[PATCH] cifs: Fix caching problem
pointed out by Dave Stahl and Vince Negri in which cifs can update the
last modify time on a server modified file without invalidating the
local cached data due to an intervening readdir.
Signed-off-by: Steve French (sfrench@us.ibm.com)
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index 7ca876b..39170cf 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -3,7 +3,7 @@
*
* Directory search handling
*
- * Copyright (C) International Business Machines Corp., 2004
+ * Copyright (C) International Business Machines Corp., 2004, 2005
* Author(s): Steve French (sfrench@us.ibm.com)
*
* This library is free software; you can redistribute it and/or modify
@@ -65,14 +65,14 @@
struct cifsTconInfo *pTcon;
int rc = 0;
- cFYI(1, ("For %s ", qstring->name));
+ cFYI(1, ("For %s", qstring->name));
cifs_sb = CIFS_SB(file->f_dentry->d_sb);
pTcon = cifs_sb->tcon;
qstring->hash = full_name_hash(qstring->name, qstring->len);
tmp_dentry = d_lookup(file->f_dentry, qstring);
if (tmp_dentry) {
- cFYI(0, (" existing dentry with inode 0x%p", tmp_dentry->d_inode));
+ cFYI(0, ("existing dentry with inode 0x%p", tmp_dentry->d_inode));
*ptmp_inode = tmp_dentry->d_inode;
/* BB overwrite old name? i.e. tmp_dentry->d_name and tmp_dentry->d_name.len??*/
if(*ptmp_inode == NULL) {
@@ -105,8 +105,11 @@
}
static void fill_in_inode(struct inode *tmp_inode,
- FILE_DIRECTORY_INFO *pfindData, int *pobject_type)
+ FILE_DIRECTORY_INFO *pfindData, int *pobject_type, int isNewInode)
{
+ loff_t local_size;
+ struct timespec local_mtime;
+
struct cifsInodeInfo *cifsInfo = CIFS_I(tmp_inode);
struct cifs_sb_info *cifs_sb = CIFS_SB(tmp_inode->i_sb);
__u32 attr = le32_to_cpu(pfindData->ExtFileAttributes);
@@ -116,6 +119,10 @@
cifsInfo->cifsAttrs = attr;
cifsInfo->time = jiffies;
+ /* save mtime and size */
+ local_mtime = tmp_inode->i_mtime;
+ local_size = tmp_inode->i_size;
+
/* Linux can not store file creation time unfortunately so ignore it */
tmp_inode->i_atime =
cifs_NTtimeToUnix(le64_to_cpu(pfindData->LastAccessTime));
@@ -134,7 +141,6 @@
tmp_inode->i_mode = cifs_sb->mnt_file_mode;
}
- cFYI(0,("CIFS FFIRST: Attributes came in as 0x%x",attr));
if (attr & ATTR_DIRECTORY) {
*pobject_type = DT_DIR;
/* override default perms since we do not lock dirs */
@@ -175,30 +181,46 @@
(unsigned long)tmp_inode->i_size, tmp_inode->i_blocks,
tmp_inode->i_blksize));
if (S_ISREG(tmp_inode->i_mode)) {
- cFYI(1, (" File inode "));
+ cFYI(1, ("File inode"));
tmp_inode->i_op = &cifs_file_inode_ops;
if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO)
tmp_inode->i_fop = &cifs_file_direct_ops;
else
tmp_inode->i_fop = &cifs_file_ops;
tmp_inode->i_data.a_ops = &cifs_addr_ops;
+
+ if(isNewInode)
+ return; /* No sense invalidating pages for new inode since we
+ have not started caching readahead file data yet */
+
+ if (timespec_equal(&tmp_inode->i_mtime, &local_mtime) &&
+ (local_size == tmp_inode->i_size)) {
+ cFYI(1, ("inode exists but unchanged"));
+ } else {
+ /* file may have changed on server */
+ cFYI(1, ("invalidate inode, readdir detected change"));
+ invalidate_remote_inode(tmp_inode);
+ }
} else if (S_ISDIR(tmp_inode->i_mode)) {
- cFYI(1, (" Directory inode"));
+ cFYI(1, ("Directory inode"));
tmp_inode->i_op = &cifs_dir_inode_ops;
tmp_inode->i_fop = &cifs_dir_ops;
} else if (S_ISLNK(tmp_inode->i_mode)) {
- cFYI(1, (" Symbolic Link inode "));
+ cFYI(1, ("Symbolic Link inode"));
tmp_inode->i_op = &cifs_symlink_inode_ops;
} else {
- cFYI(1, (" Init special inode "));
+ cFYI(1, ("Init special inode"));
init_special_inode(tmp_inode, tmp_inode->i_mode,
tmp_inode->i_rdev);
}
}
static void unix_fill_in_inode(struct inode *tmp_inode,
- FILE_UNIX_INFO *pfindData, int *pobject_type)
+ FILE_UNIX_INFO *pfindData, int *pobject_type, int isNewInode)
{
+ loff_t local_size;
+ struct timespec local_mtime;
+
struct cifsInodeInfo *cifsInfo = CIFS_I(tmp_inode);
struct cifs_sb_info *cifs_sb = CIFS_SB(tmp_inode->i_sb);
@@ -208,6 +230,10 @@
cifsInfo->time = jiffies;
atomic_inc(&cifsInfo->inUse);
+ /* save mtime and size */
+ local_mtime = tmp_inode->i_mtime;
+ local_size = tmp_inode->i_size;
+
tmp_inode->i_atime =
cifs_NTtimeToUnix(le64_to_cpu(pfindData->LastAccessTime));
tmp_inode->i_mtime =
@@ -265,6 +291,19 @@
else
tmp_inode->i_fop = &cifs_file_ops;
tmp_inode->i_data.a_ops = &cifs_addr_ops;
+
+ if(isNewInode)
+ return; /* No sense invalidating pages for new inode since we
+ have not started caching readahead file data yet */
+
+ if (timespec_equal(&tmp_inode->i_mtime, &local_mtime) &&
+ (local_size == tmp_inode->i_size)) {
+ cFYI(1, ("inode exists but unchanged"));
+ } else {
+ /* file may have changed on server */
+ cFYI(1, ("invalidate inode, readdir detected change"));
+ invalidate_remote_inode(tmp_inode);
+ }
} else if (S_ISDIR(tmp_inode->i_mode)) {
cFYI(1, ("Directory inode"));
tmp_inode->i_op = &cifs_dir_inode_ops;
@@ -321,7 +360,7 @@
return -ENOMEM;
}
- cFYI(1, ("Full path: %s start at: %lld ", full_path, file->f_pos));
+ cFYI(1, ("Full path: %s start at: %lld", full_path, file->f_pos));
ffirst_retry:
/* test for Unix extensions */
@@ -666,10 +705,15 @@
insert_inode_hash(tmp_inode);
}
+ /* we pass in rc below, indicating whether it is a new inode,
+ so we can figure out whether to invalidate the inode cached
+ data if the file has changed */
if(pCifsF->srch_inf.info_level == SMB_FIND_FILE_UNIX) {
- unix_fill_in_inode(tmp_inode,(FILE_UNIX_INFO *)pfindEntry,&obj_type);
+ unix_fill_in_inode(tmp_inode,
+ (FILE_UNIX_INFO *)pfindEntry,&obj_type, rc);
} else {
- fill_in_inode(tmp_inode,(FILE_DIRECTORY_INFO *)pfindEntry,&obj_type);
+ fill_in_inode(tmp_inode,
+ (FILE_DIRECTORY_INFO *)pfindEntry,&obj_type, rc);
}
rc = filldir(direntry,qstring.name,qstring.len,file->f_pos,tmp_inode->i_ino,obj_type);