| Message ID | 1350998691-22348-1-git-send-email-shirishpargaonkar@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 23 Oct 2012 08:24:51 -0500 shirishpargaonkar@gmail.com wrote: > From: Shirish Pargaonkar <shirishpargaonkar@gmail.com> > > > 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. > Question: are alternate data streams really part of the protocol per-se? Or are they an implementation detail of the exported filesystem? Is it possible that a (say non-windows) server could export a filesystem that did allow ':' in a filename without posix extensions? If so, are we at risk of treating such a file as an alternate data stream instead of a separate file altogether? Is there a way to distinguish such a situation? > One operation that does not work is Rename (0x7). > I'm confused. What does this have to do with rename? > > Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com> > --- > 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; > } >
On Tue, Oct 23, 2012 at 9:41 AM, Jeff Layton <jlayton@redhat.com> wrote: > On Tue, 23 Oct 2012 08:24:51 -0500 > shirishpargaonkar@gmail.com wrote: > >> From: Shirish Pargaonkar <shirishpargaonkar@gmail.com> >> >> >> 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. >> > > Question: are alternate data streams really part of the protocol > per-se? Or are they an implementation detail of the exported > filesystem? Is it possible that a (say non-windows) server could export > a filesystem that did allow ':' in a filename without posix extensions? > > If so, are we at risk of treating such a file as an alternate data > stream instead of a separate file altogether? Is there a way to > distinguish such a situation? > Jeff, they are not part of the protocol, part of the implementation details of the exported file system. It is possible that a cifs/smb server such as a non-windows server which does not support posix extensions could export a file system that does allow ':' in a filename but it would not be a issue because file ids / unique ids at the server would be different. >> One operation that does not work is Rename (0x7). >> > > I'm confused. What does this have to do with rename? > I was stating the observation that, for a file stream, against a Windows server, cifs/smb operation of renaming that file stream either to a regular file or to a another file stream fails. (whereas create / delete / lookup etc. operations succeed). >> >> Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com> >> --- >> 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; >> } >> > > > -- > Jeff Layton <jlayton@redhat.com> -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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; }