merged On Fri, Feb 24, 2012 at 12:12 PM, Jeff Layton <[email protected]> wrote: > On Fri, 24 Feb 2012 11:59:25 -0600 > Shirish Pargaonkar <[email protected]> wrote: > >> On Thu, Feb 23, 2012 at 8:37 AM, Jeff Layton <[email protected]> wrote: >> > The cifs code will attempt to open files on lookup under certain >> > circumstances. What happens though if we find that the file we opened >> > was actually a FIFO or other special file? >> > >> > Currently, the open filehandle just ends up being leaked leading to >> > a dentry refcount mismatch and oops on umount. Fix this by having the >> > code close the filehandle on the server if it turns out not to be a >> > regular file. While we're at it, change this spaghetti if statement >> > into a switch too. >> > >> > Cc: [email protected] >> > Reported-by: CAI Qian <[email protected]> >> > Signed-off-by: Jeff Layton <[email protected]> >> > --- >> > fs/cifs/dir.c | 20 ++++++++++++++++++-- >> > 1 files changed, 18 insertions(+), 2 deletions(-) >> > >> > diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c >> > index 63a196b..bc7e244 100644 >> > --- a/fs/cifs/dir.c >> > +++ b/fs/cifs/dir.c >> > @@ -584,10 +584,26 @@ cifs_lookup(struct inode *parent_dir_inode, struct >> > dentry *direntry, >> > * If either that or op not supported returned, >> > follow >> > * the normal lookup. >> > */ >> > - if ((rc == 0) || (rc == -ENOENT)) >> > + switch (rc) { >> > + case 0: >> > + /* >> > + * The server may allow us to open things >> > like >> > + * FIFOs, but the client isn't set up to >> > deal >> > + * with that. If it's not a regular file, >> > just >> > + * close it and proceed as if it were a >> > normal >> > + * lookup. >> > + */ >> > + if (newInode && >> > !S_ISREG(newInode->i_mode)) { >> > + CIFSSMBClose(xid, pTcon, >> > fileHandle); >> > + break; >> > + } >> > + case -ENOENT: >> > posix_open = true; >> > - else if ((rc == -EINVAL) || (rc != -EOPNOTSUPP)) >> > + case -EOPNOTSUPP: >> > + break; >> > + default: >> > pTcon->broken_posix_open = true; >> > + } >> > } >> > if (!posix_open) >> > rc = cifs_get_inode_info_unix(&newInode, full_path, >> > -- >> > 1.7.7.6 >> > >> > -- >> > To unsubscribe from this list: send the line "unsubscribe linux-cifs" in >> > the body of a message to [email protected] >> > More majordomo info at http://vger.kernel.org/majordomo-info.html >> >> One more thing, should CIFSPOSIXDelFile should be called to match >> CIFSPOSIXOpen or CIFSMBClose is just as good enough? > > I don't think so... > > If the FIFO was already there, then you clearly don't want to remove > it. Note that in this case, we're not failing anything -- just getting > rid of the open filehandle and corresponding CIFS open when we realize > that it's not a normal file. > > -- > Jeff Layton <[email protected]>
-- Thanks, Steve -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
