/* * 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); sb->state = cpu_to_le32(bitmap->flags);Lines 1–500 of 2195. Load more
/* * 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); sb->state = cpu_to_le32(bitmap->flags);