X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fum%2Fdrivers%2Fubd_kern.c;h=49c047b75cc556cbda484a5c6166d23d5b137f7c;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=9b4820ec993a1f7a5883ee7f6c7368b6d70249ee;hpb=6a77f38946aaee1cd85eeec6cf4229b204c15071;p=linux-2.6.git diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index 9b4820ec9..49c047b75 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -1,4 +1,4 @@ -/* +/* * Copyright (C) 2000 Jeff Dike (jdike@karaya.com) * Licensed under the GPL */ @@ -20,12 +20,10 @@ #define MAJOR_NR UBD_MAJOR #define UBD_SHIFT 4 -#include "linux/config.h" #include "linux/module.h" #include "linux/blkdev.h" #include "linux/hdreg.h" #include "linux/init.h" -#include "linux/devfs_fs_kernel.h" #include "linux/cdrom.h" #include "linux/proc_fs.h" #include "linux/ctype.h" @@ -35,6 +33,7 @@ #include "linux/blkpg.h" #include "linux/genhd.h" #include "linux/spinlock.h" +#include "linux/platform_device.h" #include "asm/segment.h" #include "asm/uaccess.h" #include "asm/irq.h" @@ -49,13 +48,12 @@ #include "irq_user.h" #include "irq_kern.h" #include "ubd_user.h" -#include "2_5compat.h" #include "os.h" #include "mem.h" #include "mem_kern.h" #include "cow.h" -enum ubd_req { UBD_READ, UBD_WRITE, UBD_MMAP }; +enum ubd_req { UBD_READ, UBD_WRITE }; struct io_thread_req { enum ubd_req op; @@ -68,12 +66,10 @@ struct io_thread_req { unsigned long sector_mask; unsigned long long cow_offset; unsigned long bitmap_words[2]; - int map_fd; - unsigned long long map_offset; int error; }; -extern int open_ubd_file(char *file, struct openflags *openflags, +extern int open_ubd_file(char *file, struct openflags *openflags, int shared, char **backing_file_out, int *bitmap_offset_out, unsigned long *bitmap_len_out, int *data_offset_out, int *create_cow_out); @@ -110,27 +106,30 @@ static inline void ubd_set_bit(__u64 bit, unsigned char *data) #define DRIVER_NAME "uml-blkdev" +/* Can be taken in interrupt context, and is passed to the block layer to lock + * the request queue. Kernel side code knows that. */ static DEFINE_SPINLOCK(ubd_io_lock); -static DEFINE_SPINLOCK(ubd_lock); -static void (*do_ubd)(void); +static DEFINE_MUTEX(ubd_lock); + +/* XXX - this made sense in 2.4 days, now it's only used as a boolean, and + * probably it doesn't make sense even for that. */ +static int do_ubd; static int ubd_open(struct inode * inode, struct file * filp); static int ubd_release(struct inode * inode, struct file * file); static int ubd_ioctl(struct inode * inode, struct file * file, unsigned int cmd, unsigned long arg); +static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo); -#define MAX_DEV (8) - -/* Changed in early boot */ -static int ubd_do_mmap = 0; -#define UBD_MMAP_BLOCK_SIZE PAGE_SIZE +#define MAX_DEV (16) static struct block_device_operations ubd_blops = { .owner = THIS_MODULE, .open = ubd_open, .release = ubd_release, .ioctl = ubd_ioctl, + .getgeo = ubd_getgeo, }; /* Protected by the queue_lock */ @@ -141,7 +140,7 @@ static int fake_major = MAJOR_NR; static struct gendisk *ubd_gendisk[MAX_DEV]; static struct gendisk *fake_gendisk[MAX_DEV]; - + #ifdef CONFIG_BLK_DEV_UBD_SYNC #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 1, .c = 0, \ .cl = 1 }) @@ -156,7 +155,9 @@ static struct gendisk *fake_gendisk[MAX_DEV]; static struct openflags global_openflags = OPEN_FLAGS; struct cow { + /* backing file name */ char *file; + /* backing file fd */ int fd; unsigned long *bitmap; unsigned long bitmap_len; @@ -165,21 +166,18 @@ struct cow { }; struct ubd { + /* name (and fd, below) of the file opened for writing, either the + * backing or the cow file. */ char *file; int count; int fd; __u64 size; struct openflags boot_openflags; struct openflags openflags; - int no_cow; + unsigned shared:1; + unsigned no_cow:1; struct cow cow; struct platform_device pdev; - - int map_writes; - int map_reads; - int nomap_writes; - int nomap_reads; - int write_maps; }; #define DEFAULT_COW { \ @@ -198,26 +196,11 @@ struct ubd { .boot_openflags = OPEN_FLAGS, \ .openflags = OPEN_FLAGS, \ .no_cow = 0, \ + .shared = 0, \ .cow = DEFAULT_COW, \ - .map_writes = 0, \ - .map_reads = 0, \ - .nomap_writes = 0, \ - .nomap_reads = 0, \ - .write_maps = 0, \ } -struct ubd ubd_dev[MAX_DEV] = { [ 0 ... MAX_DEV - 1 ] = DEFAULT_UBD }; - -static int ubd0_init(void) -{ - struct ubd *dev = &ubd_dev[0]; - - if(dev->file == NULL) - dev->file = "root_fs"; - return(0); -} - -__initcall(ubd0_init); +struct ubd ubd_devs[MAX_DEV] = { [ 0 ... MAX_DEV - 1 ] = DEFAULT_UBD }; /* Only changed by fake_ide_setup which is a setup */ static int fake_ide = 0; @@ -291,7 +274,7 @@ static int parse_unit(char **ptr) return(-1); *ptr = end; } - else if (('a' <= *str) && (*str <= 'h')) { + else if (('a' <= *str) && (*str <= 'z')) { n = *str - 'a'; str++; *ptr = str; @@ -299,9 +282,13 @@ static int parse_unit(char **ptr) return(n); } +/* If *index_out == -1 at exit, the passed option was a general one; + * otherwise, the str pointer is used (and owned) inside ubd_devs array, so it + * should not be freed on exit. + */ static int ubd_setup_common(char *str, int *index_out) { - struct ubd *dev; + struct ubd *ubd_dev; struct openflags flags = global_openflags; char *backing_file; int n, err, i; @@ -313,38 +300,31 @@ static int ubd_setup_common(char *str, int *index_out) int major; str++; - if(!strcmp(str, "mmap")){ - CHOOSE_MODE(printk("mmap not supported by the ubd " - "driver in tt mode\n"), - ubd_do_mmap = 1); - return(0); - } - if(!strcmp(str, "sync")){ global_openflags = of_sync(global_openflags); return(0); } major = simple_strtoul(str, &end, 0); if((*end != '\0') || (end == str)){ - printk(KERN_ERR + printk(KERN_ERR "ubd_setup : didn't parse major number\n"); return(1); } err = 1; - spin_lock(&ubd_lock); + mutex_lock(&ubd_lock); if(fake_major != MAJOR_NR){ printk(KERN_ERR "Can't assign a fake major twice\n"); goto out1; } - + fake_major = major; printk(KERN_INFO "Setting extra ubd major number to %d\n", major); err = 0; out1: - spin_unlock(&ubd_lock); + mutex_unlock(&ubd_lock); return(err); } @@ -361,10 +341,10 @@ static int ubd_setup_common(char *str, int *index_out) } err = 1; - spin_lock(&ubd_lock); + mutex_lock(&ubd_lock); - dev = &ubd_dev[n]; - if(dev->file != NULL){ + ubd_dev = &ubd_devs[n]; + if(ubd_dev->file != NULL){ printk(KERN_ERR "ubd_setup : device already configured\n"); goto out; } @@ -372,7 +352,7 @@ static int ubd_setup_common(char *str, int *index_out) if (index_out) *index_out = n; - for (i = 0; i < 4; i++) { + for (i = 0; i < sizeof("rscd="); i++) { switch (*str) { case 'r': flags.w = 0; @@ -381,13 +361,16 @@ static int ubd_setup_common(char *str, int *index_out) flags.s = 1; break; case 'd': - dev->no_cow = 1; + ubd_dev->no_cow = 1; + break; + case 'c': + ubd_dev->shared = 1; break; case '=': str++; goto break_loop; default: - printk(KERN_ERR "ubd_setup : Expected '=' or flag letter (r,s or d)\n"); + printk(KERN_ERR "ubd_setup : Expected '=' or flag letter (r, s, c, or d)\n"); goto out; } str++; @@ -408,7 +391,7 @@ break_loop: } if(backing_file){ - if(dev->no_cow) + if(ubd_dev->no_cow) printk(KERN_ERR "Can't specify both 'd' and a " "cow file\n"); else { @@ -416,11 +399,11 @@ break_loop: backing_file++; } } - dev->file = str; - dev->cow.file = backing_file; - dev->boot_openflags = flags; + ubd_dev->file = str; + ubd_dev->cow.file = backing_file; + ubd_dev->boot_openflags = flags; out: - spin_unlock(&ubd_lock); + mutex_unlock(&ubd_lock); return(err); } @@ -453,6 +436,22 @@ __uml_help(ubd_setup, " an 's' will cause data to be written to disk on the host immediately.\n\n" ); +static int udb_setup(char *str) +{ + printk("udb%s specified on command line is almost certainly a ubd -> " + "udb TYPO\n", str); + return(1); +} + +__setup("udb", udb_setup); +__uml_help(udb_setup, +"udb\n" +" This option is here solely to catch ubd -> udb typos, which can be\n" +" to impossible to catch visually unless you specifically look for\n" +" them. The only result of any option starting with 'udb' is an error\n" +" in the boot output.\n\n" +); + static int fakehd_set = 0; static int fakehd(char *str) { @@ -474,8 +473,9 @@ int thread_fd = -1; /* Changed by ubd_handler, which is serialized because interrupts only * happen on CPU 0. + * XXX: currently unused. */ -int intr_count = 0; +static int intr_count = 0; /* call ubd_finish if you need to serialize */ static void __ubd_finish(struct request *req, int error) @@ -495,6 +495,8 @@ static void __ubd_finish(struct request *req, int error) end_request(req, 1); } +/* Callable only from interrupt context - otherwise you need to do + * spin_lock_irq()/spin_lock_irqsave() */ static inline void ubd_finish(struct request *req, int error) { spin_lock(&ubd_io_lock); @@ -502,14 +504,15 @@ static inline void ubd_finish(struct request *req, int error) spin_unlock(&ubd_io_lock); } -/* Called without ubd_io_lock held */ +/* XXX - move this inside ubd_intr. */ +/* Called without ubd_io_lock held, and only in interrupt context. */ static void ubd_handler(void) { struct io_thread_req req; struct request *rq = elv_next_request(ubd_queue); - int n, err; + int n; - do_ubd = NULL; + do_ubd = 0; intr_count++; n = os_read_file(thread_fd, &req, sizeof(req)); if(n != sizeof(req)){ @@ -520,26 +523,15 @@ static void ubd_handler(void) spin_unlock(&ubd_io_lock); return; } - - if((req.op != UBD_MMAP) && - ((req.offset != ((__u64) (rq->sector)) << 9) || - (req.length != (rq->current_nr_sectors) << 9))) - panic("I/O op mismatch"); - - if(req.map_fd != -1){ - err = physmem_subst_mapping(req.buffer, req.map_fd, - req.map_offset, 1); - if(err) - printk("ubd_handler - physmem_subst_mapping failed, " - "err = %d\n", -err); - } ubd_finish(rq, req.error); reactivate_fd(thread_fd, UBD_IRQ); + spin_lock(&ubd_io_lock); do_ubd_request(ubd_queue); + spin_unlock(&ubd_io_lock); } -static irqreturn_t ubd_intr(int irq, void *dev, struct pt_regs *unused) +static irqreturn_t ubd_intr(int irq, void *dev) { ubd_handler(); return(IRQ_HANDLED); @@ -550,98 +542,100 @@ static int io_pid = -1; void kill_io_thread(void) { - if(io_pid != -1) + if(io_pid != -1) os_kill_process(io_pid, 1); } __uml_exitcall(kill_io_thread); -static int ubd_file_size(struct ubd *dev, __u64 *size_out) +static inline int ubd_file_size(struct ubd *ubd_dev, __u64 *size_out) { char *file; - file = dev->cow.file ? dev->cow.file : dev->file; + file = ubd_dev->cow.file ? ubd_dev->cow.file : ubd_dev->file; return(os_file_size(file, size_out)); } -static void ubd_close(struct ubd *dev) +static void ubd_close_dev(struct ubd *ubd_dev) { - if(ubd_do_mmap) - physmem_forget_descriptor(dev->fd); - os_close_file(dev->fd); - if(dev->cow.file == NULL) + os_close_file(ubd_dev->fd); + if(ubd_dev->cow.file == NULL) return; - if(ubd_do_mmap) - physmem_forget_descriptor(dev->cow.fd); - os_close_file(dev->cow.fd); - vfree(dev->cow.bitmap); - dev->cow.bitmap = NULL; + os_close_file(ubd_dev->cow.fd); + vfree(ubd_dev->cow.bitmap); + ubd_dev->cow.bitmap = NULL; } -static int ubd_open_dev(struct ubd *dev) +static int ubd_open_dev(struct ubd *ubd_dev) { struct openflags flags; char **back_ptr; int err, create_cow, *create_ptr; + int fd; - dev->openflags = dev->boot_openflags; + ubd_dev->openflags = ubd_dev->boot_openflags; create_cow = 0; - create_ptr = (dev->cow.file != NULL) ? &create_cow : NULL; - back_ptr = dev->no_cow ? NULL : &dev->cow.file; - dev->fd = open_ubd_file(dev->file, &dev->openflags, back_ptr, - &dev->cow.bitmap_offset, &dev->cow.bitmap_len, - &dev->cow.data_offset, create_ptr); - - if((dev->fd == -ENOENT) && create_cow){ - dev->fd = create_cow_file(dev->file, dev->cow.file, - dev->openflags, 1 << 9, PAGE_SIZE, - &dev->cow.bitmap_offset, - &dev->cow.bitmap_len, - &dev->cow.data_offset); - if(dev->fd >= 0){ + create_ptr = (ubd_dev->cow.file != NULL) ? &create_cow : NULL; + back_ptr = ubd_dev->no_cow ? NULL : &ubd_dev->cow.file; + + fd = open_ubd_file(ubd_dev->file, &ubd_dev->openflags, ubd_dev->shared, + back_ptr, &ubd_dev->cow.bitmap_offset, + &ubd_dev->cow.bitmap_len, &ubd_dev->cow.data_offset, + create_ptr); + + if((fd == -ENOENT) && create_cow){ + fd = create_cow_file(ubd_dev->file, ubd_dev->cow.file, + ubd_dev->openflags, 1 << 9, PAGE_SIZE, + &ubd_dev->cow.bitmap_offset, + &ubd_dev->cow.bitmap_len, + &ubd_dev->cow.data_offset); + if(fd >= 0){ printk(KERN_INFO "Creating \"%s\" as COW file for " - "\"%s\"\n", dev->file, dev->cow.file); + "\"%s\"\n", ubd_dev->file, ubd_dev->cow.file); } } - if(dev->fd < 0) return(dev->fd); + if(fd < 0){ + printk("Failed to open '%s', errno = %d\n", ubd_dev->file, + -fd); + return fd; + } + ubd_dev->fd = fd; - if(dev->cow.file != NULL){ + if(ubd_dev->cow.file != NULL){ err = -ENOMEM; - dev->cow.bitmap = (void *) vmalloc(dev->cow.bitmap_len); - if(dev->cow.bitmap == NULL){ + ubd_dev->cow.bitmap = (void *) vmalloc(ubd_dev->cow.bitmap_len); + if(ubd_dev->cow.bitmap == NULL){ printk(KERN_ERR "Failed to vmalloc COW bitmap\n"); goto error; } flush_tlb_kernel_vm(); - err = read_cow_bitmap(dev->fd, dev->cow.bitmap, - dev->cow.bitmap_offset, - dev->cow.bitmap_len); + err = read_cow_bitmap(ubd_dev->fd, ubd_dev->cow.bitmap, + ubd_dev->cow.bitmap_offset, + ubd_dev->cow.bitmap_len); if(err < 0) goto error; - flags = dev->openflags; + flags = ubd_dev->openflags; flags.w = 0; - err = open_ubd_file(dev->cow.file, &flags, NULL, NULL, NULL, - NULL, NULL); + err = open_ubd_file(ubd_dev->cow.file, &flags, ubd_dev->shared, NULL, + NULL, NULL, NULL, NULL); if(err < 0) goto error; - dev->cow.fd = err; + ubd_dev->cow.fd = err; } return(0); error: - os_close_file(dev->fd); + os_close_file(ubd_dev->fd); return(err); } -static int ubd_new_disk(int major, u64 size, int unit, +static int ubd_disk_register(int major, u64 size, int unit, struct gendisk **disk_out) { struct gendisk *disk; - char from[sizeof("ubd/nnnnn\0")], to[sizeof("discnnnnn/disc\0")]; - int err; disk = alloc_disk(1 << UBD_SHIFT); if(disk == NULL) @@ -651,30 +645,20 @@ static int ubd_new_disk(int major, u64 size, int unit, disk->first_minor = unit << UBD_SHIFT; disk->fops = &ubd_blops; set_capacity(disk, size / 512); - if(major == MAJOR_NR){ + if(major == MAJOR_NR) sprintf(disk->disk_name, "ubd%c", 'a' + unit); - sprintf(disk->devfs_name, "ubd/disc%d", unit); - sprintf(from, "ubd/%d", unit); - sprintf(to, "disc%d/disc", unit); - err = devfs_mk_symlink(from, to); - if(err) - printk("ubd_new_disk failed to make link from %s to " - "%s, error = %d\n", from, to, err); - } - else { + else sprintf(disk->disk_name, "ubd_fake%d", unit); - sprintf(disk->devfs_name, "ubd_fake/disc%d", unit); - } /* sysfs register (not for ide fake devices) */ if (major == MAJOR_NR) { - ubd_dev[unit].pdev.id = unit; - ubd_dev[unit].pdev.name = DRIVER_NAME; - platform_device_register(&ubd_dev[unit].pdev); - disk->driverfs_dev = &ubd_dev[unit].pdev.dev; + ubd_devs[unit].pdev.id = unit; + ubd_devs[unit].pdev.name = DRIVER_NAME; + platform_device_register(&ubd_devs[unit].pdev); + disk->driverfs_dev = &ubd_devs[unit].pdev.dev; } - disk->private_data = &ubd_dev[unit]; + disk->private_data = &ubd_devs[unit]; disk->queue = ubd_queue; add_disk(disk); @@ -686,27 +670,25 @@ static int ubd_new_disk(int major, u64 size, int unit, static int ubd_add(int n) { - struct ubd *dev = &ubd_dev[n]; + struct ubd *ubd_dev = &ubd_devs[n]; int err; - if(dev->file == NULL) - return(-ENODEV); - - if (ubd_open_dev(dev)) - return(-ENODEV); + err = -ENODEV; + if(ubd_dev->file == NULL) + goto out; - err = ubd_file_size(dev, &dev->size); + err = ubd_file_size(ubd_dev, &ubd_dev->size); if(err < 0) - return(err); + goto out; - dev->size = ROUND_BLOCK(dev->size); + ubd_dev->size = ROUND_BLOCK(ubd_dev->size); + + err = ubd_disk_register(MAJOR_NR, ubd_dev->size, n, &ubd_gendisk[n]); + if(err) + goto out; - err = ubd_new_disk(MAJOR_NR, dev->size, n, &ubd_gendisk[n]); - if(err) - return(err); - if(fake_major != MAJOR_NR) - ubd_new_disk(fake_major, dev->size, n, + ubd_disk_register(fake_major, ubd_dev->size, n, &fake_gendisk[n]); /* perhaps this should also be under the "if (fake_major)" above */ @@ -714,93 +696,107 @@ static int ubd_add(int n) if (fake_ide) make_ide_entries(ubd_gendisk[n]->disk_name); - ubd_close(dev); - return 0; + err = 0; +out: + return err; } static int ubd_config(char *str) { - int n, err; + int n, ret; - str = uml_strdup(str); - if(str == NULL){ + str = kstrdup(str, GFP_KERNEL); + if (str == NULL) { printk(KERN_ERR "ubd_config failed to strdup string\n"); - return(1); + ret = 1; + goto out; } - err = ubd_setup_common(str, &n); - if(err){ - kfree(str); - return(-1); + ret = ubd_setup_common(str, &n); + if (ret) { + ret = -1; + goto err_free; + } + if (n == -1) { + ret = 0; + goto err_free; } - if(n == -1) return(0); - spin_lock(&ubd_lock); - err = ubd_add(n); - if(err) - ubd_dev[n].file = NULL; - spin_unlock(&ubd_lock); + mutex_lock(&ubd_lock); + ret = ubd_add(n); + if (ret) + ubd_devs[n].file = NULL; + mutex_unlock(&ubd_lock); - return(err); +out: + return ret; + +err_free: + kfree(str); + goto out; } static int ubd_get_config(char *name, char *str, int size, char **error_out) { - struct ubd *dev; - char *end; + struct ubd *ubd_dev; int n, len = 0; - n = simple_strtoul(name, &end, 0); - if((*end != '\0') || (end == name)){ - *error_out = "ubd_get_config : didn't parse device number"; - return(-1); - } - + n = parse_unit(&name); if((n >= MAX_DEV) || (n < 0)){ *error_out = "ubd_get_config : device number out of range"; return(-1); } - dev = &ubd_dev[n]; - spin_lock(&ubd_lock); + ubd_dev = &ubd_devs[n]; + mutex_lock(&ubd_lock); - if(dev->file == NULL){ + if(ubd_dev->file == NULL){ CONFIG_CHUNK(str, size, len, "", 1); goto out; } - CONFIG_CHUNK(str, size, len, dev->file, 0); + CONFIG_CHUNK(str, size, len, ubd_dev->file, 0); - if(dev->cow.file != NULL){ + if(ubd_dev->cow.file != NULL){ CONFIG_CHUNK(str, size, len, ",", 0); - CONFIG_CHUNK(str, size, len, dev->cow.file, 1); + CONFIG_CHUNK(str, size, len, ubd_dev->cow.file, 1); } else CONFIG_CHUNK(str, size, len, "", 1); out: - spin_unlock(&ubd_lock); + mutex_unlock(&ubd_lock); return(len); } -static int ubd_remove(char *str) +static int ubd_id(char **str, int *start_out, int *end_out) { - struct ubd *dev; - int n, err = -ENODEV; + int n; - n = parse_unit(&str); + n = parse_unit(str); + *start_out = 0; + *end_out = MAX_DEV - 1; + return n; +} - if((n < 0) || (n >= MAX_DEV)) - return(err); +static int ubd_remove(int n) +{ + struct ubd *ubd_dev; + int err = -ENODEV; - dev = &ubd_dev[n]; - if(dev->count > 0) - return(-EBUSY); /* you cannot remove a open disk */ - - err = 0; - spin_lock(&ubd_lock); + mutex_lock(&ubd_lock); if(ubd_gendisk[n] == NULL) goto out; + ubd_dev = &ubd_devs[n]; + + if(ubd_dev->file == NULL) + goto out; + + /* you cannot remove a open disk */ + err = -EBUSY; + if(ubd_dev->count > 0) + goto out; + del_gendisk(ubd_gendisk[n]); put_disk(ubd_gendisk[n]); ubd_gendisk[n] = NULL; @@ -811,22 +807,24 @@ static int ubd_remove(char *str) fake_gendisk[n] = NULL; } - platform_device_unregister(&dev->pdev); - *dev = ((struct ubd) DEFAULT_UBD); + platform_device_unregister(&ubd_dev->pdev); + *ubd_dev = ((struct ubd) DEFAULT_UBD); err = 0; - out: - spin_unlock(&ubd_lock); - return(err); +out: + mutex_unlock(&ubd_lock); + return err; } +/* All these are called by mconsole in process context and without ubd-specific locks. */ static struct mc_device ubd_mc = { .name = "ubd", .config = ubd_config, .get_config = ubd_get_config, + .id = ubd_id, .remove = ubd_remove, }; -static int ubd_mc_init(void) +static int __init ubd_mc_init(void) { mconsole_register_dev(&ubd_mc); return 0; @@ -834,16 +832,27 @@ static int ubd_mc_init(void) __initcall(ubd_mc_init); -static struct device_driver ubd_driver = { - .name = DRIVER_NAME, - .bus = &platform_bus_type, +static int __init ubd0_init(void) +{ + struct ubd *ubd_dev = &ubd_devs[0]; + + if(ubd_dev->file == NULL) + ubd_dev->file = "root_fs"; + return(0); +} + +__initcall(ubd0_init); + +static struct platform_driver ubd_driver = { + .driver = { + .name = DRIVER_NAME, + }, }; -int ubd_init(void) +static int __init ubd_init(void) { int i; - devfs_mk_dir("ubd"); if (register_blkdev(MAJOR_NR, "ubd")) return -1; @@ -857,19 +866,18 @@ int ubd_init(void) char name[sizeof("ubd_nnn\0")]; snprintf(name, sizeof(name), "ubd_%d", fake_major); - devfs_mk_dir(name); if (register_blkdev(fake_major, "ubd")) return -1; } - driver_register(&ubd_driver); - for (i = 0; i < MAX_DEV; i++) + platform_driver_register(&ubd_driver); + for (i = 0; i < MAX_DEV; i++) ubd_add(i); return 0; } late_initcall(ubd_init); -int ubd_driver_init(void){ +static int __init ubd_driver_init(void){ unsigned long stack; int err; @@ -880,20 +888,20 @@ int ubd_driver_init(void){ * enough. So use anyway the io thread. */ } stack = alloc_stack(0, 0); - io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *), + io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *), &thread_fd); if(io_pid < 0){ - printk(KERN_ERR + printk(KERN_ERR "ubd : Failed to start I/O thread (errno = %d) - " "falling back to synchronous I/O\n", -io_pid); io_pid = -1; return(0); } - err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr, - SA_INTERRUPT, "ubd", ubd_dev); + err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr, + IRQF_DISABLED, "ubd", ubd_devs); if(err != 0) printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err); - return(err); + return 0; } device_initcall(ubd_driver_init); @@ -901,22 +909,26 @@ device_initcall(ubd_driver_init); static int ubd_open(struct inode *inode, struct file *filp) { struct gendisk *disk = inode->i_bdev->bd_disk; - struct ubd *dev = disk->private_data; + struct ubd *ubd_dev = disk->private_data; int err = 0; - if(dev->count == 0){ - err = ubd_open_dev(dev); + if(ubd_dev->count == 0){ + err = ubd_open_dev(ubd_dev); if(err){ printk(KERN_ERR "%s: Can't open \"%s\": errno = %d\n", - disk->disk_name, dev->file, -err); + disk->disk_name, ubd_dev->file, -err); goto out; } } - dev->count++; - if((filp->f_mode & FMODE_WRITE) && !dev->openflags.w){ - if(--dev->count == 0) ubd_close(dev); + ubd_dev->count++; + set_disk_ro(disk, !ubd_dev->openflags.w); + + /* This should no more be needed. And it didn't work anyway to exclude + * read-write remounting of filesystems.*/ + /*if((filp->f_mode & FMODE_WRITE) && !ubd_dev->openflags.w){ + if(--ubd_dev->count == 0) ubd_close_dev(ubd_dev); err = -EROFS; - } + }*/ out: return(err); } @@ -924,10 +936,10 @@ static int ubd_open(struct inode *inode, struct file *filp) static int ubd_release(struct inode * inode, struct file * file) { struct gendisk *disk = inode->i_bdev->bd_disk; - struct ubd *dev = disk->private_data; + struct ubd *ubd_dev = disk->private_data; - if(--dev->count == 0) - ubd_close(dev); + if(--ubd_dev->count == 0) + ubd_close_dev(ubd_dev); return(0); } @@ -982,7 +994,7 @@ static void cowify_req(struct io_thread_req *req, unsigned long *bitmap, if(req->op == UBD_READ) { for(i = 0; i < req->length >> 9; i++){ if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) - ubd_set_bit(i, (unsigned char *) + ubd_set_bit(i, (unsigned char *) &req->sector_mask); } } @@ -991,99 +1003,17 @@ static void cowify_req(struct io_thread_req *req, unsigned long *bitmap, req->bitmap_words, bitmap_len); } -static int mmap_fd(struct request *req, struct ubd *dev, __u64 offset) -{ - __u64 sector; - unsigned char *bitmap; - int bit, i; - - /* mmap must have been requested on the command line */ - if(!ubd_do_mmap) - return(-1); - - /* The buffer must be page aligned */ - if(((unsigned long) req->buffer % UBD_MMAP_BLOCK_SIZE) != 0) - return(-1); - - /* The request must be a page long */ - if((req->current_nr_sectors << 9) != PAGE_SIZE) - return(-1); - - if(dev->cow.file == NULL) - return(dev->fd); - - sector = offset >> 9; - bitmap = (unsigned char *) dev->cow.bitmap; - bit = ubd_test_bit(sector, bitmap); - - for(i = 1; i < req->current_nr_sectors; i++){ - if(ubd_test_bit(sector + i, bitmap) != bit) - return(-1); - } - - if(bit || (rq_data_dir(req) == WRITE)) - offset += dev->cow.data_offset; - - /* The data on disk must be page aligned */ - if((offset % UBD_MMAP_BLOCK_SIZE) != 0) - return(-1); - - return(bit ? dev->fd : dev->cow.fd); -} - -static int prepare_mmap_request(struct ubd *dev, int fd, __u64 offset, - struct request *req, - struct io_thread_req *io_req) -{ - int err; - - if(rq_data_dir(req) == WRITE){ - /* Writes are almost no-ops since the new data is already in the - * host page cache - */ - dev->map_writes++; - if(dev->cow.file != NULL) - cowify_bitmap(io_req->offset, io_req->length, - &io_req->sector_mask, &io_req->cow_offset, - dev->cow.bitmap, dev->cow.bitmap_offset, - io_req->bitmap_words, - dev->cow.bitmap_len); - } - else { - int w; - - if((dev->cow.file != NULL) && (fd == dev->cow.fd)) - w = 0; - else w = dev->openflags.w; - - if((dev->cow.file != NULL) && (fd == dev->fd)) - offset += dev->cow.data_offset; - - err = physmem_subst_mapping(req->buffer, fd, offset, w); - if(err){ - printk("physmem_subst_mapping failed, err = %d\n", - -err); - return(1); - } - dev->map_reads++; - } - io_req->op = UBD_MMAP; - io_req->buffer = req->buffer; - return(0); -} - /* Called with ubd_io_lock held */ static int prepare_request(struct request *req, struct io_thread_req *io_req) { struct gendisk *disk = req->rq_disk; - struct ubd *dev = disk->private_data; + struct ubd *ubd_dev = disk->private_data; __u64 offset; - int len, fd; - - if(req->rq_status == RQ_INACTIVE) return(1); + int len; - if((rq_data_dir(req) == WRITE) && !dev->openflags.w){ - printk("Write attempted on readonly ubd device %s\n", + /* This should be impossible now */ + if((rq_data_dir(req) == WRITE) && !ubd_dev->openflags.w){ + printk("Write attempted on readonly ubd device %s\n", disk->disk_name); end_request(req, 0); return(1); @@ -1092,45 +1022,23 @@ static int prepare_request(struct request *req, struct io_thread_req *io_req) offset = ((__u64) req->sector) << 9; len = req->current_nr_sectors << 9; - io_req->fds[0] = (dev->cow.file != NULL) ? dev->cow.fd : dev->fd; - io_req->fds[1] = dev->fd; - io_req->map_fd = -1; + io_req->fds[0] = (ubd_dev->cow.file != NULL) ? ubd_dev->cow.fd : ubd_dev->fd; + io_req->fds[1] = ubd_dev->fd; io_req->cow_offset = -1; io_req->offset = offset; io_req->length = len; io_req->error = 0; io_req->sector_mask = 0; - fd = mmap_fd(req, dev, io_req->offset); - if(fd > 0){ - /* If mmapping is otherwise OK, but the first access to the - * page is a write, then it's not mapped in yet. So we have - * to write the data to disk first, then we can map the disk - * page in and continue normally from there. - */ - if((rq_data_dir(req) == WRITE) && !is_remapped(req->buffer)){ - io_req->map_fd = dev->fd; - io_req->map_offset = io_req->offset + - dev->cow.data_offset; - dev->write_maps++; - } - else return(prepare_mmap_request(dev, fd, io_req->offset, req, - io_req)); - } - - if(rq_data_dir(req) == READ) - dev->nomap_reads++; - else dev->nomap_writes++; - io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE; io_req->offsets[0] = 0; - io_req->offsets[1] = dev->cow.data_offset; + io_req->offsets[1] = ubd_dev->cow.data_offset; io_req->buffer = req->buffer; io_req->sectorsize = 1 << 9; - if(dev->cow.file != NULL) - cowify_req(io_req, dev->cow.bitmap, dev->cow.bitmap_offset, - dev->cow.bitmap_len); + if(ubd_dev->cow.file != NULL) + cowify_req(io_req, ubd_dev->cow.bitmap, ubd_dev->cow.bitmap_offset, + ubd_dev->cow.bitmap_len); return(0); } @@ -1156,7 +1064,7 @@ static void do_ubd_request(request_queue_t *q) return; err = prepare_request(req, &io_req); if(!err){ - do_ubd = ubd_handler; + do_ubd = 1; n = os_write_file(thread_fd, (char *) &io_req, sizeof(io_req)); if(n != sizeof(io_req)) @@ -1166,11 +1074,20 @@ static void do_ubd_request(request_queue_t *q) } } +static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo) +{ + struct ubd *ubd_dev = bdev->bd_disk->private_data; + + geo->heads = 128; + geo->sectors = 32; + geo->cylinders = ubd_dev->size / (128 * 32 * 512); + return 0; +} + static int ubd_ioctl(struct inode * inode, struct file * file, unsigned int cmd, unsigned long arg) { - struct hd_geometry __user *loc = (struct hd_geometry __user *) arg; - struct ubd *dev = inode->i_bdev->bd_disk->private_data; + struct ubd *ubd_dev = inode->i_bdev->bd_disk->private_data; struct hd_driveid ubd_id = { .cyls = 0, .heads = 128, @@ -1178,18 +1095,9 @@ static int ubd_ioctl(struct inode * inode, struct file * file, }; switch (cmd) { - struct hd_geometry g; struct cdrom_volctrl volume; - case HDIO_GETGEO: - if(!loc) return(-EINVAL); - g.heads = 128; - g.sectors = 32; - g.cylinders = dev->size / (128 * 32 * 512); - g.start = get_start_sect(inode->i_bdev); - return(copy_to_user(loc, &g, sizeof(g)) ? -EFAULT : 0); - case HDIO_GET_IDENTITY: - ubd_id.cyls = dev->size / (128 * 32 * 512); + ubd_id.cyls = ubd_dev->size / (128 * 32 * 512); if(copy_to_user((char __user *) arg, (char *) &ubd_id, sizeof(ubd_id))) return(-EFAULT); @@ -1209,173 +1117,39 @@ static int ubd_ioctl(struct inode * inode, struct file * file, return(-EINVAL); } -static int ubd_check_remapped(int fd, unsigned long address, int is_write, - __u64 offset) -{ - __u64 bitmap_offset; - unsigned long new_bitmap[2]; - int i, err, n; - - /* If it's not a write access, we can't do anything about it */ - if(!is_write) - return(0); - - /* We have a write */ - for(i = 0; i < sizeof(ubd_dev) / sizeof(ubd_dev[0]); i++){ - struct ubd *dev = &ubd_dev[i]; - - if((dev->fd != fd) && (dev->cow.fd != fd)) - continue; - - /* It's a write to a ubd device */ - - if(!dev->openflags.w){ - /* It's a write access on a read-only device - probably - * shouldn't happen. If the kernel is trying to change - * something with no intention of writing it back out, - * then this message will clue us in that this needs - * fixing - */ - printk("Write access to mapped page from readonly ubd " - "device %d\n", i); - return(0); - } - - /* It's a write to a writeable ubd device - it must be COWed - * because, otherwise, the page would have been mapped in - * writeable - */ - - if(!dev->cow.file) - panic("Write fault on writeable non-COW ubd device %d", - i); - - /* It should also be an access to the backing file since the - * COW pages should be mapped in read-write - */ - - if(fd == dev->fd) - panic("Write fault on a backing page of ubd " - "device %d\n", i); - - /* So, we do the write, copying the backing data to the COW - * file... - */ - - err = os_seek_file(dev->fd, offset + dev->cow.data_offset); - if(err < 0) - panic("Couldn't seek to %lld in COW file of ubd " - "device %d, err = %d", - offset + dev->cow.data_offset, i, -err); - - n = os_write_file(dev->fd, (void *) address, PAGE_SIZE); - if(n != PAGE_SIZE) - panic("Couldn't copy data to COW file of ubd " - "device %d, err = %d", i, -n); - - /* ... updating the COW bitmap... */ - - cowify_bitmap(offset, PAGE_SIZE, NULL, &bitmap_offset, - dev->cow.bitmap, dev->cow.bitmap_offset, - new_bitmap, dev->cow.bitmap_len); - - err = os_seek_file(dev->fd, bitmap_offset); - if(err < 0) - panic("Couldn't seek to %lld in COW file of ubd " - "device %d, err = %d", bitmap_offset, i, -err); - - n = os_write_file(dev->fd, new_bitmap, sizeof(new_bitmap)); - if(n != sizeof(new_bitmap)) - panic("Couldn't update bitmap of ubd device %d, " - "err = %d", i, -n); - - /* Maybe we can map the COW page in, and maybe we can't. If - * it is a pre-V3 COW file, we can't, since the alignment will - * be wrong. If it is a V3 or later COW file which has been - * moved to a system with a larger page size, then maybe we - * can't, depending on the exact location of the page. - */ - - offset += dev->cow.data_offset; - - /* Remove the remapping, putting the original anonymous page - * back. If the COW file can be mapped in, that is done. - * Otherwise, the COW page is read in. - */ - - if(!physmem_remove_mapping((void *) address)) - panic("Address 0x%lx not remapped by ubd device %d", - address, i); - if((offset % UBD_MMAP_BLOCK_SIZE) == 0) - physmem_subst_mapping((void *) address, dev->fd, - offset, 1); - else { - err = os_seek_file(dev->fd, offset); - if(err < 0) - panic("Couldn't seek to %lld in COW file of " - "ubd device %d, err = %d", offset, i, - -err); - - n = os_read_file(dev->fd, (void *) address, PAGE_SIZE); - if(n != PAGE_SIZE) - panic("Failed to read page from offset %llx of " - "COW file of ubd device %d, err = %d", - offset, i, -n); - } - - return(1); - } - - /* It's not a write on a ubd device */ - return(0); -} - -static struct remapper ubd_remapper = { - .list = LIST_HEAD_INIT(ubd_remapper.list), - .proc = ubd_check_remapped, -}; - -static int ubd_remapper_setup(void) -{ - if(ubd_do_mmap) - register_remapper(&ubd_remapper); - - return(0); -} - -__initcall(ubd_remapper_setup); - -static int same_backing_files(char *from_cmdline, char *from_cow, char *cow) +static int path_requires_switch(char *from_cmdline, char *from_cow, char *cow) { struct uml_stat buf1, buf2; int err; - if(from_cmdline == NULL) return(1); - if(!strcmp(from_cmdline, from_cow)) return(1); + if(from_cmdline == NULL) + return 0; + if(!strcmp(from_cmdline, from_cow)) + return 0; err = os_stat_file(from_cmdline, &buf1); if(err < 0){ printk("Couldn't stat '%s', err = %d\n", from_cmdline, -err); - return(1); + return 0; } err = os_stat_file(from_cow, &buf2); if(err < 0){ printk("Couldn't stat '%s', err = %d\n", from_cow, -err); - return(1); + return 1; } if((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino)) - return(1); + return 0; printk("Backing file mismatch - \"%s\" requested,\n" "\"%s\" specified in COW header of \"%s\"\n", from_cmdline, from_cow, cow); - return(0); + return 1; } static int backing_file_mismatch(char *file, __u64 size, time_t mtime) { unsigned long modtime; - long long actual; + unsigned long long actual; int err; err = os_file_modtime(file, &modtime); @@ -1422,7 +1196,7 @@ int read_cow_bitmap(int fd, void *buf, int offset, int len) return(0); } -int open_ubd_file(char *file, struct openflags *openflags, +int open_ubd_file(char *file, struct openflags *openflags, int shared, char **backing_file_out, int *bitmap_offset_out, unsigned long *bitmap_len_out, int *data_offset_out, int *create_cow_out) @@ -1431,27 +1205,34 @@ int open_ubd_file(char *file, struct openflags *openflags, unsigned long long size; __u32 version, align; char *backing_file; - int fd, err, sectorsize, same, mode = 0644; + int fd, err, sectorsize, asked_switch, mode = 0644; fd = os_open_file(file, *openflags, mode); - if(fd < 0){ - if((fd == -ENOENT) && (create_cow_out != NULL)) + if (fd < 0) { + if ((fd == -ENOENT) && (create_cow_out != NULL)) *create_cow_out = 1; - if(!openflags->w || - ((fd != -EROFS) && (fd != -EACCES))) return(fd); + if (!openflags->w || + ((fd != -EROFS) && (fd != -EACCES))) + return fd; openflags->w = 0; fd = os_open_file(file, *openflags, mode); - if(fd < 0) - return(fd); + if (fd < 0) + return fd; } - err = os_lock_file(fd, openflags->w); - if(err < 0){ - printk("Failed to lock '%s', err = %d\n", file, -err); - goto out_close; + if(shared) + printk("Not locking \"%s\" on the host\n", file); + else { + err = os_lock_file(fd, openflags->w); + if(err < 0){ + printk("Failed to lock '%s', err = %d\n", file, -err); + goto out_close; + } } - if(backing_file_out == NULL) return(fd); + /* Successful return case! */ + if(backing_file_out == NULL) + return(fd); err = read_cow_header(file_reader, &fd, &version, &backing_file, &mtime, &size, §orsize, &align, bitmap_offset_out); @@ -1460,34 +1241,34 @@ int open_ubd_file(char *file, struct openflags *openflags, "errno = %d\n", file, -err); goto out_close; } - if(err) return(fd); - - if(backing_file_out == NULL) return(fd); + if(err) + return(fd); - same = same_backing_files(*backing_file_out, backing_file, file); + asked_switch = path_requires_switch(*backing_file_out, backing_file, file); - if(!same && !backing_file_mismatch(*backing_file_out, size, mtime)){ + /* Allow switching only if no mismatch. */ + if (asked_switch && !backing_file_mismatch(*backing_file_out, size, mtime)) { printk("Switching backing file to '%s'\n", *backing_file_out); err = write_cow_header(file, fd, *backing_file_out, sectorsize, align, &size); - if(err){ + if (err) { printk("Switch failed, errno = %d\n", -err); - return(err); + goto out_close; } - } - else { + } else { *backing_file_out = backing_file; err = backing_file_mismatch(*backing_file_out, size, mtime); - if(err) goto out_close; + if (err) + goto out_close; } cow_sizes(version, size, sectorsize, align, *bitmap_offset_out, bitmap_len_out, data_offset_out); - return(fd); + return fd; out_close: os_close_file(fd); - return(err); + return err; } int create_cow_file(char *cow_file, char *backing_file, struct openflags flags, @@ -1497,7 +1278,7 @@ int create_cow_file(char *cow_file, char *backing_file, struct openflags flags, int err, fd; flags.c = 1; - fd = open_ubd_file(cow_file, &flags, NULL, NULL, NULL, NULL, NULL); + fd = open_ubd_file(cow_file, &flags, 0, NULL, NULL, NULL, NULL, NULL); if(fd < 0){ err = fd; printk("Open of COW file '%s' failed, errno = %d\n", cow_file, @@ -1547,15 +1328,6 @@ void do_io(struct io_thread_req *req) int err; __u64 off; - if(req->op == UBD_MMAP){ - /* Touch the page to force the host to do any necessary IO to - * get it into memory - */ - n = *((volatile int *) req->buffer); - req->error = update_bitmap(req); - return; - } - nsectors = req->length / req->sectorsize; start = 0; do { @@ -1591,8 +1363,7 @@ void do_io(struct io_thread_req *req) } } while((n < len) && (n != 0)); if (n < len) memset(&buf[n], 0, len - n); - } - else { + } else { n = os_write_file(req->fds[bit], buf, len); if(n != len){ printk("do_io - write failed err = %d " @@ -1613,8 +1384,8 @@ void do_io(struct io_thread_req *req) */ int kernel_fd = -1; -/* Only changed by the io thread */ -int io_count = 0; +/* Only changed by the io thread. XXX: currently unused. */ +static int io_count = 0; int io_thread(void *arg) { @@ -1641,15 +1412,6 @@ int io_thread(void *arg) printk("io_thread - write failed, fd = %d, err = %d\n", kernel_fd, -n); } -} -/* - * Overrides for Emacs so that we follow Linus's tabbing style. - * Emacs will notice this stuff at the end of the file and automatically - * adjust the settings for this buffer only. This must remain at the end - * of the file. - * --------------------------------------------------------------------------- - * Local variables: - * c-file-style: "linux" - * End: - */ + return 0; +}