| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| WANG Cong | 2694 | 36.93% | 1 | 0.90% |
| Jeff Dike | 1900 | 26.05% | 38 | 34.23% |
| Anton Ivanov | 1042 | 14.28% | 10 | 9.01% |
| Paolo 'Blaisorblade' Giarrusso | 839 | 11.50% | 13 | 11.71% |
| Richard Weinberger | 324 | 4.44% | 4 | 3.60% |
| Christoph Hellwig | 207 | 2.84% | 5 | 4.50% |
| Al Viro | 82 | 1.12% | 9 | 8.11% |
| Arnd Bergmann | 41 | 0.56% | 4 | 3.60% |
| Bartlomiej Zolnierkiewicz | 35 | 0.48% | 1 | 0.90% |
| Jens Axboe | 33 | 0.45% | 4 | 3.60% |
| Gerd Knorr | 17 | 0.23% | 1 | 0.90% |
| Alexey Dobriyan | 11 | 0.15% | 2 | 1.80% |
| Dan J Williams | 11 | 0.15% | 1 | 0.90% |
| Greg Kroah-Hartman | 8 | 0.11% | 1 | 0.90% |
| Américo Wang | 7 | 0.10% | 1 | 0.90% |
| Daniel Walter | 6 | 0.08% | 1 | 0.90% |
| Kees Cook | 6 | 0.08% | 1 | 0.90% |
| Martin Pärtel | 5 | 0.07% | 1 | 0.90% |
| Tejun Heo | 4 | 0.05% | 2 | 1.80% |
| Jiri Olsa | 4 | 0.05% | 1 | 0.90% |
| Michael Christie | 3 | 0.04% | 1 | 0.90% |
| Miklos Szeredi | 3 | 0.04% | 1 | 0.90% |
| Gabriel Krisman Bertazi | 3 | 0.04% | 2 | 1.80% |
| Thomas Gleixner | 3 | 0.04% | 1 | 0.90% |
| Hannes Reinecke | 2 | 0.03% | 1 | 0.90% |
| Alex Dewar | 2 | 0.03% | 1 | 0.90% |
| Martin K. Petersen | 2 | 0.03% | 2 | 1.80% |
| Yong Zhang | 1 | 0.01% | 1 | 0.90% |
| Total | 7295 | 111 |
// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2018 Cambridge Greys Ltd * Copyright (C) 2015-2016 Anton Ivanov (aivanov@brocade.com) * Copyright (C) 2000 Jeff Dike (jdike@karaya.com) */ /* 2001-09-28...2002-04-17 * Partition stuff by James_McMechan@hotmail.com * old style ubd by setting UBD_SHIFT to 0 * 2002-09-27...2002-10-18 massive tinkering for 2.5 * partitions have changed in 2.5 * 2003-01-29 more tinkering for 2.5.59-1 * This should now address the sysfs problems and has * the symlink for devfs to allow for booting with * the common /dev/ubd/discX/... names rather than * only /dev/ubdN/discN this version also has lots of * clean ups preparing for ubd-many. * James McMechan */ #define UBD_SHIFT 4 #include <linux/module.h> #include <linux/init.h> #include <linux/blkdev.h> #include <linux/blk-mq.h> #include <linux/ata.h> #include <linux/hdreg.h> #include <linux/cdrom.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/ctype.h> #include <linux/slab.h> #include <linux/vmalloc.h> #include <linux/platform_device.h> #include <linux/scatterlist.h> #include <asm/tlbflush.h> #include <kern_util.h> #include "mconsole_kern.h" #include <init.h> #include <irq_kern.h> #include "ubd.h" #include <os.h> #include "cow.h" /* Max request size is determined by sector mask - 32K */ #define UBD_MAX_REQUEST (8 * sizeof(long)) struct io_thread_req { struct request *req; int fds[2]; unsigned long offsets[2]; unsigned long long offset; unsigned long length; char *buffer; int sectorsize; unsigned long sector_mask; unsigned long long cow_offset; unsigned long bitmap_words[2]; int error; }; static struct io_thread_req * (*irq_req_buffer)[]; static struct io_thread_req *irq_remainder; static int irq_remainder_size; static struct io_thread_req * (*io_req_buffer)[]; static struct io_thread_req *io_remainder; static int io_remainder_size; static inline int ubd_test_bit(__u64 bit, unsigned char *data) { __u64 n; int bits, off; bits = sizeof(data[0]) * 8; n = bit / bits; off = bit % bits; return (data[n] & (1 << off)) != 0; } static inline void ubd_set_bit(__u64 bit, unsigned char *data) { __u64 n; int bits, off; bits = sizeof(data[0]) * 8; n = bit / bits; off = bit % bits; data[n] |= (1 << off); } /*End stuff from ubd_user.h*/ #define DRIVER_NAME "uml-blkdev" static DEFINE_MUTEX(ubd_lock); static DEFINE_MUTEX(ubd_mutex); /* replaces BKL, might not be needed */ static int ubd_open(struct block_device *bdev, fmode_t mode); static void ubd_release(struct gendisk *disk, fmode_t mode); static int ubd_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg); static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo); #define MAX_DEV (16) static const struct block_device_operations ubd_blops = { .owner = THIS_MODULE, .open = ubd_open, .release = ubd_release, .ioctl = ubd_ioctl, .compat_ioctl = blkdev_compat_ptr_ioctl, .getgeo = ubd_getgeo, }; /* Protected by ubd_lock */ static int fake_major = UBD_MAJOR; 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 }) #else #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 0, .c = 0, \ .cl = 1 }) #endif 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; int bitmap_offset; int data_offset; }; #define MAX_SG 64 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; unsigned shared:1; unsigned no_cow:1; unsigned no_trim:1; struct cow cow; struct platform_device pdev; struct request_queue *queue; struct blk_mq_tag_set tag_set; spinlock_t lock; }; #define DEFAULT_COW { \ .file = NULL, \ .fd = -1, \ .bitmap = NULL, \ .bitmap_offset = 0, \ .data_offset = 0, \ } #define DEFAULT_UBD { \ .file = NULL, \ .count = 0, \ .fd = -1, \ .size = -1, \ .boot_openflags = OPEN_FLAGS, \ .openflags = OPEN_FLAGS, \ .no_cow = 0, \ .no_trim = 0, \ .shared = 0, \ .cow = DEFAULT_COW, \ .lock = __SPIN_LOCK_UNLOCKED(ubd_devs.lock), \ } /* Protected by ubd_lock */ static 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; static struct proc_dir_entry *proc_ide_root = NULL; static struct proc_dir_entry *proc_ide = NULL; static blk_status_t ubd_queue_rq(struct blk_mq_hw_ctx *hctx, const struct blk_mq_queue_data *bd); static void make_proc_ide(void) { proc_ide_root = proc_mkdir("ide", NULL); proc_ide = proc_mkdir("ide0", proc_ide_root); } static int fake_ide_media_proc_show(struct seq_file *m, void *v) { seq_puts(m, "disk\n"); return 0; } static void make_ide_entries(const char *dev_name) { struct proc_dir_entry *dir, *ent; char name[64]; if(proc_ide_root == NULL) make_proc_ide(); dir = proc_mkdir(dev_name, proc_ide); if(!dir) return; ent = proc_create_single("media", S_IRUGO, dir, fake_ide_media_proc_show); if(!ent) return; snprintf(name, sizeof(name), "ide0/%s", dev_name); proc_symlink(dev_name, proc_ide_root, name); } static int fake_ide_setup(char *str) { fake_ide = 1; return 1; } __setup("fake_ide", fake_ide_setup); __uml_help(fake_ide_setup, "fake_ide\n" " Create ide0 entries that map onto ubd devices.\n\n" ); static int parse_unit(char **ptr) { char *str = *ptr, *end; int n = -1; if(isdigit(*str)) { n = simple_strtoul(str, &end, 0); if(end == str) return -1; *ptr = end; } else if (('a' <= *str) && (*str <= 'z')) { n = *str - 'a'; str++; *ptr = str; } 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, char **error_out) { struct ubd *ubd_dev; struct openflags flags = global_openflags; char *backing_file; int n, err = 0, i; if(index_out) *index_out = -1; n = *str; if(n == '='){ char *end; int major; str++; if(!strcmp(str, "sync")){ global_openflags = of_sync(global_openflags); return err; } err = -EINVAL; major = simple_strtoul(str, &end, 0); if((*end != '\0') || (end == str)){ *error_out = "Didn't parse major number"; return err; } mutex_lock(&ubd_lock); if (fake_major != UBD_MAJOR) { *error_out = "Can't assign a fake major twice"; goto out1; } fake_major = major; printk(KERN_INFO "Setting extra ubd major number to %d\n", major); err = 0; out1: mutex_unlock(&ubd_lock); return err; } n = parse_unit(&str); if(n < 0){ *error_out = "Couldn't parse device number"; return -EINVAL; } if(n >= MAX_DEV){ *error_out = "Device number out of range"; return 1; } err = -EBUSY; mutex_lock(&ubd_lock); ubd_dev = &ubd_devs[n]; if(ubd_dev->file != NULL){ *error_out = "Device is already configured"; goto out; } if (index_out) *index_out = n; err = -EINVAL; for (i = 0; i < sizeof("rscdt="); i++) { switch (*str) { case 'r': flags.w = 0; break; case 's': flags.s = 1; break; case 'd': ubd_dev->no_cow = 1; break; case 'c': ubd_dev->shared = 1; break; case 't': ubd_dev->no_trim = 1; break; case '=': str++; goto break_loop; default: *error_out = "Expected '=' or flag letter " "(r, s, c, t or d)"; goto out; } str++; } if (*str == '=') *error_out = "Too many flags specified"; else *error_out = "Missing '='"; goto out; break_loop: backing_file = strchr(str, ','); if (backing_file == NULL) backing_file = strchr(str, ':'); if(backing_file != NULL){ if(ubd_dev->no_cow){ *error_out = "Can't specify both 'd' and a cow file"; goto out; } else { *backing_file = '\0'; backing_file++; } } err = 0; ubd_dev->file = str; ubd_dev->cow.file = backing_file; ubd_dev->boot_openflags = flags; out: mutex_unlock(&ubd_lock); return err; } static int ubd_setup(char *str) { char *error; int err; err = ubd_setup_common(str, NULL, &error); if(err) printk(KERN_ERR "Failed to initialize device with \"%s\" : " "%s\n", str, error); return 1; } __setup("ubd", ubd_setup); __uml_help(ubd_setup, "ubd<n><flags>=<filename>[(:|,)<filename2>]\n" " This is used to associate a device with a file in the underlying\n" " filesystem. When specifying two filenames, the first one is the\n" " COW name and the second is the backing file name. As separator you can\n" " use either a ':' or a ',': the first one allows writing things like;\n" " ubd0=~/Uml/root_cow:~/Uml/root_backing_file\n" " while with a ',' the shell would not expand the 2nd '~'.\n" " When using only one filename, UML will detect whether to treat it like\n" " a COW file or a backing file. To override this detection, add the 'd'\n" " flag:\n" " ubd0d=BackingFile\n" " Usually, there is a filesystem in the file, but \n" " that's not required. Swap devices containing swap files can be\n" " specified like this. Also, a file which doesn't contain a\n" " filesystem can have its contents read in the virtual \n" " machine by running 'dd' on the device. <n> must be in the range\n" " 0 to 7. Appending an 'r' to the number will cause that device\n" " to be mounted read-only. For example ubd1r=./ext_fs. Appending\n" " an 's' will cause data to be written to disk on the host immediately.\n" " 'c' will cause the device to be treated as being shared between multiple\n" " UMLs and file locking will be turned off - this is appropriate for a\n" " cluster filesystem and inappropriate at almost all other times.\n\n" " 't' will disable trim/discard support on the device (enabled by default).\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" ); /* Only changed by ubd_init, which is an initcall. */ static int thread_fd = -1; /* Function to read several request pointers at a time * handling fractional reads if (and as) needed */ static int bulk_req_safe_read( int fd, struct io_thread_req * (*request_buffer)[], struct io_thread_req **remainder, int *remainder_size, int max_recs ) { int n = 0; int res = 0; if (*remainder_size > 0) { memmove( (char *) request_buffer, (char *) remainder, *remainder_size ); n = *remainder_size; } res = os_read_file( fd, ((char *) request_buffer) + *remainder_size, sizeof(struct io_thread_req *)*max_recs - *remainder_size ); if (res > 0) { n += res; if ((n % sizeof(struct io_thread_req *)) > 0) { /* * Read somehow returned not a multiple of dword * theoretically possible, but never observed in the * wild, so read routine must be able to handle it */ *remainder_size = n % sizeof(struct io_thread_req *); WARN(*remainder_size > 0, "UBD IPC read returned a partial result"); memmove( remainder, ((char *) request_buffer) + (n/sizeof(struct io_thread_req *))*sizeof(struct io_thread_req *), *remainder_size ); n = n - *remainder_size; } } else { n = res; } return n; } /* Called without dev->lock held, and only in interrupt context. */ static void ubd_handler(void) { int n; int count; while(1){ n = bulk_req_safe_read( thread_fd, irq_req_buffer, &irq_remainder, &irq_remainder_size, UBD_REQ_BUFFER_SIZE ); if (n < 0) { if(n == -EAGAIN) break; printk(KERN_ERR "spurious interrupt in ubd_handler, " "err = %d\n", -n); return; } for (count = 0; count < n/sizeof(struct io_thread_req *); count++) { struct io_thread_req *io_req = (*irq_req_buffer)[count]; if ((io_req->error == BLK_STS_NOTSUPP) && (req_op(io_req->req) == REQ_OP_DISCARD)) { blk_queue_max_discard_sectors(io_req->req->q, 0); blk_queue_max_write_zeroes_sectors(io_req->req->q, 0); blk_queue_flag_clear(QUEUE_FLAG_DISCARD, io_req->req->q); } if ((io_req->error) || (io_req->buffer == NULL)) blk_mq_end_request(io_req->req, io_req->error); else { if (!blk_update_request(io_req->req, io_req->error, io_req->length)) __blk_mq_end_request(io_req->req, io_req->error); } kfree(io_req); } } } static irqreturn_t ubd_intr(int irq, void *dev) { ubd_handler(); return IRQ_HANDLED; } /* Only changed by ubd_init, which is an initcall. */ static int io_pid = -1; static void kill_io_thread(void) { if(io_pid != -1) os_kill_process(io_pid, 1); } __uml_exitcall(kill_io_thread); static inline int ubd_file_size(struct ubd *ubd_dev, __u64 *size_out) { char *file; int fd; int err; __u32 version; __u32 align; char *backing_file; time64_t mtime; unsigned long long size; int sector_size; int bitmap_offset; if (ubd_dev->file && ubd_dev->cow.file) { file = ubd_dev->cow.file; goto out; } fd = os_open_file(ubd_dev->file, of_read(OPENFLAGS()), 0); if (fd < 0) return fd; err = read_cow_header(file_reader, &fd, &version, &backing_file, \ &mtime, &size, §or_size, &align, &bitmap_offset); os_close_file(fd); if(err == -EINVAL) file = ubd_dev->file; else file = backing_file; out: return os_file_size(file, size_out); } static int read_cow_bitmap(int fd, void *buf, int offset, int len) { int err; err = os_pread_file(fd, buf, len, offset); if (err < 0) return err; return 0; } static int backing_file_mismatch(char *file, __u64 size, time64_t mtime) { time64_t modtime; unsigned long long actual; int err; err = os_file_modtime(file, &modtime); if (err < 0) { printk(KERN_ERR "Failed to get modification time of backing " "file \"%s\", err = %d\n", file, -err); return err; } err = os_file_size(file, &actual); if (err < 0) { printk(KERN_ERR "Failed to get size of backing file \"%s\", " "err = %d\n", file, -err); return err; } if (actual != size) { /*__u64 can be a long on AMD64 and with %lu GCC complains; so * the typecast.*/ printk(KERN_ERR "Size mismatch (%llu vs %llu) of COW header " "vs backing file\n", (unsigned long long) size, actual); return -EINVAL; } if (modtime != mtime) { printk(KERN_ERR "mtime mismatch (%lld vs %lld) of COW header vs " "backing file\n", mtime, modtime); return -EINVAL; } return 0; } 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 0; if (!strcmp(from_cmdline, from_cow)) return 0; err = os_stat_file(from_cmdline, &buf1); if (err < 0) { printk(KERN_ERR "Couldn't stat '%s', err = %d\n", from_cmdline, -err); return 0; } err = os_stat_file(from_cow, &buf2); if (err < 0) { printk(KERN_ERR "Couldn't stat '%s', err = %d\n", from_cow, -err); return 1; } if ((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino)) return 0; printk(KERN_ERR "Backing file mismatch - \"%s\" requested, " "\"%s\" specified in COW header of \"%s\"\n", from_cmdline, from_cow, cow); return 1; } static 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) { time64_t mtime; unsigned long long size; __u32 version, align; char *backing_file; 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)) *create_cow_out = 1; 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 (shared) printk(KERN_INFO "Not locking \"%s\" on the host\n", file); else { err = os_lock_file(fd, openflags->w); if (err < 0) { printk(KERN_ERR "Failed to lock '%s', err = %d\n", file, -err); goto out_close; } } /* 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); if (err && (*backing_file_out != NULL)) { printk(KERN_ERR "Failed to read COW header from COW file " "\"%s\", errno = %d\n", file, -err); goto out_close; } if (err) return fd; asked_switch = path_requires_switch(*backing_file_out, backing_file, file); /* Allow switching only if no mismatch. */ if (asked_switch && !backing_file_mismatch(*backing_file_out, size, mtime)) { printk(KERN_ERR "Switching backing file to '%s'\n", *backing_file_out); err = write_cow_header(file, fd, *backing_file_out, sectorsize, align, &size); if (err) { printk(KERN_ERR "Switch failed, errno = %d\n", -err); goto out_close; } } else { *backing_file_out = backing_file; err = backing_file_mismatch(*backing_file_out, size, mtime); if (err) goto out_close; } cow_sizes(version, size, sectorsize, align, *bitmap_offset_out, bitmap_len_out, data_offset_out); return fd; out_close: os_close_file(fd); return err; } static int create_cow_file(char *cow_file, char *backing_file, struct openflags flags, int sectorsize, int alignment, int *bitmap_offset_out, unsigned long *bitmap_len_out, int *data_offset_out) { int err, fd; flags.c = 1; fd = open_ubd_file(cow_file, &flags, 0, NULL, NULL, NULL, NULL, NULL); if (fd < 0) { err = fd; printk(KERN_ERR "Open of COW file '%s' failed, errno = %d\n", cow_file, -err); goto out; } err = init_cow_file(fd, cow_file, backing_file, sectorsize, alignment, bitmap_offset_out, bitmap_len_out, data_offset_out); if (!err) return fd; os_close_file(fd); out: return err; } static void ubd_close_dev(struct ubd *ubd_dev) { os_close_file(ubd_dev->fd); if(ubd_dev->cow.file == NULL) return; os_close_file(ubd_dev->cow.fd); vfree(ubd_dev->cow.bitmap); ubd_dev->cow.bitmap = NULL; } static int ubd_open_dev(struct ubd *ubd_dev) { struct openflags flags; char **back_ptr; int err, create_cow, *create_ptr; int fd; ubd_dev->openflags = ubd_dev->boot_openflags; create_cow = 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, SECTOR_SIZE, 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", ubd_dev->file, ubd_dev->cow.file); } } if(fd < 0){ printk("Failed to open '%s', errno = %d\n", ubd_dev->file, -fd); return fd; } ubd_dev->fd = fd; if(ubd_dev->cow.file != NULL){ blk_queue_max_hw_sectors(ubd_dev->queue, 8 * sizeof(long)); err = -ENOMEM; ubd_dev->cow.bitmap = 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(ubd_dev->fd, ubd_dev->cow.bitmap, ubd_dev->cow.bitmap_offset, ubd_dev->cow.bitmap_len); if(err < 0) goto error; flags = ubd_dev->openflags; flags.w = 0; err = open_ubd_file(ubd_dev->cow.file, &flags, ubd_dev->shared, NULL, NULL, NULL, NULL, NULL); if(err < 0) goto error; ubd_dev->cow.fd = err; } if (ubd_dev->no_trim == 0) { ubd_dev->queue->limits.discard_granularity = SECTOR_SIZE; ubd_dev->queue->limits.discard_alignment = SECTOR_SIZE; blk_queue_max_discard_sectors(ubd_dev->queue, UBD_MAX_REQUEST); blk_queue_max_write_zeroes_sectors(ubd_dev->queue, UBD_MAX_REQUEST); blk_queue_flag_set(QUEUE_FLAG_DISCARD, ubd_dev->queue); } blk_queue_flag_set(QUEUE_FLAG_NONROT, ubd_dev->queue); return 0; error: os_close_file(ubd_dev->fd); return err; } static void ubd_device_release(struct device *dev) { struct ubd *ubd_dev = dev_get_drvdata(dev); blk_cleanup_queue(ubd_dev->queue); blk_mq_free_tag_set(&ubd_dev->tag_set); *ubd_dev = ((struct ubd) DEFAULT_UBD); } static int ubd_disk_register(int major, u64 size, int unit, struct gendisk **disk_out) { struct device *parent = NULL; struct gendisk *disk; disk = alloc_disk(1 << UBD_SHIFT); if(disk == NULL) return -ENOMEM; disk->major = major; disk->first_minor = unit << UBD_SHIFT; disk->fops = &ubd_blops; set_capacity(disk, size / 512); if (major == UBD_MAJOR) sprintf(disk->disk_name, "ubd%c", 'a' + unit); else sprintf(disk->disk_name, "ubd_fake%d", unit); /* sysfs register (not for ide fake devices) */ if (major == UBD_MAJOR) { ubd_devs[unit].pdev.id = unit; ubd_devs[unit].pdev.name = DRIVER_NAME; ubd_devs[unit].pdev.dev.release = ubd_device_release; dev_set_drvdata(&ubd_devs[unit].pdev.dev, &ubd_devs[unit]); platform_device_register(&ubd_devs[unit].pdev); parent = &ubd_devs[unit].pdev.dev; } disk->private_data = &ubd_devs[unit]; disk->queue = ubd_devs[unit].queue; device_add_disk(parent, disk, NULL); *disk_out = disk; return 0; } #define ROUND_BLOCK(n) ((n + (SECTOR_SIZE - 1)) & (-SECTOR_SIZE)) static const struct blk_mq_ops ubd_mq_ops = { .queue_rq = ubd_queue_rq, }; static int ubd_add(int n, char **error_out) { struct ubd *ubd_dev = &ubd_devs[n]; int err = 0; if(ubd_dev->file == NULL) goto out; err = ubd_file_size(ubd_dev, &ubd_dev->size); if(err < 0){ *error_out = "Couldn't determine size of device's file"; goto out; } ubd_dev->size = ROUND_BLOCK(ubd_dev->size); ubd_dev->tag_set.ops = &ubd_mq_ops; ubd_dev->tag_set.queue_depth = 64; ubd_dev->tag_set.numa_node = NUMA_NO_NODE; ubd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; ubd_dev->tag_set.driver_data = ubd_dev; ubd_dev->tag_set.nr_hw_queues = 1; err = blk_mq_alloc_tag_set(&ubd_dev->tag_set); if (err) goto out; ubd_dev->queue = blk_mq_init_queue(&ubd_dev->tag_set); if (IS_ERR(ubd_dev->queue)) { err = PTR_ERR(ubd_dev->queue); goto out_cleanup_tags; } ubd_dev->queue->queuedata = ubd_dev; blk_queue_write_cache(ubd_dev->queue, true, false); blk_queue_max_segments(ubd_dev->queue, MAX_SG); err = ubd_disk_register(UBD_MAJOR, ubd_dev->size, n, &ubd_gendisk[n]); if(err){ *error_out = "Failed to register device"; goto out_cleanup_tags; } if (fake_major != UBD_MAJOR) ubd_disk_register(fake_major, ubd_dev->size, n, &fake_gendisk[n]); /* * Perhaps this should also be under the "if (fake_major)" above * using the fake_disk->disk_name */ if (fake_ide) make_ide_entries(ubd_gendisk[n]->disk_name); err = 0; out: return err; out_cleanup_tags: blk_mq_free_tag_set(&ubd_dev->tag_set); if (!(IS_ERR(ubd_dev->queue))) blk_cleanup_queue(ubd_dev->queue); goto out; } static int ubd_config(char *str, char **error_out) { int n, ret; /* This string is possibly broken up and stored, so it's only * freed if ubd_setup_common fails, or if only general options * were set. */ str = kstrdup(str, GFP_KERNEL); if (str == NULL) { *error_out = "Failed to allocate memory"; return -ENOMEM; } ret = ubd_setup_common(str, &n, error_out); if (ret) goto err_free; if (n == -1) { ret = 0; goto err_free; } mutex_lock(&ubd_lock); ret = ubd_add(n, error_out); if (ret) ubd_devs[n].file = NULL; mutex_unlock(&ubd_lock); 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 *ubd_dev; int n, len = 0; n = parse_unit(&name); if((n >= MAX_DEV) || (n < 0)){ *error_out = "ubd_get_config : device number out of range"; return -1; } ubd_dev = &ubd_devs[n]; mutex_lock(&ubd_lock); if(ubd_dev->file == NULL){ CONFIG_CHUNK(str, size, len, "", 1); goto out; } CONFIG_CHUNK(str, size, len, ubd_dev->file, 0); if(ubd_dev->cow.file != NULL){ CONFIG_CHUNK(str, size, len, ",", 0); CONFIG_CHUNK(str, size, len, ubd_dev->cow.file, 1); } else CONFIG_CHUNK(str, size, len, "", 1); out: mutex_unlock(&ubd_lock); return len; } static int ubd_id(char **str, int *start_out, int *end_out) { int n; n = parse_unit(str); *start_out = 0; *end_out = MAX_DEV - 1; return n; } static int ubd_remove(int n, char **error_out) { struct gendisk *disk = ubd_gendisk[n]; struct ubd *ubd_dev; int err = -ENODEV; mutex_lock(&ubd_lock); 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; ubd_gendisk[n] = NULL; if(disk != NULL){ del_gendisk(disk); put_disk(disk); } if(fake_gendisk[n] != NULL){ del_gendisk(fake_gendisk[n]); put_disk(fake_gendisk[n]); fake_gendisk[n] = NULL; } err = 0; platform_device_unregister(&ubd_dev->pdev); out: mutex_unlock(&ubd_lock); return err; } /* All these are called by mconsole in process context and without * ubd-specific locks. The structure itself is const except for .list. */ static struct mc_device ubd_mc = { .list = LIST_HEAD_INIT(ubd_mc.list), .name = "ubd", .config = ubd_config, .get_config = ubd_get_config, .id = ubd_id, .remove = ubd_remove, }; static int __init ubd_mc_init(void) { mconsole_register_dev(&ubd_mc); return 0; } __initcall(ubd_mc_init); static int __init ubd0_init(void) { struct ubd *ubd_dev = &ubd_devs[0]; mutex_lock(&ubd_lock); if(ubd_dev->file == NULL) ubd_dev->file = "root_fs"; mutex_unlock(&ubd_lock); return 0; } __initcall(ubd0_init); /* Used in ubd_init, which is an initcall */ static struct platform_driver ubd_driver = { .driver = { .name = DRIVER_NAME, }, }; static int __init ubd_init(void) { char *error; int i, err; if (register_blkdev(UBD_MAJOR, "ubd")) return -1; if (fake_major != UBD_MAJOR) { char name[sizeof("ubd_nnn\0")]; snprintf(name, sizeof(name), "ubd_%d", fake_major); if (register_blkdev(fake_major, "ubd")) return -1; } irq_req_buffer = kmalloc_array(UBD_REQ_BUFFER_SIZE, sizeof(struct io_thread_req *), GFP_KERNEL ); irq_remainder = 0; if (irq_req_buffer == NULL) { printk(KERN_ERR "Failed to initialize ubd buffering\n"); return -1; } io_req_buffer = kmalloc_array(UBD_REQ_BUFFER_SIZE, sizeof(struct io_thread_req *), GFP_KERNEL ); io_remainder = 0; if (io_req_buffer == NULL) { printk(KERN_ERR "Failed to initialize ubd buffering\n"); return -1; } platform_driver_register(&ubd_driver); mutex_lock(&ubd_lock); for (i = 0; i < MAX_DEV; i++){ err = ubd_add(i, &error); if(err) printk(KERN_ERR "Failed to initialize ubd device %d :" "%s\n", i, error); } mutex_unlock(&ubd_lock); return 0; } late_initcall(ubd_init); static int __init ubd_driver_init(void){ unsigned long stack; int err; /* Set by CONFIG_BLK_DEV_UBD_SYNC or ubd=sync.*/ if(global_openflags.s){ printk(KERN_INFO "ubd: Synchronous mode\n"); /* Letting ubd=sync be like using ubd#s= instead of ubd#= is * enough. So use anyway the io thread. */ } stack = alloc_stack(0, 0); io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *), &thread_fd); if(io_pid < 0){ 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, 0, "ubd", ubd_devs); if(err != 0) printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err); return 0; } device_initcall(ubd_driver_init); static int ubd_open(struct block_device *bdev, fmode_t mode) { struct gendisk *disk = bdev->bd_disk; struct ubd *ubd_dev = disk->private_data; int err = 0; mutex_lock(&ubd_mutex); 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, ubd_dev->file, -err); goto out; } } 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((mode & FMODE_WRITE) && !ubd_dev->openflags.w){ if(--ubd_dev->count == 0) ubd_close_dev(ubd_dev); err = -EROFS; }*/ out: mutex_unlock(&ubd_mutex); return err; } static void ubd_release(struct gendisk *disk, fmode_t mode) { struct ubd *ubd_dev = disk->private_data; mutex_lock(&ubd_mutex); if(--ubd_dev->count == 0) ubd_close_dev(ubd_dev); mutex_unlock(&ubd_mutex); } static void cowify_bitmap(__u64 io_offset, int length, unsigned long *cow_mask, __u64 *cow_offset, unsigned long *bitmap, __u64 bitmap_offset, unsigned long *bitmap_words, __u64 bitmap_len) { __u64 sector = io_offset >> SECTOR_SHIFT; int i, update_bitmap = 0; for (i = 0; i < length >> SECTOR_SHIFT; i++) { if(cow_mask != NULL) ubd_set_bit(i, (unsigned char *) cow_mask); if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) continue; update_bitmap = 1; ubd_set_bit(sector + i, (unsigned char *) bitmap); } if(!update_bitmap) return; *cow_offset = sector / (sizeof(unsigned long) * 8); /* This takes care of the case where we're exactly at the end of the * device, and *cow_offset + 1 is off the end. So, just back it up * by one word. Thanks to Lynn Kerby for the fix and James McMechan * for the original diagnosis. */ if (*cow_offset == (DIV_ROUND_UP(bitmap_len, sizeof(unsigned long)) - 1)) (*cow_offset)--; bitmap_words[0] = bitmap[*cow_offset]; bitmap_words[1] = bitmap[*cow_offset + 1]; *cow_offset *= sizeof(unsigned long); *cow_offset += bitmap_offset; } static void cowify_req(struct io_thread_req *req, unsigned long *bitmap, __u64 bitmap_offset, __u64 bitmap_len) { __u64 sector = req->offset >> SECTOR_SHIFT; int i; if (req->length > (sizeof(req->sector_mask) * 8) << SECTOR_SHIFT) panic("Operation too long"); if (req_op(req->req) == REQ_OP_READ) { for (i = 0; i < req->length >> SECTOR_SHIFT; i++) { if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) ubd_set_bit(i, (unsigned char *) &req->sector_mask); } } else cowify_bitmap(req->offset, req->length, &req->sector_mask, &req->cow_offset, bitmap, bitmap_offset, req->bitmap_words, bitmap_len); } static int ubd_queue_one_vec(struct blk_mq_hw_ctx *hctx, struct request *req, u64 off, struct bio_vec *bvec) { struct ubd *dev = hctx->queue->queuedata; struct io_thread_req *io_req; int ret; io_req = kmalloc(sizeof(struct io_thread_req), GFP_ATOMIC); if (!io_req) return -ENOMEM; io_req->req = req; if (dev->cow.file) io_req->fds[0] = dev->cow.fd; else io_req->fds[0] = dev->fd; io_req->error = 0; if (bvec != NULL) { io_req->buffer = page_address(bvec->bv_page) + bvec->bv_offset; io_req->length = bvec->bv_len; } else { io_req->buffer = NULL; io_req->length = blk_rq_bytes(req); } io_req->sectorsize = SECTOR_SIZE; io_req->fds[1] = dev->fd; io_req->cow_offset = -1; io_req->offset = off; io_req->sector_mask = 0; io_req->offsets[0] = 0; io_req->offsets[1] = dev->cow.data_offset; if (dev->cow.file) cowify_req(io_req, dev->cow.bitmap, dev->cow.bitmap_offset, dev->cow.bitmap_len); ret = os_write_file(thread_fd, &io_req, sizeof(io_req)); if (ret != sizeof(io_req)) { if (ret != -EAGAIN) pr_err("write to io thread failed: %d\n", -ret); kfree(io_req); } return ret; } static int queue_rw_req(struct blk_mq_hw_ctx *hctx, struct request *req) { struct req_iterator iter; struct bio_vec bvec; int ret; u64 off = (u64)blk_rq_pos(req) << SECTOR_SHIFT; rq_for_each_segment(bvec, req, iter) { ret = ubd_queue_one_vec(hctx, req, off, &bvec); if (ret < 0) return ret; off += bvec.bv_len; } return 0; } static blk_status_t ubd_queue_rq(struct blk_mq_hw_ctx *hctx, const struct blk_mq_queue_data *bd) { struct ubd *ubd_dev = hctx->queue->queuedata; struct request *req = bd->rq; int ret = 0, res = BLK_STS_OK; blk_mq_start_request(req); spin_lock_irq(&ubd_dev->lock); switch (req_op(req)) { /* operations with no lentgth/offset arguments */ case REQ_OP_FLUSH: ret = ubd_queue_one_vec(hctx, req, 0, NULL); break; case REQ_OP_READ: case REQ_OP_WRITE: ret = queue_rw_req(hctx, req); break; case REQ_OP_DISCARD: case REQ_OP_WRITE_ZEROES: ret = ubd_queue_one_vec(hctx, req, (u64)blk_rq_pos(req) << 9, NULL); break; default: WARN_ON_ONCE(1); res = BLK_STS_NOTSUPP; } spin_unlock_irq(&ubd_dev->lock); if (ret < 0) { if (ret == -ENOMEM) res = BLK_STS_RESOURCE; else res = BLK_STS_DEV_RESOURCE; } return res; } 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 block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg) { struct ubd *ubd_dev = bdev->bd_disk->private_data; u16 ubd_id[ATA_ID_WORDS]; switch (cmd) { struct cdrom_volctrl volume; case HDIO_GET_IDENTITY: memset(&ubd_id, 0, ATA_ID_WORDS * 2); ubd_id[ATA_ID_CYLS] = ubd_dev->size / (128 * 32 * 512); ubd_id[ATA_ID_HEADS] = 128; ubd_id[ATA_ID_SECTORS] = 32; if(copy_to_user((char __user *) arg, (char *) &ubd_id, sizeof(ubd_id))) return -EFAULT; return 0; case CDROMVOLREAD: if(copy_from_user(&volume, (char __user *) arg, sizeof(volume))) return -EFAULT; volume.channel0 = 255; volume.channel1 = 255; volume.channel2 = 255; volume.channel3 = 255; if(copy_to_user((char __user *) arg, &volume, sizeof(volume))) return -EFAULT; return 0; } return -EINVAL; } static int map_error(int error_code) { switch (error_code) { case 0: return BLK_STS_OK; case ENOSYS: case EOPNOTSUPP: return BLK_STS_NOTSUPP; case ENOSPC: return BLK_STS_NOSPC; } return BLK_STS_IOERR; } /* * Everything from here onwards *IS NOT PART OF THE KERNEL* * * The following functions are part of UML hypervisor code. * All functions from here onwards are executed as a helper * thread and are not allowed to execute any kernel functions. * * Any communication must occur strictly via shared memory and IPC. * * Do not add printks, locks, kernel memory operations, etc - it * will result in unpredictable behaviour and/or crashes. */ static int update_bitmap(struct io_thread_req *req) { int n; if(req->cow_offset == -1) return map_error(0); n = os_pwrite_file(req->fds[1], &req->bitmap_words, sizeof(req->bitmap_words), req->cow_offset); if (n != sizeof(req->bitmap_words)) return map_error(-n); return map_error(0); } static void do_io(struct io_thread_req *req) { char *buf = NULL; unsigned long len; int n, nsectors, start, end, bit; __u64 off; /* FLUSH is really a special case, we cannot "case" it with others */ if (req_op(req->req) == REQ_OP_FLUSH) { /* fds[0] is always either the rw image or our cow file */ req->error = map_error(-os_sync_file(req->fds[0])); return; } nsectors = req->length / req->sectorsize; start = 0; do { bit = ubd_test_bit(start, (unsigned char *) &req->sector_mask); end = start; while((end < nsectors) && (ubd_test_bit(end, (unsigned char *) &req->sector_mask) == bit)) end++; off = req->offset + req->offsets[bit] + start * req->sectorsize; len = (end - start) * req->sectorsize; if (req->buffer != NULL) buf = &req->buffer[start * req->sectorsize]; switch (req_op(req->req)) { case REQ_OP_READ: n = 0; do { buf = &buf[n]; len -= n; n = os_pread_file(req->fds[bit], buf, len, off); if (n < 0) { req->error = map_error(-n); return; } } while((n < len) && (n != 0)); if (n < len) memset(&buf[n], 0, len - n); break; case REQ_OP_WRITE: n = os_pwrite_file(req->fds[bit], buf, len, off); if(n != len){ req->error = map_error(-n); return; } break; case REQ_OP_DISCARD: case REQ_OP_WRITE_ZEROES: n = os_falloc_punch(req->fds[bit], off, len); if (n) { req->error = map_error(-n); return; } break; default: WARN_ON_ONCE(1); req->error = BLK_STS_NOTSUPP; return; } start = end; } while(start < nsectors); req->error = update_bitmap(req); } /* Changed in start_io_thread, which is serialized by being called only * from ubd_init, which is an initcall. */ int kernel_fd = -1; /* Only changed by the io thread. XXX: currently unused. */ static int io_count = 0; int io_thread(void *arg) { int n, count, written, res; os_fix_helper_signals(); while(1){ n = bulk_req_safe_read( kernel_fd, io_req_buffer, &io_remainder, &io_remainder_size, UBD_REQ_BUFFER_SIZE ); if (n <= 0) { if (n == -EAGAIN) ubd_read_poll(-1); continue; } for (count = 0; count < n/sizeof(struct io_thread_req *); count++) { io_count++; do_io((*io_req_buffer)[count]); } written = 0; do { res = os_write_file(kernel_fd, ((char *) io_req_buffer) + written, n - written); if (res >= 0) { written += res; } if (written < n) { ubd_write_poll(-1); } } while (written < n); } return 0; }
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