From 560d388950ceda5e7c7cdef7f3d9a8ff297bbf9d Mon Sep 17 00:00:00 2001 From: Rabin Vincent Date: Wed, 3 May 2017 17:17:21 +0200 Subject: [PATCH 1/6] CIFS: silence lockdep splat in cifs_relock_file() cifs_relock_file() can perform a down_write() on the inode's lock_sem even though it was already performed in cifs_strict_readv(). Lockdep complains about this. AFAICS, there is no problem here, and lockdep just needs to be told that this nesting is OK. ============================================= [ INFO: possible recursive locking detected ] 4.11.0+ #20 Not tainted --------------------------------------------- cat/701 is trying to acquire lock: (&cifsi->lock_sem){++++.+}, at: cifs_reopen_file+0x7a7/0xc00 but task is already holding lock: (&cifsi->lock_sem){++++.+}, at: cifs_strict_readv+0x177/0x310 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&cifsi->lock_sem); lock(&cifsi->lock_sem); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by cat/701: #0: (&cifsi->lock_sem){++++.+}, at: cifs_strict_readv+0x177/0x310 stack backtrace: CPU: 0 PID: 701 Comm: cat Not tainted 4.11.0+ #20 Call Trace: dump_stack+0x85/0xc2 __lock_acquire+0x17dd/0x2260 ? trace_hardirqs_on_thunk+0x1a/0x1c ? preempt_schedule_irq+0x6b/0x80 lock_acquire+0xcc/0x260 ? lock_acquire+0xcc/0x260 ? cifs_reopen_file+0x7a7/0xc00 down_read+0x2d/0x70 ? cifs_reopen_file+0x7a7/0xc00 cifs_reopen_file+0x7a7/0xc00 ? printk+0x43/0x4b cifs_readpage_worker+0x327/0x8a0 cifs_readpage+0x8c/0x2a0 generic_file_read_iter+0x692/0xd00 cifs_strict_readv+0x29f/0x310 generic_file_splice_read+0x11c/0x1c0 do_splice_to+0xa5/0xc0 splice_direct_to_actor+0xfa/0x350 ? generic_pipe_buf_nosteal+0x10/0x10 do_splice_direct+0xb5/0xe0 do_sendfile+0x278/0x3a0 SyS_sendfile64+0xc4/0xe0 entry_SYSCALL_64_fastpath+0x1f/0xbe Signed-off-by: Rabin Vincent Acked-by: Pavel Shilovsky Signed-off-by: Steve French --- fs/cifs/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 6ef78ad838e6..0fd081bd2a2f 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -582,7 +582,7 @@ cifs_relock_file(struct cifsFileInfo *cfile) struct cifs_tcon *tcon = tlink_tcon(cfile->tlink); int rc = 0; - down_read(&cinode->lock_sem); + down_read_nested(&cinode->lock_sem, SINGLE_DEPTH_NESTING); if (cinode->can_cache_brlcks) { /* can cache locks - no need to relock */ up_read(&cinode->lock_sem); From de1892b887eeb85ce458a93979c2108e6f329618 Mon Sep 17 00:00:00 2001 From: Steve French Date: Thu, 4 May 2017 07:54:04 -0500 Subject: [PATCH 2/6] Don't delay freeing mids when blocked on slow socket write of request When processing responses, and in particular freeing mids (DeleteMidQEntry), which is very important since it also frees the associated buffers (cifs_buf_release), we can block a long time if (writes to) socket is slow due to low memory or networking issues. We can block in send (smb request) waiting for memory, and be blocked in processing responess (which could free memory if we let it) - since they both grab the server->srv_mutex. In practice, in the DeleteMidQEntry case - there is no reason we need to grab the srv_mutex so remove these around DeleteMidQEntry, and it allows us to free memory faster. Signed-off-by: Steve French Acked-by: Pavel Shilovsky --- fs/cifs/cifssmb.c | 7 ------- fs/cifs/smb2pdu.c | 7 ------- fs/cifs/transport.c | 2 -- 3 files changed, 16 deletions(-) diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index 4c01b3f9abf0..4de3186d8a71 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -697,9 +697,7 @@ cifs_echo_callback(struct mid_q_entry *mid) { struct TCP_Server_Info *server = mid->callback_data; - mutex_lock(&server->srv_mutex); DeleteMidQEntry(mid); - mutex_unlock(&server->srv_mutex); add_credits(server, 1, CIFS_ECHO_OP); } @@ -1599,9 +1597,7 @@ cifs_readv_callback(struct mid_q_entry *mid) } queue_work(cifsiod_wq, &rdata->work); - mutex_lock(&server->srv_mutex); DeleteMidQEntry(mid); - mutex_unlock(&server->srv_mutex); add_credits(server, 1, 0); } @@ -2058,7 +2054,6 @@ cifs_writev_callback(struct mid_q_entry *mid) { struct cifs_writedata *wdata = mid->callback_data; struct cifs_tcon *tcon = tlink_tcon(wdata->cfile->tlink); - struct TCP_Server_Info *server = tcon->ses->server; unsigned int written; WRITE_RSP *smb = (WRITE_RSP *)mid->resp_buf; @@ -2095,9 +2090,7 @@ cifs_writev_callback(struct mid_q_entry *mid) } queue_work(cifsiod_wq, &wdata->work); - mutex_lock(&server->srv_mutex); DeleteMidQEntry(mid); - mutex_unlock(&server->srv_mutex); add_credits(tcon->ses->server, 1, 0); } diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 48ff7703b919..e0517f499c38 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -2173,9 +2173,7 @@ smb2_echo_callback(struct mid_q_entry *mid) if (mid->mid_state == MID_RESPONSE_RECEIVED) credits_received = le16_to_cpu(rsp->hdr.sync_hdr.CreditRequest); - mutex_lock(&server->srv_mutex); DeleteMidQEntry(mid); - mutex_unlock(&server->srv_mutex); add_credits(server, credits_received, CIFS_ECHO_OP); } @@ -2433,9 +2431,7 @@ smb2_readv_callback(struct mid_q_entry *mid) cifs_stats_fail_inc(tcon, SMB2_READ_HE); queue_work(cifsiod_wq, &rdata->work); - mutex_lock(&server->srv_mutex); DeleteMidQEntry(mid); - mutex_unlock(&server->srv_mutex); add_credits(server, credits_received, 0); } @@ -2594,7 +2590,6 @@ smb2_writev_callback(struct mid_q_entry *mid) { struct cifs_writedata *wdata = mid->callback_data; struct cifs_tcon *tcon = tlink_tcon(wdata->cfile->tlink); - struct TCP_Server_Info *server = tcon->ses->server; unsigned int written; struct smb2_write_rsp *rsp = (struct smb2_write_rsp *)mid->resp_buf; unsigned int credits_received = 1; @@ -2634,9 +2629,7 @@ smb2_writev_callback(struct mid_q_entry *mid) cifs_stats_fail_inc(tcon, SMB2_WRITE_HE); queue_work(cifsiod_wq, &wdata->work); - mutex_lock(&server->srv_mutex); DeleteMidQEntry(mid); - mutex_unlock(&server->srv_mutex); add_credits(tcon->ses->server, credits_received, 0); } diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index 4d64b5b8fc9c..de589d0d3739 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -613,9 +613,7 @@ cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server) } spin_unlock(&GlobalMid_Lock); - mutex_lock(&server->srv_mutex); DeleteMidQEntry(mid); - mutex_unlock(&server->srv_mutex); return rc; } From ecdcf622eb74b52cebde1387a7a1852a787d8050 Mon Sep 17 00:00:00 2001 From: Joe Perches via samba-technical Date: Sun, 7 May 2017 01:31:47 -0700 Subject: [PATCH 3/6] cifs: cifsacl: Use a temporary ops variable to reduce code length Create an ops variable to store tcon->ses->server->ops and cache indirections and reduce code size a trivial bit. $ size fs/cifs/cifsacl.o* text data bss dec hex filename 5338 136 8 5482 156a fs/cifs/cifsacl.o.new 5371 136 8 5515 158b fs/cifs/cifsacl.o.old Signed-off-by: Joe Perches Acked-by: Shirish Pargaonkar Signed-off-by: Steve French --- fs/cifs/cifsacl.c | 30 ++++++++++++++---------------- 1 file changed, 14 insertions(+), 16 deletions(-) diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c index 15bac390dff9..b98436f5c7c7 100644 --- a/fs/cifs/cifsacl.c +++ b/fs/cifs/cifsacl.c @@ -1135,20 +1135,19 @@ cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr, u32 acllen = 0; int rc = 0; struct tcon_link *tlink = cifs_sb_tlink(cifs_sb); - struct cifs_tcon *tcon; + struct smb_version_operations *ops; cifs_dbg(NOISY, "converting ACL to mode for %s\n", path); if (IS_ERR(tlink)) return PTR_ERR(tlink); - tcon = tlink_tcon(tlink); - if (pfid && (tcon->ses->server->ops->get_acl_by_fid)) - pntsd = tcon->ses->server->ops->get_acl_by_fid(cifs_sb, pfid, - &acllen); - else if (tcon->ses->server->ops->get_acl) - pntsd = tcon->ses->server->ops->get_acl(cifs_sb, inode, path, - &acllen); + ops = tlink_tcon(tlink)->ses->server->ops; + + if (pfid && (ops->get_acl_by_fid)) + pntsd = ops->get_acl_by_fid(cifs_sb, pfid, &acllen); + else if (ops->get_acl) + pntsd = ops->get_acl(cifs_sb, inode, path, &acllen); else { cifs_put_tlink(tlink); return -EOPNOTSUPP; @@ -1181,23 +1180,23 @@ id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 nmode, struct cifs_ntsd *pnntsd = NULL; /* modified acl to be sent to server */ struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); struct tcon_link *tlink = cifs_sb_tlink(cifs_sb); - struct cifs_tcon *tcon; + struct smb_version_operations *ops; if (IS_ERR(tlink)) return PTR_ERR(tlink); - tcon = tlink_tcon(tlink); + + ops = tlink_tcon(tlink)->ses->server->ops; cifs_dbg(NOISY, "set ACL from mode for %s\n", path); /* Get the security descriptor */ - if (tcon->ses->server->ops->get_acl == NULL) { + if (ops->get_acl == NULL) { cifs_put_tlink(tlink); return -EOPNOTSUPP; } - pntsd = tcon->ses->server->ops->get_acl(cifs_sb, inode, path, - &secdesclen); + pntsd = ops->get_acl(cifs_sb, inode, path, &secdesclen); if (IS_ERR(pntsd)) { rc = PTR_ERR(pntsd); cifs_dbg(VFS, "%s: error %d getting sec desc\n", __func__, rc); @@ -1224,13 +1223,12 @@ id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 nmode, cifs_dbg(NOISY, "build_sec_desc rc: %d\n", rc); - if (tcon->ses->server->ops->set_acl == NULL) + if (ops->set_acl == NULL) rc = -EOPNOTSUPP; if (!rc) { /* Set the security descriptor */ - rc = tcon->ses->server->ops->set_acl(pnntsd, secdesclen, inode, - path, aclflag); + rc = ops->set_acl(pnntsd, secdesclen, inode, path, aclflag); cifs_dbg(NOISY, "set_cifs_acl rc: %d\n", rc); } cifs_put_tlink(tlink); From cd1230070ae1c12fd34cf6a557bfa81bf9311009 Mon Sep 17 00:00:00 2001 From: Christophe JAILLET Date: Fri, 12 May 2017 17:59:32 +0200 Subject: [PATCH 4/6] SMB2: Fix share type handling In fs/cifs/smb2pdu.h, we have: #define SMB2_SHARE_TYPE_DISK 0x01 #define SMB2_SHARE_TYPE_PIPE 0x02 #define SMB2_SHARE_TYPE_PRINT 0x03 Knowing that, with the current code, the SMB2_SHARE_TYPE_PRINT case can never trigger and printer share would be interpreted as disk share. So, test the ShareType value for equality instead. Fixes: faaf946a7d5b ("CIFS: Add tree connect/disconnect capability for SMB2") Signed-off-by: Christophe JAILLET Acked-by: Aurelien Aptel Signed-off-by: Steve French --- fs/cifs/smb2pdu.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index e0517f499c38..e4afdaae743f 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -1240,15 +1240,19 @@ SMB2_tcon(const unsigned int xid, struct cifs_ses *ses, const char *tree, goto tcon_exit; } - if (rsp->ShareType & SMB2_SHARE_TYPE_DISK) + switch (rsp->ShareType) { + case SMB2_SHARE_TYPE_DISK: cifs_dbg(FYI, "connection to disk share\n"); - else if (rsp->ShareType & SMB2_SHARE_TYPE_PIPE) { + break; + case SMB2_SHARE_TYPE_PIPE: tcon->ipc = true; cifs_dbg(FYI, "connection to pipe share\n"); - } else if (rsp->ShareType & SMB2_SHARE_TYPE_PRINT) { - tcon->print = true; + break; + case SMB2_SHARE_TYPE_PRINT: + tcon->ipc = true; cifs_dbg(FYI, "connection to printer\n"); - } else { + break; + default: cifs_dbg(VFS, "unknown share type %d\n", rsp->ShareType); rc = -EOPNOTSUPP; goto tcon_error_exit; From 4328fea77ca30ef6af938ae3f263a3d055a9c0e6 Mon Sep 17 00:00:00 2001 From: Karim Eshapa Date: Fri, 12 May 2017 01:53:38 +0200 Subject: [PATCH 5/6] fs: cifs: transport: Use time_after for time comparison Use time_after kernel macro for time comparison that has safety check. Signed-off-by: Karim Eshapa Signed-off-by: Steve French --- fs/cifs/transport.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index de589d0d3739..47a125ece11e 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -94,7 +94,7 @@ DeleteMidQEntry(struct mid_q_entry *midEntry) now = jiffies; /* commands taking longer than one second are indications that something is wrong, unless it is quite a slow link or server */ - if ((now - midEntry->when_alloc) > HZ) { + if (time_after(now, midEntry->when_alloc + HZ)) { if ((cifsFYI & CIFS_TIMER) && (midEntry->command != command)) { pr_debug(" CIFS slow rsp: cmd %d mid %llu", midEntry->command, midEntry->mid); From 67b4c889cc835a2a6e2ff4e20544a33e37e2875d Mon Sep 17 00:00:00 2001 From: Steve French Date: Fri, 12 May 2017 20:59:10 -0500 Subject: [PATCH 6/6] [CIFS] Minor cleanup of xattr query function Some minor cleanup of cifs query xattr functions (will also make SMB3 xattr implementation cleaner as well). Signed-off-by: Steve French --- fs/cifs/cifsglob.h | 2 +- fs/cifs/cifsproto.h | 3 +-- fs/cifs/cifssmb.c | 4 +++- fs/cifs/inode.c | 3 +-- fs/cifs/xattr.c | 6 ++---- 5 files changed, 8 insertions(+), 10 deletions(-) diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 8be55be70faf..bcc7d9acad64 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -418,7 +418,7 @@ struct smb_version_operations { int (*validate_negotiate)(const unsigned int, struct cifs_tcon *); ssize_t (*query_all_EAs)(const unsigned int, struct cifs_tcon *, const unsigned char *, const unsigned char *, char *, - size_t, const struct nls_table *, int); + size_t, struct cifs_sb_info *); int (*set_EA)(const unsigned int, struct cifs_tcon *, const char *, const char *, const void *, const __u16, const struct nls_table *, int); diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h index e49958c3f8bb..6eb3147132e3 100644 --- a/fs/cifs/cifsproto.h +++ b/fs/cifs/cifsproto.h @@ -480,8 +480,7 @@ extern int CIFSSMBCopy(unsigned int xid, extern ssize_t CIFSSMBQAllEAs(const unsigned int xid, struct cifs_tcon *tcon, const unsigned char *searchName, const unsigned char *ea_name, char *EAData, - size_t bufsize, const struct nls_table *nls_codepage, - int remap_special_chars); + size_t bufsize, struct cifs_sb_info *cifs_sb); extern int CIFSSMBSetEA(const unsigned int xid, struct cifs_tcon *tcon, const char *fileName, const char *ea_name, const void *ea_value, const __u16 ea_value_len, diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index 4de3186d8a71..fbb0d4cbda41 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -6069,11 +6069,13 @@ ssize_t CIFSSMBQAllEAs(const unsigned int xid, struct cifs_tcon *tcon, const unsigned char *searchName, const unsigned char *ea_name, char *EAData, size_t buf_size, - const struct nls_table *nls_codepage, int remap) + struct cifs_sb_info *cifs_sb) { /* BB assumes one setup word */ TRANSACTION2_QPI_REQ *pSMB = NULL; TRANSACTION2_QPI_RSP *pSMBr = NULL; + int remap = cifs_remap(cifs_sb); + struct nls_table *nls_codepage = cifs_sb->local_nls; int rc = 0; int bytes_returned; int list_len; diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c index c3b2fa0b2ec8..4d1fcd76d022 100644 --- a/fs/cifs/inode.c +++ b/fs/cifs/inode.c @@ -563,8 +563,7 @@ static int cifs_sfu_mode(struct cifs_fattr *fattr, const unsigned char *path, rc = tcon->ses->server->ops->query_all_EAs(xid, tcon, path, "SETFILEBITS", ea_value, 4 /* size of buf */, - cifs_sb->local_nls, - cifs_remap(cifs_sb)); + cifs_sb); cifs_put_tlink(tlink); if (rc < 0) return (int)rc; diff --git a/fs/cifs/xattr.c b/fs/cifs/xattr.c index 20af5187ba63..3cb5c9e2d4e7 100644 --- a/fs/cifs/xattr.c +++ b/fs/cifs/xattr.c @@ -235,8 +235,7 @@ static int cifs_xattr_get(const struct xattr_handler *handler, if (pTcon->ses->server->ops->query_all_EAs) rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon, - full_path, name, value, size, - cifs_sb->local_nls, cifs_remap(cifs_sb)); + full_path, name, value, size, cifs_sb); break; case XATTR_CIFS_ACL: { @@ -336,8 +335,7 @@ ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size) if (pTcon->ses->server->ops->query_all_EAs) rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon, - full_path, NULL, data, buf_size, - cifs_sb->local_nls, cifs_remap(cifs_sb)); + full_path, NULL, data, buf_size, cifs_sb); list_ea_exit: kfree(full_path); free_xid(xid);