CIFS: SMBD: work around gcc -Wmaybe-uninitialized warning
Subsystems (2)
PATCH 1/1 CIFS: SMBD: work around gcc -Wmaybe-uninitialized warning
GCC versions from 4.9 to 6.3 produce a false-positive warning when dealing with a conditional spin_lock_irqsave():
fs/cifs/smbdirect.c: In function 'smbd_recv_buf':include/linux/spinlock.h:260:3: warning: 'flags' may be used uninitialized in this function [-Wmaybe-uninitialized]
This function calls some sleeping interfaces, so it is clear that it does not get called with interrupts disabled and there is no need to save the irq state before taking the spinlock. This lets us remove the variable, which makes the function slightly more efficient and avoids the warning.
A further cleanup could do the same change for other functions in this file, but I did not want to take this too far for now.
--- fs/cifs/smbdirect.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-)
fs/cifs/smbdirect.c +6 -9
@@ -1862,7 +1862,6 @@ int smbd_recv_buf(struct smbd_connection *info, char *buf, unsigned int size)int to_copy, to_read, data_read, offset;u32 data_length, remaining_data_length, data_offset;int rc; -unsigned long flags; again:if (info->transport_status !=SMBD_CONNECTED ) {
@@ -1935,15 +1934,13 @@ int smbd_recv_buf(struct smbd_connection *info, char *buf, unsigned int size)* end of the queue */ if (!queue_length) -spin_lock_irqsave ( - &info->reassembly_queue_lock, - flags); +spin_lock_irq ( + &info->reassembly_queue_lock);list_del (&response->list); queue_removed++;if (!queue_length) -spin_unlock_irqrestore ( - &info->reassembly_queue_lock, - flags); +spin_unlock_irq ( + &info->reassembly_queue_lock); info->count_reassembly_queue--; info->count_dequeue_reassembly_queue++;
@@ -1963,10 +1960,10 @@ int smbd_recv_buf(struct smbd_connection *info, char *buf, unsigned int size) to_read, data_read, offset); } -spin_lock_irqsave (&info->reassembly_queue_lock, flags); +spin_lock_irq (&info->reassembly_queue_lock); info->reassembly_data_length -= data_read; info->reassembly_queue_length -= queue_removed; -spin_unlock_irqrestore (&info->reassembly_queue_lock, flags); +spin_unlock_irq (&info->reassembly_queue_lock); info->first_entry_offset = offset; log_read(INFO, "returning to thread data_read=%d "
Signature · 1 line
2.9.0
Quoted 12 lines
GCC versions from 4.9 to 6.3 produce a false-positive warning when dealing with a conditional
spin_lock_irqsave():
fs/cifs/smbdirect.c: In function 'smbd_recv_buf':include/linux/spinlock.h:260:3: warning: 'flags' may be used uninitialized in this function [-Wmaybe-uninitialized]This function calls some sleeping interfaces, so it is clear that it does not get called with interrupts disabled and there is no need to save the irq state before taking the spinlock. This lets us remove the variable, which makes the function slightly more efficient and avoids the warning.
Quoted 6 lines
A further cleanup could do the same change for other functions in this file, but I did not want to take this too far for now.
Fixes ac69f66e54ca ("CIFS: SMBD: Implement function to receive data viaRDMA receive")
Signed-off-by Arnd Bergmann <[email protected]>
Quoted 60 lines
--- fs/cifs/smbdirect.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-)fs/cifs/smbdirect.c index renamed from fs/cifs/smbdirect.c +0
-0
f527e22650f5..f9234ed83a60100644fs/cifs/smbdirect.c +0
-1@@ -1862,7 +1862,6 @@ int smbd_recv_buf(struct smbd_connection *info, char *buf, unsigned int size) int to_copy, to_read, data_read, offset;u32 data_length, remaining_data_length, data_offset;int rc; -unsigned long flags; again:if (
info->transport_status!=SMBD_CONNECTED) { @@ -1935,15
+1934,13 @@ intsmbd_recv_buf(struct smbd_connection *info, char *buf, unsigned int size)fs/cifs/smbdirect.c +0
-2* end of the queue */ if (!queue_length) - spin_lock_irqsave( - &info-Quoted 1 line
reassembly_queue_lock,fs/cifs/smbdirect.c +2
-1- flags); + spin_lock_irq( + &info-Quoted 1 line
reassembly_queue_lock);fs/cifs/smbdirect.c +0
-2list_del (&response->list); queue_removed++;if (!queue_length) - spin_unlock_irqrestore( - &info-Quoted 1 line
reassembly_queue_lock,fs/cifs/smbdirect.c +2
-1- flags); + spin_unlock_irq( + &info-Quoted 1 line
reassembly_queue_lock);fs/cifs/smbdirect.c +0
-0info->count_reassembly_queue--; info-Quoted 1 line
count_dequeue_reassembly_queue++;
fs/cifs/smbdirect.c +2
-2@@ -1963,10 +1960,10 @@ int smbd_recv_buf(struct smbd_connection *info, char *buf, unsigned int size) to_read, data_read, offset); } -spin_lock_irqsave (&info->reassembly_queue_lock, flags); +spin_lock_irq (&info->reassembly_queue_lock); info->reassembly_data_length -= data_read; info->reassembly_queue_length -= queue_removed; -spin_unlock_irqrestore (&info->reassembly_queue_lock, flags); +spin_unlock_irq (&info->reassembly_queue_lock);fs/cifs/smbdirect.c +0
-1info->first_entry_offset = offset; log_read(INFO, "returning to thread data_read=%d " --2.9.0
Steve French
Appliedmerged into cifs-2.6.git for-next
Also noticed a few sparse warnings in the same file that need to be cleaned up
Quoted 73 lines · Arnd Bergmann
GCC versions from 4.9 to 6.3 produce a false-positive warning when dealing with a conditional
spin_lock_irqsave():
fs/cifs/smbdirect.c: In function 'smbd_recv_buf':include/linux/spinlock.h:260:3: warning: 'flags' may be used uninitialized in this function [-Wmaybe-uninitialized]This function calls some sleeping interfaces, so it is clear that it does not get called with interrupts disabled and there is no need to save the irq state before taking the spinlock. This lets us remove the variable, which makes the function slightly more efficient and avoids the warning.
A further cleanup could do the same change for other functions in this file, but I did not want to take this too far for now.
Fixes ac69f66e54ca ("CIFS: SMBD: Implement function to receive data via RDMA receive")Signed-off-by Arnd Bergmann <[email protected]>--- fs/cifs/smbdirect.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-)fs/cifs/smbdirect.c +6
-10@@ -1862,7 +1862,6 @@ int smbd_recv_buf(struct smbd_connection *info, char *buf, unsigned int size)int to_copy, to_read, data_read, offset;u32 data_length, remaining_data_length, data_offset;int rc; -unsigned long flags; again:if (info->transport_status !=SMBD_CONNECTED ) {@@ -1935,15 +1934,13 @@ int smbd_recv_buf(struct smbd_connection *info, char *buf, unsigned int size)* end of the queue */ if (!queue_length) -spin_lock_irqsave ( - &info->reassembly_queue_lock, - flags); +spin_lock_irq ( + &info->reassembly_queue_lock);list_del (&response->list); queue_removed++;if (!queue_length) -spin_unlock_irqrestore ( - &info->reassembly_queue_lock, - flags); +spin_unlock_irq ( + &info->reassembly_queue_lock); info->count_reassembly_queue--; info->count_dequeue_reassembly_queue++;@@ -1963,10 +1960,10 @@ int smbd_recv_buf(struct smbd_connection *info, char *buf, unsigned int size) to_read, data_read, offset); } -spin_lock_irqsave (&info->reassembly_queue_lock, flags); +spin_lock_irq (&info->reassembly_queue_lock); info->reassembly_data_length -= data_read; info->reassembly_queue_length -= queue_removed; -spin_unlock_irqrestore (&info->reassembly_queue_lock, flags); +spin_unlock_irq (&info->reassembly_queue_lock); info->first_entry_offset = offset; log_read(INFO, "returning to thread data_read=%d " --2.9.0
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Signature · 3 lines
Thanks, Steve