_WRITE)
                 rc = filemap_write_and_wait(inode->i_mapping);
-                /* reset wb rc if we were able to write out dirty pages */
-                if (!rc) {
-                        rc = CIFS_I(inode)->write_behind_rc;
-                        CIFS_I(inode)->write_behind_rc = 0;
-                }
-        }
 
         cFYI(1, "Flush inode %p file %p rc %d", inode, file, rc);
 
@@ -2274,7 +2260,7 @@ void cifs_oplock_break(struct work_struct *work)
                                                   oplock_break);
         struct inode *inode = cfile->dentry->d_inode;
         struct cifsInodeInfo *cinode = CIFS_I(inode);
-        int rc, waitrc = 0;
+        int rc = 0;
 
         if (inode && S_ISREG(inode->i_mode)) {
                 if (cinode->clientCanCacheRead)
@@ -2283,13 +2269,10 @@ void cifs_oplock_break(struct work_struct *work)
                         break_lease(inode, O_WRONLY);
                 rc = filemap_fdatawrite(inode->i_mapping);
                 if (cinode->clientCanCacheRead == 0) {
-                        waitrc = filemap_fdatawait(inode->i_mapping);
+                        rc = filemap_fdatawait(inode->i_mapping);
+                        mapping_set_error(inode->i_mapping, rc);
                         invalidate_remote_inode(inode);
                 }
-                if (!rc)
-                        rc = waitrc;
-                if (rc)
-                        cinode->write_behind_rc = rc;
                 cFYI(1, "Oplock flush inode %p rc %d", inode, rc);
         }
 
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 94979309698a..39869c3c3efb 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1682,8 +1682,7 @@ cifs_invalidate_mapping(struct inode *inode)
         /* write back any cached data */
         if (inode->i_mapping && inode->i_mapping->nrpages != 0) {
                 rc = filemap_write_and_wait(inode->i_mapping);
-                if (rc)
-                        cifs_i->write_behind_rc = rc;
+                mapping_set_error(inode->i_mapping, rc);
         }
         invalidate_remote_inode(inode);
         cifs_fscache_reset_inode_cookie(inode);
@@ -1943,10 +1942,8 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs)
          * the flush returns error?
          */
         rc = filemap_write_and_wait(inode->i_mapping);
-        if (rc != 0) {
-                cifsInode->write_behind_rc = rc;
-                rc = 0;
-        }
+        mapping_set_error(inode->i_mapping, rc);
+        rc = 0;
 
         if (attrs->ia_valid & ATTR_SIZE) {
                 rc = cifs_set_file_size(inode, attrs, xid, full_path);
@@ -2087,10 +2084,8 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
          * the flush returns error?
          */
         rc = filemap_write_and_wait(inode->i_mapping);
-        if (rc != 0) {
-                cifsInode->write_behind_rc = rc;
-                rc = 0;
-        }
+        mapping_set_error(inode->i_mapping, rc);
+        rc = 0;
 
         if (attrs->ia_valid & ATTR_SIZE) {
                 rc = cifs_set_file_size(inode, attrs, xid, full_path);