From: Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx>
Add support of Alternate Data Streams (ads).
The generic access flags that cifs client currently employs are sufficient
for alternate data streams as well (MS-CIFS 2.2.4.64.1).
The stream file and stream type are specified using : after the file name,
so that is used to differentiate between a regular file and its
alternate data streams and stream types.
Since they all have the same file id, each path name,
file name:stream name:stream type, has a separate inode with that same
file id but a distinct private data (path name) in that inode to
distinguish them.
This scheme applies only to non-posix compliant servers such as Windows.
One operation that does not work is Rename (0x7).
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx>
---
fs/cifs/cifsfs.c | 1 +
fs/cifs/cifsglob.h | 2 ++
fs/cifs/inode.c | 31 ++++++++++++++++++++++++++++++-
3 files changed, 33 insertions(+), 1 deletions(-)
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index a41044a..1a02c81 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -264,6 +264,7 @@ cifs_evict_inode(struct inode *inode)
{
truncate_inode_pages(&inode->i_data, 0);
clear_inode(inode);
+ kfree(inode->i_private);
cifs_fscache_release_inode_cookie(inode);
}
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index f5af252..26d65c7 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1251,6 +1251,7 @@ struct dfs_info3_param {
#define CIFS_FATTR_DELETE_PENDING 0x2
#define CIFS_FATTR_NEED_REVAL 0x4
#define CIFS_FATTR_INO_COLLISION 0x8
+#define CIFS_FATTR_ALTDATASTR 0x10
struct cifs_fattr {
u32 cf_flags;
@@ -1268,6 +1269,7 @@ struct cifs_fattr {
struct timespec cf_atime;
struct timespec cf_mtime;
struct timespec cf_ctime;
+ char *cf_private;
};
static inline void free_dfs_info_param(struct dfs_info3_param *param)
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index afdff79..b7c6dcf 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -615,10 +615,12 @@ cifs_get_inode_info(struct inode **inode, const char *full_path,
struct tcon_link *tlink;
struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
char *buf = NULL;
+ char *altstr = NULL;
bool adjust_tz = false;
struct cifs_fattr fattr;
struct cifs_search_info *srchinf = NULL;
+ fattr.cf_private = NULL;
tlink = cifs_sb_tlink(cifs_sb);
if (IS_ERR(tlink))
return PTR_ERR(tlink);
@@ -746,9 +748,26 @@ cifs_get_inode_info(struct inode **inode, const char *full_path,
}
if (!*inode) {
+ altstr = strchr(full_path, ':');
+ if (altstr) {
+ fattr.cf_private = kstrdup(altstr, GFP_KERNEL);
+ if (!fattr.cf_private) {
+ rc = -ENOMEM;
+ goto cgii_exit;
+ }
+ fattr.cf_flags |= CIFS_FATTR_ALTDATASTR;
+ }
+
*inode = cifs_iget(sb, &fattr);
- if (!*inode)
+ if (*inode) {
+ if (altstr && !((*inode)->i_private))
+ (*inode)->i_private = fattr.cf_private;
+ else
+ kfree(fattr.cf_private);
+ } else {
rc = -ENOMEM;
+ kfree(fattr.cf_private);
+ }
} else {
cifs_fattr_to_inode(*inode, &fattr);
}
@@ -784,6 +803,16 @@ cifs_find_inode(struct inode *inode, void *opaque)
if (S_ISDIR(inode->i_mode) && !hlist_empty(&inode->i_dentry))
fattr->cf_flags |= CIFS_FATTR_INO_COLLISION;
+ /* looking for an inode of a alternate data stream (full pathname) */
+ if (fattr->cf_flags & CIFS_FATTR_ALTDATASTR) {
+ if (!(inode->i_private)) {
+ return 0;
+ } else {
+ if (strcmp(inode->i_private, fattr->cf_private))
+ return 0;
+ }
+ }
+
return 1;
}
--
1.6.0.2
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