/* * 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). */ #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" #include <linux/dm-dirty-log.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 #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 = kzalloc(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; /* this page has not been allocated yet */ spin_unlock_irq(&bitmap->lock); mappage = bitmap_alloc_page(bitmap); spin_lock_irq(&bitmap->lock); if (mappage == 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 */ if (!bitmap->bp[page].map) bitmap->bp[page].hijacked = 1; } else if (bitmap->bp[page].map || bitmap->bp[page].hijacked) { /* somebody beat us to getting the page */ bitmap_free_page(bitmap, mappage); return 0; } else { /* no page was in place and we have one, so install it */ bitmap->bp[page].map = mappage; bitmap->missing_pages--; } 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; } else { /* normal case, free the page */ ptr = bitmap->bp[page].map; bitmap->bp[page].map = NULL; bitmap->missing_pages++; bitmap_free_page(bitmap, ptr); } } /* * 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, loff_t 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; int did_alloc = 0; if (!page) { page = alloc_page(GFP_KERNEL); if (!page) return ERR_PTR(-ENOMEM); did_alloc = 1; } list_for_each_entry(rdev, &mddev->disks, same_set) { if (! test_bit(In_sync, &rdev->flags) || test_bit(Faulty, &rdev->flags)) continue; target = offset + index * (PAGE_SIZE/512); if (sync_page_io(rdev, target, roundup(size, bdev_logical_block_size(rdev->bdev)), page, READ, true)) { page->index = index; attach_page_buffers(page, NULL); /* so that free_buffer will * quietly no-op */ return page; } } if (did_alloc) put_page(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; struct block_device *bdev; mddev_t *mddev = bitmap->mddev; while ((rdev = next_active_rdev(rdev, mddev)) != NULL) { int size = PAGE_SIZE; loff_t offset = mddev->bitmap_info.offset; bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev; if (page->index == bitmap->file_pages-1) size = roundup(bitmap->last_page_size, bdev_logical_block_size(bdev)); /* Just make sure we aren't corrupting data or * metadata */ if (mddev->external) { /* Bitmap could be anywhere. */ if (rdev->sb_start + offset + (page->index * (PAGE_SIZE/512)) > rdev->data_offset && rdev->sb_start + offset < (rdev->data_offset + mddev->dev_sectors + (PAGE_SIZE/512))) goto bad_alignment; } else if (offset < 0) { /* DATA BITMAP METADATA */ if (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 + offset) /* data runs in to bitmap */ goto bad_alignment; } else if (rdev->sb_start < rdev->data_offset) { /* METADATA BITMAP DATA */ if (rdev->sb_start + 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 + 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 | REQ_SYNC, 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 @ %llu)\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 @ %llu): %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; if (bitmap->mddev->bitmap_info.external) 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 = 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); } /* Just in case these have been changed via sysfs: */ sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ); sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind); 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 = 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->mddev->bitmap_info.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 = kmap_atomic(bitmap->sb_page, KM_USER0); chunksize = le32_to_cpu(sb->chunksize); daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ; 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) 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->mddev->bitmap_info.chunksize = chunksize; bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep; bitmap->mddev->bitmap_info.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 = 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 */ /* * on-disk bitmap: * * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap * file a page at a time. There's a superblock at the start of the file. */ /* calculate the index of the page that contains this bit */ static inline unsigned long file_page_index(struct bitmap *bitmap, unsigned long chunk) { if (!bitmap->mddev->bitmap_info.external) chunk += sizeof(bitmap_super_t) << 3; return chunk >> PAGE_BIT_SHIFT; } /* calculate the (bit) offset of this bit within a page */ static inline unsigned long file_page_offset(struct bitmap *bitmap, unsigned long chunk) { if (!bitmap->mddev->bitmap_info.external) chunk += sizeof(bitmap_super_t) << 3; return 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 (bitmap->filemap == NULL) return NULL; if (file_page_index(bitmap, chunk) >= bitmap->file_pages) return NULL; return bitmap->filemap[file_page_index(bitmap, chunk) - file_page_index(bitmap, 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] != sb_page) /* 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) { if (page) __set_bit((page->index<<2) + attr, bitmap->filemap_attr); else __set_bit(attr, &bitmap->logattrs); } static inline void clear_page_attr(struct bitmap *bitmap, struct page *page, enum bitmap_page_attr attr) { if (page) __clear_bit((page->index<<2) + attr, bitmap->filemap_attr); else __clear_bit(attr, &bitmap->logattrs); } static inline unsigned long test_page_attr(struct bitmap *bitmap, struct page *page, enum bitmap_page_attr attr) { if (page) return test_bit((page->index<<2) + attr, bitmap->filemap_attr); else return test_bit(attr, &bitmap->logattrs); } /* * 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 = NULL; void *kaddr; unsigned long chunk = block >> CHUNK_BLOCK_SHIFT(bitmap); if (!bitmap->filemap) { struct dm_dirty_log *log = bitmap->mddev->bitmap_info.log; if (log) log->type->mark_region(log, chunk); } else { page = filemap_get_page(bitmap, chunk); if (!page) return; bit = file_page_offset(bitmap, chunk); /* set the bit */ kaddr = kmap_atomic(page, KM_USER0); if (bitmap->flags & BITMAP_HOSTENDIAN) set_bit(bit, kaddr); else __test_and_set_bit_le(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; if (!bitmap->filemap) { /* Must be using a dirty_log */ struct dm_dirty_log *log = bitmap->mddev->bitmap_info.log; dirty = test_and_clear_bit(BITMAP_PAGE_DIRTY, &bitmap->logattrs); need_write = test_and_clear_bit(BITMAP_PAGE_NEEDWRITE, &bitmap->logattrs); if (dirty || need_write) if (log->type->flush(log)) bitmap->flags |= BITMAP_WRITE_ERROR; goto out; } /* 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); } out: if (bitmap->flags & BITMAP_WRITE_ERROR) bitmap_file_kick(bitmap); } EXPORT_SYMBOL(bitmap_unplug); 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->mddev->bitmap_info.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 = DIV_ROUND_UP(bitmap->chunks, 8); if (!bitmap->mddev->bitmap_info.external) bytes += sizeof(bitmap_super_t); num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE); if (file && i_size_read(file->f_mapping->host) < bytes) { printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n", bmname(bitmap), (unsigned long) i_size_read(file->f_mapping->host), bytes); 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(bitmap, i); bit = file_page_offset(bitmap, 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 - index * PAGE_SIZE; else count = PAGE_SIZE; if (index == 0 && bitmap->sb_page) { /* * 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) page = read_sb_page( bitmap->mddev, bitmap->mddev->bitmap_info.offset, page, index, count); } else if (file) { page = read_page(file, index, bitmap, count); offset = 0; } else { page = read_sb_page(bitmap->mddev, bitmap->mddev->bitmap_info.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 = test_bit_le(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; bitmap_checkfree(bitmap, page); } static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap, sector_t offset, sector_t *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; sector_t blocks; void *paddr; struct dm_dirty_log *log = mddev->bitmap_info.log; /* 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->mddev->bitmap_info.daemon_sleep)) 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) { if (!log) /* error or shutdown */ break; } else 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->mddev->bitmap_info.external == 0) { 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); if (!bitmap->need_sync) 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 (*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 && !bitmap->need_sync) { /* we can clear the bit */ *bmc = 0; bitmap_count_page(bitmap, (sector_t)j << CHUNK_BLOCK_SHIFT(bitmap), -1); /* clear the bit */ if (page) { paddr = kmap_atomic(page, KM_USER0); if (bitmap->flags & BITMAP_HOSTENDIAN) clear_bit(file_page_offset(bitmap, j), paddr); else __test_and_clear_bit_le(file_page_offset(bitmap, j), paddr); kunmap_atomic(paddr, KM_USER0); } else log->type->clear_region(log, j); } } else j |= PAGE_COUNTER_MASK; } spin_unlock_irqrestore(&bitmap->lock, flags); /* now sync the final page */ if (lastpage != NULL || log != 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); if (lastpage) write_page(bitmap, lastpage, 0); else if (log->type->flush(log)) bitmap->flags |= BITMAP_WRITE_ERROR; } 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->mddev->bitmap_info.daemon_sleep; mutex_unlock(&mddev->bitmap_info.mutex); } static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap, sector_t offset, sector_t *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; int err; err = bitmap_checkpage(bitmap, page, create); if (bitmap->bp[page].hijacked || bitmap->bp[page].map == NULL) csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap) + PAGE_COUNTER_SHIFT - 1); else csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap)); *blocks = csize - (offset & (csize - 1)); if (err < 0) 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); return &((bitmap_counter_t *) &bitmap->bp[page].map)[hi]; } else /* page is allocated */ 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) { int bw; atomic_inc(&bitmap->behind_writes); bw = atomic_read(&bitmap->behind_writes); if (bw > bitmap->behind_writes_used) bitmap->behind_writes_used = bw; PRINTK(KERN_DEBUG "inc write-behind count %d/%d\n", bw, bitmap->max_write_behind); } while (sectors) { sector_t 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); io_schedule(); finish_wait(&bitmap->overflow_wait, &__wait); continue; } switch (*bmc) { case 0: bitmap_file_set_bit(bitmap, offset); bitmap_count_page(bitmap, offset, 1); /* 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; } EXPORT_SYMBOL(bitmap_startwrite); void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int success, int behind) { if (!bitmap) return; if (behind) { if (atomic_dec_and_test(&bitmap->behind_writes)) wake_up(&bitmap->behind_wait); 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) { sector_t 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; sysfs_notify_dirent_safe(bitmap->sysfs_can_clear); } 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; } } EXPORT_SYMBOL(bitmap_endwrite); static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *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, sector_t *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; sector_t blocks1; *blocks = 0; while (*blocks < (PAGE_SIZE>>9)) { rv |= __bitmap_start_sync(bitmap, offset, &blocks1, degraded); offset += blocks1; *blocks += blocks1; } return rv; } EXPORT_SYMBOL(bitmap_start_sync); void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted) { bitmap_counter_t *bmc; unsigned long flags; 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 (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; } EXPORT_SYMBOL(bitmap_end_sync); 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; sector_t blocks; if (!bitmap) return; while (sector < bitmap->mddev->resync_max_sectors) { bitmap_end_sync(bitmap, sector, &blocks, 0); sector += blocks; } } EXPORT_SYMBOL(bitmap_close_sync); void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector) { sector_t s = 0; sector_t blocks; if (!bitmap) return; if (sector == 0) { bitmap->last_end_sync = jiffies; return; } if (time_before(jiffies, (bitmap->last_end_sync + bitmap->mddev->bitmap_info.daemon_sleep))) return; wait_event(bitmap->mddev->recovery_wait, atomic_read(&bitmap->mddev->recovery_active) == 0); bitmap->mddev->curr_resync_completed = sector; 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"); } EXPORT_SYMBOL(bitmap_cond_end_sync); 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 */ sector_t 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); if (sec < bitmap->mddev->recovery_cp) /* We are asserting that the array is dirty, * so move the recovery_cp address back so * that it is obvious that it is dirty */ bitmap->mddev->recovery_cp = sec; } } /* * flush out any pending updates */ void bitmap_flush(mddev_t *mddev) { struct bitmap *bitmap = mddev->bitmap; long sleep; if (!bitmap) /* there was no bitmap */ return; /* run the daemon_work three time to ensure everything is flushed * that can be */ sleep = mddev->bitmap_info.daemon_sleep * 2; bitmap->daemon_lastrun -= sleep; bitmap_daemon_work(mddev); bitmap->daemon_lastrun -= sleep; bitmap_daemon_work(mddev); bitmap->daemon_lastrun -= sleep; bitmap_daemon_work(mddev); 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; if (bitmap->sysfs_can_clear) sysfs_put(bitmap->sysfs_can_clear); 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; struct sysfs_dirent *bm = NULL; BUILD_BUG_ON(sizeof(bitmap_super_t) != 256); if (!file && !mddev->bitmap_info.offset && !mddev->bitmap_info.log) /* bitmap disabled, nothing to do */ return 0; BUG_ON(file && mddev->bitmap_info.offset); BUG_ON(mddev->bitmap_info.offset && mddev->bitmap_info.log); 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); init_waitqueue_head(&bitmap->behind_wait); bitmap->mddev = mddev; if (mddev->kobj.sd) bm = sysfs_get_dirent(mddev->kobj.sd, NULL, "bitmap"); if (bm) { bitmap->sysfs_can_clear = sysfs_get_dirent(bm, NULL, "can_clear"); sysfs_put(bm); } else bitmap->sysfs_can_clear = NULL; bitmap->file = file; 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, 1); } /* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */ if (!mddev->bitmap_info.external) err = bitmap_read_sb(bitmap); else { err = 0; if (mddev->bitmap_info.chunksize == 0 || mddev->bitmap_info.daemon_sleep == 0) /* chunksize and time_base need to be * set first. */ err = -EINVAL; } if (err) goto error; bitmap->daemon_lastrun = jiffies; bitmap->chunkshift = ffz(~mddev->bitmap_info.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; printk(KERN_INFO "created bitmap (%lu pages) for device %s\n", pages, bmname(bitmap)); mddev->bitmap = bitmap; return (bitmap->flags & BITMAP_WRITE_ERROR) ? -EIO : 0; error: bitmap_free(bitmap); return err; } int bitmap_load(mddev_t *mddev) { int err = 0; sector_t sector = 0; struct bitmap *bitmap = mddev->bitmap; if (!bitmap) goto out; /* Clear out old bitmap info first: Either there is none, or we * are resuming after someone else has possibly changed things, * so we should forget old cached info. * All chunks should be clean, but some might need_sync. */ while (sector < mddev->resync_max_sectors) { sector_t blocks; bitmap_start_sync(bitmap, sector, &blocks, 0); sector += blocks; } bitmap_close_sync(bitmap); if (mddev->bitmap_info.log) { unsigned long i; struct dm_dirty_log *log = mddev->bitmap_info.log; for (i = 0; i < bitmap->chunks; i++) if (!log->type->in_sync(log, i, 1)) bitmap_set_memory_bits(bitmap, (sector_t)i << CHUNK_BLOCK_SHIFT(bitmap), 1); } else { sector_t 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 out; mddev->thread->timeout = mddev->bitmap_info.daemon_sleep; md_wakeup_thread(mddev->thread); bitmap_update_sb(bitmap); if (bitmap->flags & BITMAP_WRITE_ERROR) err = -EIO; out: return err; } EXPORT_SYMBOL_GPL(bitmap_load); static ssize_t location_show(mddev_t *mddev, char *page) { ssize_t len; if (mddev->bitmap_info.file) len = sprintf(page, "file"); else if (mddev->bitmap_info.offset) len = sprintf(page, "%+lld", (long long)mddev->bitmap_info.offset); else len = sprintf(page, "none"); len += sprintf(page+len, "\n"); return len; } static ssize_t location_store(mddev_t *mddev, const char *buf, size_t len) { if (mddev->pers) { if (!mddev->pers->quiesce) return -EBUSY; if (mddev->recovery || mddev->sync_thread) return -EBUSY; } if (mddev->bitmap || mddev->bitmap_info.file || mddev->bitmap_info.offset) { /* bitmap already configured. Only option is to clear it */ if (strncmp(buf, "none", 4) != 0) return -EBUSY; if (mddev->pers) { mddev->pers->quiesce(mddev, 1); bitmap_destroy(mddev); mddev->pers->quiesce(mddev, 0); } mddev->bitmap_info.offset = 0; if (mddev->bitmap_info.file) { struct file *f = mddev->bitmap_info.file; mddev->bitmap_info.file = NULL; restore_bitmap_write_access(f); fput(f); } } else { /* No bitmap, OK to set a location */ long long offset; if (strncmp(buf, "none", 4) == 0) /* nothing to be done */; else if (strncmp(buf, "file:", 5) == 0) { /* Not supported yet */ return -EINVAL; } else { int rv; if (buf[0] == '+') rv = strict_strtoll(buf+1, 10, &offset); else rv = strict_strtoll(buf, 10, &offset); if (rv) return rv; if (offset == 0) return -EINVAL; if (mddev->bitmap_info.external == 0 && mddev->major_version == 0 && offset != mddev->bitmap_info.default_offset) return -EINVAL; mddev->bitmap_info.offset = offset; if (mddev->pers) { mddev->pers->quiesce(mddev, 1); rv = bitmap_create(mddev); if (rv) { bitmap_destroy(mddev); mddev->bitmap_info.offset = 0; } mddev->pers->quiesce(mddev, 0); if (rv) return rv; } } } if (!mddev->external) { /* Ensure new bitmap info is stored in * metadata promptly. */ set_bit(MD_CHANGE_DEVS, &mddev->flags); md_wakeup_thread(mddev->thread); } return len; } static struct md_sysfs_entry bitmap_location = __ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store); static ssize_t timeout_show(mddev_t *mddev, char *page) { ssize_t len; unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ; unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ; len = sprintf(page, "%lu", secs); if (jifs) len += sprintf(page+len, ".%03u", jiffies_to_msecs(jifs)); len += sprintf(page+len, "\n"); return len; } static ssize_t timeout_store(mddev_t *mddev, const char *buf, size_t len) { /* timeout can be set at any time */ unsigned long timeout; int rv = strict_strtoul_scaled(buf, &timeout, 4); if (rv) return rv; /* just to make sure we don't overflow... */ if (timeout >= LONG_MAX / HZ) return -EINVAL; timeout = timeout * HZ / 10000; if (timeout >= MAX_SCHEDULE_TIMEOUT) timeout = MAX_SCHEDULE_TIMEOUT-1; if (timeout < 1) timeout = 1; mddev->bitmap_info.daemon_sleep = timeout; if (mddev->thread) { /* if thread->timeout is MAX_SCHEDULE_TIMEOUT, then * the bitmap is all clean and we don't need to * adjust the timeout right now */ if (mddev->thread->timeout < MAX_SCHEDULE_TIMEOUT) { mddev->thread->timeout = timeout; md_wakeup_thread(mddev->thread); } } return len; } static struct md_sysfs_entry bitmap_timeout = __ATTR(time_base, S_IRUGO|S_IWUSR, timeout_show, timeout_store); static ssize_t backlog_show(mddev_t *mddev, char *page) { return sprintf(page, "%lu\n", mddev->bitmap_info.max_write_behind); } static ssize_t backlog_store(mddev_t *mddev, const char *buf, size_t len) { unsigned long backlog; int rv = strict_strtoul(buf, 10, &backlog); if (rv) return rv; if (backlog > COUNTER_MAX) return -EINVAL; mddev->bitmap_info.max_write_behind = backlog; return len; } static struct md_sysfs_entry bitmap_backlog = __ATTR(backlog, S_IRUGO|S_IWUSR, backlog_show, backlog_store); static ssize_t chunksize_show(mddev_t *mddev, char *page) { return sprintf(page, "%lu\n", mddev->bitmap_info.chunksize); } static ssize_t chunksize_store(mddev_t *mddev, const char *buf, size_t len) { /* Can only be changed when no bitmap is active */ int rv; unsigned long csize; if (mddev->bitmap) return -EBUSY; rv = strict_strtoul(buf, 10, &csize); if (rv) return rv; if (csize < 512 || !is_power_of_2(csize)) return -EINVAL; mddev->bitmap_info.chunksize = csize; return len; } static struct md_sysfs_entry bitmap_chunksize = __ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store); static ssize_t metadata_show(mddev_t *mddev, char *page) { return sprintf(page, "%s\n", (mddev->bitmap_info.external ? "external" : "internal")); } static ssize_t metadata_store(mddev_t *mddev, const char *buf, size_t len) { if (mddev->bitmap || mddev->bitmap_info.file || mddev->bitmap_info.offset) return -EBUSY; if (strncmp(buf, "external", 8) == 0) mddev->bitmap_info.external = 1; else if (strncmp(buf, "internal", 8) == 0) mddev->bitmap_info.external = 0; else return -EINVAL; return len; } static struct md_sysfs_entry bitmap_metadata = __ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store); static ssize_t can_clear_show(mddev_t *mddev, char *page) { int len; if (mddev->bitmap) len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ? "false" : "true")); else len = sprintf(page, "\n"); return len; } static ssize_t can_clear_store(mddev_t *mddev, const char *buf, size_t len) { if (mddev->bitmap == NULL) return -ENOENT; if (strncmp(buf, "false", 5) == 0) mddev->bitmap->need_sync = 1; else if (strncmp(buf, "true", 4) == 0) { if (mddev->degraded) return -EBUSY; mddev->bitmap->need_sync = 0; } else return -EINVAL; return len; } static struct md_sysfs_entry bitmap_can_clear = __ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store); static ssize_t behind_writes_used_show(mddev_t *mddev, char *page) { if (mddev->bitmap == NULL) return sprintf(page, "0\n"); return sprintf(page, "%lu\n", mddev->bitmap->behind_writes_used); } static ssize_t behind_writes_used_reset(mddev_t *mddev, const char *buf, size_t len) { if (mddev->bitmap) mddev->bitmap->behind_writes_used = 0; return len; } static struct md_sysfs_entry max_backlog_used = __ATTR(max_backlog_used, S_IRUGO | S_IWUSR, behind_writes_used_show, behind_writes_used_reset); static struct attribute *md_bitmap_attrs[] = { &bitmap_location.attr, &bitmap_timeout.attr, &bitmap_backlog.attr, &bitmap_chunksize.attr, &bitmap_metadata.attr, &bitmap_can_clear.attr, &max_backlog_used.attr, NULL }; struct attribute_group md_bitmap_group = { .name = "bitmap", .attrs = md_bitmap_attrs, };