| /* |
| * bitmap.c two-level bitmap (C) Peter T. Breuer (ptb@ot.uc3m.es) 2003 |
| * |
| * bitmap_create - sets up the bitmap structure |
| * bitmap_destroy - destroys the bitmap structure |
| * |
| * additions, Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.: |
| * - added disk storage for bitmap |
| * - changes to allow various bitmap chunk sizes |
| */ |
| |
| /* |
| * Still to do: |
| * |
| * flush after percent set rather than just time based. (maybe both). |
| * wait if count gets too high, wake when it drops to half. |
| */ |
| |
| #include <linux/blkdev.h> |
| #include <linux/module.h> |
| #include <linux/errno.h> |
| #include <linux/slab.h> |
| #include <linux/init.h> |
| #include <linux/timer.h> |
| #include <linux/sched.h> |
| #include <linux/list.h> |
| #include <linux/file.h> |
| #include <linux/mount.h> |
| #include <linux/buffer_head.h> |
| #include "md.h" |
| #include "bitmap.h" |
| |
| /* debug macros */ |
| |
| #define DEBUG 0 |
| |
| #if DEBUG |
| /* these are for debugging purposes only! */ |
| |
| /* define one and only one of these */ |
| #define INJECT_FAULTS_1 0 /* cause bitmap_alloc_page to fail always */ |
| #define INJECT_FAULTS_2 0 /* cause bitmap file to be kicked when first bit set*/ |
| #define INJECT_FAULTS_3 0 /* treat bitmap file as kicked at init time */ |
| #define INJECT_FAULTS_4 0 /* undef */ |
| #define INJECT_FAULTS_5 0 /* undef */ |
| #define INJECT_FAULTS_6 0 |
| |
| /* if these are defined, the driver will fail! debug only */ |
| #define INJECT_FATAL_FAULT_1 0 /* fail kmalloc, causing bitmap_create to fail */ |
| #define INJECT_FATAL_FAULT_2 0 /* undef */ |
| #define INJECT_FATAL_FAULT_3 0 /* undef */ |
| #endif |
| |
| //#define DPRINTK PRINTK /* set this NULL to avoid verbose debug output */ |
| #define DPRINTK(x...) do { } while(0) |
| |
| #ifndef PRINTK |
| # if DEBUG > 0 |
| # define PRINTK(x...) printk(KERN_DEBUG x) |
| # else |
| # define PRINTK(x...) |
| # endif |
| #endif |
| |
| static inline char * bmname(struct bitmap *bitmap) |
| { |
| return bitmap->mddev ? mdname(bitmap->mddev) : "mdX"; |
| } |
| |
| |
| /* |
| * just a placeholder - calls kmalloc for bitmap pages |
| */ |
| static unsigned char *bitmap_alloc_page(struct bitmap *bitmap) |
| { |
| unsigned char *page; |
| |
| #ifdef INJECT_FAULTS_1 |
| page = NULL; |
| #else |
| page = kmalloc(PAGE_SIZE, GFP_NOIO); |
| #endif |
| if (!page) |
| printk("%s: bitmap_alloc_page FAILED\n", bmname(bitmap)); |
| else |
| PRINTK("%s: bitmap_alloc_page: allocated page at %p\n", |
| bmname(bitmap), page); |
| return page; |
| } |
| |
| /* |
| * for now just a placeholder -- just calls kfree for bitmap pages |
| */ |
| static void bitmap_free_page(struct bitmap *bitmap, unsigned char *page) |
| { |
| PRINTK("%s: bitmap_free_page: free page %p\n", bmname(bitmap), page); |
| kfree(page); |
| } |
| |
| /* |
| * check a page and, if necessary, allocate it (or hijack it if the alloc fails) |
| * |
| * 1) check to see if this page is allocated, if it's not then try to alloc |
| * 2) if the alloc fails, set the page's hijacked flag so we'll use the |
| * page pointer directly as a counter |
| * |
| * if we find our page, we increment the page's refcount so that it stays |
| * allocated while we're using it |
| */ |
| static int bitmap_checkpage(struct bitmap *bitmap, unsigned long page, int create) |
| __releases(bitmap->lock) |
| __acquires(bitmap->lock) |
| { |
| unsigned char *mappage; |
| |
| if (page >= bitmap->pages) { |
| /* This can happen if bitmap_start_sync goes beyond |
| * End-of-device while looking for a whole page. |
| * It is harmless. |
| */ |
| return -EINVAL; |
| } |
| |
| |
| if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */ |
| return 0; |
| |
| if (bitmap->bp[page].map) /* page is already allocated, just return */ |
| return 0; |
| |
| if (!create) |
| return -ENOENT; |
| |
| spin_unlock_irq(&bitmap->lock); |
| |
| /* this page has not been allocated yet */ |
| |
| if ((mappage = bitmap_alloc_page(bitmap)) == NULL) { |
| PRINTK("%s: bitmap map page allocation failed, hijacking\n", |
| bmname(bitmap)); |
| /* failed - set the hijacked flag so that we can use the |
| * pointer as a counter */ |
| spin_lock_irq(&bitmap->lock); |
| if (!bitmap->bp[page].map) |
| bitmap->bp[page].hijacked = 1; |
| goto out; |
| } |
| |
| /* got a page */ |
| |
| spin_lock_irq(&bitmap->lock); |
| |
| /* recheck the page */ |
| |
| if (bitmap->bp[page].map || bitmap->bp[page].hijacked) { |
| /* somebody beat us to getting the page */ |
| bitmap_free_page(bitmap, mappage); |
| return 0; |
| } |
| |
| /* no page was in place and we have one, so install it */ |
| |
| memset(mappage, 0, PAGE_SIZE); |
| bitmap->bp[page].map = mappage; |
| bitmap->missing_pages--; |
| out: |
| return 0; |
| } |
| |
| |
| /* if page is completely empty, put it back on the free list, or dealloc it */ |
| /* if page was hijacked, unmark the flag so it might get alloced next time */ |
| /* Note: lock should be held when calling this */ |
| static void bitmap_checkfree(struct bitmap *bitmap, unsigned long page) |
| { |
| char *ptr; |
| |
| if (bitmap->bp[page].count) /* page is still busy */ |
| return; |
| |
| /* page is no longer in use, it can be released */ |
| |
| if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */ |
| bitmap->bp[page].hijacked = 0; |
| bitmap->bp[page].map = NULL; |
| return; |
| } |
| |
| /* normal case, free the page */ |
| |
| #if 0 |
| /* actually ... let's not. We will probably need the page again exactly when |
| * memory is tight and we are flusing to disk |
| */ |
| return; |
| #else |
| ptr = bitmap->bp[page].map; |
| bitmap->bp[page].map = NULL; |
| bitmap->missing_pages++; |
| bitmap_free_page(bitmap, ptr); |
| return; |
| #endif |
| } |
| |
| |
| /* |
| * bitmap file handling - read and write the bitmap file and its superblock |
| */ |
| |
| /* |
| * basic page I/O operations |
| */ |
| |
| /* IO operations when bitmap is stored near all superblocks */ |
| static struct page *read_sb_page(mddev_t *mddev, long offset, |
| struct page *page, |
| unsigned long index, int size) |
| { |
| /* choose a good rdev and read the page from there */ |
| |
| mdk_rdev_t *rdev; |
| sector_t target; |
| |
| if (!page) |
| page = alloc_page(GFP_KERNEL); |
| if (!page) |
| return ERR_PTR(-ENOMEM); |
| |
| list_for_each_entry(rdev, &mddev->disks, same_set) { |
| if (! test_bit(In_sync, &rdev->flags) |
| || test_bit(Faulty, &rdev->flags)) |
| continue; |
| |
| target = rdev->sb_start + offset + index * (PAGE_SIZE/512); |
| |
| if (sync_page_io(rdev->bdev, target, |
| roundup(size, bdev_logical_block_size(rdev->bdev)), |
| page, READ)) { |
| page->index = index; |
| attach_page_buffers(page, NULL); /* so that free_buffer will |
| * quietly no-op */ |
| return page; |
| } |
| } |
| return ERR_PTR(-EIO); |
| |
| } |
| |
| static mdk_rdev_t *next_active_rdev(mdk_rdev_t *rdev, mddev_t *mddev) |
| { |
| /* Iterate the disks of an mddev, using rcu to protect access to the |
| * linked list, and raising the refcount of devices we return to ensure |
| * they don't disappear while in use. |
| * As devices are only added or removed when raid_disk is < 0 and |
| * nr_pending is 0 and In_sync is clear, the entries we return will |
| * still be in the same position on the list when we re-enter |
| * list_for_each_continue_rcu. |
| */ |
| struct list_head *pos; |
| rcu_read_lock(); |
| if (rdev == NULL) |
| /* start at the beginning */ |
| pos = &mddev->disks; |
| else { |
| /* release the previous rdev and start from there. */ |
| rdev_dec_pending(rdev, mddev); |
| pos = &rdev->same_set; |
| } |
| list_for_each_continue_rcu(pos, &mddev->disks) { |
| rdev = list_entry(pos, mdk_rdev_t, same_set); |
| if (rdev->raid_disk >= 0 && |
| !test_bit(Faulty, &rdev->flags)) { |
| /* this is a usable devices */ |
| atomic_inc(&rdev->nr_pending); |
| rcu_read_unlock(); |
| return rdev; |
| } |
| } |
| rcu_read_unlock(); |
| return NULL; |
| } |
| |
| static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait) |
| { |
| mdk_rdev_t *rdev = NULL; |
| mddev_t *mddev = bitmap->mddev; |
| |
| while ((rdev = next_active_rdev(rdev, mddev)) != NULL) { |
| int size = PAGE_SIZE; |
| if (page->index == bitmap->file_pages-1) |
| size = roundup(bitmap->last_page_size, |
| bdev_logical_block_size(rdev->bdev)); |
| /* Just make sure we aren't corrupting data or |
| * metadata |
| */ |
| if (bitmap->offset < 0) { |
| /* DATA BITMAP METADATA */ |
| if (bitmap->offset |
| + (long)(page->index * (PAGE_SIZE/512)) |
| + size/512 > 0) |
| /* bitmap runs in to metadata */ |
| goto bad_alignment; |
| if (rdev->data_offset + mddev->dev_sectors |
| > rdev->sb_start + bitmap->offset) |
| /* data runs in to bitmap */ |
| goto bad_alignment; |
| } else if (rdev->sb_start < rdev->data_offset) { |
| /* METADATA BITMAP DATA */ |
| if (rdev->sb_start |
| + bitmap->offset |
| + page->index*(PAGE_SIZE/512) + size/512 |
| > rdev->data_offset) |
| /* bitmap runs in to data */ |
| goto bad_alignment; |
| } else { |
| /* DATA METADATA BITMAP - no problems */ |
| } |
| md_super_write(mddev, rdev, |
| rdev->sb_start + bitmap->offset |
| + page->index * (PAGE_SIZE/512), |
| size, |
| page); |
| } |
| |
| if (wait) |
| md_super_wait(mddev); |
| return 0; |
| |
| bad_alignment: |
| return -EINVAL; |
| } |
| |
| static void bitmap_file_kick(struct bitmap *bitmap); |
| /* |
| * write out a page to a file |
| */ |
| static void write_page(struct bitmap *bitmap, struct page *page, int wait) |
| { |
| struct buffer_head *bh; |
| |
| if (bitmap->file == NULL) { |
| switch (write_sb_page(bitmap, page, wait)) { |
| case -EINVAL: |
| bitmap->flags |= BITMAP_WRITE_ERROR; |
| } |
| } else { |
| |
| bh = page_buffers(page); |
| |
| while (bh && bh->b_blocknr) { |
| atomic_inc(&bitmap->pending_writes); |
| set_buffer_locked(bh); |
| set_buffer_mapped(bh); |
| submit_bh(WRITE, bh); |
| bh = bh->b_this_page; |
| } |
| |
| if (wait) { |
| wait_event(bitmap->write_wait, |
| atomic_read(&bitmap->pending_writes)==0); |
| } |
| } |
| if (bitmap->flags & BITMAP_WRITE_ERROR) |
| bitmap_file_kick(bitmap); |
| } |
| |
| static void end_bitmap_write(struct buffer_head *bh, int uptodate) |
| { |
| struct bitmap *bitmap = bh->b_private; |
| unsigned long flags; |
| |
| if (!uptodate) { |
| spin_lock_irqsave(&bitmap->lock, flags); |
| bitmap->flags |= BITMAP_WRITE_ERROR; |
| spin_unlock_irqrestore(&bitmap->lock, flags); |
| } |
| if (atomic_dec_and_test(&bitmap->pending_writes)) |
| wake_up(&bitmap->write_wait); |
| } |
| |
| /* copied from buffer.c */ |
| static void |
| __clear_page_buffers(struct page *page) |
| { |
| ClearPagePrivate(page); |
| set_page_private(page, 0); |
| page_cache_release(page); |
| } |
| static void free_buffers(struct page *page) |
| { |
| struct buffer_head *bh = page_buffers(page); |
| |
| while (bh) { |
| struct buffer_head *next = bh->b_this_page; |
| free_buffer_head(bh); |
| bh = next; |
| } |
| __clear_page_buffers(page); |
| put_page(page); |
| } |
| |
| /* read a page from a file. |
| * We both read the page, and attach buffers to the page to record the |
| * address of each block (using bmap). These addresses will be used |
| * to write the block later, completely bypassing the filesystem. |
| * This usage is similar to how swap files are handled, and allows us |
| * to write to a file with no concerns of memory allocation failing. |
| */ |
| static struct page *read_page(struct file *file, unsigned long index, |
| struct bitmap *bitmap, |
| unsigned long count) |
| { |
| struct page *page = NULL; |
| struct inode *inode = file->f_path.dentry->d_inode; |
| struct buffer_head *bh; |
| sector_t block; |
| |
| PRINTK("read bitmap file (%dB @ %Lu)\n", (int)PAGE_SIZE, |
| (unsigned long long)index << PAGE_SHIFT); |
| |
| page = alloc_page(GFP_KERNEL); |
| if (!page) |
| page = ERR_PTR(-ENOMEM); |
| if (IS_ERR(page)) |
| goto out; |
| |
| bh = alloc_page_buffers(page, 1<<inode->i_blkbits, 0); |
| if (!bh) { |
| put_page(page); |
| page = ERR_PTR(-ENOMEM); |
| goto out; |
| } |
| attach_page_buffers(page, bh); |
| block = index << (PAGE_SHIFT - inode->i_blkbits); |
| while (bh) { |
| if (count == 0) |
| bh->b_blocknr = 0; |
| else { |
| bh->b_blocknr = bmap(inode, block); |
| if (bh->b_blocknr == 0) { |
| /* Cannot use this file! */ |
| free_buffers(page); |
| page = ERR_PTR(-EINVAL); |
| goto out; |
| } |
| bh->b_bdev = inode->i_sb->s_bdev; |
| if (count < (1<<inode->i_blkbits)) |
| count = 0; |
| else |
| count -= (1<<inode->i_blkbits); |
| |
| bh->b_end_io = end_bitmap_write; |
| bh->b_private = bitmap; |
| atomic_inc(&bitmap->pending_writes); |
| set_buffer_locked(bh); |
| set_buffer_mapped(bh); |
| submit_bh(READ, bh); |
| } |
| block++; |
| bh = bh->b_this_page; |
| } |
| page->index = index; |
| |
| wait_event(bitmap->write_wait, |
| atomic_read(&bitmap->pending_writes)==0); |
| if (bitmap->flags & BITMAP_WRITE_ERROR) { |
| free_buffers(page); |
| page = ERR_PTR(-EIO); |
| } |
| out: |
| if (IS_ERR(page)) |
| printk(KERN_ALERT "md: bitmap read error: (%dB @ %Lu): %ld\n", |
| (int)PAGE_SIZE, |
| (unsigned long long)index << PAGE_SHIFT, |
| PTR_ERR(page)); |
| return page; |
| } |
| |
| /* |
| * bitmap file superblock operations |
| */ |
| |
| /* update the event counter and sync the superblock to disk */ |
| void bitmap_update_sb(struct bitmap *bitmap) |
| { |
| bitmap_super_t *sb; |
| unsigned long flags; |
| |
| if (!bitmap || !bitmap->mddev) /* no bitmap for this array */ |
| return; |
| spin_lock_irqsave(&bitmap->lock, flags); |
| if (!bitmap->sb_page) { /* no superblock */ |
| spin_unlock_irqrestore(&bitmap->lock, flags); |
| return; |
| } |
| spin_unlock_irqrestore(&bitmap->lock, flags); |
| sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0); |
| sb->events = cpu_to_le64(bitmap->mddev->events); |
| if (bitmap->mddev->events < bitmap->events_cleared) { |
| /* rocking back to read-only */ |
| bitmap->events_cleared = bitmap->mddev->events; |
| sb->events_cleared = cpu_to_le64(bitmap->events_cleared); |
| } |
| kunmap_atomic(sb, KM_USER0); |
| write_page(bitmap, bitmap->sb_page, 1); |
| } |
| |
| /* print out the bitmap file superblock */ |
| void bitmap_print_sb(struct bitmap *bitmap) |
| { |
| bitmap_super_t *sb; |
| |
| if (!bitmap || !bitmap->sb_page) |
| return; |
| sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0); |
| printk(KERN_DEBUG "%s: bitmap file superblock:\n", bmname(bitmap)); |
| printk(KERN_DEBUG " magic: %08x\n", le32_to_cpu(sb->magic)); |
| printk(KERN_DEBUG " version: %d\n", le32_to_cpu(sb->version)); |
| printk(KERN_DEBUG " uuid: %08x.%08x.%08x.%08x\n", |
| *(__u32 *)(sb->uuid+0), |
| *(__u32 *)(sb->uuid+4), |
| *(__u32 *)(sb->uuid+8), |
| *(__u32 *)(sb->uuid+12)); |
| printk(KERN_DEBUG " events: %llu\n", |
| (unsigned long long) le64_to_cpu(sb->events)); |
| printk(KERN_DEBUG "events cleared: %llu\n", |
| (unsigned long long) le64_to_cpu(sb->events_cleared)); |
| printk(KERN_DEBUG " state: %08x\n", le32_to_cpu(sb->state)); |
| printk(KERN_DEBUG " chunksize: %d B\n", le32_to_cpu(sb->chunksize)); |
| printk(KERN_DEBUG " daemon sleep: %ds\n", le32_to_cpu(sb->daemon_sleep)); |
| printk(KERN_DEBUG " sync size: %llu KB\n", |
| (unsigned long long)le64_to_cpu(sb->sync_size)/2); |
| printk(KERN_DEBUG "max write behind: %d\n", le32_to_cpu(sb->write_behind)); |
| kunmap_atomic(sb, KM_USER0); |
| } |
| |
| /* read the superblock from the bitmap file and initialize some bitmap fields */ |
| static int bitmap_read_sb(struct bitmap *bitmap) |
| { |
| char *reason = NULL; |
| bitmap_super_t *sb; |
| unsigned long chunksize, daemon_sleep, write_behind; |
| unsigned long long events; |
| int err = -EINVAL; |
| |
| /* page 0 is the superblock, read it... */ |
| if (bitmap->file) { |
| loff_t isize = i_size_read(bitmap->file->f_mapping->host); |
| int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize; |
| |
| bitmap->sb_page = read_page(bitmap->file, 0, bitmap, bytes); |
| } else { |
| bitmap->sb_page = read_sb_page(bitmap->mddev, bitmap->offset, |
| NULL, |
| 0, sizeof(bitmap_super_t)); |
| } |
| if (IS_ERR(bitmap->sb_page)) { |
| err = PTR_ERR(bitmap->sb_page); |
| bitmap->sb_page = NULL; |
| return err; |
| } |
| |
| sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0); |
| |
| chunksize = le32_to_cpu(sb->chunksize); |
| daemon_sleep = le32_to_cpu(sb->daemon_sleep); |
| write_behind = le32_to_cpu(sb->write_behind); |
| |
| /* verify that the bitmap-specific fields are valid */ |
| if (sb->magic != cpu_to_le32(BITMAP_MAGIC)) |
| reason = "bad magic"; |
| else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO || |
| le32_to_cpu(sb->version) > BITMAP_MAJOR_HI) |
| reason = "unrecognized superblock version"; |
| else if (chunksize < 512) |
| reason = "bitmap chunksize too small"; |
| else if ((1 << ffz(~chunksize)) != chunksize) |
| reason = "bitmap chunksize not a power of 2"; |
| else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT / HZ) |
| reason = "daemon sleep period out of range"; |
| else if (write_behind > COUNTER_MAX) |
| reason = "write-behind limit out of range (0 - 16383)"; |
| if (reason) { |
| printk(KERN_INFO "%s: invalid bitmap file superblock: %s\n", |
| bmname(bitmap), reason); |
| goto out; |
| } |
| |
| /* keep the array size field of the bitmap superblock up to date */ |
| sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors); |
| |
| if (!bitmap->mddev->persistent) |
| goto success; |
| |
| /* |
| * if we have a persistent array superblock, compare the |
| * bitmap's UUID and event counter to the mddev's |
| */ |
| if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) { |
| printk(KERN_INFO "%s: bitmap superblock UUID mismatch\n", |
| bmname(bitmap)); |
| goto out; |
| } |
| events = le64_to_cpu(sb->events); |
| if (events < bitmap->mddev->events) { |
| printk(KERN_INFO "%s: bitmap file is out of date (%llu < %llu) " |
| "-- forcing full recovery\n", bmname(bitmap), events, |
| (unsigned long long) bitmap->mddev->events); |
| sb->state |= cpu_to_le32(BITMAP_STALE); |
| } |
| success: |
| /* assign fields using values from superblock */ |
| bitmap->chunksize = chunksize; |
| bitmap->daemon_sleep = daemon_sleep; |
| bitmap->daemon_lastrun = jiffies; |
| bitmap->max_write_behind = write_behind; |
| bitmap->flags |= le32_to_cpu(sb->state); |
| if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN) |
| bitmap->flags |= BITMAP_HOSTENDIAN; |
| bitmap->events_cleared = le64_to_cpu(sb->events_cleared); |
| if (sb->state & cpu_to_le32(BITMAP_STALE)) |
| bitmap->events_cleared = bitmap->mddev->events; |
| err = 0; |
| out: |
| kunmap_atomic(sb, KM_USER0); |
| if (err) |
| bitmap_print_sb(bitmap); |
| return err; |
| } |
| |
| enum bitmap_mask_op { |
| MASK_SET, |
| MASK_UNSET |
| }; |
| |
| /* record the state of the bitmap in the superblock. Return the old value */ |
| static int bitmap_mask_state(struct bitmap *bitmap, enum bitmap_state bits, |
| enum bitmap_mask_op op) |
| { |
| bitmap_super_t *sb; |
| unsigned long flags; |
| int old; |
| |
| spin_lock_irqsave(&bitmap->lock, flags); |
| if (!bitmap->sb_page) { /* can't set the state */ |
| spin_unlock_irqrestore(&bitmap->lock, flags); |
| return 0; |
| } |
| spin_unlock_irqrestore(&bitmap->lock, flags); |
| sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0); |
| old = le32_to_cpu(sb->state) & bits; |
| switch (op) { |
| case MASK_SET: sb->state |= cpu_to_le32(bits); |
| break; |
| case MASK_UNSET: sb->state &= cpu_to_le32(~bits); |
| break; |
| default: BUG(); |
| } |
| kunmap_atomic(sb, KM_USER0); |
| return old; |
| } |
| |
| /* |
| * general bitmap file operations |
| */ |
| |
| /* calculate the index of the page that contains this bit */ |
| static inline unsigned long file_page_index(unsigned long chunk) |
| { |
| return CHUNK_BIT_OFFSET(chunk) >> PAGE_BIT_SHIFT; |
| } |
| |
| /* calculate the (bit) offset of this bit within a page */ |
| static inline unsigned long file_page_offset(unsigned long chunk) |
| { |
| return CHUNK_BIT_OFFSET(chunk) & (PAGE_BITS - 1); |
| } |
| |
| /* |
| * return a pointer to the page in the filemap that contains the given bit |
| * |
| * this lookup is complicated by the fact that the bitmap sb might be exactly |
| * 1 page (e.g., x86) or less than 1 page -- so the bitmap might start on page |
| * 0 or page 1 |
| */ |
| static inline struct page *filemap_get_page(struct bitmap *bitmap, |
| unsigned long chunk) |
| { |
| if (file_page_index(chunk) >= bitmap->file_pages) return NULL; |
| return bitmap->filemap[file_page_index(chunk) - file_page_index(0)]; |
| } |
| |
| |
| static void bitmap_file_unmap(struct bitmap *bitmap) |
| { |
| struct page **map, *sb_page; |
| unsigned long *attr; |
| int pages; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&bitmap->lock, flags); |
| map = bitmap->filemap; |
| bitmap->filemap = NULL; |
| attr = bitmap->filemap_attr; |
| bitmap->filemap_attr = NULL; |
| pages = bitmap->file_pages; |
| bitmap->file_pages = 0; |
| sb_page = bitmap->sb_page; |
| bitmap->sb_page = NULL; |
| spin_unlock_irqrestore(&bitmap->lock, flags); |
| |
| while (pages--) |
| if (map[pages]->index != 0) /* 0 is sb_page, release it below */ |
| free_buffers(map[pages]); |
| kfree(map); |
| kfree(attr); |
| |
| if (sb_page) |
| free_buffers(sb_page); |
| } |
| |
| static void bitmap_file_put(struct bitmap *bitmap) |
| { |
| struct file *file; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&bitmap->lock, flags); |
| file = bitmap->file; |
| bitmap->file = NULL; |
| spin_unlock_irqrestore(&bitmap->lock, flags); |
| |
| if (file) |
| wait_event(bitmap->write_wait, |
| atomic_read(&bitmap->pending_writes)==0); |
| bitmap_file_unmap(bitmap); |
| |
| if (file) { |
| struct inode *inode = file->f_path.dentry->d_inode; |
| invalidate_mapping_pages(inode->i_mapping, 0, -1); |
| fput(file); |
| } |
| } |
| |
| |
| /* |
| * bitmap_file_kick - if an error occurs while manipulating the bitmap file |
| * then it is no longer reliable, so we stop using it and we mark the file |
| * as failed in the superblock |
| */ |
| static void bitmap_file_kick(struct bitmap *bitmap) |
| { |
| char *path, *ptr = NULL; |
| |
| if (bitmap_mask_state(bitmap, BITMAP_STALE, MASK_SET) == 0) { |
| bitmap_update_sb(bitmap); |
| |
| if (bitmap->file) { |
| path = kmalloc(PAGE_SIZE, GFP_KERNEL); |
| if (path) |
| ptr = d_path(&bitmap->file->f_path, path, |
| PAGE_SIZE); |
| |
| |
| printk(KERN_ALERT |
| "%s: kicking failed bitmap file %s from array!\n", |
| bmname(bitmap), IS_ERR(ptr) ? "" : ptr); |
| |
| kfree(path); |
| } else |
| printk(KERN_ALERT |
| "%s: disabling internal bitmap due to errors\n", |
| bmname(bitmap)); |
| } |
| |
| bitmap_file_put(bitmap); |
| |
| return; |
| } |
| |
| enum bitmap_page_attr { |
| BITMAP_PAGE_DIRTY = 0, // there are set bits that need to be synced |
| BITMAP_PAGE_CLEAN = 1, // there are bits that might need to be cleared |
| BITMAP_PAGE_NEEDWRITE=2, // there are cleared bits that need to be synced |
| }; |
| |
| static inline void set_page_attr(struct bitmap *bitmap, struct page *page, |
| enum bitmap_page_attr attr) |
| { |
| __set_bit((page->index<<2) + attr, bitmap->filemap_attr); |
| } |
| |
| static inline void clear_page_attr(struct bitmap *bitmap, struct page *page, |
| enum bitmap_page_attr attr) |
| { |
| __clear_bit((page->index<<2) + attr, bitmap->filemap_attr); |
| } |
| |
| static inline unsigned long test_page_attr(struct bitmap *bitmap, struct page *page, |
| enum bitmap_page_attr attr) |
| { |
| return test_bit((page->index<<2) + attr, bitmap->filemap_attr); |
| } |
| |
| /* |
| * bitmap_file_set_bit -- called before performing a write to the md device |
| * to set (and eventually sync) a particular bit in the bitmap file |
| * |
| * we set the bit immediately, then we record the page number so that |
| * when an unplug occurs, we can flush the dirty pages out to disk |
| */ |
| static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block) |
| { |
| unsigned long bit; |
| struct page *page; |
| void *kaddr; |
| unsigned long chunk = block >> CHUNK_BLOCK_SHIFT(bitmap); |
| |
| if (!bitmap->filemap) { |
| return; |
| } |
| |
| page = filemap_get_page(bitmap, chunk); |
| if (!page) return; |
| bit = file_page_offset(chunk); |
| |
| /* set the bit */ |
| kaddr = kmap_atomic(page, KM_USER0); |
| if (bitmap->flags & BITMAP_HOSTENDIAN) |
| set_bit(bit, kaddr); |
| else |
| ext2_set_bit(bit, kaddr); |
| kunmap_atomic(kaddr, KM_USER0); |
| PRINTK("set file bit %lu page %lu\n", bit, page->index); |
| |
| /* record page number so it gets flushed to disk when unplug occurs */ |
| set_page_attr(bitmap, page, BITMAP_PAGE_DIRTY); |
| |
| } |
| |
| /* this gets called when the md device is ready to unplug its underlying |
| * (slave) device queues -- before we let any writes go down, we need to |
| * sync the dirty pages of the bitmap file to disk */ |
| void bitmap_unplug(struct bitmap *bitmap) |
| { |
| unsigned long i, flags; |
| int dirty, need_write; |
| struct page *page; |
| int wait = 0; |
| |
| if (!bitmap) |
| return; |
| |
| /* look at each page to see if there are any set bits that need to be |
| * flushed out to disk */ |
| for (i = 0; i < bitmap->file_pages; i++) { |
| spin_lock_irqsave(&bitmap->lock, flags); |
| if (!bitmap->filemap) { |
| spin_unlock_irqrestore(&bitmap->lock, flags); |
| return; |
| } |
| page = bitmap->filemap[i]; |
| dirty = test_page_attr(bitmap, page, BITMAP_PAGE_DIRTY); |
| need_write = test_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE); |
| clear_page_attr(bitmap, page, BITMAP_PAGE_DIRTY); |
| clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE); |
| if (dirty) |
| wait = 1; |
| spin_unlock_irqrestore(&bitmap->lock, flags); |
| |
| if (dirty | need_write) |
| write_page(bitmap, page, 0); |
| } |
| if (wait) { /* if any writes were performed, we need to wait on them */ |
| if (bitmap->file) |
| wait_event(bitmap->write_wait, |
| atomic_read(&bitmap->pending_writes)==0); |
| else |
| md_super_wait(bitmap->mddev); |
| } |
| if (bitmap->flags & BITMAP_WRITE_ERROR) |
| bitmap_file_kick(bitmap); |
| } |
| |
| static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed); |
| /* * bitmap_init_from_disk -- called at bitmap_create time to initialize |
| * the in-memory bitmap from the on-disk bitmap -- also, sets up the |
| * memory mapping of the bitmap file |
| * Special cases: |
| * if there's no bitmap file, or if the bitmap file had been |
| * previously kicked from the array, we mark all the bits as |
| * 1's in order to cause a full resync. |
| * |
| * We ignore all bits for sectors that end earlier than 'start'. |
| * This is used when reading an out-of-date bitmap... |
| */ |
| static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start) |
| { |
| unsigned long i, chunks, index, oldindex, bit; |
| struct page *page = NULL, *oldpage = NULL; |
| unsigned long num_pages, bit_cnt = 0; |
| struct file *file; |
| unsigned long bytes, offset; |
| int outofdate; |
| int ret = -ENOSPC; |
| void *paddr; |
| |
| chunks = bitmap->chunks; |
| file = bitmap->file; |
| |
| BUG_ON(!file && !bitmap->offset); |
| |
| #ifdef INJECT_FAULTS_3 |
| outofdate = 1; |
| #else |
| outofdate = bitmap->flags & BITMAP_STALE; |
| #endif |
| if (outofdate) |
| printk(KERN_INFO "%s: bitmap file is out of date, doing full " |
| "recovery\n", bmname(bitmap)); |
| |
| bytes = (chunks + 7) / 8; |
| |
| num_pages = (bytes + sizeof(bitmap_super_t) + PAGE_SIZE - 1) / PAGE_SIZE; |
| |
| if (file && i_size_read(file->f_mapping->host) < bytes + sizeof(bitmap_super_t)) { |
| printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n", |
| bmname(bitmap), |
| (unsigned long) i_size_read(file->f_mapping->host), |
| bytes + sizeof(bitmap_super_t)); |
| goto err; |
| } |
| |
| ret = -ENOMEM; |
| |
| bitmap->filemap = kmalloc(sizeof(struct page *) * num_pages, GFP_KERNEL); |
| if (!bitmap->filemap) |
| goto err; |
| |
| /* We need 4 bits per page, rounded up to a multiple of sizeof(unsigned long) */ |
| bitmap->filemap_attr = kzalloc( |
| roundup( DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)), |
| GFP_KERNEL); |
| if (!bitmap->filemap_attr) |
| goto err; |
| |
| oldindex = ~0L; |
| |
| for (i = 0; i < chunks; i++) { |
| int b; |
| index = file_page_index(i); |
| bit = file_page_offset(i); |
| if (index != oldindex) { /* this is a new page, read it in */ |
| int count; |
| /* unmap the old page, we're done with it */ |
| if (index == num_pages-1) |
| count = bytes + sizeof(bitmap_super_t) |
| - index * PAGE_SIZE; |
| else |
| count = PAGE_SIZE; |
| if (index == 0) { |
| /* |
| * if we're here then the superblock page |
| * contains some bits (PAGE_SIZE != sizeof sb) |
| * we've already read it in, so just use it |
| */ |
| page = bitmap->sb_page; |
| offset = sizeof(bitmap_super_t); |
| if (!file) |
| read_sb_page(bitmap->mddev, |
| bitmap->offset, |
| page, |
| index, count); |
| } else if (file) { |
| page = read_page(file, index, bitmap, count); |
| offset = 0; |
| } else { |
| page = read_sb_page(bitmap->mddev, bitmap->offset, |
| NULL, |
| index, count); |
| offset = 0; |
| } |
| if (IS_ERR(page)) { /* read error */ |
| ret = PTR_ERR(page); |
| goto err; |
| } |
| |
| oldindex = index; |
| oldpage = page; |
| |
| bitmap->filemap[bitmap->file_pages++] = page; |
| bitmap->last_page_size = count; |
| |
| if (outofdate) { |
| /* |
| * if bitmap is out of date, dirty the |
| * whole page and write it out |
| */ |
| paddr = kmap_atomic(page, KM_USER0); |
| memset(paddr + offset, 0xff, |
| PAGE_SIZE - offset); |
| kunmap_atomic(paddr, KM_USER0); |
| write_page(bitmap, page, 1); |
| |
| ret = -EIO; |
| if (bitmap->flags & BITMAP_WRITE_ERROR) |
| goto err; |
| } |
| } |
| paddr = kmap_atomic(page, KM_USER0); |
| if (bitmap->flags & BITMAP_HOSTENDIAN) |
| b = test_bit(bit, paddr); |
| else |
| b = ext2_test_bit(bit, paddr); |
| kunmap_atomic(paddr, KM_USER0); |
| if (b) { |
| /* if the disk bit is set, set the memory bit */ |
| int needed = ((sector_t)(i+1) << (CHUNK_BLOCK_SHIFT(bitmap)) |
| >= start); |
| bitmap_set_memory_bits(bitmap, |
| (sector_t)i << CHUNK_BLOCK_SHIFT(bitmap), |
| needed); |
| bit_cnt++; |
| set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN); |
| } |
| } |
| |
| /* everything went OK */ |
| ret = 0; |
| bitmap_mask_state(bitmap, BITMAP_STALE, MASK_UNSET); |
| |
| if (bit_cnt) { /* Kick recovery if any bits were set */ |
| set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery); |
| md_wakeup_thread(bitmap->mddev->thread); |
| } |
| |
| printk(KERN_INFO "%s: bitmap initialized from disk: " |
| "read %lu/%lu pages, set %lu bits\n", |
| bmname(bitmap), bitmap->file_pages, num_pages, bit_cnt); |
| |
| return 0; |
| |
| err: |
| printk(KERN_INFO "%s: bitmap initialisation failed: %d\n", |
| bmname(bitmap), ret); |
| return ret; |
| } |
| |
| void bitmap_write_all(struct bitmap *bitmap) |
| { |
| /* We don't actually write all bitmap blocks here, |
| * just flag them as needing to be written |
| */ |
| int i; |
| |
| for (i=0; i < bitmap->file_pages; i++) |
| set_page_attr(bitmap, bitmap->filemap[i], |
| BITMAP_PAGE_NEEDWRITE); |
| } |
| |
| |
| static void bitmap_count_page(struct bitmap *bitmap, sector_t offset, int inc) |
| { |
| sector_t chunk = offset >> CHUNK_BLOCK_SHIFT(bitmap); |
| unsigned long page = chunk >> PAGE_COUNTER_SHIFT; |
| bitmap->bp[page].count += inc; |
| /* |
| if (page == 0) printk("count page 0, offset %llu: %d gives %d\n", |
| (unsigned long long)offset, inc, bitmap->bp[page].count); |
| */ |
| bitmap_checkfree(bitmap, page); |
| } |
| static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap, |
| sector_t offset, int *blocks, |
| int create); |
| |
| /* |
| * bitmap daemon -- periodically wakes up to clean bits and flush pages |
| * out to disk |
| */ |
| |
| void bitmap_daemon_work(mddev_t *mddev) |
| { |
| struct bitmap *bitmap; |
| unsigned long j; |
| unsigned long flags; |
| struct page *page = NULL, *lastpage = NULL; |
| int blocks; |
| void *paddr; |
| |
| /* Use a mutex to guard daemon_work against |
| * bitmap_destroy. |
| */ |
| mutex_lock(&mddev->bitmap_info.mutex); |
| bitmap = mddev->bitmap; |
| if (bitmap == NULL) { |
| mutex_unlock(&mddev->bitmap_info.mutex); |
| return; |
| } |
| if (time_before(jiffies, bitmap->daemon_lastrun + bitmap->daemon_sleep*HZ)) |
| goto done; |
| |
| bitmap->daemon_lastrun = jiffies; |
| if (bitmap->allclean) { |
| bitmap->mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT; |
| goto done; |
| } |
| bitmap->allclean = 1; |
| |
| spin_lock_irqsave(&bitmap->lock, flags); |
| for (j = 0; j < bitmap->chunks; j++) { |
| bitmap_counter_t *bmc; |
| if (!bitmap->filemap) |
| /* error or shutdown */ |
| break; |
| |
| page = filemap_get_page(bitmap, j); |
| |
| if (page != lastpage) { |
| /* skip this page unless it's marked as needing cleaning */ |
| if (!test_page_attr(bitmap, page, BITMAP_PAGE_CLEAN)) { |
| int need_write = test_page_attr(bitmap, page, |
| BITMAP_PAGE_NEEDWRITE); |
| if (need_write) |
| clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE); |
| |
| spin_unlock_irqrestore(&bitmap->lock, flags); |
| if (need_write) { |
| write_page(bitmap, page, 0); |
| bitmap->allclean = 0; |
| } |
| spin_lock_irqsave(&bitmap->lock, flags); |
| j |= (PAGE_BITS - 1); |
| continue; |
| } |
| |
| /* grab the new page, sync and release the old */ |
| if (lastpage != NULL) { |
| if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) { |
| clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE); |
| spin_unlock_irqrestore(&bitmap->lock, flags); |
| write_page(bitmap, lastpage, 0); |
| } else { |
| set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE); |
| spin_unlock_irqrestore(&bitmap->lock, flags); |
| } |
| } else |
| spin_unlock_irqrestore(&bitmap->lock, flags); |
| lastpage = page; |
| |
| /* We are possibly going to clear some bits, so make |
| * sure that events_cleared is up-to-date. |
| */ |
| if (bitmap->need_sync) { |
| bitmap_super_t *sb; |
| bitmap->need_sync = 0; |
| sb = kmap_atomic(bitmap->sb_page, KM_USER0); |
| sb->events_cleared = |
| cpu_to_le64(bitmap->events_cleared); |
| kunmap_atomic(sb, KM_USER0); |
| write_page(bitmap, bitmap->sb_page, 1); |
| } |
| spin_lock_irqsave(&bitmap->lock, flags); |
| clear_page_attr(bitmap, page, BITMAP_PAGE_CLEAN); |
| } |
| bmc = bitmap_get_counter(bitmap, |
| (sector_t)j << CHUNK_BLOCK_SHIFT(bitmap), |
| &blocks, 0); |
| if (bmc) { |
| /* |
| if (j < 100) printk("bitmap: j=%lu, *bmc = 0x%x\n", j, *bmc); |
| */ |
| if (*bmc) |
| bitmap->allclean = 0; |
| |
| if (*bmc == 2) { |
| *bmc=1; /* maybe clear the bit next time */ |
| set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN); |
| } else if (*bmc == 1) { |
| /* we can clear the bit */ |
| *bmc = 0; |
| bitmap_count_page(bitmap, |
| (sector_t)j << CHUNK_BLOCK_SHIFT(bitmap), |
| -1); |
| |
| /* clear the bit */ |
| paddr = kmap_atomic(page, KM_USER0); |
| if (bitmap->flags & BITMAP_HOSTENDIAN) |
| clear_bit(file_page_offset(j), paddr); |
| else |
| ext2_clear_bit(file_page_offset(j), paddr); |
| kunmap_atomic(paddr, KM_USER0); |
| } |
| } else |
| j |= PAGE_COUNTER_MASK; |
| } |
| spin_unlock_irqrestore(&bitmap->lock, flags); |
| |
| /* now sync the final page */ |
| if (lastpage != NULL) { |
| spin_lock_irqsave(&bitmap->lock, flags); |
| if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) { |
| clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE); |
| spin_unlock_irqrestore(&bitmap->lock, flags); |
| write_page(bitmap, lastpage, 0); |
| } else { |
| set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE); |
| spin_unlock_irqrestore(&bitmap->lock, flags); |
| } |
| } |
| |
| done: |
| if (bitmap->allclean == 0) |
| bitmap->mddev->thread->timeout = bitmap->daemon_sleep * HZ; |
| mutex_unlock(&mddev->bitmap_info.mutex); |
| } |
| |
| static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap, |
| sector_t offset, int *blocks, |
| int create) |
| __releases(bitmap->lock) |
| __acquires(bitmap->lock) |
| { |
| /* If 'create', we might release the lock and reclaim it. |
| * The lock must have been taken with interrupts enabled. |
| * If !create, we don't release the lock. |
| */ |
| sector_t chunk = offset >> CHUNK_BLOCK_SHIFT(bitmap); |
| unsigned long page = chunk >> PAGE_COUNTER_SHIFT; |
| unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT; |
| sector_t csize; |
| |
| if (bitmap_checkpage(bitmap, page, create) < 0) { |
| csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap)); |
| *blocks = csize - (offset & (csize- 1)); |
| return NULL; |
| } |
| /* now locked ... */ |
| |
| if (bitmap->bp[page].hijacked) { /* hijacked pointer */ |
| /* should we use the first or second counter field |
| * of the hijacked pointer? */ |
| int hi = (pageoff > PAGE_COUNTER_MASK); |
| csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap) + |
| PAGE_COUNTER_SHIFT - 1); |
| *blocks = csize - (offset & (csize- 1)); |
| return &((bitmap_counter_t *) |
| &bitmap->bp[page].map)[hi]; |
| } else { /* page is allocated */ |
| csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap)); |
| *blocks = csize - (offset & (csize- 1)); |
| return (bitmap_counter_t *) |
| &(bitmap->bp[page].map[pageoff]); |
| } |
| } |
| |
| int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind) |
| { |
| if (!bitmap) return 0; |
| |
| if (behind) { |
| atomic_inc(&bitmap->behind_writes); |
| PRINTK(KERN_DEBUG "inc write-behind count %d/%d\n", |
| atomic_read(&bitmap->behind_writes), bitmap->max_write_behind); |
| } |
| |
| while (sectors) { |
| int blocks; |
| bitmap_counter_t *bmc; |
| |
| spin_lock_irq(&bitmap->lock); |
| bmc = bitmap_get_counter(bitmap, offset, &blocks, 1); |
| if (!bmc) { |
| spin_unlock_irq(&bitmap->lock); |
| return 0; |
| } |
| |
| if (unlikely((*bmc & COUNTER_MAX) == COUNTER_MAX)) { |
| DEFINE_WAIT(__wait); |
| /* note that it is safe to do the prepare_to_wait |
| * after the test as long as we do it before dropping |
| * the spinlock. |
| */ |
| prepare_to_wait(&bitmap->overflow_wait, &__wait, |
| TASK_UNINTERRUPTIBLE); |
| spin_unlock_irq(&bitmap->lock); |
| blk_unplug(bitmap->mddev->queue); |
| schedule(); |
| finish_wait(&bitmap->overflow_wait, &__wait); |
| continue; |
| } |
| |
| switch(*bmc) { |
| case 0: |
| bitmap_file_set_bit(bitmap, offset); |
| bitmap_count_page(bitmap,offset, 1); |
| blk_plug_device_unlocked(bitmap->mddev->queue); |
| /* fall through */ |
| case 1: |
| *bmc = 2; |
| } |
| |
| (*bmc)++; |
| |
| spin_unlock_irq(&bitmap->lock); |
| |
| offset += blocks; |
| if (sectors > blocks) |
| sectors -= blocks; |
| else sectors = 0; |
| } |
| bitmap->allclean = 0; |
| return 0; |
| } |
| |
| void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, |
| int success, int behind) |
| { |
| if (!bitmap) return; |
| if (behind) { |
| atomic_dec(&bitmap->behind_writes); |
| PRINTK(KERN_DEBUG "dec write-behind count %d/%d\n", |
| atomic_read(&bitmap->behind_writes), bitmap->max_write_behind); |
| } |
| if (bitmap->mddev->degraded) |
| /* Never clear bits or update events_cleared when degraded */ |
| success = 0; |
| |
| while (sectors) { |
| int blocks; |
| unsigned long flags; |
| bitmap_counter_t *bmc; |
| |
| spin_lock_irqsave(&bitmap->lock, flags); |
| bmc = bitmap_get_counter(bitmap, offset, &blocks, 0); |
| if (!bmc) { |
| spin_unlock_irqrestore(&bitmap->lock, flags); |
| return; |
| } |
| |
| if (success && |
| bitmap->events_cleared < bitmap->mddev->events) { |
| bitmap->events_cleared = bitmap->mddev->events; |
| bitmap->need_sync = 1; |
| } |
| |
| if (!success && ! (*bmc & NEEDED_MASK)) |
| *bmc |= NEEDED_MASK; |
| |
| if ((*bmc & COUNTER_MAX) == COUNTER_MAX) |
| wake_up(&bitmap->overflow_wait); |
| |
| (*bmc)--; |
| if (*bmc <= 2) { |
| set_page_attr(bitmap, |
| filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)), |
| BITMAP_PAGE_CLEAN); |
| } |
| spin_unlock_irqrestore(&bitmap->lock, flags); |
| offset += blocks; |
| if (sectors > blocks) |
| sectors -= blocks; |
| else sectors = 0; |
| } |
| } |
| |
| static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, int *blocks, |
| int degraded) |
| { |
| bitmap_counter_t *bmc; |
| int rv; |
| if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */ |
| *blocks = 1024; |
| return 1; /* always resync if no bitmap */ |
| } |
| spin_lock_irq(&bitmap->lock); |
| bmc = bitmap_get_counter(bitmap, offset, blocks, 0); |
| rv = 0; |
| if (bmc) { |
| /* locked */ |
| if (RESYNC(*bmc)) |
| rv = 1; |
| else if (NEEDED(*bmc)) { |
| rv = 1; |
| if (!degraded) { /* don't set/clear bits if degraded */ |
| *bmc |= RESYNC_MASK; |
| *bmc &= ~NEEDED_MASK; |
| } |
| } |
| } |
| spin_unlock_irq(&bitmap->lock); |
| bitmap->allclean = 0; |
| return rv; |
| } |
| |
| int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, int *blocks, |
| int degraded) |
| { |
| /* bitmap_start_sync must always report on multiples of whole |
| * pages, otherwise resync (which is very PAGE_SIZE based) will |
| * get confused. |
| * So call __bitmap_start_sync repeatedly (if needed) until |
| * At least PAGE_SIZE>>9 blocks are covered. |
| * Return the 'or' of the result. |
| */ |
| int rv = 0; |
| int blocks1; |
| |
| *blocks = 0; |
| while (*blocks < (PAGE_SIZE>>9)) { |
| rv |= __bitmap_start_sync(bitmap, offset, |
| &blocks1, degraded); |
| offset += blocks1; |
| *blocks += blocks1; |
| } |
| return rv; |
| } |
| |
| void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, int *blocks, int aborted) |
| { |
| bitmap_counter_t *bmc; |
| unsigned long flags; |
| /* |
| if (offset == 0) printk("bitmap_end_sync 0 (%d)\n", aborted); |
| */ if (bitmap == NULL) { |
| *blocks = 1024; |
| return; |
| } |
| spin_lock_irqsave(&bitmap->lock, flags); |
| bmc = bitmap_get_counter(bitmap, offset, blocks, 0); |
| if (bmc == NULL) |
| goto unlock; |
| /* locked */ |
| /* |
| if (offset == 0) printk("bitmap_end sync found 0x%x, blocks %d\n", *bmc, *blocks); |
| */ |
| if (RESYNC(*bmc)) { |
| *bmc &= ~RESYNC_MASK; |
| |
| if (!NEEDED(*bmc) && aborted) |
| *bmc |= NEEDED_MASK; |
| else { |
| if (*bmc <= 2) { |
| set_page_attr(bitmap, |
| filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)), |
| BITMAP_PAGE_CLEAN); |
| } |
| } |
| } |
| unlock: |
| spin_unlock_irqrestore(&bitmap->lock, flags); |
| bitmap->allclean = 0; |
| } |
| |
| void bitmap_close_sync(struct bitmap *bitmap) |
| { |
| /* Sync has finished, and any bitmap chunks that weren't synced |
| * properly have been aborted. It remains to us to clear the |
| * RESYNC bit wherever it is still on |
| */ |
| sector_t sector = 0; |
| int blocks; |
| if (!bitmap) |
| return; |
| while (sector < bitmap->mddev->resync_max_sectors) { |
| bitmap_end_sync(bitmap, sector, &blocks, 0); |
| sector += blocks; |
| } |
| } |
| |
| void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector) |
| { |
| sector_t s = 0; |
| int blocks; |
| |
| if (!bitmap) |
| return; |
| if (sector == 0) { |
| bitmap->last_end_sync = jiffies; |
| return; |
| } |
| if (time_before(jiffies, (bitmap->last_end_sync |
| + bitmap->daemon_sleep * HZ))) |
| return; |
| wait_event(bitmap->mddev->recovery_wait, |
| atomic_read(&bitmap->mddev->recovery_active) == 0); |
| |
| bitmap->mddev->curr_resync_completed = bitmap->mddev->curr_resync; |
| set_bit(MD_CHANGE_CLEAN, &bitmap->mddev->flags); |
| sector &= ~((1ULL << CHUNK_BLOCK_SHIFT(bitmap)) - 1); |
| s = 0; |
| while (s < sector && s < bitmap->mddev->resync_max_sectors) { |
| bitmap_end_sync(bitmap, s, &blocks, 0); |
| s += blocks; |
| } |
| bitmap->last_end_sync = jiffies; |
| sysfs_notify(&bitmap->mddev->kobj, NULL, "sync_completed"); |
| } |
| |
| static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed) |
| { |
| /* For each chunk covered by any of these sectors, set the |
| * counter to 1 and set resync_needed. They should all |
| * be 0 at this point |
| */ |
| |
| int secs; |
| bitmap_counter_t *bmc; |
| spin_lock_irq(&bitmap->lock); |
| bmc = bitmap_get_counter(bitmap, offset, &secs, 1); |
| if (!bmc) { |
| spin_unlock_irq(&bitmap->lock); |
| return; |
| } |
| if (! *bmc) { |
| struct page *page; |
| *bmc = 1 | (needed?NEEDED_MASK:0); |
| bitmap_count_page(bitmap, offset, 1); |
| page = filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)); |
| set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN); |
| } |
| spin_unlock_irq(&bitmap->lock); |
| bitmap->allclean = 0; |
| } |
| |
| /* dirty the memory and file bits for bitmap chunks "s" to "e" */ |
| void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e) |
| { |
| unsigned long chunk; |
| |
| for (chunk = s; chunk <= e; chunk++) { |
| sector_t sec = (sector_t)chunk << CHUNK_BLOCK_SHIFT(bitmap); |
| bitmap_set_memory_bits(bitmap, sec, 1); |
| bitmap_file_set_bit(bitmap, sec); |
| } |
| } |
| |
| /* |
| * flush out any pending updates |
| */ |
| void bitmap_flush(mddev_t *mddev) |
| { |
| struct bitmap *bitmap = mddev->bitmap; |
| int sleep; |
| |
| if (!bitmap) /* there was no bitmap */ |
| return; |
| |
| /* run the daemon_work three time to ensure everything is flushed |
| * that can be |
| */ |
| sleep = bitmap->daemon_sleep; |
| bitmap->daemon_sleep = 0; |
| bitmap_daemon_work(mddev); |
| bitmap_daemon_work(mddev); |
| bitmap_daemon_work(mddev); |
| bitmap->daemon_sleep = sleep; |
| bitmap_update_sb(bitmap); |
| } |
| |
| /* |
| * free memory that was allocated |
| */ |
| static void bitmap_free(struct bitmap *bitmap) |
| { |
| unsigned long k, pages; |
| struct bitmap_page *bp; |
| |
| if (!bitmap) /* there was no bitmap */ |
| return; |
| |
| /* release the bitmap file and kill the daemon */ |
| bitmap_file_put(bitmap); |
| |
| bp = bitmap->bp; |
| pages = bitmap->pages; |
| |
| /* free all allocated memory */ |
| |
| if (bp) /* deallocate the page memory */ |
| for (k = 0; k < pages; k++) |
| if (bp[k].map && !bp[k].hijacked) |
| kfree(bp[k].map); |
| kfree(bp); |
| kfree(bitmap); |
| } |
| |
| void bitmap_destroy(mddev_t *mddev) |
| { |
| struct bitmap *bitmap = mddev->bitmap; |
| |
| if (!bitmap) /* there was no bitmap */ |
| return; |
| |
| mutex_lock(&mddev->bitmap_info.mutex); |
| mddev->bitmap = NULL; /* disconnect from the md device */ |
| mutex_unlock(&mddev->bitmap_info.mutex); |
| if (mddev->thread) |
| mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT; |
| |
| bitmap_free(bitmap); |
| } |
| |
| /* |
| * initialize the bitmap structure |
| * if this returns an error, bitmap_destroy must be called to do clean up |
| */ |
| int bitmap_create(mddev_t *mddev) |
| { |
| struct bitmap *bitmap; |
| sector_t blocks = mddev->resync_max_sectors; |
| unsigned long chunks; |
| unsigned long pages; |
| struct file *file = mddev->bitmap_info.file; |
| int err; |
| sector_t start; |
| |
| BUILD_BUG_ON(sizeof(bitmap_super_t) != 256); |
| |
| if (!file && !mddev->bitmap_info.offset) /* bitmap disabled, nothing to do */ |
| return 0; |
| |
| BUG_ON(file && mddev->bitmap_info.offset); |
| |
| bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL); |
| if (!bitmap) |
| return -ENOMEM; |
| |
| spin_lock_init(&bitmap->lock); |
| atomic_set(&bitmap->pending_writes, 0); |
| init_waitqueue_head(&bitmap->write_wait); |
| init_waitqueue_head(&bitmap->overflow_wait); |
| |
| bitmap->mddev = mddev; |
| |
| bitmap->file = file; |
| bitmap->offset = mddev->bitmap_info.offset; |
| if (file) { |
| get_file(file); |
| /* As future accesses to this file will use bmap, |
| * and bypass the page cache, we must sync the file |
| * first. |
| */ |
| vfs_fsync(file, file->f_dentry, 1); |
| } |
| /* read superblock from bitmap file (this sets bitmap->chunksize) */ |
| err = bitmap_read_sb(bitmap); |
| if (err) |
| goto error; |
| |
| bitmap->chunkshift = ffz(~bitmap->chunksize); |
| |
| /* now that chunksize and chunkshift are set, we can use these macros */ |
| chunks = (blocks + CHUNK_BLOCK_RATIO(bitmap) - 1) >> |
| CHUNK_BLOCK_SHIFT(bitmap); |
| pages = (chunks + PAGE_COUNTER_RATIO - 1) / PAGE_COUNTER_RATIO; |
| |
| BUG_ON(!pages); |
| |
| bitmap->chunks = chunks; |
| bitmap->pages = pages; |
| bitmap->missing_pages = pages; |
| bitmap->counter_bits = COUNTER_BITS; |
| |
| bitmap->syncchunk = ~0UL; |
| |
| #ifdef INJECT_FATAL_FAULT_1 |
| bitmap->bp = NULL; |
| #else |
| bitmap->bp = kzalloc(pages * sizeof(*bitmap->bp), GFP_KERNEL); |
| #endif |
| err = -ENOMEM; |
| if (!bitmap->bp) |
| goto error; |
| |
| /* now that we have some pages available, initialize the in-memory |
| * bitmap from the on-disk bitmap */ |
| start = 0; |
| if (mddev->degraded == 0 |
| || bitmap->events_cleared == mddev->events) |
| /* no need to keep dirty bits to optimise a re-add of a missing device */ |
| start = mddev->recovery_cp; |
| err = bitmap_init_from_disk(bitmap, start); |
| |
| if (err) |
| goto error; |
| |
| printk(KERN_INFO "created bitmap (%lu pages) for device %s\n", |
| pages, bmname(bitmap)); |
| |
| mddev->bitmap = bitmap; |
| |
| mddev->thread->timeout = bitmap->daemon_sleep * HZ; |
| |
| bitmap_update_sb(bitmap); |
| |
| return (bitmap->flags & BITMAP_WRITE_ERROR) ? -EIO : 0; |
| |
| error: |
| bitmap_free(bitmap); |
| return err; |
| } |
| |
| /* the bitmap API -- for raid personalities */ |
| EXPORT_SYMBOL(bitmap_startwrite); |
| EXPORT_SYMBOL(bitmap_endwrite); |
| EXPORT_SYMBOL(bitmap_start_sync); |
| EXPORT_SYMBOL(bitmap_end_sync); |
| EXPORT_SYMBOL(bitmap_unplug); |
| EXPORT_SYMBOL(bitmap_close_sync); |
| EXPORT_SYMBOL(bitmap_cond_end_sync); |