Revision 020ac5b6bef15785f9dde9de89d2734ff97da733 authored by Artem Bityutskiy on 31 May 2012, 23:26:12 UTC, committed by Linus Torvalds on 01 June 2012, 00:49:27 UTC
This is patchset makes fatfs stop using the VFS '->write_super()' method for writing out the FSINFO block. The final goal is to get rid of the 'sync_supers()' kernel thread. This kernel thread wakes up every 5 seconds (by default) and calls '->write_super()' for all mounted file-systems. And the bad thing is that this is done even if all the superblocks are clean. Moreover, some file-systems do not even need this end they do not register the '->write_super()' method at all (e.g., btrfs). So 'sync_supers()' most often just generates useless wake-ups and wastes power. I am trying to make all file-systems independent of '->write_super()' and plan to remove 'sync_supers()' and '->write_super' completely once there are no more users. The '->write_supers()' method is mostly used by baroque file-systems like hfs, udf, etc. Modern file-systems like btrfs and xfs do not use it. This justifies removing this stuff from VFS completely and make every FS self-manage own superblock. Tested with xfstests. This patch: Preparation for further changes. It introduces a special inode ('fsinfo_inode') in FAT file-system which we'll later use for managing the FSINFO block. Note, this there is already one special inode ('fat_inode') which is used for managing the FAT tables. Introduce new 'MSDOS_FSINFO_INO' constant for this special inode. It is safe to do because FAT file-system does not store inode numbers on the media but generates them run-time. I've also cleaned up the comment to existing 'MSDOS_ROOT_INO' constant, while on it. Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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amdtp.h
#ifndef SOUND_FIREWIRE_AMDTP_H_INCLUDED
#define SOUND_FIREWIRE_AMDTP_H_INCLUDED
#include <linux/interrupt.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include "packets-buffer.h"
/**
* enum cip_out_flags - describes details of the streaming protocol
* @CIP_NONBLOCKING: In non-blocking mode, each packet contains
* sample_rate/8000 samples, with rounding up or down to adjust
* for clock skew and left-over fractional samples. This should
* be used if supported by the device.
*/
enum cip_out_flags {
CIP_NONBLOCKING = 0,
};
/**
* enum cip_sfc - a stream's sample rate
*/
enum cip_sfc {
CIP_SFC_32000 = 0,
CIP_SFC_44100 = 1,
CIP_SFC_48000 = 2,
CIP_SFC_88200 = 3,
CIP_SFC_96000 = 4,
CIP_SFC_176400 = 5,
CIP_SFC_192000 = 6,
};
#define AMDTP_OUT_PCM_FORMAT_BITS (SNDRV_PCM_FMTBIT_S16 | \
SNDRV_PCM_FMTBIT_S32)
struct fw_unit;
struct fw_iso_context;
struct snd_pcm_substream;
struct amdtp_out_stream {
struct fw_unit *unit;
enum cip_out_flags flags;
struct fw_iso_context *context;
struct mutex mutex;
enum cip_sfc sfc;
unsigned int data_block_quadlets;
unsigned int pcm_channels;
unsigned int midi_ports;
void (*transfer_samples)(struct amdtp_out_stream *s,
struct snd_pcm_substream *pcm,
__be32 *buffer, unsigned int frames);
unsigned int syt_interval;
unsigned int source_node_id_field;
struct iso_packets_buffer buffer;
struct snd_pcm_substream *pcm;
struct tasklet_struct period_tasklet;
int packet_index;
unsigned int data_block_counter;
unsigned int data_block_state;
unsigned int last_syt_offset;
unsigned int syt_offset_state;
unsigned int pcm_buffer_pointer;
unsigned int pcm_period_pointer;
bool pointer_flush;
};
int amdtp_out_stream_init(struct amdtp_out_stream *s, struct fw_unit *unit,
enum cip_out_flags flags);
void amdtp_out_stream_destroy(struct amdtp_out_stream *s);
void amdtp_out_stream_set_rate(struct amdtp_out_stream *s, unsigned int rate);
unsigned int amdtp_out_stream_get_max_payload(struct amdtp_out_stream *s);
int amdtp_out_stream_start(struct amdtp_out_stream *s, int channel, int speed);
void amdtp_out_stream_update(struct amdtp_out_stream *s);
void amdtp_out_stream_stop(struct amdtp_out_stream *s);
void amdtp_out_stream_set_pcm_format(struct amdtp_out_stream *s,
snd_pcm_format_t format);
void amdtp_out_stream_pcm_prepare(struct amdtp_out_stream *s);
unsigned long amdtp_out_stream_pcm_pointer(struct amdtp_out_stream *s);
void amdtp_out_stream_pcm_abort(struct amdtp_out_stream *s);
/**
* amdtp_out_stream_set_pcm - configure format of PCM samples
* @s: the AMDTP output stream to be configured
* @pcm_channels: the number of PCM samples in each data block, to be encoded
* as AM824 multi-bit linear audio
*
* This function must not be called while the stream is running.
*/
static inline void amdtp_out_stream_set_pcm(struct amdtp_out_stream *s,
unsigned int pcm_channels)
{
s->pcm_channels = pcm_channels;
}
/**
* amdtp_out_stream_set_midi - configure format of MIDI data
* @s: the AMDTP output stream to be configured
* @midi_ports: the number of MIDI ports (i.e., MPX-MIDI Data Channels)
*
* This function must not be called while the stream is running.
*/
static inline void amdtp_out_stream_set_midi(struct amdtp_out_stream *s,
unsigned int midi_ports)
{
s->midi_ports = midi_ports;
}
/**
* amdtp_out_streaming_error - check for streaming error
* @s: the AMDTP output stream
*
* If this function returns true, the stream's packet queue has stopped due to
* an asynchronous error.
*/
static inline bool amdtp_out_streaming_error(struct amdtp_out_stream *s)
{
return s->packet_index < 0;
}
/**
* amdtp_out_stream_pcm_trigger - start/stop playback from a PCM device
* @s: the AMDTP output stream
* @pcm: the PCM device to be started, or %NULL to stop the current device
*
* Call this function on a running isochronous stream to enable the actual
* transmission of PCM data. This function should be called from the PCM
* device's .trigger callback.
*/
static inline void amdtp_out_stream_pcm_trigger(struct amdtp_out_stream *s,
struct snd_pcm_substream *pcm)
{
ACCESS_ONCE(s->pcm) = pcm;
}
static inline bool cip_sfc_is_base_44100(enum cip_sfc sfc)
{
return sfc & 1;
}
#endif
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