Revision 7ce9d5d1f3c8736511daa413c64985a05b2feee3 authored by Eric Sandeen on 04 March 2009, 23:38:18 UTC, committed by Theodore Ts'o on 04 March 2009, 23:38:18 UTC
I was seeing fsck errors on inode bitmaps after a 4 thread dbench run on a 4 cpu machine: Inode bitmap differences: -50736 -(50752--50753) etc... I believe that this is because ext4_free_inode() uses atomic bitops, and although ext4_new_inode() *used* to also use atomic bitops for synchronization, commit 393418676a7602e1d7d3f6e560159c65c8cbd50e changed this to use the sb_bgl_lock, so that we could also synchronize against read_inode_bitmap and initialization of uninit inode tables. However, that change left ext4_free_inode using atomic bitops, which I think leaves no synchronization between setting & unsetting bits in the inode table. The below patch fixes it for me, although I wonder if we're getting at all heavy-handed with this spinlock... Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
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iso.h
/*
* IEEE 1394 for Linux
*
* kernel ISO transmission/reception
*
* Copyright (C) 2002 Maas Digital LLC
*
* This code is licensed under the GPL. See the file COPYING in the root
* directory of the kernel sources for details.
*/
#ifndef IEEE1394_ISO_H
#define IEEE1394_ISO_H
#include <linux/spinlock_types.h>
#include <linux/wait.h>
#include <asm/atomic.h>
#include <asm/types.h>
#include "dma.h"
struct hpsb_host;
/* high-level ISO interface */
/*
* This API sends and receives isochronous packets on a large,
* virtually-contiguous kernel memory buffer. The buffer may be mapped
* into a user-space process for zero-copy transmission and reception.
*
* There are no explicit boundaries between packets in the buffer. A
* packet may be transmitted or received at any location. However,
* low-level drivers may impose certain restrictions on alignment or
* size of packets. (e.g. in OHCI no packet may cross a page boundary,
* and packets should be quadlet-aligned)
*/
/* Packet descriptor - the API maintains a ring buffer of these packet
* descriptors in kernel memory (hpsb_iso.infos[]). */
struct hpsb_iso_packet_info {
/* offset of data payload relative to the first byte of the buffer */
__u32 offset;
/* length of the data payload, in bytes (not including the isochronous
* header) */
__u16 len;
/* (recv only) the cycle number (mod 8000) on which the packet was
* received */
__u16 cycle;
/* (recv only) channel on which the packet was received */
__u8 channel;
/* 2-bit 'tag' and 4-bit 'sy' fields of the isochronous header */
__u8 tag;
__u8 sy;
/* length in bytes of the packet including header/trailer.
* MUST be at structure end, since the first part of this structure is
* also defined in raw1394.h (i.e. struct raw1394_iso_packet_info), is
* copied to userspace and is accessed there through libraw1394. */
__u16 total_len;
};
enum hpsb_iso_type { HPSB_ISO_RECV = 0, HPSB_ISO_XMIT = 1 };
/* The mode of the dma when receiving iso data. Must be supported by chip */
enum raw1394_iso_dma_recv_mode {
HPSB_ISO_DMA_DEFAULT = -1,
HPSB_ISO_DMA_OLD_ABI = 0,
HPSB_ISO_DMA_BUFFERFILL = 1,
HPSB_ISO_DMA_PACKET_PER_BUFFER = 2
};
struct hpsb_iso {
enum hpsb_iso_type type;
/* pointer to low-level driver and its private data */
struct hpsb_host *host;
void *hostdata;
/* a function to be called (from interrupt context) after
* outgoing packets have been sent, or incoming packets have
* arrived */
void (*callback)(struct hpsb_iso*);
/* wait for buffer space */
wait_queue_head_t waitq;
int speed; /* IEEE1394_SPEED_100, 200, or 400 */
int channel; /* -1 if multichannel */
int dma_mode; /* dma receive mode */
/* greatest # of packets between interrupts - controls
* the maximum latency of the buffer */
int irq_interval;
/* the buffer for packet data payloads */
struct dma_region data_buf;
/* size of data_buf, in bytes (always a multiple of PAGE_SIZE) */
unsigned int buf_size;
/* # of packets in the ringbuffer */
unsigned int buf_packets;
/* protects packet cursors */
spinlock_t lock;
/* the index of the next packet that will be produced
or consumed by the user */
int first_packet;
/* the index of the next packet that will be transmitted
or received by the 1394 hardware */
int pkt_dma;
/* how many packets, starting at first_packet:
* (transmit) are ready to be filled with data
* (receive) contain received data */
int n_ready_packets;
/* how many times the buffer has overflowed or underflowed */
atomic_t overflows;
/* how many cycles were skipped for a given context */
atomic_t skips;
/* Current number of bytes lost in discarded packets */
int bytes_discarded;
/* private flags to track initialization progress */
#define HPSB_ISO_DRIVER_INIT (1<<0)
#define HPSB_ISO_DRIVER_STARTED (1<<1)
unsigned int flags;
/* # of packets left to prebuffer (xmit only) */
int prebuffer;
/* starting cycle for DMA (xmit only) */
int start_cycle;
/* cycle at which next packet will be transmitted,
* -1 if not known */
int xmit_cycle;
/* ringbuffer of packet descriptors in regular kernel memory
* XXX Keep this last, since we use over-allocated memory from
* this entry to fill this field. */
struct hpsb_iso_packet_info *infos;
};
/* functions available to high-level drivers (e.g. raw1394) */
struct hpsb_iso* hpsb_iso_xmit_init(struct hpsb_host *host,
unsigned int data_buf_size,
unsigned int buf_packets,
int channel,
int speed,
int irq_interval,
void (*callback)(struct hpsb_iso*));
struct hpsb_iso* hpsb_iso_recv_init(struct hpsb_host *host,
unsigned int data_buf_size,
unsigned int buf_packets,
int channel,
int dma_mode,
int irq_interval,
void (*callback)(struct hpsb_iso*));
int hpsb_iso_recv_listen_channel(struct hpsb_iso *iso, unsigned char channel);
int hpsb_iso_recv_unlisten_channel(struct hpsb_iso *iso, unsigned char channel);
int hpsb_iso_recv_set_channel_mask(struct hpsb_iso *iso, u64 mask);
int hpsb_iso_xmit_start(struct hpsb_iso *iso, int start_on_cycle,
int prebuffer);
int hpsb_iso_recv_start(struct hpsb_iso *iso, int start_on_cycle,
int tag_mask, int sync);
void hpsb_iso_stop(struct hpsb_iso *iso);
void hpsb_iso_shutdown(struct hpsb_iso *iso);
int hpsb_iso_xmit_queue_packet(struct hpsb_iso *iso, u32 offset, u16 len,
u8 tag, u8 sy);
int hpsb_iso_xmit_sync(struct hpsb_iso *iso);
int hpsb_iso_recv_release_packets(struct hpsb_iso *recv,
unsigned int n_packets);
int hpsb_iso_recv_flush(struct hpsb_iso *iso);
int hpsb_iso_n_ready(struct hpsb_iso *iso);
/* the following are callbacks available to low-level drivers */
void hpsb_iso_packet_sent(struct hpsb_iso *iso, int cycle, int error);
void hpsb_iso_packet_received(struct hpsb_iso *iso, u32 offset, u16 len,
u16 total_len, u16 cycle, u8 channel, u8 tag,
u8 sy);
void hpsb_iso_wake(struct hpsb_iso *iso);
#endif /* IEEE1394_ISO_H */
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