linux/drivers/target/target_core_file.h
Nicholas Bellinger a4dff3043c target/file: Use O_DSYNC by default for FILEIO backends
Convert to use O_DSYNC for all cases at FILEIO backend creation time to
avoid the extra syncing of pure timestamp updates with legacy O_SYNC during
default operation as recommended by hch.  Continue to do this independently of
Write Cache Enable (WCE) bit, as WCE=0 is currently the default for all backend
devices and enabled by user on per device basis via attrib/emulate_write_cache.

This patch drops the now unnecessary fd_buffered_io= token usage that was
originally signalling when to explictly disable O_SYNC at backend creation
time for buffered I/O operation.  This can end up being dangerous for a number
of reasons during physical node failure, so go ahead and drop this option
for now when O_DSYNC is used as the default.

Also allow explict FUA WRITEs -> vfs_fsync_range() call to function in
fd_execute_cmd() independently of WCE bit setting.

Reported-by: Christoph Hellwig <hch@lst.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2012-06-02 23:47:20 -07:00

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C

#ifndef TARGET_CORE_FILE_H
#define TARGET_CORE_FILE_H
#define FD_VERSION "4.0"
#define FD_MAX_DEV_NAME 256
#define FD_DEVICE_QUEUE_DEPTH 32
#define FD_MAX_DEVICE_QUEUE_DEPTH 128
#define FD_BLOCKSIZE 512
#define FD_MAX_SECTORS 1024
#define RRF_EMULATE_CDB 0x01
#define RRF_GOT_LBA 0x02
#define FBDF_HAS_PATH 0x01
#define FBDF_HAS_SIZE 0x02
struct fd_dev {
u32 fbd_flags;
unsigned char fd_dev_name[FD_MAX_DEV_NAME];
/* Unique Ramdisk Device ID in Ramdisk HBA */
u32 fd_dev_id;
/* Number of SG tables in sg_table_array */
u32 fd_table_count;
u32 fd_queue_depth;
u32 fd_block_size;
unsigned long long fd_dev_size;
struct file *fd_file;
/* FILEIO HBA device is connected to */
struct fd_host *fd_host;
} ____cacheline_aligned;
struct fd_host {
u32 fd_host_dev_id_count;
/* Unique FILEIO Host ID */
u32 fd_host_id;
} ____cacheline_aligned;
#endif /* TARGET_CORE_FILE_H */