| From: |
| Andries.Brouwer@cwi.nl |
| To: |
| akpm@digeo.com, axboe@suse.de, clemens@endorphin.org,
torvalds@transmeta.com |
| Subject: |
| [PATCH - RFC] loop.c |
| Date: |
| Sat, 21 Jun 2003 17:07:47 +0200 (MEST) |
| Cc: |
| jari.ruusu@pp.inet.fi, linux-kernel@vger.kernel.org |
For a long time we have had a somewhat unfortunate situation
where people wanting to use cryptoloop had to collect some
kernel patches and util-linux patches elsewhere.
Now that we have crypto in the kernel this can be rectified.
As far as I can see this requires two things:
- crypto transfer functions must be registered with loop.c,
that is, loop_register_transfer() must be called
- loop.c must be fixed
The first point is handled by cryptoloop-0.2-2.5.58.diff.
Concerning the second point, several patches are floating around.
Below a patch that Jari Ruusu sent me.
This is a RFC.
Clemens - any comments on the crypto side?
Jens - any comments on the block I/O side?
Andries
diff -u --recursive --new-file -X /linux/dontdiff a/drivers/block/loop.c b/drivers/block/loop.c
--- a/drivers/block/loop.c Sun Jun 15 01:40:53 2003
+++ b/drivers/block/loop.c Sat Jun 21 16:42:20 2003
@@ -39,19 +39,30 @@
* Support up to 256 loop devices
* Heinz Mauelshagen <mge@sistina.com>, Feb 2002
*
+ * IV is now passed as (512 byte) sector number.
+ * Jari Ruusu <jari.ruusu@pp.inet.fi>, May 18 2001
+ *
+ * External encryption module locking bug fixed.
+ * Ingo Rohloff <rohloff@in.tum.de>, June 21 2001
+ *
+ * Make device backed loop work with swap (pre-allocated buffers + queue rewrite).
+ * Jari Ruusu <jari.ruusu@pp.inet.fi>, September 2 2001
+ *
+ * Ported 'pre-allocated buffers + queue rewrite' to BIO for 2.5 kernels
+ * Ben Slusky <sluskyb@stwing.org>, March 1 2002
+ * Jari Ruusu <jari.ruusu@pp.inet.fi>, March 27 2002
+ *
+ * File backed code now uses file->f_op->read/write. Based on Andrew Morton's idea.
+ * Jari Ruusu <jari.ruusu@pp.inet.fi>, May 23 2002
+ *
+ * Exported hard sector size correctly, fixed file-backed-loop-on-tmpfs bug,
+ * plus many more enhancements and optimizations.
+ * Adam J. Richter <adam@yggdrasil.com>, Aug 2002
+ *
+ *
* Still To Fix:
* - Advisory locking is ignored here.
* - Should use an own CAP_* category instead of CAP_SYS_ADMIN
- *
- * WARNING/FIXME:
- * - The block number as IV passing to low level transfer functions is broken:
- * it passes the underlying device's block number instead of the
- * offset. This makes it change for a given block when the file is
- * moved/restored/copied and also doesn't work over NFS.
- * AV, Feb 12, 2000: we pass the logical block number now. It fixes the
- * problem above. Encryption modules that used to rely on the old scheme
- * should just call ->i_mapping->bmap() to calculate the physical block
- * number.
*/
#include <linux/config.h>
@@ -65,7 +76,7 @@
#include <linux/errno.h>
#include <linux/major.h>
#include <linux/wait.h>
-#include <linux/blk.h>
+#include <linux/blkdev.h>
#include <linux/blkpg.h>
#include <linux/init.h>
#include <linux/devfs_fs_kernel.h>
@@ -80,7 +91,6 @@
#include <asm/uaccess.h>
static int max_loop = 8;
-static struct loop_device *loop_dev;
static struct gendisk **disks;
/*
@@ -89,13 +99,10 @@
static int transfer_none(struct loop_device *lo, int cmd, char *raw_buf,
char *loop_buf, int size, sector_t real_block)
{
- if (raw_buf != loop_buf) {
- if (cmd == READ)
- memcpy(loop_buf, raw_buf, size);
- else
- memcpy(raw_buf, loop_buf, size);
- }
+ /* this code is only called from file backed loop */
+ /* and that code expects this function to be no-op */
+ cond_resched();
return 0;
}
@@ -117,10 +124,16 @@
keysize = lo->lo_encrypt_key_size;
for (i = 0; i < size; i++)
*out++ = *in++ ^ key[(i & 511) % keysize];
+ cond_resched();
return 0;
}
-static int xor_status(struct loop_device *lo, const struct loop_info64 *info)
+static int none_status(struct loop_device *lo, struct loop_info64 *info)
+{
+ return 0;
+}
+
+static int xor_status(struct loop_device *lo, struct loop_info64 *info)
{
if (info->lo_encrypt_key_size <= 0)
return -EINVAL;
@@ -130,475 +143,576 @@
struct loop_func_table none_funcs = {
.number = LO_CRYPT_NONE,
.transfer = transfer_none,
-};
+ .init = none_status,
+};
struct loop_func_table xor_funcs = {
.number = LO_CRYPT_XOR,
.transfer = transfer_xor,
- .init = xor_status
-};
+ .init = xor_status,
+};
/* xfer_funcs[0] is special - its release function is never called */
struct loop_func_table *xfer_funcs[MAX_LO_CRYPT] = {
&none_funcs,
- &xor_funcs
+ &xor_funcs,
};
-static int figure_loop_size(struct loop_device *lo)
-{
- loff_t size = lo->lo_backing_file->f_dentry->d_inode->i_mapping->host->i_size;
- sector_t x;
- /*
- * Unfortunately, if we want to do I/O on the device,
- * the number of 512-byte sectors has to fit into a sector_t.
- */
- size = (size - lo->lo_offset) >> 9;
- x = (sector_t)size;
- if ((loff_t)x != size)
- return -EFBIG;
-
- set_capacity(disks[lo->lo_number], size);
- return 0;
-}
-
-static inline int lo_do_transfer(struct loop_device *lo, int cmd, char *rbuf,
- char *lbuf, int size, sector_t rblock)
-{
- if (!lo->transfer)
- return 0;
-
- return lo->transfer(lo, cmd, rbuf, lbuf, size, rblock);
-}
-
-static int
-do_lo_send(struct loop_device *lo, struct bio_vec *bvec, int bsize, loff_t pos)
-{
- struct file *file = lo->lo_backing_file; /* kudos to NFsckingS */
- struct address_space *mapping = file->f_dentry->d_inode->i_mapping;
- struct address_space_operations *aops = mapping->a_ops;
- struct page *page;
- char *kaddr, *data;
- pgoff_t index;
- unsigned size, offset;
- int len;
- int ret = 0;
-
- down(&mapping->host->i_sem);
- index = pos >> PAGE_CACHE_SHIFT;
- offset = pos & ((pgoff_t)PAGE_CACHE_SIZE - 1);
- data = kmap(bvec->bv_page) + bvec->bv_offset;
- len = bvec->bv_len;
- while (len > 0) {
- sector_t IV = index * (PAGE_CACHE_SIZE/bsize) + offset/bsize;
- int transfer_result;
-
- size = PAGE_CACHE_SIZE - offset;
- if (size > len)
- size = len;
-
- page = grab_cache_page(mapping, index);
- if (!page)
- goto fail;
- if (aops->prepare_write(file, page, offset, offset+size))
- goto unlock;
- kaddr = kmap(page);
- transfer_result = lo_do_transfer(lo, WRITE, kaddr + offset, data, size, IV);
- if (transfer_result) {
- /*
- * The transfer failed, but we still write the data to
- * keep prepare/commit calls balanced.
- */
- printk(KERN_ERR "loop: transfer error block %llu\n",
- (unsigned long long)index);
- memset(kaddr + offset, 0, size);
- }
- flush_dcache_page(page);
- kunmap(page);
- if (aops->commit_write(file, page, offset, offset+size))
- goto unlock;
- if (transfer_result)
- goto unlock;
- data += size;
- len -= size;
- offset = 0;
- index++;
- pos += size;
- unlock_page(page);
- page_cache_release(page);
- }
- up(&mapping->host->i_sem);
-out:
- kunmap(bvec->bv_page);
- return ret;
-
-unlock:
- unlock_page(page);
- page_cache_release(page);
-fail:
- up(&mapping->host->i_sem);
- ret = -1;
- goto out;
-}
-
-static int
-lo_send(struct loop_device *lo, struct bio *bio, int bsize, loff_t pos)
-{
- unsigned vecnr;
- int ret = 0;
-
- for (vecnr = 0; vecnr < bio->bi_vcnt; vecnr++) {
- struct bio_vec *bvec = &bio->bi_io_vec[vecnr];
-
- ret = do_lo_send(lo, bvec, bsize, pos);
- if (ret < 0)
+/*
+ * First number of 'lo_prealloc' is the default number of RAM pages
+ * to pre-allocate for each device backed loop. Every (configured)
+ * device backed loop pre-allocates this amount of RAM pages unless
+ * later 'lo_prealloc' numbers provide an override. 'lo_prealloc'
+ * overrides are defined in pairs: loop_index,number_of_pages
+ */
+static int lo_prealloc[9] = { 125, -1, 0, -1, 0, -1, 0, -1, 0 };
+#define LO_PREALLOC_MIN 4 /* minimum user defined pre-allocated RAM pages */
+#define LO_PREALLOC_MAX 512 /* maximum user defined pre-allocated RAM pages */
+
+#ifdef MODULE
+MODULE_PARM(lo_prealloc, "1-9i");
+MODULE_PARM_DESC(lo_prealloc, "Number of pre-allocated pages [,index,pages]...");
+#else
+static int __init lo_prealloc_setup(char *str)
+{
+ int x, y, z;
+
+ for (x = 0; x < (sizeof(lo_prealloc) / sizeof(int)); x++) {
+ z = get_option(&str, &y);
+ if (z > 0)
+ lo_prealloc[x] = y;
+ if (z < 2)
break;
- pos += bvec->bv_len;
}
- return ret;
+ return 1;
}
+__setup("lo_prealloc=", lo_prealloc_setup);
+#endif
-struct lo_read_data {
- struct loop_device *lo;
- char *data;
- int bsize;
-};
-
-static int
-lo_read_actor(read_descriptor_t *desc, struct page *page,
- unsigned long offset, unsigned long size)
-{
- char *kaddr;
- unsigned long count = desc->count;
- struct lo_read_data *p = (struct lo_read_data*)desc->buf;
- struct loop_device *lo = p->lo;
- int IV = page->index * (PAGE_CACHE_SIZE/p->bsize) + offset/p->bsize;
+/*
+ * This is loop helper thread nice value in range
+ * from 0 (low priority) to -20 (high priority).
+ */
+static int lo_nice = -1;
- if (size > count)
- size = count;
+#ifdef MODULE
+MODULE_PARM(lo_nice, "1i");
+MODULE_PARM_DESC(lo_nice, "Loop thread scheduler nice (0 ... -20)");
+#else
+static int __init lo_nice_setup(char *str)
+{
+ int y;
+
+ if (get_option(&str, &y) == 1)
+ lo_nice = y;
+ return 1;
+}
+__setup("lo_nice=", lo_nice_setup);
+#endif
+
+struct loop_bio_extension {
+ struct bio *bioext_merge;
+ struct loop_device *bioext_loop;
+ sector_t bioext_sector;
+ int bioext_index;
+ int bioext_size;
+};
- kaddr = kmap(page);
- if (lo_do_transfer(lo, READ, kaddr + offset, p->data, size, IV)) {
- size = 0;
- printk(KERN_ERR "loop: transfer error block %ld\n",
- page->index);
- desc->error = -EINVAL;
- }
- kunmap(page);
-
- desc->count = count - size;
- desc->written += size;
- p->data += size;
- return size;
-}
+static struct loop_device **loop_dev_ptr_arr;
-static int
-do_lo_receive(struct loop_device *lo,
- struct bio_vec *bvec, int bsize, loff_t pos)
+static void loop_prealloc_cleanup(struct loop_device *lo)
{
- struct lo_read_data cookie;
- struct file *file;
- int retval;
-
- cookie.lo = lo;
- cookie.data = kmap(bvec->bv_page) + bvec->bv_offset;
- cookie.bsize = bsize;
- file = lo->lo_backing_file;
- retval = file->f_op->sendfile(file, &pos, bvec->bv_len,
- lo_read_actor, &cookie);
- kunmap(bvec->bv_page);
- return (retval < 0)? retval: 0;
+ struct bio *bio;
+
+ while ((bio = lo->lo_bio_free0)) {
+ lo->lo_bio_free0 = bio->bi_next;
+ __free_page(bio->bi_io_vec[0].bv_page);
+ kfree(bio->bi_private);
+ bio->bi_next = NULL;
+ bio_put(bio);
+ }
+ while ((bio = lo->lo_bio_free1)) {
+ lo->lo_bio_free1 = bio->bi_next;
+ /* bi_flags was used for other purpose */
+ bio->bi_flags = 0;
+ /* bi_cnt was used for other purpose */
+ atomic_set(&bio->bi_cnt, 1);
+ bio->bi_next = NULL;
+ bio_put(bio);
+ }
}
-static int
-lo_receive(struct loop_device *lo, struct bio *bio, int bsize, loff_t pos)
+static int loop_prealloc_init(struct loop_device *lo, int y)
{
- unsigned vecnr;
- int ret = 0;
+ struct bio *bio;
+ int x;
- for (vecnr = 0; vecnr < bio->bi_vcnt; vecnr++) {
- struct bio_vec *bvec = &bio->bi_io_vec[vecnr];
+ if(!y) {
+ y = lo_prealloc[0];
+ for (x = 1; x < (sizeof(lo_prealloc) / sizeof(int)); x += 2) {
+ if (lo_prealloc[x + 1] && (lo->lo_number == lo_prealloc[x])) {
+ y = lo_prealloc[x + 1];
+ break;
+ }
+ }
+ }
+ lo->lo_bio_flsh = (y * 3) / 4;
- ret = do_lo_receive(lo, bvec, bsize, pos);
- if (ret < 0)
- break;
- pos += bvec->bv_len;
+ for (x = 0; x < y; x++) {
+ bio = bio_alloc(GFP_KERNEL, 1);
+ if (!bio) {
+ fail1:
+ loop_prealloc_cleanup(lo);
+ return 1;
+ }
+ bio->bi_io_vec[0].bv_page = alloc_page(GFP_KERNEL);
+ if (!bio->bi_io_vec[0].bv_page) {
+ fail2:
+ bio->bi_next = NULL;
+ bio_put(bio);
+ goto fail1;
+ }
+ bio->bi_vcnt = 1;
+ bio->bi_private = kmalloc(sizeof(struct loop_bio_extension), GFP_KERNEL);
+ if (!bio->bi_private)
+ goto fail2;
+ bio->bi_next = lo->lo_bio_free0;
+ lo->lo_bio_free0 = bio;
+
+ bio = bio_alloc(GFP_KERNEL, 1);
+ if (!bio)
+ goto fail1;
+ bio->bi_vcnt = 1;
+ bio->bi_next = lo->lo_bio_free1;
+ lo->lo_bio_free1 = bio;
}
- return ret;
+ return 0;
}
-static inline unsigned long
-loop_get_iv(struct loop_device *lo, unsigned long sector)
+static void loop_add_queue_last(struct loop_device *lo, struct bio *bio, struct bio **q)
{
- int bs = lo->lo_blocksize;
- unsigned long offset, IV;
+ unsigned long flags;
- IV = sector / (bs >> 9) + lo->lo_offset / bs;
- offset = ((sector % (bs >> 9)) << 9) + lo->lo_offset % bs;
- if (offset >= bs)
- IV++;
+ spin_lock_irqsave(&lo->lo_lock, flags);
+ if (*q) {
+ bio->bi_next = (*q)->bi_next;
+ (*q)->bi_next = bio;
+ } else {
+ bio->bi_next = bio;
+ }
+ *q = bio;
+ spin_unlock_irqrestore(&lo->lo_lock, flags);
- return IV;
+ if (waitqueue_active(&lo->lo_bio_wait))
+ wake_up_interruptible(&lo->lo_bio_wait);
}
-static int do_bio_filebacked(struct loop_device *lo, struct bio *bio)
+static void loop_add_queue_first(struct loop_device *lo, struct bio *bio, struct bio **q)
{
- loff_t pos;
- int ret;
-
- pos = ((loff_t) bio->bi_sector << 9) + lo->lo_offset;
- if (bio_rw(bio) == WRITE)
- ret = lo_send(lo, bio, lo->lo_blocksize, pos);
- else
- ret = lo_receive(lo, bio, lo->lo_blocksize, pos);
- return ret;
+ spin_lock_irq(&lo->lo_lock);
+ if (*q) {
+ bio->bi_next = (*q)->bi_next;
+ (*q)->bi_next = bio;
+ } else {
+ bio->bi_next = bio;
+ *q = bio;
+ }
+ spin_unlock_irq(&lo->lo_lock);
}
-static int loop_end_io_transfer(struct bio *, unsigned int, int);
-
-static void loop_put_buffer(struct bio *bio)
+static struct bio *loop_get_bio(struct loop_device *lo, int *list_nr)
{
- /*
- * check bi_end_io, may just be a remapped bio
- */
- if (bio && bio->bi_end_io == loop_end_io_transfer) {
- int i;
+ struct bio *bio = NULL, *last;
- for (i = 0; i < bio->bi_vcnt; i++)
- __free_page(bio->bi_io_vec[i].bv_page);
-
- bio_put(bio);
+ spin_lock_irq(&lo->lo_lock);
+ if ((last = lo->lo_bio_que0)) {
+ bio = last->bi_next;
+ if (bio == last)
+ lo->lo_bio_que0 = NULL;
+ else
+ last->bi_next = bio->bi_next;
+ bio->bi_next = NULL;
+ *list_nr = 0;
+ } else if ((last = lo->lo_bio_que1)) {
+ bio = last->bi_next;
+ if (bio == last)
+ lo->lo_bio_que1 = NULL;
+ else
+ last->bi_next = bio->bi_next;
+ bio->bi_next = NULL;
+ *list_nr = 1;
+ } else if ((last = lo->lo_bio_que2)) {
+ bio = last->bi_next;
+ if (bio == last)
+ lo->lo_bio_que2 = NULL;
+ else
+ last->bi_next = bio->bi_next;
+ bio->bi_next = NULL;
+ *list_nr = 2;
}
+ spin_unlock_irq(&lo->lo_lock);
+ return bio;
}
-/*
- * Add bio to back of pending list
- */
-static void loop_add_bio(struct loop_device *lo, struct bio *bio)
+static void loop_put_buffer(struct loop_device *lo, struct bio *b, int flist)
{
unsigned long flags;
+ int wk;
spin_lock_irqsave(&lo->lo_lock, flags);
- if (lo->lo_biotail) {
- lo->lo_biotail->bi_next = bio;
- lo->lo_biotail = bio;
- } else
- lo->lo_bio = lo->lo_biotail = bio;
- spin_unlock_irqrestore(&lo->lo_lock, flags);
-
- up(&lo->lo_bh_mutex);
-}
-
-/*
- * Grab first pending buffer
- */
-static struct bio *loop_get_bio(struct loop_device *lo)
-{
- struct bio *bio;
-
- spin_lock_irq(&lo->lo_lock);
- if ((bio = lo->lo_bio)) {
- if (bio == lo->lo_biotail)
- lo->lo_biotail = NULL;
- lo->lo_bio = bio->bi_next;
- bio->bi_next = NULL;
+ if(!flist) {
+ b->bi_next = lo->lo_bio_free0;
+ lo->lo_bio_free0 = b;
+ wk = lo->lo_bio_need & 1;
+ } else {
+ b->bi_next = lo->lo_bio_free1;
+ lo->lo_bio_free1 = b;
+ wk = lo->lo_bio_need & 2;
}
- spin_unlock_irq(&lo->lo_lock);
+ spin_unlock_irqrestore(&lo->lo_lock, flags);
- return bio;
+ if (wk && waitqueue_active(&lo->lo_bio_wait))
+ wake_up_interruptible(&lo->lo_bio_wait);
}
-/*
- * if this was a WRITE lo->transfer stuff has already been done. for READs,
- * queue it for the loop thread and let it do the transfer out of
- * bi_end_io context (we don't want to do decrypt of a page with irqs
- * disabled)
- */
static int loop_end_io_transfer(struct bio *bio, unsigned int bytes_done, int err)
{
- struct bio *rbh = bio->bi_private;
- struct loop_device *lo = rbh->bi_bdev->bd_disk->private_data;
+ struct loop_bio_extension *extension = bio->bi_private;
+ struct bio *merge = extension->bioext_merge;
+ struct loop_device *lo = extension->bioext_loop;
+ struct bio *origbio = merge->bi_private;
+ if (err)
+ clear_bit(0, &merge->bi_flags);
if (bio->bi_size)
return 1;
-
- if (err || bio_rw(bio) == WRITE) {
- bio_endio(rbh, rbh->bi_size, err);
+ if (bio_rw(bio) == WRITE) {
+ loop_put_buffer(lo, bio, 0);
+ if (!atomic_dec_and_test(&merge->bi_cnt))
+ return 0;
+ if (bio_barrier(origbio))
+ atomic_dec(&lo->lo_bio_barr);
+ origbio->bi_next = NULL;
+ bio_endio(origbio, origbio->bi_size, test_bit(0, &merge->bi_flags) ? 0 : -EIO);
+ loop_put_buffer(lo, merge, 1);
if (atomic_dec_and_test(&lo->lo_pending))
- up(&lo->lo_bh_mutex);
- loop_put_buffer(bio);
- } else
- loop_add_bio(lo, bio);
-
+ wake_up_interruptible(&lo->lo_bio_wait);
+ } else {
+ loop_add_queue_last(lo, bio, &lo->lo_bio_que0);
+ }
return 0;
}
-static struct bio *loop_copy_bio(struct bio *rbh)
+static struct bio *loop_get_buffer(struct loop_device *lo,
+ struct bio *orig_bio, int from_thread, struct bio **merge_ptr)
{
- struct bio *bio;
- struct bio_vec *bv;
- int i;
+ struct bio *bio = NULL, *merge = *merge_ptr;
+ struct loop_bio_extension *extension;
+ unsigned long flags;
+ int len;
- bio = bio_alloc(__GFP_NOWARN, rbh->bi_vcnt);
- if (!bio)
+ /*
+ * If called from make_request and if there are unprocessed
+ * barrier requests, fail allocation so that request is
+ * inserted to end of no-merge-allocated list. This guarantees
+ * FIFO processing order of requests.
+ */
+ if (!from_thread && atomic_read(&lo->lo_bio_barr))
return NULL;
+ spin_lock_irqsave(&lo->lo_lock, flags);
+ if (!merge) {
+ merge = lo->lo_bio_free1;
+ if (merge) {
+ lo->lo_bio_free1 = merge->bi_next;
+ if (from_thread)
+ lo->lo_bio_need = 0;
+ } else {
+ if (from_thread)
+ lo->lo_bio_need = 2;
+ }
+ }
+
/*
- * iterate iovec list and alloc pages
+ * If there are unprocessed barrier requests and a merge-bio was just
+ * allocated, do not allocate a buffer-bio yet. This causes request
+ * to be moved from head of no-merge-allocated list to end of
+ * merge-allocated list. This guarantees FIFO processing order
+ * of requests.
*/
- __bio_for_each_segment(bv, rbh, i, 0) {
- struct bio_vec *bbv = &bio->bi_io_vec[i];
-
- bbv->bv_page = alloc_page(__GFP_NOWARN|__GFP_HIGHMEM);
- if (bbv->bv_page == NULL)
- goto oom;
+ if (merge && (*merge_ptr || !atomic_read(&lo->lo_bio_barr))) {
+ bio = lo->lo_bio_free0;
+ if (bio) {
+ lo->lo_bio_free0 = bio->bi_next;
+ if (from_thread)
+ lo->lo_bio_need = 0;
+ } else {
+ if (from_thread)
+ lo->lo_bio_need = 1;
+ }
+ }
+ spin_unlock_irqrestore(&lo->lo_lock, flags);
- bbv->bv_len = bv->bv_len;
- bbv->bv_offset = bv->bv_offset;
+ if (!(*merge_ptr) && merge) {
+ /*
+ * initialize "merge-bio" which is used as
+ * rendezvous point among multiple vecs
+ */
+ *merge_ptr = merge;
+ merge->bi_sector = orig_bio->bi_sector + (lo->lo_offset >> 9);
+ set_bit(0, &merge->bi_flags);
+ merge->bi_idx = orig_bio->bi_idx;
+ atomic_set(&merge->bi_cnt, orig_bio->bi_vcnt - orig_bio->bi_idx);
+ merge->bi_private = orig_bio;
}
- bio->bi_vcnt = rbh->bi_vcnt;
- bio->bi_size = rbh->bi_size;
+ if (!bio)
+ return NULL;
- return bio;
+ /*
+ * initialize one page "buffer-bio"
+ */
+ bio->bi_sector = merge->bi_sector;
+ bio->bi_next = NULL;
+ bio->bi_bdev = lo->lo_device;
+ bio->bi_flags = 0;
+ bio->bi_rw = orig_bio->bi_rw & ~(1 << BIO_RW_BARRIER);
+ if (bio_barrier(orig_bio) && ((merge->bi_idx == orig_bio->bi_idx) || (merge->bi_idx == (orig_bio->bi_vcnt - 1))))
+ bio->bi_rw |= (1 << BIO_RW_BARRIER);
+ bio->bi_vcnt = 1;
+ bio->bi_idx = 0;
+ bio->bi_phys_segments = 0;
+ bio->bi_hw_segments = 0;
+ bio->bi_size = len = orig_bio->bi_io_vec[merge->bi_idx].bv_len;
+ /* bio->bi_max_vecs not touched */
+ bio->bi_io_vec[0].bv_len = len;
+ bio->bi_io_vec[0].bv_offset = 0;
+ bio->bi_end_io = loop_end_io_transfer;
+ /* bio->bi_cnt not touched */
+ /* bio->bi_private not touched */
+ /* bio->bi_destructor not touched */
+
+ /*
+ * initialize "buffer-bio" extension. This extension is
+ * permanently glued to above "buffer-bio" via bio->bi_private
+ */
+ extension = bio->bi_private;
+ extension->bioext_merge = merge;
+ extension->bioext_loop = lo;
+ extension->bioext_sector = merge->bi_sector;
+ extension->bioext_index = merge->bi_idx;
+ extension->bioext_size = len;
-oom:
- while (--i >= 0)
- __free_page(bio->bi_io_vec[i].bv_page);
+ /*
+ * prepare "merge-bio" for next vec
+ */
+ merge->bi_sector += len >> 9;
+ merge->bi_idx++;
- bio_put(bio);
- return NULL;
+ return bio;
}
-static struct bio *loop_get_buffer(struct loop_device *lo, struct bio *rbh)
+static int figure_loop_size(struct loop_device *lo, struct block_device *bdev, loff_t info64size)
{
- struct bio *bio;
+ loff_t size, offs;
+ sector_t x;
+ int err = 0;
+
+ size = lo->lo_backing_file->f_dentry->d_inode->i_mapping->host->i_size;
+ offs = lo->lo_offset;
+ if (!(lo->lo_flags & LO_FLAGS_DO_BMAP))
+ offs &= ~((loff_t)511);
+ size = (size - offs) >> 9;
+ info64size >>= 9;
+ if ((info64size > 0) && (info64size < size))
+ size = info64size;
/*
- * When called on the page reclaim -> writepage path, this code can
- * trivially consume all memory. So we drop PF_MEMALLOC to avoid
- * stealing all the page reserves and throttle to the writeout rate.
- * pdflush will have been woken by page reclaim. Let it do its work.
+ * Unfortunately, if we want to do I/O on the device,
+ * the number of 512-byte sectors has to fit into a sector_t.
*/
- do {
- int flags = current->flags;
+ x = (sector_t)size;
+ if ((loff_t)x != size) {
+ err = -EFBIG;
+ size = 0;
+ }
- current->flags &= ~PF_MEMALLOC;
- bio = loop_copy_bio(rbh);
- if (flags & PF_MEMALLOC)
- current->flags |= PF_MEMALLOC;
-
- if (bio == NULL)
- blk_congestion_wait(WRITE, HZ/10);
- } while (bio == NULL);
+ bdev->bd_inode->i_size = size << 9; /* byte units */
+ set_capacity(disks[lo->lo_number], size); /* 512 byte units */
+ return err;
+}
- bio->bi_end_io = loop_end_io_transfer;
- bio->bi_private = rbh;
- bio->bi_sector = rbh->bi_sector + (lo->lo_offset >> 9);
- bio->bi_rw = rbh->bi_rw;
- bio->bi_bdev = lo->lo_device;
+static inline int lo_do_transfer(struct loop_device *lo, int cmd, char *rbuf,
+ char *lbuf, int size, sector_t rblock)
+{
+ if (!lo->transfer)
+ return 0;
- return bio;
+ return lo->transfer(lo, cmd, rbuf, lbuf, size, rblock);
}
-static int loop_transfer_bio(struct loop_device *lo,
- struct bio *to_bio, struct bio *from_bio)
+static int loop_file_io(struct file *file, char *buf, int size, loff_t *ppos, int w)
{
- unsigned long IV = loop_get_iv(lo, from_bio->bi_sector);
- struct bio_vec *from_bvec, *to_bvec;
- char *vto, *vfrom;
- int ret = 0, i;
+ mm_segment_t fs;
+ int x, y, z;
- __bio_for_each_segment(from_bvec, from_bio, i, 0) {
- to_bvec = &to_bio->bi_io_vec[i];
+ y = 0;
+ do {
+ z = size - y;
+ fs = get_fs();
+ set_fs(get_ds());
+ if (w) {
+ x = file->f_op->write(file, buf + y, z, ppos);
+ set_fs(fs);
+ } else {
+ x = file->f_op->read(file, buf + y, z, ppos);
+ set_fs(fs);
+ if (!x)
+ return 1;
+ }
+ if (x < 0) {
+ if ((x == -EAGAIN) || (x == -ENOMEM) || (x == -ERESTART) || (x == -EINTR)) {
+ blk_run_queues();
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(HZ / 2);
+ continue;
+ }
+ return 1;
+ }
+ y += x;
+ } while (y < size);
+ return 0;
+}
- kmap(from_bvec->bv_page);
- kmap(to_bvec->bv_page);
- vfrom = page_address(from_bvec->bv_page) + from_bvec->bv_offset;
- vto = page_address(to_bvec->bv_page) + to_bvec->bv_offset;
- ret |= lo_do_transfer(lo, bio_data_dir(to_bio), vto, vfrom,
- from_bvec->bv_len, IV);
- kunmap(from_bvec->bv_page);
- kunmap(to_bvec->bv_page);
- }
+static int do_bio_filebacked(struct loop_device *lo, struct bio *bio)
+{
+ loff_t pos;
+ struct file *file = lo->lo_backing_file;
+ char *data, *buf;
+ unsigned int size, len;
+ sector_t IV;
- return ret;
+ pos = ((loff_t) bio->bi_sector << 9) + lo->lo_offset;
+ buf = page_address(lo->lo_bio_free0->bi_io_vec[0].bv_page);
+ IV = bio->bi_sector + (lo->lo_offset >> 9);
+ do {
+ len = bio->bi_io_vec[bio->bi_idx].bv_len;
+ data = bio_data(bio);
+ while (len > 0) {
+ if (lo->lo_encrypt_type == LO_CRYPT_NONE) {
+ /* this code relies that NONE transfer is a no-op */
+ buf = data;
+ }
+ size = PAGE_SIZE;
+ if (size > len)
+ size = len;
+ if (bio_rw(bio) == WRITE) {
+ if (lo_do_transfer(lo, WRITE, buf, data, size, IV)) {
+ printk(KERN_ERR "loop%d: write transfer error, sector %llu\n", lo->lo_number, (unsigned long long)IV);
+ return -EIO;
+ }
+ if (loop_file_io(file, buf, size, &pos, 1)) {
+ printk(KERN_ERR "loop%d: write i/o error, sector %llu\n", lo->lo_number, (unsigned long long)IV);
+ return -EIO;
+ }
+ } else {
+ if (loop_file_io(file, buf, size, &pos, 0)) {
+ printk(KERN_ERR "loop%d: read i/o error, sector %llu\n", lo->lo_number, (unsigned long long)IV);
+ return -EIO;
+ }
+ if (lo_do_transfer(lo, READ, buf, data, size, IV)) {
+ printk(KERN_ERR "loop%d: read transfer error, sector %llu\n", lo->lo_number, (unsigned long long)IV);
+ return -EIO;
+ }
+ }
+ data += size;
+ len -= size;
+ IV += size >> 9;
+ }
+ } while (++bio->bi_idx < bio->bi_vcnt);
+ return 0;
}
-
-static int loop_make_request(request_queue_t *q, struct bio *old_bio)
+
+static int loop_make_request_err(request_queue_t *q, struct bio *old_bio)
+{
+ old_bio->bi_next = NULL;
+ bio_io_error(old_bio, old_bio->bi_size);
+ return 0;
+}
+
+static int loop_make_request_real(request_queue_t *q, struct bio *old_bio)
{
- struct bio *new_bio = NULL;
+ struct bio *new_bio, *merge;
struct loop_device *lo = q->queuedata;
- int rw = bio_rw(old_bio);
+ struct loop_bio_extension *extension;
+ int rw = bio_rw(old_bio), y;
+ set_current_state(TASK_RUNNING);
if (!lo)
goto out;
-
- spin_lock_irq(&lo->lo_lock);
- if (lo->lo_state != Lo_bound)
- goto inactive;
+ if ((rw == WRITE) && (lo->lo_flags & LO_FLAGS_READ_ONLY))
+ goto out;
atomic_inc(&lo->lo_pending);
- spin_unlock_irq(&lo->lo_lock);
-
- if (rw == WRITE) {
- if (lo->lo_flags & LO_FLAGS_READ_ONLY)
- goto err;
- } else if (rw == READA) {
- rw = READ;
- } else if (rw != READ) {
- printk(KERN_ERR "loop: unknown command (%x)\n", rw);
- goto err;
- }
+ blk_queue_bounce(q, &old_bio);
/*
* file backed, queue for loop_thread to handle
*/
if (lo->lo_flags & LO_FLAGS_DO_BMAP) {
- loop_add_bio(lo, old_bio);
+ loop_add_queue_last(lo, old_bio, &lo->lo_bio_que0);
return 0;
}
/*
- * piggy old buffer on original, and submit for I/O
+ * device backed, just remap bdev & sector for NONE transfer
*/
- new_bio = loop_get_buffer(lo, old_bio);
+ if (lo->lo_encrypt_type == LO_CRYPT_NONE) {
+ old_bio->bi_sector += lo->lo_offset >> 9;
+ old_bio->bi_bdev = lo->lo_device;
+ generic_make_request(old_bio);
+ if (atomic_dec_and_test(&lo->lo_pending))
+ wake_up_interruptible(&lo->lo_bio_wait);
+ return 0;
+ }
+
+ /*
+ * device backed, start reads and writes now if buffer available
+ */
+ merge = NULL;
+ if (bio_barrier(old_bio))
+ atomic_inc(&lo->lo_bio_barr);
+ try_next_old_bio_vec:
+ new_bio = loop_get_buffer(lo, old_bio, 0, &merge);
+ if (!new_bio) {
+ /* just queue request and let thread handle allocs later */
+ if (merge)
+ loop_add_queue_last(lo, merge, &lo->lo_bio_que1);
+ else
+ loop_add_queue_last(lo, old_bio, &lo->lo_bio_que2);
+ return 0;
+ }
if (rw == WRITE) {
- if (loop_transfer_bio(lo, new_bio, old_bio))
- goto err;
+ extension = new_bio->bi_private;
+ y = extension->bioext_index;
+ if (lo_do_transfer(lo, WRITE, page_address(new_bio->bi_io_vec[0].bv_page), page_address(old_bio->bi_io_vec[y].bv_page) + old_bio->bi_io_vec[y].bv_offset, extension->bioext_size, extension->bioext_sector)) {
+ clear_bit(0, &merge->bi_flags);
+ }
}
+ /* merge & old_bio may vanish during generic_make_request() */
+ /* if last vec gets processed before function returns */
+ y = (merge->bi_idx < old_bio->bi_vcnt) ? 1 : 0;
generic_make_request(new_bio);
+
+ /* other vecs may need processing too */
+ if (y)
+ goto try_next_old_bio_vec;
return 0;
-err:
- if (atomic_dec_and_test(&lo->lo_pending))
- up(&lo->lo_bh_mutex);
- loop_put_buffer(new_bio);
out:
+ old_bio->bi_next = NULL;
bio_io_error(old_bio, old_bio->bi_size);
return 0;
-inactive:
- spin_unlock_irq(&lo->lo_lock);
- goto out;
-}
-
-static inline void loop_handle_bio(struct loop_device *lo, struct bio *bio)
-{
- int ret;
-
- /*
- * For block backed loop, we know this is a READ
- */
- if (lo->lo_flags & LO_FLAGS_DO_BMAP) {
- ret = do_bio_filebacked(lo, bio);
- bio_endio(bio, bio->bi_size, ret);
- } else {
- struct bio *rbh = bio->bi_private;
-
- ret = loop_transfer_bio(lo, bio, rbh);
-
- bio_endio(rbh, rbh->bi_size, ret);
- loop_put_buffer(bio);
- }
}
/*
@@ -610,17 +724,27 @@
static int loop_thread(void *data)
{
struct loop_device *lo = data;
- struct bio *bio;
+ struct bio *bio, *xbio, *merge;
+ struct loop_bio_extension *extension;
+ int x, y, flushcnt = 0;
+ wait_queue_t waitq;
+ static const struct rlimit loop_rlim_defaults[RLIM_NLIMITS] = INIT_RLIMITS;
+ init_waitqueue_entry(&waitq, current);
+ memcpy(¤t->rlim[0], &loop_rlim_defaults[0], sizeof(current->rlim));
daemonize("loop%d", lo->lo_number);
- current->flags |= PF_IOTHREAD; /* loop can be used in an encrypted device
+ current->flags |= PF_IOTHREAD | PF_LESS_THROTTLE;
+ /* loop can be used in an encrypted device
hence, it mustn't be stopped at all because it could
be indirectly used during suspension */
- set_user_nice(current, -20);
+ if (lo_nice > 0)
+ lo_nice = 0;
+ if (lo_nice < -20)
+ lo_nice = -20;
+ set_user_nice(current, lo_nice);
- lo->lo_state = Lo_bound;
atomic_inc(&lo->lo_pending);
/*
@@ -629,23 +753,134 @@
up(&lo->lo_sem);
for (;;) {
- down_interruptible(&lo->lo_bh_mutex);
+ add_wait_queue(&lo->lo_bio_wait, &waitq);
+ for (;;) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (!atomic_read(&lo->lo_pending))
+ break;
+
+ x = 0;
+ spin_lock_irq(&lo->lo_lock);
+ if (lo->lo_bio_que0) {
+ /* don't sleep if device backed READ needs processing */
+ /* don't sleep if file backed READ/WRITE needs processing */
+ x = 1;
+ } else if (lo->lo_bio_que1) {
+ /* don't sleep if a buffer-bio is available */
+ /* don't sleep if need-buffer-bio request is not set */
+ if (lo->lo_bio_free0 || !(lo->lo_bio_need & 1))
+ x = 1;
+ } else if (lo->lo_bio_que2) {
+ /* don't sleep if a merge-bio is available */
+ /* don't sleep if need-merge-bio request is not set */
+ if (lo->lo_bio_free1 || !(lo->lo_bio_need & 2))
+ x = 1;
+ }
+ spin_unlock_irq(&lo->lo_lock);
+ if (x)
+ break;
+
+ schedule();
+ }
+ set_current_state(TASK_RUNNING);
+ remove_wait_queue(&lo->lo_bio_wait, &waitq);
+
/*
- * could be upped because of tear-down, not because of
+ * could be woken because of tear-down, not because of
* pending work
*/
if (!atomic_read(&lo->lo_pending))
break;
- bio = loop_get_bio(lo);
- if (!bio) {
- printk("loop: missing bio\n");
+ bio = loop_get_bio(lo, &x);
+ if (!bio)
continue;
+
+ /*
+ * x list tag usage(has-buffer,has-merge)
+ * --- -------- --------------------------
+ * 0 lo->lo_bio_que0 dev-r(y,y) / file-rw
+ * 1 lo->lo_bio_que1 dev-rw(n,y)
+ * 2 lo->lo_bio_que2 dev-rw(n,n)
+ */
+ if (x >= 1) {
+ /* loop_make_request_real didn't allocate a buffer, do that now */
+ if (x == 1) {
+ merge = bio;
+ bio = merge->bi_private;
+ } else {
+ merge = NULL;
+ }
+ try_next_bio_vec:
+ xbio = loop_get_buffer(lo, bio, 1, &merge);
+ if (!xbio) {
+ blk_run_queues();
+ flushcnt = 0;
+ if (merge)
+ loop_add_queue_first(lo, merge, &lo->lo_bio_que1);
+ else
+ loop_add_queue_first(lo, bio, &lo->lo_bio_que2);
+ /* lo->lo_bio_need should be non-zero now, go back to sleep */
+ continue;
+ }
+ if (bio_rw(bio) == WRITE) {
+ extension = xbio->bi_private;
+ y = extension->bioext_index;
+ if (lo_do_transfer(lo, WRITE, page_address(xbio->bi_io_vec[0].bv_page), page_address(bio->bi_io_vec[y].bv_page) + bio->bi_io_vec[y].bv_offset, extension->bioext_size, extension->bioext_sector)) {
+ clear_bit(0, &merge->bi_flags);
+ }
+ }
+
+ /* merge & bio may vanish during generic_make_request() */
+ /* if last vec gets processed before function returns */
+ y = (merge->bi_idx < bio->bi_vcnt) ? 1 : 0;
+ generic_make_request(xbio);
+
+ /* start I/O if there are no more requests lacking buffers */
+ x = 0;
+ spin_lock_irq(&lo->lo_lock);
+ if (!y && !lo->lo_bio_que1 && !lo->lo_bio_que2)
+ x = 1;
+ spin_unlock_irq(&lo->lo_lock);
+ if (x || (++flushcnt >= lo->lo_bio_flsh)) {
+ blk_run_queues();
+ flushcnt = 0;
+ }
+
+ /* other vecs may need processing too */
+ if (y)
+ goto try_next_bio_vec;
+
+ /* request not completely processed yet */
+ continue;
+ }
+
+ if (lo->lo_flags & LO_FLAGS_DO_BMAP) {
+ /* request is for file backed device */
+ y = do_bio_filebacked(lo, bio);
+ bio->bi_next = NULL;
+ bio_endio(bio, bio->bi_size, y);
+ } else {
+ /* device backed read has completed, do decrypt now */
+ extension = bio->bi_private;
+ merge = extension->bioext_merge;
+ y = extension->bioext_index;
+ xbio = merge->bi_private;
+ if (lo_do_transfer(lo, READ, page_address(bio->bi_io_vec[0].bv_page), page_address(xbio->bi_io_vec[y].bv_page) + xbio->bi_io_vec[y].bv_offset, extension->bioext_size, extension->bioext_sector)) {
+ clear_bit(0, &merge->bi_flags);
+ }
+ loop_put_buffer(lo, bio, 0);
+ if (!atomic_dec_and_test(&merge->bi_cnt))
+ continue;
+ if (bio_barrier(xbio))
+ atomic_dec(&lo->lo_bio_barr);
+ xbio->bi_next = NULL;
+ bio_endio(xbio, xbio->bi_size, test_bit(0, &merge->bi_flags) ? 0 : -EIO);
+ loop_put_buffer(lo, merge, 1);
}
- loop_handle_bio(lo, bio);
/*
- * upped both for pending work and tear-down, lo_pending
+ * woken both for pending work and tear-down, lo_pending
* will hit zero then
*/
if (atomic_dec_and_test(&lo->lo_pending))
@@ -656,23 +891,37 @@
return 0;
}
+static void loop_set_softblksz(struct loop_device *lo, struct block_device *bdev)
+{
+ int bs, x;
+
+ if (lo->lo_device)
+ bs = block_size(lo->lo_device);
+ else
+ bs = PAGE_SIZE;
+ if (lo->lo_flags & LO_FLAGS_DO_BMAP) {
+ x = (int) bdev->bd_inode->i_size;
+ if ((bs == 8192) && (x & 0x1E00))
+ bs = 4096;
+ if ((bs == 4096) && (x & 0x0E00))
+ bs = 2048;
+ if ((bs == 2048) && (x & 0x0600))
+ bs = 1024;
+ if ((bs == 1024) && (x & 0x0200))
+ bs = 512;
+ }
+ set_blocksize(bdev, bs);
+}
+
static int loop_set_fd(struct loop_device *lo, struct file *lo_file,
struct block_device *bdev, unsigned int arg)
{
struct file *file;
struct inode *inode;
struct block_device *lo_device = NULL;
- unsigned lo_blocksize;
int lo_flags = 0;
int error;
- /* This is safe, since we have a reference from open(). */
- __module_get(THIS_MODULE);
-
- error = -EBUSY;
- if (lo->lo_state != Lo_unbound)
- goto out;
-
error = -EBADF;
file = fget(arg);
if (!file)
@@ -684,30 +933,55 @@
if (!(file->f_mode & FMODE_WRITE))
lo_flags |= LO_FLAGS_READ_ONLY;
+ init_MUTEX_LOCKED(&lo->lo_sem);
+ spin_lock_init(&lo->lo_lock);
+ init_waitqueue_head(&lo->lo_bio_wait);
+ atomic_set(&lo->lo_pending, 0);
+ atomic_set(&lo->lo_bio_barr, 0);
+ lo->lo_offset = 0;
+ lo->lo_encrypt_type = 0;
+ lo->lo_encrypt_key_size = 0;
+ lo->transfer = NULL;
+ lo->lo_name[0] = 0;
+ lo->lo_init[1] = lo->lo_init[0] = 0;
+ lo->lo_key_owner = 0;
+ lo->ioctl = NULL;
+ lo->key_data = NULL;
+ lo->lo_bio_que2 = lo->lo_bio_que1 = lo->lo_bio_que0 = NULL;
+ lo->lo_bio_free1 = lo->lo_bio_free0 = NULL;
+ lo->lo_bio_flsh = lo->lo_bio_need = 0;
+ memset(&lo->key_reserved[0], 0, sizeof(lo->key_reserved));
+
if (S_ISBLK(inode->i_mode)) {
lo_device = inode->i_bdev;
if (lo_device == bdev) {
error = -EBUSY;
- goto out;
+ goto out_putf;
+ }
+ if (loop_prealloc_init(lo, 0)) {
+ error = -ENOMEM;
+ goto out_putf;
}
- lo_blocksize = block_size(lo_device);
if (bdev_read_only(lo_device))
lo_flags |= LO_FLAGS_READ_ONLY;
+ else
+ filemap_fdatawrite(inode->i_mapping);
} else if (S_ISREG(inode->i_mode)) {
- struct address_space_operations *aops = inode->i_mapping->a_ops;
/*
* If we can't read - sorry. If we only can't write - well,
* it's going to be read-only.
*/
- if (!inode->i_fop->sendfile)
+ if (!file->f_op || !file->f_op->read)
goto out_putf;
- if (!aops->prepare_write || !aops->commit_write)
+ if (!file->f_op->write)
lo_flags |= LO_FLAGS_READ_ONLY;
- lo_blocksize = inode->i_blksize;
lo_flags |= LO_FLAGS_DO_BMAP;
- error = 0;
+ if (loop_prealloc_init(lo, 1)) {
+ error = -ENOMEM;
+ goto out_putf;
+ }
} else
goto out_putf;
@@ -718,35 +992,28 @@
set_device_ro(bdev, (lo_flags & LO_FLAGS_READ_ONLY) != 0);
- lo->lo_blocksize = lo_blocksize;
lo->lo_device = lo_device;
lo->lo_flags = lo_flags;
lo->lo_backing_file = file;
- lo->transfer = NULL;
- lo->ioctl = NULL;
- if (figure_loop_size(lo)) {
+ if (figure_loop_size(lo, bdev, 0)) {
+ loop_prealloc_cleanup(lo);
error = -EFBIG;
fput(file);
goto out_putf;
}
- lo->old_gfp_mask = inode->i_mapping->gfp_mask;
- inode->i_mapping->gfp_mask &= ~(__GFP_IO|__GFP_FS);
-
- set_blocksize(bdev, lo_blocksize);
-
- lo->lo_bio = lo->lo_biotail = NULL;
/*
* set queue make_request_fn, and add limits based on lower level
* device
*/
- blk_queue_make_request(&lo->lo_queue, loop_make_request);
- lo->lo_queue.queuedata = lo;
+ blk_queue_make_request(&lo->lo_queue, loop_make_request_err);
+ blk_queue_bounce_limit(&lo->lo_queue, BLK_BOUNCE_HIGH);
+ blk_queue_max_segment_size(&lo->lo_queue, MAX_SEGMENT_SIZE);
/*
* we remap to a block device, make sure we correctly stack limits
*/
- if (S_ISBLK(inode->i_mode)) {
+ if (S_ISBLK(inode->i_mode) && lo_device) {
request_queue_t *q = bdev_get_queue(lo_device);
blk_queue_max_sectors(&lo->lo_queue, q->max_sectors);
@@ -755,8 +1022,21 @@
blk_queue_max_segment_size(&lo->lo_queue, q->max_segment_size);
blk_queue_segment_boundary(&lo->lo_queue, q->seg_boundary_mask);
blk_queue_merge_bvec(&lo->lo_queue, q->merge_bvec_fn);
+ blk_queue_hardsect_size(&lo->lo_queue, q->hardsect_size);
+ }
+ bdev->bd_openers++;
+ atomic_inc(&bdev->bd_count);
+ lo->lo_queue.queuedata = lo;
+
+ if (lo_flags & LO_FLAGS_DO_BMAP) {
+ lo->old_gfp_mask = inode->i_mapping->gfp_mask;
+ inode->i_mapping->gfp_mask = GFP_NOIO | __GFP_HIGH;
+ } else {
+ lo->old_gfp_mask = -1;
}
+ loop_set_softblksz(lo, bdev);
+
kernel_thread(loop_thread, lo, CLONE_FS | CLONE_FILES | CLONE_SIGHAND);
down(&lo->lo_sem);
@@ -766,8 +1046,6 @@
out_putf:
fput(file);
out:
- /* This is safe: open() is still holding a reference. */
- module_put(THIS_MODULE);
return error;
}
@@ -775,55 +1053,55 @@
{
int err = 0;
if (lo->lo_encrypt_type) {
- struct loop_func_table *xfer= xfer_funcs[lo->lo_encrypt_type];
+ struct loop_func_table *xfer = xfer_funcs[lo->lo_encrypt_type];
+ struct module *owner = xfer->owner;
+ lo->transfer = NULL;
if (xfer && xfer->release)
err = xfer->release(lo);
- if (xfer && xfer->unlock)
- xfer->unlock(lo);
lo->lo_encrypt_type = 0;
+ if (xfer)
+ module_put(owner);
}
return err;
}
-static int
-loop_init_xfer(struct loop_device *lo, int type, const struct loop_info64 *i)
+static int loop_init_xfer(struct loop_device *lo, int type, struct loop_info64 *i)
{
int err = 0;
if (type) {
- struct loop_func_table *xfer = xfer_funcs[type];
- if (xfer->init)
+ struct loop_func_table *xfer = xfer_funcs[type];
+ struct module *owner = xfer->owner;
+ if(!try_module_get(owner))
+ return -EINVAL;
+ if (xfer->init) {
err = xfer->init(lo, i);
- if (!err) {
- lo->lo_encrypt_type = type;
- if (xfer->lock)
- xfer->lock(lo);
+ if (err)
+ module_put(owner);
}
+ if (!err)
+ lo->lo_encrypt_type = type;
}
return err;
-}
+}
static int loop_clr_fd(struct loop_device *lo, struct block_device *bdev)
{
struct file *filp = lo->lo_backing_file;
int gfp = lo->old_gfp_mask;
- if (lo->lo_state != Lo_bound)
- return -ENXIO;
- if (lo->lo_refcnt > 1) /* we needed one fd for the ioctl */
+ if (bdev->bd_openers != 2) /* one for this fd being open plus one incremented by loop_set_fd */
return -EBUSY;
if (filp==NULL)
return -EINVAL;
- spin_lock_irq(&lo->lo_lock);
- lo->lo_state = Lo_rundown;
+ lo->lo_queue.queuedata = NULL;
+ lo->lo_queue.make_request_fn = loop_make_request_err;
if (atomic_dec_and_test(&lo->lo_pending))
- up(&lo->lo_bh_mutex);
- spin_unlock_irq(&lo->lo_lock);
-
+ wake_up_interruptible(&lo->lo_bio_wait);
down(&lo->lo_sem);
+ loop_prealloc_cleanup(lo);
lo->lo_backing_file = NULL;
-
loop_release_xfer(lo);
lo->transfer = NULL;
lo->ioctl = NULL;
@@ -832,21 +1110,22 @@
lo->lo_offset = 0;
lo->lo_encrypt_key_size = 0;
lo->lo_flags = 0;
- lo->lo_queue.queuedata = NULL;
+ lo->lo_init[1] = lo->lo_init[0] = 0;
+ lo->lo_key_owner = 0;
+ lo->key_data = NULL;
memset(lo->lo_encrypt_key, 0, LO_KEY_SIZE);
memset(lo->lo_name, 0, LO_NAME_SIZE);
invalidate_bdev(bdev, 0);
set_capacity(disks[lo->lo_number], 0);
- filp->f_dentry->d_inode->i_mapping->gfp_mask = gfp;
- lo->lo_state = Lo_unbound;
+ bdev->bd_openers--;
+ atomic_dec(&bdev->bd_count);
+ if (gfp != -1)
+ filp->f_dentry->d_inode->i_mapping->gfp_mask = gfp;
fput(filp);
- /* This is safe: open() is still holding a reference. */
- module_put(THIS_MODULE);
return 0;
}
-static int
-loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
+static int loop_set_status(struct loop_device *lo, struct block_device *bdev, struct loop_info64 *info)
{
int err;
unsigned int type;
@@ -855,10 +1134,9 @@
if (lo->lo_encrypt_key_size && lo->lo_key_owner != current->uid &&
!capable(CAP_SYS_ADMIN))
return -EPERM;
- if (lo->lo_state != Lo_bound)
- return -ENXIO;
if ((unsigned int) info->lo_encrypt_key_size > LO_KEY_SIZE)
return -EINVAL;
+
type = info->lo_encrypt_type;
if (type >= MAX_LO_CRYPT || xfer_funcs[type] == NULL)
return -EINVAL;
@@ -866,20 +1144,22 @@
return -EINVAL;
err = loop_release_xfer(lo);
- if (!err)
+ if (!err)
err = loop_init_xfer(lo, type, info);
offset = lo->lo_offset;
- if (offset != info->lo_offset) {
+ if ((offset != info->lo_offset) || info->lo_size) {
lo->lo_offset = info->lo_offset;
- if (figure_loop_size(lo)){
+ if (figure_loop_size(lo, bdev, info->lo_size)) {
err = -EFBIG;
lo->lo_offset = offset;
}
+ if (!err)
+ loop_set_softblksz(lo, bdev);
}
if (err)
- return err;
+ return err;
strlcpy(lo->lo_name, info->lo_name, LO_NAME_SIZE);
@@ -894,18 +1174,18 @@
lo->lo_key_owner = current->uid;
}
+ lo->lo_queue.make_request_fn = loop_make_request_real;
return 0;
}
static int
-loop_get_status(struct loop_device *lo, struct loop_info64 *info)
+loop_get_status(struct loop_device *lo, struct block_device *bdev,
+ struct loop_info64 *info)
{
struct file *file = lo->lo_backing_file;
struct kstat stat;
int error;
- if (lo->lo_state != Lo_bound)
- return -ENXIO;
error = vfs_getattr(file->f_vfsmnt, file->f_dentry, &stat);
if (error)
return error;
@@ -918,6 +1198,7 @@
info->lo_flags = lo->lo_flags;
strlcpy(info->lo_name, lo->lo_name, LO_NAME_SIZE);
info->lo_encrypt_type = lo->lo_encrypt_type;
+ info->lo_size = bdev->bd_inode->i_size;
if (lo->lo_encrypt_key_size && capable(CAP_SYS_ADMIN)) {
info->lo_encrypt_key_size = lo->lo_encrypt_key_size;
memcpy(info->lo_encrypt_key, lo->lo_encrypt_key,
@@ -929,6 +1210,7 @@
static void
loop_info64_from_old(const struct loop_info *info, struct loop_info64 *info64)
{
+ memset(info64, 0, sizeof(*info64));
info64->lo_number = info->lo_number;
info64->lo_device = info->lo_device;
info64->lo_inode = info->lo_inode;
@@ -944,8 +1226,9 @@
}
static int
-loop_info64_to_old(const struct loop_info64 *info64, struct loop_info *info)
+loop_info64_to_old(struct loop_info64 *info64, struct loop_info *info)
{
+ memset(info, 0, sizeof(*info));
info->lo_number = info64->lo_number;
info->lo_device = info64->lo_device;
info->lo_inode = info64->lo_inode;
@@ -970,7 +1253,7 @@
}
static int
-loop_set_status_old(struct loop_device *lo, const struct loop_info *arg)
+loop_set_status_old(struct loop_device *lo, struct block_device *bdev, const struct loop_info *arg)
{
struct loop_info info;
struct loop_info64 info64;
@@ -978,21 +1261,22 @@
if (copy_from_user(&info, arg, sizeof (struct loop_info)))
return -EFAULT;
loop_info64_from_old(&info, &info64);
- return loop_set_status(lo, &info64);
+ memset(&info.lo_encrypt_key[0], 0, sizeof(info.lo_encrypt_key));
+ return loop_set_status(lo, bdev, &info64);
}
static int
-loop_set_status64(struct loop_device *lo, const struct loop_info64 *arg)
+loop_set_status64(struct loop_device *lo, struct block_device *bdev, struct loop_info64 *arg)
{
struct loop_info64 info64;
if (copy_from_user(&info64, arg, sizeof (struct loop_info64)))
return -EFAULT;
- return loop_set_status(lo, &info64);
+ return loop_set_status(lo, bdev, &info64);
}
static int
-loop_get_status_old(struct loop_device *lo, struct loop_info *arg) {
+loop_get_status_old(struct loop_device *lo, struct block_device *bdev, struct loop_info *arg) {
struct loop_info info;
struct loop_info64 info64;
int err = 0;
@@ -1000,7 +1284,7 @@
if (!arg)
err = -EINVAL;
if (!err)
- err = loop_get_status(lo, &info64);
+ err = loop_get_status(lo, bdev, &info64);
if (!err)
err = loop_info64_to_old(&info64, &info);
if (!err && copy_to_user(arg, &info, sizeof(info)))
@@ -1010,14 +1294,14 @@
}
static int
-loop_get_status64(struct loop_device *lo, struct loop_info64 *arg) {
+loop_get_status64(struct loop_device *lo, struct block_device *bdev, struct loop_info64 *arg) {
struct loop_info64 info64;
int err = 0;
if (!arg)
err = -EINVAL;
if (!err)
- err = loop_get_status(lo, &info64);
+ err = loop_get_status(lo, bdev, &info64);
if (!err && copy_to_user(arg, &info64, sizeof(info64)))
err = -EFAULT;
@@ -1027,63 +1311,63 @@
static int lo_ioctl(struct inode * inode, struct file * file,
unsigned int cmd, unsigned long arg)
{
- struct loop_device *lo = inode->i_bdev->bd_disk->private_data;
+ struct block_device *bdev = inode->i_bdev;
+ struct loop_device *lo = bdev->bd_disk->private_data;
int err;
- down(&lo->lo_ctl_mutex);
+ down(&bdev->bd_sem);
+
+ /*
+ * LOOP_SET_FD can only be called when no device is attached.
+ * All other ioctls can only be called when a device is attached.
+ */
+ if (bdev->bd_disk->queue->queuedata != NULL) {
+ if (cmd == LOOP_SET_FD) {
+ err = -EBUSY;
+ goto out_err;
+ }
+ } else {
+ if (cmd != LOOP_SET_FD) {
+ err = -ENXIO;
+ goto out_err;
+ }
+ }
+
switch (cmd) {
case LOOP_SET_FD:
- err = loop_set_fd(lo, file, inode->i_bdev, arg);
+ err = loop_set_fd(lo, file, bdev, arg);
break;
case LOOP_CLR_FD:
- err = loop_clr_fd(lo, inode->i_bdev);
+ err = loop_clr_fd(lo, bdev);
break;
case LOOP_SET_STATUS:
- err = loop_set_status_old(lo, (struct loop_info *) arg);
+ err = loop_set_status_old(lo, bdev, (struct loop_info *) arg);
break;
case LOOP_GET_STATUS:
- err = loop_get_status_old(lo, (struct loop_info *) arg);
+ err = loop_get_status_old(lo, bdev, (struct loop_info *) arg);
break;
case LOOP_SET_STATUS64:
- err = loop_set_status64(lo, (struct loop_info64 *) arg);
+ err = loop_set_status64(lo, bdev, (struct loop_info64 *) arg);
break;
case LOOP_GET_STATUS64:
- err = loop_get_status64(lo, (struct loop_info64 *) arg);
+ err = loop_get_status64(lo, bdev, (struct loop_info64 *) arg);
break;
default:
err = lo->ioctl ? lo->ioctl(lo, cmd, arg) : -EINVAL;
}
- up(&lo->lo_ctl_mutex);
+out_err:
+ up(&bdev->bd_sem);
return err;
}
static int lo_open(struct inode *inode, struct file *file)
{
- struct loop_device *lo = inode->i_bdev->bd_disk->private_data;
- int type;
-
- down(&lo->lo_ctl_mutex);
-
- type = lo->lo_encrypt_type;
- if (type && xfer_funcs[type] && xfer_funcs[type]->lock)
- xfer_funcs[type]->lock(lo);
- lo->lo_refcnt++;
- up(&lo->lo_ctl_mutex);
return 0;
}
static int lo_release(struct inode *inode, struct file *file)
{
- struct loop_device *lo = inode->i_bdev->bd_disk->private_data;
- int type;
-
- down(&lo->lo_ctl_mutex);
- type = lo->lo_encrypt_type;
- --lo->lo_refcnt;
- if (xfer_funcs[type] && xfer_funcs[type]->unlock)
- xfer_funcs[type]->unlock(lo);
-
- up(&lo->lo_ctl_mutex);
+ sync_blockdev(inode->i_bdev);
return 0;
}
@@ -1103,7 +1387,7 @@
int loop_register_transfer(struct loop_func_table *funcs)
{
- if ((unsigned)funcs->number > MAX_LO_CRYPT || xfer_funcs[funcs->number])
+ if ((unsigned)funcs->number >= MAX_LO_CRYPT || xfer_funcs[funcs->number])
return -EINVAL;
xfer_funcs[funcs->number] = funcs;
return 0;
@@ -1112,18 +1396,20 @@
int loop_unregister_transfer(int number)
{
struct loop_device *lo;
+ int x, type;
if ((unsigned)number >= MAX_LO_CRYPT)
return -EINVAL;
- for (lo = &loop_dev[0]; lo < &loop_dev[max_loop]; lo++) {
- int type = lo->lo_encrypt_type;
- if (type == number) {
- xfer_funcs[type]->release(lo);
- lo->transfer = NULL;
- lo->lo_encrypt_type = 0;
+ for (x = 0; x < max_loop; x++) {
+ lo = loop_dev_ptr_arr[x];
+ if (!lo)
+ continue;
+ type = lo->lo_encrypt_type;
+ if (type == number) {
+ loop_release_xfer(lo);
}
}
- xfer_funcs[number] = NULL;
+ xfer_funcs[number] = NULL;
return 0;
}
@@ -1143,31 +1429,42 @@
if (register_blkdev(LOOP_MAJOR, "loop"))
return -EIO;
- devfs_mk_dir("loop");
-
- loop_dev = kmalloc(max_loop * sizeof(struct loop_device), GFP_KERNEL);
- if (!loop_dev)
- return -ENOMEM;
+ loop_dev_ptr_arr = kmalloc(max_loop * sizeof(struct loop_device *), GFP_KERNEL);
+ if (!loop_dev_ptr_arr)
+ goto out_mem1;
disks = kmalloc(max_loop * sizeof(struct gendisk *), GFP_KERNEL);
if (!disks)
- goto out_mem;
+ goto out_mem2;
+
+ for (i = 0; i < max_loop; i++) {
+ loop_dev_ptr_arr[i] = kmalloc(sizeof(struct loop_device), GFP_KERNEL);
+ if (!loop_dev_ptr_arr[i])
+ goto out_mem3;
+ }
for (i = 0; i < max_loop; i++) {
disks[i] = alloc_disk(1);
if (!disks[i])
- goto out_mem2;
+ goto out_mem4;
}
+ for (i = 0; i < (sizeof(lo_prealloc) / sizeof(int)); i += 2) {
+ if (!lo_prealloc[i])
+ continue;
+ if (lo_prealloc[i] < LO_PREALLOC_MIN)
+ lo_prealloc[i] = LO_PREALLOC_MIN;
+ if (lo_prealloc[i] > LO_PREALLOC_MAX)
+ lo_prealloc[i] = LO_PREALLOC_MAX;
+ }
+
+ devfs_mk_dir("loop");
+
for (i = 0; i < max_loop; i++) {
- struct loop_device *lo = &loop_dev[i];
+ struct loop_device *lo = loop_dev_ptr_arr[i];
struct gendisk *disk = disks[i];
- memset(lo, 0, sizeof(*lo));
- init_MUTEX(&lo->lo_ctl_mutex);
- init_MUTEX_LOCKED(&lo->lo_sem);
- init_MUTEX_LOCKED(&lo->lo_bh_mutex);
+ memset(lo, 0, sizeof(struct loop_device));
lo->lo_number = i;
- spin_lock_init(&lo->lo_lock);
disk->major = LOOP_MAJOR;
disk->first_minor = i;
disk->fops = &lo_fops;
@@ -1177,32 +1474,39 @@
disk->queue = &lo->lo_queue;
add_disk(disk);
}
+
printk(KERN_INFO "loop: loaded (max %d devices)\n", max_loop);
return 0;
-out_mem2:
+out_mem4:
while (i--)
put_disk(disks[i]);
+ i = max_loop;
+out_mem3:
+ while (i--)
+ kfree(loop_dev_ptr_arr[i]);
kfree(disks);
-out_mem:
- kfree(loop_dev);
+out_mem2:
+ kfree(loop_dev_ptr_arr);
+out_mem1:
+ unregister_blkdev(LOOP_MAJOR, "loop");
printk(KERN_ERR "loop: ran out of memory\n");
return -ENOMEM;
}
-void loop_exit(void)
+void loop_exit(void)
{
int i;
+
for (i = 0; i < max_loop; i++) {
del_gendisk(disks[i]);
put_disk(disks[i]);
+ kfree(loop_dev_ptr_arr[i]);
}
devfs_remove("loop");
- if (unregister_blkdev(LOOP_MAJOR, "loop"))
- printk(KERN_WARNING "loop: cannot unregister blkdev\n");
-
+ unregister_blkdev(LOOP_MAJOR, "loop");
kfree(disks);
- kfree(loop_dev);
+ kfree(loop_dev_ptr_arr);
}
module_init(loop_init);
diff -u --recursive --new-file -X /linux/dontdiff a/include/linux/loop.h b/include/linux/loop.h
--- a/include/linux/loop.h Sun Jun 15 01:41:06 2003
+++ b/include/linux/loop.h Sat Jun 21 16:36:53 2003
@@ -15,18 +15,19 @@
#ifdef __KERNEL__
-/* Possible states of device */
-enum {
- Lo_unbound,
- Lo_bound,
- Lo_rundown,
-};
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/module.h>
+
+/* definitions for IV metric -- cryptoapi specific */
+#define LOOP_IV_SECTOR_BITS 9
+#define LOOP_IV_SECTOR_SIZE (1 << LOOP_IV_SECTOR_BITS)
+typedef sector_t loop_iv_t;
struct loop_device {
int lo_number;
- int lo_refcnt;
- int lo_offset;
int lo_encrypt_type;
+ loff_t lo_offset;
int lo_encrypt_key_size;
int lo_flags;
int (*transfer)(struct loop_device *, int cmd,
@@ -41,28 +42,28 @@
struct file * lo_backing_file;
struct block_device *lo_device;
- unsigned lo_blocksize;
void *key_data;
char key_reserved[48]; /* for use by the filter modules */
int old_gfp_mask;
spinlock_t lo_lock;
- struct bio *lo_bio;
- struct bio *lo_biotail;
- int lo_state;
struct semaphore lo_sem;
- struct semaphore lo_ctl_mutex;
- struct semaphore lo_bh_mutex;
atomic_t lo_pending;
+ struct bio *lo_bio_que0;
+ struct bio *lo_bio_que1;
+ struct bio *lo_bio_que2;
+ struct bio *lo_bio_free0;
+ struct bio *lo_bio_free1;
+ atomic_t lo_bio_barr;
+ int lo_bio_flsh;
+ int lo_bio_need;
+ wait_queue_head_t lo_bio_wait;
+
request_queue_t lo_queue;
};
-typedef int (* transfer_proc_t)(struct loop_device *, int cmd,
- char *raw_buf, char *loop_buf, int size,
- int real_block);
-
#endif /* __KERNEL__ */
/*
@@ -102,6 +103,7 @@
__u8 lo_name[LO_NAME_SIZE];
__u8 lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
__u64 lo_init[2];
+ __u64 lo_size; /* bytes, 0 == max available */
};
/*
@@ -117,6 +119,8 @@
#define LO_CRYPT_IDEA 6
#define LO_CRYPT_DUMMY 9
#define LO_CRYPT_SKIPJACK 10
+#define LO_CRYPT_AES 16
+#define LO_CRYPT_CRYPTOAPI 18
#define MAX_LO_CRYPT 20
#ifdef __KERNEL__
@@ -125,13 +129,11 @@
int number; /* filter type */
int (*transfer)(struct loop_device *lo, int cmd, char *raw_buf,
char *loop_buf, int size, sector_t real_block);
- int (*init)(struct loop_device *, const struct loop_info64 *);
+ int (*init)(struct loop_device *, struct loop_info64 *);
/* release is called from loop_unregister_transfer or clr_fd */
int (*release)(struct loop_device *);
int (*ioctl)(struct loop_device *, int cmd, unsigned long arg);
- /* lock and unlock manage the module use counts */
- void (*lock)(struct loop_device *);
- void (*unlock)(struct loop_device *);
+ struct module *owner;
};
int loop_register_transfer(struct loop_func_table *funcs);
-
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