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1570e76233
Add a "device index" (di) for each device, and use this in the bcache api to the rest of lvm. This replaces the file descriptor (fd) in the api. The rest of lvm uses new functions bcache_set_fd(), bcache_clear_fd(), and bcache_change_fd() to control which fd bcache uses for io to a particular device. . lvm opens a dev and gets and fd. fd = open(dev); . lvm passes fd to the bcache layer and gets a di to use in the bcache api for the dev. di = bcache_set_fd(fd); . lvm uses bcache functions, passing di for the dev. bcache_write_bytes(di, ...), etc. . bcache translates di to fd to do io. . lvm closes the device and clears the di/fd bcache state. close(fd); bcache_clear_fd(di); In the bcache layer, a di-to-fd translation table (int *_fd_table) is added. When bcache needs to perform io on a di, it uses _fd_table[di]. In the following commit, lvm will make use of the new bcache_change_fd() function to change the fd that bcache uses for the dev, without dropping cached blocks.
164 lines
5.4 KiB
C
164 lines
5.4 KiB
C
/*
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* Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
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* Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved.
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*
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* This file is part of LVM2.
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*
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* This copyrighted material is made available to anyone wishing to use,
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* modify, copy, or redistribute it subject to the terms and conditions
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* of the GNU Lesser General Public License v.2.1.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this program; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#ifndef _LVM_DEVICE_H
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#define _LVM_DEVICE_H
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#include "lib/uuid/uuid.h"
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#include <fcntl.h>
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#define DEV_REGULAR 0x00000002 /* Regular file? */
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#define DEV_ALLOCED 0x00000004 /* malloc used */
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#define DEV_OPENED_RW 0x00000008 /* Opened RW */
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#define DEV_OPENED_EXCL 0x00000010 /* Opened EXCL */
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#define DEV_O_DIRECT 0x00000020 /* Use O_DIRECT */
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#define DEV_O_DIRECT_TESTED 0x00000040 /* DEV_O_DIRECT is reliable */
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#define DEV_OPEN_FAILURE 0x00000080 /* Has last open failed? */
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#define DEV_USED_FOR_LV 0x00000100 /* Is device used for an LV */
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#define DEV_ASSUMED_FOR_LV 0x00000200 /* Is device assumed for an LV */
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#define DEV_NOT_O_NOATIME 0x00000400 /* Don't use O_NOATIME */
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#define DEV_IN_BCACHE 0x00000800 /* dev fd is open and used in bcache */
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#define DEV_BCACHE_EXCL 0x00001000 /* bcache_fd should be open EXCL */
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#define DEV_FILTER_AFTER_SCAN 0x00002000 /* apply filter after bcache has data */
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#define DEV_FILTER_OUT_SCAN 0x00004000 /* filtered out during label scan */
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#define DEV_BCACHE_WRITE 0x00008000 /* bcache_fd is open with RDWR */
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#define DEV_SCAN_FOUND_LABEL 0x00010000 /* label scan read dev and found label */
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#define DEV_IS_MD_COMPONENT 0x00020000 /* device is an md component */
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#define DEV_UDEV_INFO_MISSING 0x00040000 /* we have no udev info for this device */
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/*
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* Support for external device info.
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* Any new external device info source needs to be
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* registered using EXT_REGISTER macro in dev-ext.c.
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*/
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typedef enum dev_ext_e {
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DEV_EXT_NONE,
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DEV_EXT_UDEV,
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DEV_EXT_NUM
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} dev_ext_t;
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struct dev_ext {
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int enabled;
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dev_ext_t src;
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void *handle;
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};
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/*
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* All devices in LVM will be represented by one of these.
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* pointer comparisons are valid.
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*/
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struct device {
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struct dm_list aliases; /* struct dm_str_list */
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dev_t dev;
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/* private */
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int fd;
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int open_count;
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int physical_block_size; /* From BLKPBSZGET: lowest possible sector size that the hardware can operate on without reverting to read-modify-write operations */
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int logical_block_size; /* From BLKSSZGET: lowest possible block size that the storage device can address */
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int read_ahead;
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int bcache_fd;
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int bcache_di;
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uint32_t flags;
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unsigned size_seqno;
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uint64_t size;
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uint64_t end;
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struct dev_ext ext;
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const char *duplicate_prefer_reason;
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const char *vgid; /* if device is an LV */
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const char *lvid; /* if device is an LV */
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char pvid[ID_LEN + 1]; /* if device is a PV */
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char _padding[7];
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};
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/*
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* All I/O is annotated with the reason it is performed.
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*/
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typedef enum dev_io_reason {
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DEV_IO_SIGNATURES = 0, /* Scanning device signatures */
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DEV_IO_LABEL, /* LVM PV disk label */
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DEV_IO_MDA_HEADER, /* Text format metadata area header */
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DEV_IO_MDA_CONTENT, /* Text format metadata area content */
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DEV_IO_MDA_EXTRA_HEADER, /* Header of any extra metadata areas on device */
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DEV_IO_MDA_EXTRA_CONTENT, /* Content of any extra metadata areas on device */
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DEV_IO_FMT1, /* Original LVM1 metadata format */
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DEV_IO_POOL, /* Pool metadata format */
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DEV_IO_LV, /* Content written to an LV */
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DEV_IO_LOG /* Logging messages */
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} dev_io_reason_t;
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struct device_list {
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struct dm_list list;
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struct device *dev;
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};
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struct device_area {
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struct device *dev;
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uint64_t start; /* Bytes */
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uint64_t size; /* Bytes */
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};
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/*
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* Support for external device info.
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*/
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const char *dev_ext_name(struct device *dev);
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int dev_ext_enable(struct device *dev, dev_ext_t src);
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int dev_ext_disable(struct device *dev);
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struct dev_ext *dev_ext_get(struct device *dev);
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int dev_ext_release(struct device *dev);
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/*
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* Increment current dev_size_seqno.
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* This is used to control lifetime
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* of cached device size.
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*/
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void dev_size_seqno_inc(void);
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/*
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* All io should use these routines.
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*/
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int dev_get_direct_block_sizes(struct device *dev, unsigned int *physical_block_size,
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unsigned int *logical_block_size);
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int dev_get_size(struct device *dev, uint64_t *size);
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int dev_get_read_ahead(struct device *dev, uint32_t *read_ahead);
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int dev_discard_blocks(struct device *dev, uint64_t offset_bytes, uint64_t size_bytes);
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/* Use quiet version if device number could change e.g. when opening LV */
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int dev_open(struct device *dev);
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int dev_open_quiet(struct device *dev);
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int dev_open_flags(struct device *dev, int flags, int direct, int quiet);
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int dev_open_readonly(struct device *dev);
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int dev_open_readonly_buffered(struct device *dev);
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int dev_open_readonly_quiet(struct device *dev);
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int dev_close(struct device *dev);
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int dev_close_immediate(struct device *dev);
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int dev_fd(struct device *dev);
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const char *dev_name(const struct device *dev);
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void dev_flush(struct device *dev);
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struct device *dev_create_file(const char *filename, struct device *dev,
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struct dm_str_list *alias, int use_malloc);
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void dev_destroy_file(struct device *dev);
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/* Return a valid device name from the alias list; NULL otherwise */
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const char *dev_name_confirmed(struct device *dev, int quiet);
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#endif
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