X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=fs%2Fbuffer.c;h=8a17ebb9742340a1ba0c36ebadbebd4320300d0d;hb=987b0145d94eecf292d8b301228356f44611ab7c;hp=7e9e409feaa744d13e471c1209318a0a9ef138d3;hpb=cace1c4618b6c6442b7dc973e935e7f3268e4aa7;p=linux-2.6.git diff --git a/fs/buffer.c b/fs/buffer.c index 7e9e409fe..8a17ebb97 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include #include @@ -40,6 +41,7 @@ #include #include #include +#include static int fsync_buffers_list(spinlock_t *lock, struct list_head *list); static void invalidate_bh_lrus(void); @@ -95,7 +97,7 @@ static void __clear_page_buffers(struct page *page) { ClearPagePrivate(page); - page->private = 0; + set_page_private(page, 0); page_cache_release(page); } @@ -152,14 +154,8 @@ int sync_blockdev(struct block_device *bdev) { int ret = 0; - if (bdev) { - int err; - - ret = filemap_fdatawrite(bdev->bd_inode->i_mapping); - err = filemap_fdatawait(bdev->bd_inode->i_mapping); - if (!ret) - ret = err; - } + if (bdev) + ret = filemap_write_and_wait(bdev->bd_inode->i_mapping); return ret; } EXPORT_SYMBOL(sync_blockdev); @@ -278,7 +274,7 @@ EXPORT_SYMBOL(thaw_bdev); */ static void do_sync(unsigned long wait) { - wakeup_bdflush(0); + wakeup_pdflush(0); sync_inodes(0); /* All mappings, inodes and their blockdevs */ DQUOT_SYNC(NULL); sync_supers(); /* Write the superblocks */ @@ -331,7 +327,7 @@ int file_fsync(struct file *filp, struct dentry *dentry, int datasync) return ret; } -asmlinkage long sys_fsync(unsigned int fd) +static long do_fsync(unsigned int fd, int datasync) { struct file * file; struct address_space *mapping; @@ -342,14 +338,14 @@ asmlinkage long sys_fsync(unsigned int fd) if (!file) goto out; - mapping = file->f_mapping; - ret = -EINVAL; if (!file->f_op || !file->f_op->fsync) { /* Why? We can still call filemap_fdatawrite */ goto out_putf; } + mapping = file->f_mapping; + current->flags |= PF_SYNCWRITE; ret = filemap_fdatawrite(mapping); @@ -357,11 +353,11 @@ asmlinkage long sys_fsync(unsigned int fd) * We need to protect against concurrent writers, * which could cause livelocks in fsync_buffers_list */ - down(&mapping->host->i_sem); - err = file->f_op->fsync(file, file->f_dentry, 0); + mutex_lock(&mapping->host->i_mutex); + err = file->f_op->fsync(file, file->f_dentry, datasync); if (!ret) ret = err; - up(&mapping->host->i_sem); + mutex_unlock(&mapping->host->i_mutex); err = filemap_fdatawait(mapping); if (!ret) ret = err; @@ -373,39 +369,14 @@ out: return ret; } -asmlinkage long sys_fdatasync(unsigned int fd) +asmlinkage long sys_fsync(unsigned int fd) { - struct file * file; - struct address_space *mapping; - int ret, err; - - ret = -EBADF; - file = fget(fd); - if (!file) - goto out; - - ret = -EINVAL; - if (!file->f_op || !file->f_op->fsync) - goto out_putf; - - mapping = file->f_mapping; - - current->flags |= PF_SYNCWRITE; - ret = filemap_fdatawrite(mapping); - down(&mapping->host->i_sem); - err = file->f_op->fsync(file, file->f_dentry, 1); - if (!ret) - ret = err; - up(&mapping->host->i_sem); - err = filemap_fdatawait(mapping); - if (!ret) - ret = err; - current->flags &= ~PF_SYNCWRITE; + return do_fsync(fd, 0); +} -out_putf: - fput(file); -out: - return ret; +asmlinkage long sys_fdatasync(unsigned int fd) +{ + return do_fsync(fd, 1); } /* @@ -420,7 +391,7 @@ out: * private_lock is contended then so is mapping->tree_lock). */ static struct buffer_head * -__find_get_block_slow(struct block_device *bdev, sector_t block, int unused) +__find_get_block_slow(struct block_device *bdev, sector_t block) { struct inode *bd_inode = bdev->bd_inode; struct address_space *bd_mapping = bd_inode->i_mapping; @@ -522,13 +493,13 @@ static void free_more_memory(void) struct zone **zones; pg_data_t *pgdat; - wakeup_bdflush(1024); + wakeup_pdflush(1024); yield(); for_each_pgdat(pgdat) { - zones = pgdat->node_zonelists[GFP_NOFS&GFP_ZONEMASK].zones; + zones = pgdat->node_zonelists[gfp_zone(GFP_NOFS)].zones; if (*zones) - try_to_free_pages(zones, GFP_NOFS, 0); + try_to_free_pages(zones, GFP_NOFS); } } @@ -538,8 +509,8 @@ static void free_more_memory(void) */ static void end_buffer_async_read(struct buffer_head *bh, int uptodate) { - static DEFINE_SPINLOCK(page_uptodate_lock); unsigned long flags; + struct buffer_head *first; struct buffer_head *tmp; struct page *page; int page_uptodate = 1; @@ -561,7 +532,9 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate) * two buffer heads end IO at almost the same time and both * decide that the page is now completely done. */ - spin_lock_irqsave(&page_uptodate_lock, flags); + first = page_buffers(page); + local_irq_save(flags); + bit_spin_lock(BH_Uptodate_Lock, &first->b_state); clear_buffer_async_read(bh); unlock_buffer(bh); tmp = bh; @@ -574,7 +547,8 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate) } tmp = tmp->b_this_page; } while (tmp != bh); - spin_unlock_irqrestore(&page_uptodate_lock, flags); + bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); + local_irq_restore(flags); /* * If none of the buffers had errors and they are all @@ -586,7 +560,8 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate) return; still_busy: - spin_unlock_irqrestore(&page_uptodate_lock, flags); + bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); + local_irq_restore(flags); return; } @@ -597,8 +572,8 @@ still_busy: void end_buffer_async_write(struct buffer_head *bh, int uptodate) { char b[BDEVNAME_SIZE]; - static DEFINE_SPINLOCK(page_uptodate_lock); unsigned long flags; + struct buffer_head *first; struct buffer_head *tmp; struct page *page; @@ -619,7 +594,10 @@ void end_buffer_async_write(struct buffer_head *bh, int uptodate) SetPageError(page); } - spin_lock_irqsave(&page_uptodate_lock, flags); + first = page_buffers(page); + local_irq_save(flags); + bit_spin_lock(BH_Uptodate_Lock, &first->b_state); + clear_buffer_async_write(bh); unlock_buffer(bh); tmp = bh->b_this_page; @@ -630,12 +608,14 @@ void end_buffer_async_write(struct buffer_head *bh, int uptodate) } tmp = tmp->b_this_page; } - spin_unlock_irqrestore(&page_uptodate_lock, flags); + bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); + local_irq_restore(flags); end_page_writeback(page); return; still_busy: - spin_unlock_irqrestore(&page_uptodate_lock, flags); + bit_spin_unlock(BH_Uptodate_Lock, &first->b_state); + local_irq_restore(flags); return; } @@ -933,8 +913,7 @@ static int fsync_buffers_list(spinlock_t *lock, struct list_head *list) * contents - it is a noop if I/O is still in * flight on potentially older contents. */ - wait_on_buffer(bh); - ll_rw_block(WRITE, 1, &bh); + ll_rw_block(SWRITE, 1, &bh); brelse(bh); spin_lock(lock); } @@ -1043,12 +1022,13 @@ try_again: bh->b_state = 0; atomic_set(&bh->b_count, 0); + bh->b_private = NULL; bh->b_size = size; /* Link the buffer to its page */ set_bh_page(bh, page, offset); - bh->b_end_io = NULL; + init_buffer(bh, NULL, NULL); } return head; /* @@ -1186,7 +1166,7 @@ failed: * some of those buffers may be aliases of filesystem data. * grow_dev_page() will go BUG() if this happens. */ -static inline int +static int grow_buffers(struct block_device *bdev, sector_t block, int size) { struct page *page; @@ -1199,8 +1179,21 @@ grow_buffers(struct block_device *bdev, sector_t block, int size) } while ((size << sizebits) < PAGE_SIZE); index = block >> sizebits; - block = index << sizebits; + /* + * Check for a block which wants to lie outside our maximum possible + * pagecache index. (this comparison is done using sector_t types). + */ + if (unlikely(index != block >> sizebits)) { + char b[BDEVNAME_SIZE]; + + printk(KERN_ERR "%s: requested out-of-range block %llu for " + "device %s\n", + __FUNCTION__, (unsigned long long)block, + bdevname(bdev, b)); + return -EIO; + } + block = index << sizebits; /* Create a page with the proper size buffers.. */ page = grow_dev_page(bdev, block, index, size); if (!page) @@ -1227,12 +1220,16 @@ __getblk_slow(struct block_device *bdev, sector_t block, int size) for (;;) { struct buffer_head * bh; + int ret; bh = __find_get_block(bdev, block, size); if (bh) return bh; - if (!grow_buffers(bdev, block, size)) + ret = grow_buffers(bdev, block, size); + if (ret < 0) + return NULL; + if (ret == 0) free_more_memory(); } } @@ -1412,7 +1409,7 @@ static void bh_lru_install(struct buffer_head *bh) /* * Look up the bh in this cpu's LRU. If it's there, move it to the head. */ -static inline struct buffer_head * +static struct buffer_head * lookup_bh_lru(struct block_device *bdev, sector_t block, int size) { struct buffer_head *ret = NULL; @@ -1454,7 +1451,7 @@ __find_get_block(struct block_device *bdev, sector_t block, int size) struct buffer_head *bh = lookup_bh_lru(bdev, block, size); if (bh == NULL) { - bh = __find_get_block_slow(bdev, block, size); + bh = __find_get_block_slow(bdev, block); if (bh) bh_lru_install(bh); } @@ -1494,8 +1491,10 @@ EXPORT_SYMBOL(__getblk); void __breadahead(struct block_device *bdev, sector_t block, int size) { struct buffer_head *bh = __getblk(bdev, block, size); - ll_rw_block(READA, 1, &bh); - brelse(bh); + if (likely(bh)) { + ll_rw_block(READA, 1, &bh); + brelse(bh); + } } EXPORT_SYMBOL(__breadahead); @@ -1513,7 +1512,7 @@ __bread(struct block_device *bdev, sector_t block, int size) { struct buffer_head *bh = __getblk(bdev, block, size); - if (!buffer_uptodate(bh)) + if (likely(bh) && !buffer_uptodate(bh)) bh = __bread_slow(bh); return bh; } @@ -1560,7 +1559,7 @@ EXPORT_SYMBOL(set_bh_page); /* * Called when truncating a buffer on a page completely. */ -static inline void discard_buffer(struct buffer_head * bh) +static void discard_buffer(struct buffer_head * bh) { lock_buffer(bh); clear_buffer_dirty(bh); @@ -1587,7 +1586,7 @@ static inline void discard_buffer(struct buffer_head * bh) * * NOTE: @gfp_mask may go away, and this function may become non-blocking. */ -int try_to_release_page(struct page *page, int gfp_mask) +int try_to_release_page(struct page *page, gfp_t gfp_mask) { struct address_space * const mapping = page->mapping; @@ -1653,6 +1652,15 @@ out: } EXPORT_SYMBOL(block_invalidatepage); +int do_invalidatepage(struct page *page, unsigned long offset) +{ + int (*invalidatepage)(struct page *, unsigned long); + invalidatepage = page->mapping->a_ops->invalidatepage; + if (invalidatepage == NULL) + invalidatepage = block_invalidatepage; + return (*invalidatepage)(page, offset); +} + /* * We attach and possibly dirty the buffers atomically wrt * __set_page_dirty_buffers() via private_lock. try_to_free_buffers @@ -1710,7 +1718,7 @@ void unmap_underlying_metadata(struct block_device *bdev, sector_t block) might_sleep(); - old_bh = __find_get_block_slow(bdev, block, 0); + old_bh = __find_get_block_slow(bdev, block); if (old_bh) { clear_buffer_dirty(old_bh); wait_on_buffer(old_bh); @@ -1773,7 +1781,7 @@ static int __block_write_full_page(struct inode *inode, struct page *page, * handle that here by just cleaning them. */ - block = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits); + block = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits); head = page_buffers(page); bh = head; @@ -1951,7 +1959,6 @@ static int __block_prepare_write(struct inode *inode, struct page *page, if (err) break; if (buffer_new(bh)) { - clear_buffer_new(bh); unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr); if (PageUptodate(page)) { @@ -1993,9 +2000,14 @@ static int __block_prepare_write(struct inode *inode, struct page *page, if (!buffer_uptodate(*wait_bh)) err = -EIO; } - if (!err) - return err; - + if (!err) { + bh = head; + do { + if (buffer_new(bh)) + clear_buffer_new(bh); + } while ((bh = bh->b_this_page) != head); + return 0; + } /* Error case: */ /* * Zero out any newly allocated blocks to avoid exposing stale @@ -2161,11 +2173,12 @@ int block_read_full_page(struct page *page, get_block_t *get_block) * truncates. Uses prepare/commit_write to allow the filesystem to * deal with the hole. */ -int generic_cont_expand(struct inode *inode, loff_t size) +static int __generic_cont_expand(struct inode *inode, loff_t size, + pgoff_t index, unsigned int offset) { struct address_space *mapping = inode->i_mapping; struct page *page; - unsigned long index, offset, limit; + unsigned long limit; int err; err = -EFBIG; @@ -2177,24 +2190,24 @@ int generic_cont_expand(struct inode *inode, loff_t size) if (size > inode->i_sb->s_maxbytes) goto out; - offset = (size & (PAGE_CACHE_SIZE-1)); /* Within page */ - - /* ugh. in prepare/commit_write, if from==to==start of block, we - ** skip the prepare. make sure we never send an offset for the start - ** of a block - */ - if ((offset & (inode->i_sb->s_blocksize - 1)) == 0) { - offset++; - } - index = size >> PAGE_CACHE_SHIFT; err = -ENOMEM; page = grab_cache_page(mapping, index); if (!page) goto out; err = mapping->a_ops->prepare_write(NULL, page, offset, offset); - if (!err) { - err = mapping->a_ops->commit_write(NULL, page, offset, offset); + if (err) { + /* + * ->prepare_write() may have instantiated a few blocks + * outside i_size. Trim these off again. + */ + unlock_page(page); + page_cache_release(page); + vmtruncate(inode, inode->i_size); + goto out; } + + err = mapping->a_ops->commit_write(NULL, page, offset, offset); + unlock_page(page); page_cache_release(page); if (err > 0) @@ -2203,6 +2216,36 @@ out: return err; } +int generic_cont_expand(struct inode *inode, loff_t size) +{ + pgoff_t index; + unsigned int offset; + + offset = (size & (PAGE_CACHE_SIZE - 1)); /* Within page */ + + /* ugh. in prepare/commit_write, if from==to==start of block, we + ** skip the prepare. make sure we never send an offset for the start + ** of a block + */ + if ((offset & (inode->i_sb->s_blocksize - 1)) == 0) { + /* caller must handle this extra byte. */ + offset++; + } + index = size >> PAGE_CACHE_SHIFT; + + return __generic_cont_expand(inode, size, index, offset); +} + +int generic_cont_expand_simple(struct inode *inode, loff_t size) +{ + loff_t pos = size - 1; + pgoff_t index = pos >> PAGE_CACHE_SHIFT; + unsigned int offset = (pos & (PAGE_CACHE_SIZE - 1)) + 1; + + /* prepare/commit_write can handle even if from==to==start of block. */ + return __generic_cont_expand(inode, size, index, offset); +} + /* * For moronic filesystems that do not allow holes in file. * We may have to extend the file. @@ -2314,7 +2357,7 @@ int generic_commit_write(struct file *file, struct page *page, __block_commit_write(inode,page,from,to); /* * No need to use i_size_read() here, the i_size - * cannot change under us because we hold i_sem. + * cannot change under us because we hold i_mutex. */ if (pos > inode->i_size) { i_size_write(inode, pos); @@ -2611,7 +2654,7 @@ int block_truncate_page(struct address_space *mapping, pgoff_t index = from >> PAGE_CACHE_SHIFT; unsigned offset = from & (PAGE_CACHE_SIZE-1); unsigned blocksize; - pgoff_t iblock; + sector_t iblock; unsigned length, pos; struct inode *inode = mapping->host; struct page *page; @@ -2627,7 +2670,7 @@ int block_truncate_page(struct address_space *mapping, return 0; length = blocksize - length; - iblock = index << (PAGE_CACHE_SHIFT - inode->i_blkbits); + iblock = (sector_t)index << (PAGE_CACHE_SHIFT - inode->i_blkbits); page = grab_cache_page(mapping, index); err = -ENOMEM; @@ -2708,7 +2751,7 @@ int block_write_full_page(struct page *page, get_block_t *get_block, * they may have been added in ext3_writepage(). Make them * freeable here, so the page does not leak. */ - block_invalidatepage(page, 0); + do_invalidatepage(page, 0); unlock_page(page); return 0; /* don't care */ } @@ -2805,21 +2848,22 @@ int submit_bh(int rw, struct buffer_head * bh) /** * ll_rw_block: low-level access to block devices (DEPRECATED) - * @rw: whether to %READ or %WRITE or maybe %READA (readahead) + * @rw: whether to %READ or %WRITE or %SWRITE or maybe %READA (readahead) * @nr: number of &struct buffer_heads in the array * @bhs: array of pointers to &struct buffer_head * - * ll_rw_block() takes an array of pointers to &struct buffer_heads, - * and requests an I/O operation on them, either a %READ or a %WRITE. - * The third %READA option is described in the documentation for - * generic_make_request() which ll_rw_block() calls. + * ll_rw_block() takes an array of pointers to &struct buffer_heads, and + * requests an I/O operation on them, either a %READ or a %WRITE. The third + * %SWRITE is like %WRITE only we make sure that the *current* data in buffers + * are sent to disk. The fourth %READA option is described in the documentation + * for generic_make_request() which ll_rw_block() calls. * * This function drops any buffer that it cannot get a lock on (with the - * BH_Lock state bit), any buffer that appears to be clean when doing a - * write request, and any buffer that appears to be up-to-date when doing - * read request. Further it marks as clean buffers that are processed for - * writing (the buffer cache won't assume that they are actually clean until - * the buffer gets unlocked). + * BH_Lock state bit) unless SWRITE is required, any buffer that appears to be + * clean when doing a write request, and any buffer that appears to be + * up-to-date when doing read request. Further it marks as clean buffers that + * are processed for writing (the buffer cache won't assume that they are + * actually clean until the buffer gets unlocked). * * ll_rw_block sets b_end_io to simple completion handler that marks * the buffer up-to-date (if approriate), unlocks the buffer and wakes @@ -2835,25 +2879,27 @@ void ll_rw_block(int rw, int nr, struct buffer_head *bhs[]) for (i = 0; i < nr; i++) { struct buffer_head *bh = bhs[i]; - if (test_set_buffer_locked(bh)) + if (rw == SWRITE) + lock_buffer(bh); + else if (test_set_buffer_locked(bh)) continue; - get_bh(bh); - if (rw == WRITE) { + if (rw == WRITE || rw == SWRITE) { if (test_clear_buffer_dirty(bh)) { bh->b_end_io = end_buffer_write_sync; + get_bh(bh); submit_bh(WRITE, bh); continue; } } else { if (!buffer_uptodate(bh)) { bh->b_end_io = end_buffer_read_sync; + get_bh(bh); submit_bh(rw, bh); continue; } } unlock_buffer(bh); - put_bh(bh); } } @@ -3021,6 +3067,68 @@ asmlinkage long sys_bdflush(int func, long data) return 0; } +/* + * Migration function for pages with buffers. This function can only be used + * if the underlying filesystem guarantees that no other references to "page" + * exist. + */ +#ifdef CONFIG_MIGRATION +int buffer_migrate_page(struct page *newpage, struct page *page) +{ + struct address_space *mapping = page->mapping; + struct buffer_head *bh, *head; + int rc; + + if (!mapping) + return -EAGAIN; + + if (!page_has_buffers(page)) + return migrate_page(newpage, page); + + head = page_buffers(page); + + rc = migrate_page_remove_references(newpage, page, 3); + if (rc) + return rc; + + bh = head; + do { + get_bh(bh); + lock_buffer(bh); + bh = bh->b_this_page; + + } while (bh != head); + + ClearPagePrivate(page); + set_page_private(newpage, page_private(page)); + set_page_private(page, 0); + put_page(page); + get_page(newpage); + + bh = head; + do { + set_bh_page(bh, newpage, bh_offset(bh)); + bh = bh->b_this_page; + + } while (bh != head); + + SetPagePrivate(newpage); + + migrate_page_copy(newpage, page); + + bh = head; + do { + unlock_buffer(bh); + put_bh(bh); + bh = bh->b_this_page; + + } while (bh != head); + + return 0; +} +EXPORT_SYMBOL(buffer_migrate_page); +#endif + /* * Buffer-head allocation */ @@ -3054,14 +3162,13 @@ static void recalc_bh_state(void) buffer_heads_over_limit = (tot > max_buffer_heads); } -struct buffer_head *alloc_buffer_head(unsigned int __nocast gfp_flags) +struct buffer_head *alloc_buffer_head(gfp_t gfp_flags) { struct buffer_head *ret = kmem_cache_alloc(bh_cachep, gfp_flags); if (ret) { - preempt_disable(); - __get_cpu_var(bh_accounting).nr++; + get_cpu_var(bh_accounting).nr++; recalc_bh_state(); - preempt_enable(); + put_cpu_var(bh_accounting); } return ret; } @@ -3071,10 +3178,9 @@ void free_buffer_head(struct buffer_head *bh) { BUG_ON(!list_empty(&bh->b_assoc_buffers)); kmem_cache_free(bh_cachep, bh); - preempt_disable(); - __get_cpu_var(bh_accounting).nr--; + get_cpu_var(bh_accounting).nr--; recalc_bh_state(); - preempt_enable(); + put_cpu_var(bh_accounting); } EXPORT_SYMBOL(free_buffer_head); @@ -3145,6 +3251,7 @@ EXPORT_SYMBOL(fsync_bdev); EXPORT_SYMBOL(generic_block_bmap); EXPORT_SYMBOL(generic_commit_write); EXPORT_SYMBOL(generic_cont_expand); +EXPORT_SYMBOL(generic_cont_expand_simple); EXPORT_SYMBOL(init_buffer); EXPORT_SYMBOL(invalidate_bdev); EXPORT_SYMBOL(ll_rw_block);