[linux-cifs-client] [linux-cifs-client[[patch] Attempt #2 to handle null nameidata
Shirish Pargaonkar
shirishpargaonkar at gmail.com
Thu Apr 8 13:40:47 MDT 2010
On Thu, Apr 8, 2010 at 2:34 PM, Jeff Layton <jlayton at samba.org> wrote:
> On Wed, 7 Apr 2010 11:19:10 -0500
> shirishpargaonkar at gmail.com wrote:
>
>> While creating a file on a server which supports unix extensions
>> such as Samba, if a file is being created which does not supply
>> nameidata (i.e. nd is null), cifs client can oops when calling
>> cifs_posix_open.
>>
>> Signed-off-by: Shirish Pargaonkar <shirishpargaonkar at gmail.com>
>> Reported-by: Eugene Teo <eugeneteo at kernel.sg>
>> ---
>>
>
> This patch is hideous, but I suppose it's the best that can be done
> short of rewriting this code to have a sane API.
>
>> diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
>> index 88e2bc4..efb8772 100644
>> --- a/fs/cifs/cifsproto.h
>> +++ b/fs/cifs/cifsproto.h
>> @@ -95,8 +95,10 @@ extern struct cifsFileInfo *cifs_new_fileinfo(struct inode *newinode,
>> __u16 fileHandle, struct file *file,
>> struct vfsmount *mnt, unsigned int oflags);
>> extern int cifs_posix_open(char *full_path, struct inode **pinode,
>> - struct vfsmount *mnt, int mode, int oflags,
>> - __u32 *poplock, __u16 *pnetfid, int xid);
>> + struct vfsmount *mnt,
>> + struct super_block *sb,
>> + int mode, int oflags,
>> + __u32 *poplock, __u16 *pnetfid, int xid);
>> extern void cifs_unix_basic_to_fattr(struct cifs_fattr *fattr,
>> FILE_UNIX_BASIC_INFO *info,
>> struct cifs_sb_info *cifs_sb);
>> diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
>> index 6ccf726..9e9d48f 100644
>> --- a/fs/cifs/dir.c
>> +++ b/fs/cifs/dir.c
>> @@ -183,13 +183,14 @@ cifs_new_fileinfo(struct inode *newinode, __u16 fileHandle,
>> }
>>
>> int cifs_posix_open(char *full_path, struct inode **pinode,
>> - struct vfsmount *mnt, int mode, int oflags,
>> - __u32 *poplock, __u16 *pnetfid, int xid)
>> + struct vfsmount *mnt, struct super_block *sb,
>> + int mode, int oflags,
>> + __u32 *poplock, __u16 *pnetfid, int xid)
>> {
>> int rc;
>> FILE_UNIX_BASIC_INFO *presp_data;
>> __u32 posix_flags = 0;
>> - struct cifs_sb_info *cifs_sb = CIFS_SB(mnt->mnt_sb);
>> + struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
>> struct cifs_fattr fattr;
>>
>> cFYI(1, ("posix open %s", full_path));
>> @@ -242,7 +243,7 @@ int cifs_posix_open(char *full_path, struct inode **pinode,
>>
>> /* get new inode and set it up */
>> if (*pinode == NULL) {
>> - *pinode = cifs_iget(mnt->mnt_sb, &fattr);
>> + *pinode = cifs_iget(sb, &fattr);
>> if (!*pinode) {
>> rc = -ENOMEM;
>> goto posix_open_ret;
>> @@ -251,7 +252,8 @@ int cifs_posix_open(char *full_path, struct inode **pinode,
>> cifs_fattr_to_inode(*pinode, &fattr);
>> }
>>
>> - cifs_new_fileinfo(*pinode, *pnetfid, NULL, mnt, oflags);
>> + if (mnt)
>> + cifs_new_fileinfo(*pinode, *pnetfid, NULL, mnt, oflags);
>>
>
> The cifs_create codepath closes the file (via CIFSSMBClose) when nd is
> NULL. The NULL mnt case here is analogous, right? Shouldn't it also
> CIFSSMBClose the file?
Jeff, not sure I understand. In case of null nd, cifs_create will
close the file
whether posix open or regular open (or legacy open) gets called or not.
Regards,
Shirish
>
>> posix_open_ret:
>> kfree(presp_data);
>> @@ -315,13 +317,14 @@ cifs_create(struct inode *inode, struct dentry *direntry, int mode,
>> if (nd && (nd->flags & LOOKUP_OPEN))
>> oflags = nd->intent.open.flags;
>> else
>> - oflags = FMODE_READ;
>> + oflags = FMODE_READ | SMB_O_CREAT;
>>
>> if (tcon->unix_ext && (tcon->ses->capabilities & CAP_UNIX) &&
>> (CIFS_UNIX_POSIX_PATH_OPS_CAP &
>> le64_to_cpu(tcon->fsUnixInfo.Capability))) {
>> - rc = cifs_posix_open(full_path, &newinode, nd->path.mnt,
>> - mode, oflags, &oplock, &fileHandle, xid);
>> + rc = cifs_posix_open(full_path, &newinode,
>> + nd ? nd->path.mnt : NULL,
>> + inode->i_sb, mode, oflags, &oplock, &fileHandle, xid);
>> /* EIO could indicate that (posix open) operation is not
>> supported, despite what server claimed in capability
>> negotation. EREMOTE indicates DFS junction, which is not
>> @@ -678,6 +681,7 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
>> (nd->flags & LOOKUP_OPEN) && !pTcon->broken_posix_open &&
>> (nd->intent.open.flags & O_CREAT)) {
>> rc = cifs_posix_open(full_path, &newInode, nd->path.mnt,
>> + parent_dir_inode->i_sb,
>> nd->intent.open.create_mode,
>> nd->intent.open.flags, &oplock,
>> &fileHandle, xid);
>> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
>> index 3d8f8a9..503a459 100644
>> --- a/fs/cifs/file.c
>> +++ b/fs/cifs/file.c
>> @@ -297,10 +297,12 @@ int cifs_open(struct inode *inode, struct file *file)
>> (CIFS_UNIX_POSIX_PATH_OPS_CAP &
>> le64_to_cpu(tcon->fsUnixInfo.Capability))) {
>> int oflags = (int) cifs_posix_convert_flags(file->f_flags);
>> + oflags |= SMB_O_CREAT;
>> /* can not refresh inode info since size could be stale */
>> rc = cifs_posix_open(full_path, &inode, file->f_path.mnt,
>> - cifs_sb->mnt_file_mode /* ignored */,
>> - oflags, &oplock, &netfid, xid);
>> + inode->i_sb,
>> + cifs_sb->mnt_file_mode /* ignored */,
>> + oflags, &oplock, &netfid, xid);
>> if (rc == 0) {
>> cFYI(1, ("posix open succeeded"));
>> /* no need for special case handling of setting mode
>> @@ -512,8 +514,9 @@ reopen_error_exit:
>> int oflags = (int) cifs_posix_convert_flags(file->f_flags);
>> /* can not refresh inode info since size could be stale */
>> rc = cifs_posix_open(full_path, NULL, file->f_path.mnt,
>> - cifs_sb->mnt_file_mode /* ignored */,
>> - oflags, &oplock, &netfid, xid);
>> + inode->i_sb,
>> + cifs_sb->mnt_file_mode /* ignored */,
>> + oflags, &oplock, &netfid, xid);
>> if (rc == 0) {
>> cFYI(1, ("posix reopen succeeded"));
>> goto reopen_success;
>> _______________________________________________
>> linux-cifs-client mailing list
>> linux-cifs-client at lists.samba.org
>> https://lists.samba.org/mailman/listinfo/linux-cifs-client
>>
>
> Ugly, but I suppose it's all that can reasonably be done short of
> making all of this code use a more sane API.
>
> --
> Jeff Layton <jlayton at samba.org>
>
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