From 855ec613ca7e1953d96d7ea81af90392678788f5 Mon Sep 17 00:00:00 2001 From: Paolo 'Blaisorblade' Giarrusso Date: Sun, 9 Oct 2005 21:37:35 +0200 Subject: [PATCH] uml: restore include breakage, breaking binary format of COW driver Commit 44456d37b59d8e541936ed26d8b6e08d27e88ac1, between 2.6.13-rc3 and -rc4, was a "nice cleanup" which broke something. Revert the offending part. It broke because: a) because this part doesn't fall under the description b) the author didn't know what he was doing here c) the author didn't try to compile the existing code and see that it worked perfectly. d) the author didn't ask us what was happening e) you didn't either, and somebody there should have learned that UML is a bit different. In fact, UML is special in linking to host libc and using its includes. In particular, since host includes always define both __BIG_ENDIAN and __LITTLE_ENDIAN, ntohll() macros started thinking to be in a big-endian world; and on-disk compatibility was broken. Many thanks go to Nix for reporting the problem and correctly diagnosing an endianness problem. Btw, this patch restores the previous code, which worked; but the definitions would be uncorrect if used in kernelspace files. Next patch addresses that. Cc: Nix , Olaf Hering Signed-off-by: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Linus Torvalds --- arch/um/drivers/cow.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/um/drivers') diff --git a/arch/um/drivers/cow.h b/arch/um/drivers/cow.h index 4fcf3a8d13f..4fcbe8b1b77 100644 --- a/arch/um/drivers/cow.h +++ b/arch/um/drivers/cow.h @@ -3,10 +3,10 @@ #include -#if defined(__BIG_ENDIAN) +#if __BYTE_ORDER == __BIG_ENDIAN # define ntohll(x) (x) # define htonll(x) (x) -#elif defined(__LITTLE_ENDIAN) +#elif __BYTE_ORDER == __LITTLE_ENDIAN # define ntohll(x) bswap_64(x) # define htonll(x) bswap_64(x) #else -- cgit From 028c0cc16e429ae24d9b8aacc64f4438bdfac0cc Mon Sep 17 00:00:00 2001 From: Paolo 'Blaisorblade' Giarrusso Date: Sun, 9 Oct 2005 21:37:45 +0200 Subject: [PATCH] uml: cleanup byte order macros for COW driver After restoring the existing code, make it work also when included in kernelspace code (which isn't currently the case, but at least this will prevent people from "fixing" it as just happened). Whitespace is fixed in next patch - it cluttered the diff too much. Signed-off-by: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Linus Torvalds --- arch/um/drivers/cow.h | 27 ++++++++++++++++++++++++++- arch/um/drivers/cow_user.c | 1 - 2 files changed, 26 insertions(+), 2 deletions(-) (limited to 'arch/um/drivers') diff --git a/arch/um/drivers/cow.h b/arch/um/drivers/cow.h index 4fcbe8b1b77..c54e20a3d21 100644 --- a/arch/um/drivers/cow.h +++ b/arch/um/drivers/cow.h @@ -3,6 +3,26 @@ #include +#if defined(__KERNEL__) + +# include + +# if defined(__BIG_ENDIAN) +# define ntohll(x) (x) +# define htonll(x) (x) +# elif defined(__LITTLE_ENDIAN) +# define ntohll(x) be64_to_cpu(x) +# define htonll(x) cpu_to_be64(x) +# else +# error "Could not determine byte order" +# endif + +#else +/* For the definition of ntohl, htonl and __BYTE_ORDER */ +#include +#include +#if defined(__BYTE_ORDER) + #if __BYTE_ORDER == __BIG_ENDIAN # define ntohll(x) (x) # define htonll(x) (x) @@ -10,8 +30,13 @@ # define ntohll(x) bswap_64(x) # define htonll(x) bswap_64(x) #else -#error "__BYTE_ORDER not defined" +# error "Could not determine byte order: __BYTE_ORDER uncorrectly defined" +#endif + +#else /* ! defined(__BYTE_ORDER) */ +# error "Could not determine byte order: __BYTE_ORDER not defined" #endif +#endif /* ! defined(__KERNEL__) */ extern int init_cow_file(int fd, char *cow_file, char *backing_file, int sectorsize, int alignment, int *bitmap_offset_out, diff --git a/arch/um/drivers/cow_user.c b/arch/um/drivers/cow_user.c index a8ce6fc3ef2..fbe2217db5d 100644 --- a/arch/um/drivers/cow_user.c +++ b/arch/um/drivers/cow_user.c @@ -9,7 +9,6 @@ #include #include #include -#include #include "os.h" -- cgit From 52a2d3e45e06012a662f627177729d3196ba8903 Mon Sep 17 00:00:00 2001 From: Paolo 'Blaisorblade' Giarrusso Date: Sun, 9 Oct 2005 21:37:53 +0200 Subject: [PATCH] uml: cleanup whitespace for COW driver Fix whitespace - I split this off the previous patch for easier review. Signed-off-by: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Linus Torvalds --- arch/um/drivers/cow.h | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'arch/um/drivers') diff --git a/arch/um/drivers/cow.h b/arch/um/drivers/cow.h index c54e20a3d21..dc36b222100 100644 --- a/arch/um/drivers/cow.h +++ b/arch/um/drivers/cow.h @@ -23,15 +23,15 @@ #include #if defined(__BYTE_ORDER) -#if __BYTE_ORDER == __BIG_ENDIAN -# define ntohll(x) (x) -# define htonll(x) (x) -#elif __BYTE_ORDER == __LITTLE_ENDIAN -# define ntohll(x) bswap_64(x) -# define htonll(x) bswap_64(x) -#else -# error "Could not determine byte order: __BYTE_ORDER uncorrectly defined" -#endif +# if __BYTE_ORDER == __BIG_ENDIAN +# define ntohll(x) (x) +# define htonll(x) (x) +# elif __BYTE_ORDER == __LITTLE_ENDIAN +# define ntohll(x) bswap_64(x) +# define htonll(x) bswap_64(x) +# else +# error "Could not determine byte order: __BYTE_ORDER uncorrectly defined" +# endif #else /* ! defined(__BYTE_ORDER) */ # error "Could not determine byte order: __BYTE_ORDER not defined" -- cgit From 91acb21f084aa244f26839406ae7ed8aa3668058 Mon Sep 17 00:00:00 2001 From: Jeff Dike Date: Mon, 10 Oct 2005 23:10:32 -0400 Subject: [PATCH] uml: revert block driver use of host AIO The patch to use host AIO support that I submitted early after 2.6.13 exposed some problems in the block driver. I have fixes for these, but am not comfortable putting them into 2.6.14 at this late date. So, this patch reverts the use of host AIO. I will resubmit the original patch, plus fixes to the driver after 2.6.14 in order to get a reasonable amount of testing before they're exposed to the general public. Signed-off-by: Jeff Dike Signed-off-by: Linus Torvalds --- arch/um/drivers/Makefile | 2 +- arch/um/drivers/ubd_kern.c | 556 +++++++++++++++++++++++++-------------------- arch/um/drivers/ubd_user.c | 75 ++++++ 3 files changed, 386 insertions(+), 247 deletions(-) create mode 100644 arch/um/drivers/ubd_user.c (limited to 'arch/um/drivers') diff --git a/arch/um/drivers/Makefile b/arch/um/drivers/Makefile index 783e18cae09..de17d4c6e02 100644 --- a/arch/um/drivers/Makefile +++ b/arch/um/drivers/Makefile @@ -13,7 +13,7 @@ mcast-objs := mcast_kern.o mcast_user.o net-objs := net_kern.o net_user.o mconsole-objs := mconsole_kern.o mconsole_user.o hostaudio-objs := hostaudio_kern.o -ubd-objs := ubd_kern.o +ubd-objs := ubd_kern.o ubd_user.o port-objs := port_kern.o port_user.o harddog-objs := harddog_kern.o harddog_user.o diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index e77a38da435..f73134333f6 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -35,7 +35,6 @@ #include "linux/blkpg.h" #include "linux/genhd.h" #include "linux/spinlock.h" -#include "asm/atomic.h" #include "asm/segment.h" #include "asm/uaccess.h" #include "asm/irq.h" @@ -54,21 +53,20 @@ #include "mem.h" #include "mem_kern.h" #include "cow.h" -#include "aio.h" enum ubd_req { UBD_READ, UBD_WRITE }; struct io_thread_req { - enum aio_type op; + enum ubd_req op; int fds[2]; unsigned long offsets[2]; unsigned long long offset; unsigned long length; char *buffer; int sectorsize; - int bitmap_offset; - long bitmap_start; - long bitmap_end; + unsigned long sector_mask; + unsigned long long cow_offset; + unsigned long bitmap_words[2]; int error; }; @@ -82,31 +80,28 @@ extern int create_cow_file(char *cow_file, char *backing_file, unsigned long *bitmap_len_out, int *data_offset_out); extern int read_cow_bitmap(int fd, void *buf, int offset, int len); -extern void do_io(struct io_thread_req *req, struct request *r, - unsigned long *bitmap); +extern void do_io(struct io_thread_req *req); -static inline int ubd_test_bit(__u64 bit, void *data) +static inline int ubd_test_bit(__u64 bit, unsigned char *data) { - unsigned char *buffer = data; __u64 n; int bits, off; - bits = sizeof(buffer[0]) * 8; + bits = sizeof(data[0]) * 8; n = bit / bits; off = bit % bits; - return((buffer[n] & (1 << off)) != 0); + return((data[n] & (1 << off)) != 0); } -static inline void ubd_set_bit(__u64 bit, void *data) +static inline void ubd_set_bit(__u64 bit, unsigned char *data) { - unsigned char *buffer = data; __u64 n; int bits, off; - bits = sizeof(buffer[0]) * 8; + bits = sizeof(data[0]) * 8; n = bit / bits; off = bit % bits; - buffer[n] |= (1 << off); + data[n] |= (1 << off); } /*End stuff from ubd_user.h*/ @@ -115,6 +110,8 @@ static inline void ubd_set_bit(__u64 bit, void *data) static DEFINE_SPINLOCK(ubd_io_lock); static DEFINE_SPINLOCK(ubd_lock); +static void (*do_ubd)(void); + 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, @@ -161,8 +158,6 @@ struct cow { int data_offset; }; -#define MAX_SG 64 - struct ubd { char *file; int count; @@ -173,7 +168,6 @@ struct ubd { int no_cow; struct cow cow; struct platform_device pdev; - struct scatterlist sg[MAX_SG]; }; #define DEFAULT_COW { \ @@ -466,114 +460,81 @@ __uml_help(fakehd, ); static void do_ubd_request(request_queue_t * q); -static int in_ubd; + +/* Only changed by ubd_init, which is an initcall. */ +int thread_fd = -1; /* Changed by ubd_handler, which is serialized because interrupts only * happen on CPU 0. */ int intr_count = 0; -static void ubd_end_request(struct request *req, int bytes, int uptodate) +/* call ubd_finish if you need to serialize */ +static void __ubd_finish(struct request *req, int error) { - if (!end_that_request_first(req, uptodate, bytes >> 9)) { - add_disk_randomness(req->rq_disk); - end_that_request_last(req); + int nsect; + + if(error){ + end_request(req, 0); + return; } + nsect = req->current_nr_sectors; + req->sector += nsect; + req->buffer += nsect << 9; + req->errors = 0; + req->nr_sectors -= nsect; + req->current_nr_sectors = 0; + end_request(req, 1); } -/* call ubd_finish if you need to serialize */ -static void __ubd_finish(struct request *req, int bytes) +static inline void ubd_finish(struct request *req, int error) { - if(bytes < 0){ - ubd_end_request(req, 0, 0); - return; - } - - ubd_end_request(req, bytes, 1); + spin_lock(&ubd_io_lock); + __ubd_finish(req, error); + spin_unlock(&ubd_io_lock); } -static inline void ubd_finish(struct request *req, int bytes) +/* Called without ubd_io_lock held */ +static void ubd_handler(void) { - spin_lock(&ubd_io_lock); - __ubd_finish(req, bytes); - spin_unlock(&ubd_io_lock); + struct io_thread_req req; + struct request *rq = elv_next_request(ubd_queue); + int n; + + do_ubd = NULL; + intr_count++; + n = os_read_file(thread_fd, &req, sizeof(req)); + if(n != sizeof(req)){ + printk(KERN_ERR "Pid %d - spurious interrupt in ubd_handler, " + "err = %d\n", os_getpid(), -n); + spin_lock(&ubd_io_lock); + end_request(rq, 0); + spin_unlock(&ubd_io_lock); + return; + } + + ubd_finish(rq, req.error); + reactivate_fd(thread_fd, UBD_IRQ); + do_ubd_request(ubd_queue); } -struct bitmap_io { - atomic_t count; - struct aio_context aio; -}; - -struct ubd_aio { - struct aio_context aio; - struct request *req; - int len; - struct bitmap_io *bitmap; - void *bitmap_buf; -}; - -static int ubd_reply_fd = -1; - static irqreturn_t ubd_intr(int irq, void *dev, struct pt_regs *unused) { - struct aio_thread_reply reply; - struct ubd_aio *aio; - struct request *req; - int err, n, fd = (int) (long) dev; - - while(1){ - err = os_read_file(fd, &reply, sizeof(reply)); - if(err == -EAGAIN) - break; - if(err < 0){ - printk("ubd_aio_handler - read returned err %d\n", - -err); - break; - } - - aio = container_of(reply.data, struct ubd_aio, aio); - n = reply.err; - - if(n == 0){ - req = aio->req; - req->nr_sectors -= aio->len >> 9; - - if((aio->bitmap != NULL) && - (atomic_dec_and_test(&aio->bitmap->count))){ - aio->aio = aio->bitmap->aio; - aio->len = 0; - kfree(aio->bitmap); - aio->bitmap = NULL; - submit_aio(&aio->aio); - } - else { - if((req->nr_sectors == 0) && - (aio->bitmap == NULL)){ - int len = req->hard_nr_sectors << 9; - ubd_finish(req, len); - } - - if(aio->bitmap_buf != NULL) - kfree(aio->bitmap_buf); - kfree(aio); - } - } - else if(n < 0){ - ubd_finish(aio->req, n); - if(aio->bitmap != NULL) - kfree(aio->bitmap); - if(aio->bitmap_buf != NULL) - kfree(aio->bitmap_buf); - kfree(aio); - } - } - reactivate_fd(fd, UBD_IRQ); + ubd_handler(); + return(IRQ_HANDLED); +} - do_ubd_request(ubd_queue); +/* Only changed by ubd_init, which is an initcall. */ +static int io_pid = -1; - return(IRQ_HANDLED); +void kill_io_thread(void) +{ + 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) { char *file; @@ -608,7 +569,7 @@ static int ubd_open_dev(struct ubd *dev) &dev->cow.data_offset, create_ptr); if((dev->fd == -ENOENT) && create_cow){ - dev->fd = create_cow_file(dev->file, dev->cow.file, + dev->fd = create_cow_file(dev->file, dev->cow.file, dev->openflags, 1 << 9, PAGE_SIZE, &dev->cow.bitmap_offset, &dev->cow.bitmap_len, @@ -870,10 +831,6 @@ int ubd_init(void) { int i; - ubd_reply_fd = init_aio_irq(UBD_IRQ, "ubd", ubd_intr); - if(ubd_reply_fd < 0) - printk("Setting up ubd AIO failed, err = %d\n", ubd_reply_fd); - devfs_mk_dir("ubd"); if (register_blkdev(MAJOR_NR, "ubd")) return -1; @@ -884,7 +841,6 @@ int ubd_init(void) return -1; } - blk_queue_max_hw_segments(ubd_queue, MAX_SG); if (fake_major != MAJOR_NR) { char name[sizeof("ubd_nnn\0")]; @@ -896,12 +852,40 @@ int ubd_init(void) 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){ + 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, + SA_INTERRUPT, "ubd", ubd_dev); + if(err != 0) + printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err); + return(err); +} + +device_initcall(ubd_driver_init); + static int ubd_open(struct inode *inode, struct file *filp) { struct gendisk *disk = inode->i_bdev->bd_disk; @@ -939,55 +923,105 @@ static int ubd_release(struct inode * inode, struct file * file) return(0); } -static void cowify_bitmap(struct io_thread_req *req, unsigned long *bitmap) +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 = req->offset / req->sectorsize; - int i; + __u64 sector = io_offset >> 9; + int i, update_bitmap = 0; + + for(i = 0; i < length >> 9; i++){ + if(cow_mask != NULL) + ubd_set_bit(i, (unsigned char *) cow_mask); + if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) + continue; - for(i = 0; i < req->length / req->sectorsize; i++){ - if(ubd_test_bit(sector + i, bitmap)) - continue; + update_bitmap = 1; + ubd_set_bit(sector + i, (unsigned char *) bitmap); + } + + if(!update_bitmap) + return; - if(req->bitmap_start == -1) - req->bitmap_start = sector + i; - req->bitmap_end = sector + i + 1; + *cow_offset = sector / (sizeof(unsigned long) * 8); - ubd_set_bit(sector + i, bitmap); - } + /* 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 == ((bitmap_len + sizeof(unsigned long) - 1) / + 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 >> 9; + int i; + + if(req->length > (sizeof(req->sector_mask) * 8) << 9) + panic("Operation too long"); + + 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 *) + &req->sector_mask); + } + } + else cowify_bitmap(req->offset, req->length, &req->sector_mask, + &req->cow_offset, bitmap, bitmap_offset, + req->bitmap_words, bitmap_len); } /* Called with ubd_io_lock held */ -static int prepare_request(struct request *req, struct io_thread_req *io_req, - unsigned long long offset, int page_offset, - int len, struct page *page) +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; + __u64 offset; + int len; + + if(req->rq_status == RQ_INACTIVE) return(1); /* This should be impossible now */ if((rq_data_dir(req) == WRITE) && !dev->openflags.w){ printk("Write attempted on readonly ubd device %s\n", disk->disk_name); - ubd_end_request(req, 0, 0); + end_request(req, 0); return(1); } + 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->cow_offset = -1; io_req->offset = offset; io_req->length = len; io_req->error = 0; - io_req->op = (rq_data_dir(req) == READ) ? AIO_READ : AIO_WRITE; + io_req->sector_mask = 0; + + 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->buffer = page_address(page) + page_offset; + io_req->buffer = req->buffer; io_req->sectorsize = 1 << 9; - io_req->bitmap_offset = dev->cow.bitmap_offset; - io_req->bitmap_start = -1; - io_req->bitmap_end = -1; - if((dev->cow.file != NULL) && (io_req->op == UBD_WRITE)) - cowify_bitmap(io_req, dev->cow.bitmap); + if(dev->cow.file != NULL) + cowify_req(io_req, dev->cow.bitmap, dev->cow.bitmap_offset, + dev->cow.bitmap_len); + return(0); } @@ -996,36 +1030,30 @@ static void do_ubd_request(request_queue_t *q) { struct io_thread_req io_req; struct request *req; - __u64 sector; - int err; - - if(in_ubd) - return; - in_ubd = 1; - while((req = elv_next_request(q)) != NULL){ - struct gendisk *disk = req->rq_disk; - struct ubd *dev = disk->private_data; - int n, i; - - blkdev_dequeue_request(req); - - sector = req->sector; - n = blk_rq_map_sg(q, req, dev->sg); - - for(i = 0; i < n; i++){ - struct scatterlist *sg = &dev->sg[i]; - - err = prepare_request(req, &io_req, sector << 9, - sg->offset, sg->length, - sg->page); - if(err) - continue; - - sector += sg->length >> 9; - do_io(&io_req, req, dev->cow.bitmap); + int err, n; + + if(thread_fd == -1){ + while((req = elv_next_request(q)) != NULL){ + err = prepare_request(req, &io_req); + if(!err){ + do_io(&io_req); + __ubd_finish(req, io_req.error); + } + } + } + else { + if(do_ubd || (req = elv_next_request(q)) == NULL) + return; + err = prepare_request(req, &io_req); + if(!err){ + do_ubd = ubd_handler; + n = os_write_file(thread_fd, (char *) &io_req, + sizeof(io_req)); + if(n != sizeof(io_req)) + printk("write to io thread failed, " + "errno = %d\n", -n); } } - in_ubd = 0; } static int ubd_ioctl(struct inode * inode, struct file * file, @@ -1241,95 +1269,131 @@ int create_cow_file(char *cow_file, char *backing_file, struct openflags flags, return(err); } -void do_io(struct io_thread_req *req, struct request *r, unsigned long *bitmap) +static int update_bitmap(struct io_thread_req *req) { - struct ubd_aio *aio; - struct bitmap_io *bitmap_io = NULL; - char *buf; - void *bitmap_buf = NULL; - unsigned long len, sector; - int nsectors, start, end, bit, err; - __u64 off; - - if(req->bitmap_start != -1){ - /* Round up to the nearest word */ - int round = sizeof(unsigned long); - len = (req->bitmap_end - req->bitmap_start + - round * 8 - 1) / (round * 8); - len *= round; - - off = req->bitmap_start / (8 * round); - off *= round; - - bitmap_io = kmalloc(sizeof(*bitmap_io), GFP_KERNEL); - if(bitmap_io == NULL){ - printk("Failed to kmalloc bitmap IO\n"); - req->error = 1; - return; - } + int n; - bitmap_buf = kmalloc(len, GFP_KERNEL); - if(bitmap_buf == NULL){ - printk("do_io : kmalloc of bitmap chunk " - "failed\n"); - kfree(bitmap_io); - req->error = 1; - return; - } - memcpy(bitmap_buf, &bitmap[off / sizeof(bitmap[0])], len); - - *bitmap_io = ((struct bitmap_io) - { .count = ATOMIC_INIT(0), - .aio = INIT_AIO(AIO_WRITE, req->fds[1], - bitmap_buf, len, - req->bitmap_offset + off, - ubd_reply_fd) } ); - } + if(req->cow_offset == -1) + return(0); - nsectors = req->length / req->sectorsize; - start = 0; - end = nsectors; - bit = 0; - do { - if(bitmap != NULL){ - sector = req->offset / req->sectorsize; - bit = ubd_test_bit(sector + start, bitmap); - end = start; - while((end < nsectors) && - (ubd_test_bit(sector + end, bitmap) == bit)) - end++; - } + n = os_seek_file(req->fds[1], req->cow_offset); + if(n < 0){ + printk("do_io - bitmap lseek failed : err = %d\n", -n); + return(1); + } - off = req->offsets[bit] + req->offset + - start * req->sectorsize; - len = (end - start) * req->sectorsize; - buf = &req->buffer[start * req->sectorsize]; + n = os_write_file(req->fds[1], &req->bitmap_words, + sizeof(req->bitmap_words)); + if(n != sizeof(req->bitmap_words)){ + printk("do_io - bitmap update failed, err = %d fd = %d\n", -n, + req->fds[1]); + return(1); + } - aio = kmalloc(sizeof(*aio), GFP_KERNEL); - if(aio == NULL){ - req->error = 1; - return; - } + return(0); +} - *aio = ((struct ubd_aio) - { .aio = INIT_AIO(req->op, req->fds[bit], buf, - len, off, ubd_reply_fd), - .len = len, - .req = r, - .bitmap = bitmap_io, - .bitmap_buf = bitmap_buf }); - - if(aio->bitmap != NULL) - atomic_inc(&aio->bitmap->count); - - err = submit_aio(&aio->aio); - if(err){ - printk("do_io - submit_aio failed, " - "err = %d\n", err); - req->error = 1; - return; - } +void do_io(struct io_thread_req *req) +{ + char *buf; + unsigned long len; + int n, nsectors, start, end, bit; + int err; + __u64 off; + + 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; + buf = &req->buffer[start * req->sectorsize]; + + err = os_seek_file(req->fds[bit], off); + if(err < 0){ + printk("do_io - lseek failed : err = %d\n", -err); + req->error = 1; + return; + } + if(req->op == UBD_READ){ + n = 0; + do { + buf = &buf[n]; + len -= n; + n = os_read_file(req->fds[bit], buf, len); + if (n < 0) { + printk("do_io - read failed, err = %d " + "fd = %d\n", -n, req->fds[bit]); + req->error = 1; + return; + } + } while((n < len) && (n != 0)); + if (n < len) memset(&buf[n], 0, len - n); + } else { + n = os_write_file(req->fds[bit], buf, len); + if(n != len){ + printk("do_io - write failed err = %d " + "fd = %d\n", -n, req->fds[bit]); + req->error = 1; + return; + } + } + + start = end; + } while(start < nsectors); - 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 */ +int io_count = 0; + +int io_thread(void *arg) +{ + struct io_thread_req req; + int n; + + ignore_sigwinch_sig(); + while(1){ + n = os_read_file(kernel_fd, &req, sizeof(req)); + if(n != sizeof(req)){ + if(n < 0) + printk("io_thread - read failed, fd = %d, " + "err = %d\n", kernel_fd, -n); + else { + printk("io_thread - short read, fd = %d, " + "length = %d\n", kernel_fd, n); + } + continue; + } + io_count++; + do_io(&req); + n = os_write_file(kernel_fd, &req, sizeof(req)); + if(n != sizeof(req)) + 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: + */ diff --git a/arch/um/drivers/ubd_user.c b/arch/um/drivers/ubd_user.c new file mode 100644 index 00000000000..b94d2bc4fe0 --- /dev/null +++ b/arch/um/drivers/ubd_user.c @@ -0,0 +1,75 @@ +/* + * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com) + * Copyright (C) 2001 Ridgerun,Inc (glonnon@ridgerun.com) + * Licensed under the GPL + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "asm/types.h" +#include "user_util.h" +#include "kern_util.h" +#include "user.h" +#include "ubd_user.h" +#include "os.h" +#include "cow.h" + +#include +#include + +void ignore_sigwinch_sig(void) +{ + signal(SIGWINCH, SIG_IGN); +} + +int start_io_thread(unsigned long sp, int *fd_out) +{ + int pid, fds[2], err; + + err = os_pipe(fds, 1, 1); + if(err < 0){ + printk("start_io_thread - os_pipe failed, err = %d\n", -err); + goto out; + } + + kernel_fd = fds[0]; + *fd_out = fds[1]; + + pid = clone(io_thread, (void *) sp, CLONE_FILES | CLONE_VM | SIGCHLD, + NULL); + if(pid < 0){ + printk("start_io_thread - clone failed : errno = %d\n", errno); + err = -errno; + goto out_close; + } + + return(pid); + + out_close: + os_close_file(fds[0]); + os_close_file(fds[1]); + kernel_fd = -1; + *fd_out = -1; + out: + return(err); +} + +/* + * 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: + */ -- cgit