On Mon, Oct 14, 2019 at 11:29 PM Sasha Levin <sashal@xxxxxxxxxx> wrote:
>
> On Mon, Oct 14, 2019 at 12:38:57PM -0400, David Wysochanski wrote:
> >Unless there is objections, let me try to fix this up.
> >Thanks.
>
> Hi David,
>
> This was mostly due to missing fe768d51c832e ("CIFS: Return error code
> when getting file handle for writeback"). I've adjusted the context and
> queued it for 4.19. However, if you do end up fixing it up on your side
> please share it with me and I'll confirm that I did the right thing.
>
> --
> Thanks,
> Sasha
See attached for my 4.19 backport so you can compare.
From 1621c660af09098aa3ebc8ca78dd0c170f0f437b Mon Sep 17 00:00:00 2001
From: Dave Wysochanski <dwysocha@xxxxxxxxxx>
Date: Thu, 3 Oct 2019 15:16:27 +1000
Subject: [PATCH] cifs: use cifsInodeInfo->open_file_lock while iterating to
avoid a panic
Commit 487317c99477 ("cifs: add spinlock for the openFileList to
cifsInodeInfo") added cifsInodeInfo->open_file_lock spin_lock to protect
the openFileList, but missed a few places where cifs_inode->openFileList
was enumerated. Change these remaining tcon->open_file_lock to
cifsInodeInfo->open_file_lock to avoid panic in is_size_safe_to_change.
[17313.245641] RIP: 0010:is_size_safe_to_change+0x57/0xb0 [cifs]
[17313.245645] Code: 68 40 48 89 ef e8 19 67 b7 f1 48 8b 43 40 48 8d 4b 40 48 8d 50 f0 48 39 c1 75 0f eb 47 48 8b 42 10 48 8d 50 f0 48 39 c1 74 3a <8b> 80 88 00 00 00 83 c0 01 a8 02 74 e6 48 89 ef c6 07 00 0f 1f 40
[17313.245649] RSP: 0018:ffff94ae1baefa30 EFLAGS: 00010202
[17313.245654] RAX: dead000000000100 RBX: ffff88dc72243300 RCX: ffff88dc72243340
[17313.245657] RDX: dead0000000000f0 RSI: 00000000098f7940 RDI: ffff88dd3102f040
[17313.245659] RBP: ffff88dd3102f040 R08: 0000000000000000 R09: ffff94ae1baefc40
[17313.245661] R10: ffffcdc8bb1c4e80 R11: ffffcdc8b50adb08 R12: 00000000098f7940
[17313.245663] R13: ffff88dc72243300 R14: ffff88dbc8f19600 R15: ffff88dc72243428
[17313.245667] FS: 00007fb145485700(0000) GS:ffff88dd3e000000(0000) knlGS:0000000000000000
[17313.245670] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[17313.245672] CR2: 0000026bb46c6000 CR3: 0000004edb110003 CR4: 00000000007606e0
[17313.245753] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[17313.245756] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[17313.245759] PKRU: 55555554
[17313.245761] Call Trace:
[17313.245803] cifs_fattr_to_inode+0x16b/0x580 [cifs]
[17313.245838] cifs_get_inode_info+0x35c/0xa60 [cifs]
[17313.245852] ? kmem_cache_alloc_trace+0x151/0x1d0
[17313.245885] cifs_open+0x38f/0x990 [cifs]
[17313.245921] ? cifs_revalidate_dentry_attr+0x3e/0x350 [cifs]
[17313.245953] ? cifsFileInfo_get+0x30/0x30 [cifs]
[17313.245960] ? do_dentry_open+0x132/0x330
[17313.245963] do_dentry_open+0x132/0x330
[17313.245969] path_openat+0x573/0x14d0
[17313.245974] do_filp_open+0x93/0x100
[17313.245979] ? __check_object_size+0xa3/0x181
[17313.245986] ? audit_alloc_name+0x7e/0xd0
[17313.245992] do_sys_open+0x184/0x220
[17313.245999] do_syscall_64+0x5b/0x1b0
Fixes: 487317c99477 ("cifs: add spinlock for the openFileList to cifsInodeInfo")
CC: Stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Dave Wysochanski <dwysocha@xxxxxxxxxx>
Reviewed-by: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
(cherry picked from commit cb248819d209d113e45fed459773991518e8e80b)
Conflicts:
fs/cifs/file.c
---
fs/cifs/file.c | 27 +++++++++++----------------
1 file changed, 11 insertions(+), 16 deletions(-)
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 8703b5f26f45..26027d85ffd5 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1835,13 +1835,12 @@ struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
{
struct cifsFileInfo *open_file = NULL;
struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
- struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
/* only filter by fsuid on multiuser mounts */
if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
fsuid_only = false;
- spin_lock(&tcon->open_file_lock);
+ spin_lock(&cifs_inode->open_file_lock);
/* we could simply get the first_list_entry since write-only entries
are always at the end of the list but since the first entry might
have a close pending, we go through the whole list */
@@ -1853,7 +1852,7 @@ struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
/* found a good file */
/* lock it so it will not be closed on us */
cifsFileInfo_get(open_file);
- spin_unlock(&tcon->open_file_lock);
+ spin_unlock(&cifs_inode->open_file_lock);
return open_file;
} /* else might as well continue, and look for
another, or simply have the caller reopen it
@@ -1861,7 +1860,7 @@ struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
} else /* write only file */
break; /* write only files are last so must be done */
}
- spin_unlock(&tcon->open_file_lock);
+ spin_unlock(&cifs_inode->open_file_lock);
return NULL;
}
@@ -1870,7 +1869,6 @@ struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
{
struct cifsFileInfo *open_file, *inv_file = NULL;
struct cifs_sb_info *cifs_sb;
- struct cifs_tcon *tcon;
bool any_available = false;
int rc;
unsigned int refind = 0;
@@ -1886,16 +1884,15 @@ struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
}
cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
- tcon = cifs_sb_master_tcon(cifs_sb);
/* only filter by fsuid on multiuser mounts */
if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
fsuid_only = false;
- spin_lock(&tcon->open_file_lock);
+ spin_lock(&cifs_inode->open_file_lock);
refind_writable:
if (refind > MAX_REOPEN_ATT) {
- spin_unlock(&tcon->open_file_lock);
+ spin_unlock(&cifs_inode->open_file_lock);
return NULL;
}
list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
@@ -1907,7 +1904,7 @@ struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
if (!open_file->invalidHandle) {
/* found a good writable file */
cifsFileInfo_get(open_file);
- spin_unlock(&tcon->open_file_lock);
+ spin_unlock(&cifs_inode->open_file_lock);
return open_file;
} else {
if (!inv_file)
@@ -1926,7 +1923,7 @@ struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
cifsFileInfo_get(inv_file);
}
- spin_unlock(&tcon->open_file_lock);
+ spin_unlock(&cifs_inode->open_file_lock);
if (inv_file) {
rc = cifs_reopen_file(inv_file, false);
@@ -1940,7 +1937,7 @@ struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
cifsFileInfo_put(inv_file);
++refind;
inv_file = NULL;
- spin_lock(&tcon->open_file_lock);
+ spin_lock(&cifs_inode->open_file_lock);
goto refind_writable;
}
}
@@ -4001,17 +3998,15 @@ static int cifs_readpage(struct file *file, struct page *page)
static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
{
struct cifsFileInfo *open_file;
- struct cifs_tcon *tcon =
- cifs_sb_master_tcon(CIFS_SB(cifs_inode->vfs_inode.i_sb));
- spin_lock(&tcon->open_file_lock);
+ spin_lock(&cifs_inode->open_file_lock);
list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
- spin_unlock(&tcon->open_file_lock);
+ spin_unlock(&cifs_inode->open_file_lock);
return 1;
}
}
- spin_unlock(&tcon->open_file_lock);
+ spin_unlock(&cifs_inode->open_file_lock);
return 0;
}
--
1.8.3.1
