/* * 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/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 <linux/raid/md.h> #include <linux/raid/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) { unsigned char *mappage; if (page >= bitmap->pages) { printk(KERN_ALERT "%s: invalid bitmap page request: %lu (> %lu)\n", bmname(bitmap), page, bitmap->pages-1); 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, unsigned long index) { /* choose a good rdev and read the page from there */ mdk_rdev_t *rdev; struct list_head *tmp; struct page *page = alloc_page(GFP_KERNEL); sector_t target; if (!page) return ERR_PTR(-ENOMEM); rdev_for_each(rdev, tmp, mddev) { 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, PAGE_SIZE, 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(In_sync, &rdev->flags) && !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_hardsect_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->size*2 > 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: rcu_read_unlock(); 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, 0); } 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 < PAGE_SIZE) 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); } else if (file) { page = read_page(file, index, bitmap, count); offset = 0; } else { page = read_sb_page(bitmap->mddev, bitmap->offset, index); offset = 0; } if (IS_ERR(page)) { /* read error */ ret = PTR_ERR(page); goto err; } oldindex = index; oldpage = page; 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) { /* release, page not in filemap yet */ put_page(page); goto err; } } bitmap->filemap[bitmap->file_pages++] = page; bitmap->last_page_size = count; } 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 */ bitmap_set_memory_bits(bitmap, i << CHUNK_BLOCK_SHIFT(bitmap), ((i+1) << (CHUNK_BLOCK_SHIFT(bitmap)) >= start) ); 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(struct bitmap *bitmap) { unsigned long j; unsigned long flags; struct page *page = NULL, *lastpage = NULL; int blocks; void *paddr; if (bitmap == NULL) 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; return; } bitmap->allclean = 1; for (j = 0; j < bitmap->chunks; j++) { bitmap_counter_t *bmc; spin_lock_irqsave(&bitmap->lock, flags); if (!bitmap->filemap) { /* error or shutdown */ spin_unlock_irqrestore(&bitmap->lock, flags); 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; } 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, 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, 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); } } 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; } static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap, sector_t offset, int *blocks, int create) { /* 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); } 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; } } 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; } 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); 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; } 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 = 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(bitmap); bitmap_daemon_work(bitmap); bitmap_daemon_work(bitmap); 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; mddev->bitmap = NULL; /* disconnect from the md device */ 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; unsigned long blocks = mddev->resync_max_sectors; unsigned long chunks; unsigned long pages; struct file *file = mddev->bitmap_file; int err; sector_t start; BUILD_BUG_ON(sizeof(bitmap_super_t) != 256); if (!file && !mddev->bitmap_offset) /* bitmap disabled, nothing to do */ return 0; BUG_ON(file && mddev->bitmap_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_offset; if (file) { get_file(file); do_sync_mapping_range(file->f_mapping, 0, LLONG_MAX, SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE | SYNC_FILE_RANGE_WAIT_AFTER); } /* 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_RATIO(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);