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authorPavel Shilovsky <pshilov@microsoft.com>2019-01-29 12:15:11 -0800
committerSteve French <stfrench@microsoft.com>2019-03-05 18:10:04 -0600
commitfe768d51c832ebde70a83221b0633dc7bc9640a6 (patch)
tree06304ab7a40e0372eb79a3af3014e59c4eadc4d0 /fs/cifs/file.c
parentc4b8f657d55b4ed60cb0a2187e940706de23f2b2 (diff)
downloadlinux-fe768d51c832ebde70a83221b0633dc7bc9640a6.tar.bz2
CIFS: Return error code when getting file handle for writeback
Now we just return NULL cifsFileInfo pointer in cases we didn't find or couldn't reopen a file. This hides errors from cifs_reopen_file() especially retryable errors which should be handled appropriately. Create new cifs_get_writable_file() routine that returns error codes from cifs_reopen_file() and use it in the writeback codepath. Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/cifs/file.c')
-rw-r--r--fs/cifs/file.c90
1 files changed, 61 insertions, 29 deletions
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 8d5fec497792..9b53f33137b3 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1842,24 +1842,30 @@ struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
return NULL;
}
-struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
- bool fsuid_only)
+/* Return -EBADF if no handle is found and general rc otherwise */
+int
+cifs_get_writable_file(struct cifsInodeInfo *cifs_inode, bool fsuid_only,
+ struct cifsFileInfo **ret_file)
{
struct cifsFileInfo *open_file, *inv_file = NULL;
struct cifs_sb_info *cifs_sb;
struct cifs_tcon *tcon;
bool any_available = false;
- int rc;
+ int rc = -EBADF;
unsigned int refind = 0;
- /* Having a null inode here (because mapping->host was set to zero by
- the VFS or MM) should not happen but we had reports of on oops (due to
- it being zero) during stress testcases so we need to check for it */
+ *ret_file = NULL;
+
+ /*
+ * Having a null inode here (because mapping->host was set to zero by
+ * the VFS or MM) should not happen but we had reports of on oops (due
+ * to it being zero) during stress testcases so we need to check for it
+ */
if (cifs_inode == NULL) {
cifs_dbg(VFS, "Null inode passed to cifs_writeable_file\n");
dump_stack();
- return NULL;
+ return rc;
}
cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
@@ -1873,7 +1879,7 @@ struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
refind_writable:
if (refind > MAX_REOPEN_ATT) {
spin_unlock(&tcon->open_file_lock);
- return NULL;
+ return rc;
}
list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
if (!any_available && open_file->pid != current->tgid)
@@ -1885,7 +1891,8 @@ refind_writable:
/* found a good writable file */
cifsFileInfo_get(open_file);
spin_unlock(&tcon->open_file_lock);
- return open_file;
+ *ret_file = open_file;
+ return 0;
} else {
if (!inv_file)
inv_file = open_file;
@@ -1907,22 +1914,35 @@ refind_writable:
if (inv_file) {
rc = cifs_reopen_file(inv_file, false);
- if (!rc)
- return inv_file;
- else {
- spin_lock(&tcon->open_file_lock);
- list_move_tail(&inv_file->flist,
- &cifs_inode->openFileList);
- spin_unlock(&tcon->open_file_lock);
- cifsFileInfo_put(inv_file);
- ++refind;
- inv_file = NULL;
- spin_lock(&tcon->open_file_lock);
- goto refind_writable;
+ if (!rc) {
+ *ret_file = inv_file;
+ return 0;
}
+
+ spin_lock(&tcon->open_file_lock);
+ list_move_tail(&inv_file->flist, &cifs_inode->openFileList);
+ spin_unlock(&tcon->open_file_lock);
+ cifsFileInfo_put(inv_file);
+ ++refind;
+ inv_file = NULL;
+ spin_lock(&tcon->open_file_lock);
+ goto refind_writable;
}
- return NULL;
+ return rc;
+}
+
+struct cifsFileInfo *
+find_writable_file(struct cifsInodeInfo *cifs_inode, bool fsuid_only)
+{
+ struct cifsFileInfo *cfile;
+ int rc;
+
+ rc = cifs_get_writable_file(cifs_inode, fsuid_only, &cfile);
+ if (rc)
+ cifs_dbg(FYI, "couldn't find writable handle rc=%d", rc);
+
+ return cfile;
}
static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
@@ -1959,8 +1979,8 @@ static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
if (mapping->host->i_size - offset < (loff_t)to)
to = (unsigned)(mapping->host->i_size - offset);
- open_file = find_writable_file(CIFS_I(mapping->host), false);
- if (open_file) {
+ rc = cifs_get_writable_file(CIFS_I(mapping->host), false, &open_file);
+ if (!rc) {
bytes_written = cifs_write(open_file, open_file->pid,
write_data, to - from, &offset);
cifsFileInfo_put(open_file);
@@ -1970,9 +1990,12 @@ static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
rc = 0;
else if (bytes_written < 0)
rc = bytes_written;
+ else
+ rc = -EFAULT;
} else {
- cifs_dbg(FYI, "No writeable filehandles for inode\n");
- rc = -EIO;
+ cifs_dbg(FYI, "No writable handle for write page rc=%d\n", rc);
+ if (!is_retryable_error(rc))
+ rc = -EIO;
}
kunmap(page);
@@ -2144,11 +2167,16 @@ retry:
pgoff_t next = 0, tofind, saved_index = index;
struct cifs_credits credits_on_stack;
struct cifs_credits *credits = &credits_on_stack;
+ int get_file_rc = 0;
if (cfile)
cifsFileInfo_put(cfile);
- cfile = find_writable_file(CIFS_I(inode), false);
+ rc = cifs_get_writable_file(CIFS_I(inode), false, &cfile);
+
+ /* in case of an error store it to return later */
+ if (rc)
+ get_file_rc = rc;
rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
&wsize, credits);
@@ -2189,8 +2217,12 @@ retry:
cfile = NULL;
if (!wdata->cfile) {
- cifs_dbg(VFS, "No writable handle in writepages\n");
- rc = -EBADF;
+ cifs_dbg(VFS, "No writable handle in writepages rc=%d\n",
+ get_file_rc);
+ if (is_retryable_error(get_file_rc))
+ rc = get_file_rc;
+ else
+ rc = -EBADF;
} else
rc = wdata_send_pages(wdata, nr_pages, mapping, wbc);