* [PATCH 0/1] dont leak -EAGAIN
@ 2020-02-18 4:18 Ronnie Sahlberg
2020-02-18 4:18 ` [PATCH] cifs: don't leak -EAGAIN for stat() during reconnect Ronnie Sahlberg
0 siblings, 1 reply; 2+ messages in thread
From: Ronnie Sahlberg @ 2020-02-18 4:18 UTC (permalink / raw)
To: linux-cifs
Steve, List
Please find a small patch to fix an issue where during a session reconnect we may leak
-EAGAIN back to the application instead of retrying the operation once reconnect has completed.
This can affects for example the stat() call :
stat("/mnt", 0x55b802c096f8) = -1 EAGAIN (Resource temporarily unavailable) <0.002447>
causing applications such as 'ls' to fail with an error as this is not a valid return
for stat()
^ permalink raw reply [flat|nested] 2+ messages in thread
* [PATCH] cifs: don't leak -EAGAIN for stat() during reconnect
2020-02-18 4:18 [PATCH 0/1] dont leak -EAGAIN Ronnie Sahlberg
@ 2020-02-18 4:18 ` Ronnie Sahlberg
0 siblings, 0 replies; 2+ messages in thread
From: Ronnie Sahlberg @ 2020-02-18 4:18 UTC (permalink / raw)
To: linux-cifs; +Cc: Ronnie Sahlberg
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 | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index b5e6635c578e..cf36dcd9dafd 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -2073,7 +2073,9 @@ 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;
+again:
if (inode == NULL)
return -ENOENT;
@@ -2099,6 +2101,8 @@ int cifs_revalidate_dentry_attr(struct dentry *dentry)
else
rc = cifs_get_inode_info(&inode, full_path, NULL, sb,
xid, NULL);
+ if (rc == -EAGAIN && count++ < 10)
+ goto again;
out:
kfree(full_path);
--
2.13.6
^ permalink raw reply related [flat|nested] 2+ messages in thread
end of thread, other threads:[~2020-02-18 4:18 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-02-18 4:18 [PATCH 0/1] dont leak -EAGAIN Ronnie Sahlberg
2020-02-18 4:18 ` [PATCH] cifs: don't leak -EAGAIN for stat() during reconnect Ronnie Sahlberg
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).