| Message ID | 20200218044829.15629-1-lsahlber@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | cifs: don't leak -EAGAIN for stat() during reconnect | expand |
Hi Ronnie, Ronnie Sahlberg <lsahlber@redhat.com> writes: > Fix this by re-trying the operation from within cifs_revalidate_dentry_attr() > if cifs_get_inode_info*() returns -EAGAIN. Would it make sense to use is_retryable_error() instead of checking for just EAGAIN? It also checks for interruption errors. Cheers,
On Tue, Feb 18, 2020 at 9:47 PM Aurélien Aptel <aaptel@suse.com> wrote: > > Hi Ronnie, > > Ronnie Sahlberg <lsahlber@redhat.com> writes: > > Fix this by re-trying the operation from within cifs_revalidate_dentry_attr() > > if cifs_get_inode_info*() returns -EAGAIN. > > Would it make sense to use is_retryable_error() instead of checking for > just EAGAIN? It also checks for interruption errors. Makes sense. Thanks. > > Cheers, > -- > Aurélien Aptel / SUSE Labs Samba Team > GPG: 1839 CB5F 9F5B FB9B AA97 8C99 03C8 A49B 521B D5D3 > SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg, DE > GF: Felix Imendörffer, Mary Higgins, Sri Rasiah HRB 247165 (AG München)
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c index b5e6635c578e..1c6f659110d0 100644 --- a/fs/cifs/inode.c +++ b/fs/cifs/inode.c @@ -2073,6 +2073,7 @@ int cifs_revalidate_dentry_attr(struct dentry *dentry) struct inode *inode = d_inode(dentry); struct super_block *sb = dentry->d_sb; char *full_path = NULL; + int count = 0; if (inode == NULL) return -ENOENT; @@ -2094,15 +2095,18 @@ int cifs_revalidate_dentry_attr(struct dentry *dentry) full_path, inode, inode->i_count.counter, dentry, cifs_get_time(dentry), jiffies); +again: if (cifs_sb_master_tcon(CIFS_SB(sb))->unix_ext) rc = cifs_get_inode_info_unix(&inode, full_path, sb, xid); else rc = cifs_get_inode_info(&inode, full_path, NULL, sb, xid, NULL); - + if (rc == -EAGAIN && count++ < 10) + goto again; out: kfree(full_path); free_xid(xid); + return rc; }
If from cifs_revalidate_dentry_attr() the SMB2/QUERY_INFO call fails with an error, such as STATUS_SESSION_EXPIRED, causing the session to be reconnected it is possible we will leak -EAGAIN back to the application even for system calls such as stat() where this is not a valid error. Fix this by re-trying the operation from within cifs_revalidate_dentry_attr() if cifs_get_inode_info*() returns -EAGAIN. This fixes stat() and possibly also other system calls that uses cifs_revalidate_dentry*(). Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> --- fs/cifs/inode.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)