diff options
Diffstat (limited to 'fs/reiserfs/file.c')
| -rw-r--r-- | fs/reiserfs/file.c | 1240 |
1 files changed, 1 insertions, 1239 deletions
diff --git a/fs/reiserfs/file.c b/fs/reiserfs/file.c index 2070aee..a804903 100644 --- a/fs/reiserfs/file.c +++ b/fs/reiserfs/file.c @@ -153,608 +153,6 @@ static int reiserfs_sync_file(struct file *p_s_filp, return (n_err < 0) ? -EIO : 0; } -/* I really do not want to play with memory shortage right now, so - to simplify the code, we are not going to write more than this much pages at - a time. This still should considerably improve performance compared to 4k - at a time case. This is 32 pages of 4k size. */ -#define REISERFS_WRITE_PAGES_AT_A_TIME (128 * 1024) / PAGE_CACHE_SIZE - -/* Allocates blocks for a file to fulfil write request. - Maps all unmapped but prepared pages from the list. - Updates metadata with newly allocated blocknumbers as needed */ -static int reiserfs_allocate_blocks_for_region(struct reiserfs_transaction_handle *th, struct inode *inode, /* Inode we work with */ - loff_t pos, /* Writing position */ - int num_pages, /* number of pages write going - to touch */ - int write_bytes, /* amount of bytes to write */ - struct page **prepared_pages, /* array of - prepared pages - */ - int blocks_to_allocate /* Amount of blocks we - need to allocate to - fit the data into file - */ - ) -{ - struct cpu_key key; // cpu key of item that we are going to deal with - struct item_head *ih; // pointer to item head that we are going to deal with - struct buffer_head *bh; // Buffer head that contains items that we are going to deal with - __le32 *item; // pointer to item we are going to deal with - INITIALIZE_PATH(path); // path to item, that we are going to deal with. - b_blocknr_t *allocated_blocks; // Pointer to a place where allocated blocknumbers would be stored. - reiserfs_blocknr_hint_t hint; // hint structure for block allocator. - size_t res; // return value of various functions that we call. - int curr_block; // current block used to keep track of unmapped blocks. - int i; // loop counter - int itempos; // position in item - unsigned int from = (pos & (PAGE_CACHE_SIZE - 1)); // writing position in - // first page - unsigned int to = ((pos + write_bytes - 1) & (PAGE_CACHE_SIZE - 1)) + 1; /* last modified byte offset in last page */ - __u64 hole_size; // amount of blocks for a file hole, if it needed to be created. - int modifying_this_item = 0; // Flag for items traversal code to keep track - // of the fact that we already prepared - // current block for journal - int will_prealloc = 0; - RFALSE(!blocks_to_allocate, - "green-9004: tried to allocate zero blocks?"); - - /* only preallocate if this is a small write */ - if (REISERFS_I(inode)->i_prealloc_count || - (!(write_bytes & (inode->i_sb->s_blocksize - 1)) && - blocks_to_allocate < - REISERFS_SB(inode->i_sb)->s_alloc_options.preallocsize)) - will_prealloc = - REISERFS_SB(inode->i_sb)->s_alloc_options.preallocsize; - - allocated_blocks = kmalloc((blocks_to_allocate + will_prealloc) * - sizeof(b_blocknr_t), GFP_NOFS); - if (!allocated_blocks) - return -ENOMEM; - - /* First we compose a key to point at the writing position, we want to do - that outside of any locking region. */ - make_cpu_key(&key, inode, pos + 1, TYPE_ANY, 3 /*key length */ ); - - /* If we came here, it means we absolutely need to open a transaction, - since we need to allocate some blocks */ - reiserfs_write_lock(inode->i_sb); // Journaling stuff and we need that. - res = journal_begin(th, inode->i_sb, JOURNAL_PER_BALANCE_CNT * 3 + 1 + 2 * REISERFS_QUOTA_TRANS_BLOCKS(inode->i_sb)); // Wish I know if this number enough - if (res) - goto error_exit; - reiserfs_update_inode_transaction(inode); - - /* Look for the in-tree position of our write, need path for block allocator */ - res = search_for_position_by_key(inode->i_sb, &key, &path); - if (res == IO_ERROR) { - res = -EIO; - goto error_exit; - } - - /* Allocate blocks */ - /* First fill in "hint" structure for block allocator */ - hint.th = th; // transaction handle. - hint.path = &path; // Path, so that block allocator can determine packing locality or whatever it needs to determine. - hint.inode = inode; // Inode is needed by block allocator too. - hint.search_start = 0; // We have no hint on where to search free blocks for block allocator. - hint.key = key.on_disk_key; // on disk key of file. - hint.block = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9); // Number of disk blocks this file occupies already. - hint.formatted_node = 0; // We are allocating blocks for unformatted node. - hint.preallocate = will_prealloc; - - /* Call block allocator to allocate blocks */ - res = - reiserfs_allocate_blocknrs(&hint, allocated_blocks, - blocks_to_allocate, blocks_to_allocate); - if (res != CARRY_ON) { - if (res == NO_DISK_SPACE) { - /* We flush the transaction in case of no space. This way some - blocks might become free */ - SB_JOURNAL(inode->i_sb)->j_must_wait = 1; - res = restart_transaction(th, inode, &path); - if (res) - goto error_exit; - - /* We might have scheduled, so search again */ - res = - search_for_position_by_key(inode->i_sb, &key, - &path); - if (res == IO_ERROR) { - res = -EIO; - goto error_exit; - } - - /* update changed info for hint structure. */ - res = - reiserfs_allocate_blocknrs(&hint, allocated_blocks, - blocks_to_allocate, - blocks_to_allocate); - if (res != CARRY_ON) { - res = res == QUOTA_EXCEEDED ? -EDQUOT : -ENOSPC; - pathrelse(&path); - goto error_exit; - } - } else { - res = res == QUOTA_EXCEEDED ? -EDQUOT : -ENOSPC; - pathrelse(&path); - goto error_exit; - } - } -#ifdef __BIG_ENDIAN - // Too bad, I have not found any way to convert a given region from - // cpu format to little endian format - { - int i; - for (i = 0; i < blocks_to_allocate; i++) - allocated_blocks[i] = cpu_to_le32(allocated_blocks[i]); - } -#endif - - /* Blocks allocating well might have scheduled and tree might have changed, - let's search the tree again */ - /* find where in the tree our write should go */ - res = search_for_position_by_key(inode->i_sb, &key, &path); - if (res == IO_ERROR) { - res = -EIO; - goto error_exit_free_blocks; - } - - bh = get_last_bh(&path); // Get a bufferhead for last element in path. - ih = get_ih(&path); // Get a pointer to last item head in path. - item = get_item(&path); // Get a pointer to last item in path - - /* Let's see what we have found */ - if (res != POSITION_FOUND) { /* position not found, this means that we - might need to append file with holes - first */ - // Since we are writing past the file's end, we need to find out if - // there is a hole that needs to be inserted before our writing - // position, and how many blocks it is going to cover (we need to - // populate pointers to file blocks representing the hole with zeros) - - { - int item_offset = 1; - /* - * if ih is stat data, its offset is 0 and we don't want to - * add 1 to pos in the hole_size calculation - */ - if (is_statdata_le_ih(ih)) - item_offset = 0; - hole_size = (pos + item_offset - - (le_key_k_offset - (get_inode_item_key_version(inode), - &(ih->ih_key)) + op_bytes_number(ih, - inode-> - i_sb-> - s_blocksize))) - >> inode->i_sb->s_blocksize_bits; - } - - if (hole_size > 0) { - int to_paste = min_t(__u64, hole_size, MAX_ITEM_LEN(inode->i_sb->s_blocksize) / UNFM_P_SIZE); // How much data to insert first time. - /* area filled with zeroes, to supply as list of zero blocknumbers - We allocate it outside of loop just in case loop would spin for - several iterations. */ - char *zeros = kzalloc(to_paste * UNFM_P_SIZE, GFP_ATOMIC); // We cannot insert more than MAX_ITEM_LEN bytes anyway. - if (!zeros) { - res = -ENOMEM; - goto error_exit_free_blocks; - } - do { - to_paste = - min_t(__u64, hole_size, - MAX_ITEM_LEN(inode->i_sb-> - s_blocksize) / - UNFM_P_SIZE); - if (is_indirect_le_ih(ih)) { - /* Ok, there is existing indirect item already. Need to append it */ - /* Calculate position past inserted item */ - make_cpu_key(&key, inode, - le_key_k_offset - (get_inode_item_key_version - (inode), - &(ih->ih_key)) + - op_bytes_number(ih, - inode-> - i_sb-> - s_blocksize), - TYPE_INDIRECT, 3); - res = - reiserfs_paste_into_item(th, &path, - &key, - inode, - (char *) - zeros, - UNFM_P_SIZE - * - to_paste); - if (res) { - kfree(zeros); - goto error_exit_free_blocks; - } - } else if (is_statdata_le_ih(ih)) { - /* No existing item, create it */ - /* item head for new item */ - struct item_head ins_ih; - - /* create a key for our new item */ - make_cpu_key(&key, inode, 1, - TYPE_INDIRECT, 3); - - /* Create new item head for our new item */ - make_le_item_head(&ins_ih, &key, - key.version, 1, - TYPE_INDIRECT, - to_paste * - UNFM_P_SIZE, - 0 /* free space */ ); - - /* Find where such item should live in the tree */ - res = - search_item(inode->i_sb, &key, - &path); - if (res != ITEM_NOT_FOUND) { - /* item should not exist, otherwise we have error */ - if (res != -ENOSPC) { - reiserfs_warning(inode-> - i_sb, - "green-9008: search_by_key (%K) returned %d", - &key, - res); - } - res = -EIO; - kfree(zeros); - goto error_exit_free_blocks; - } - res = - reiserfs_insert_item(th, &path, - &key, &ins_ih, - inode, - (char *)zeros); - } else { - reiserfs_panic(inode->i_sb, - "green-9011: Unexpected key type %K\n", - &key); - } - if (res) { - kfree(zeros); - goto error_exit_free_blocks; - } - /* Now we want to check if transaction is too full, and if it is - we restart it. This will also free the path. */ - if (journal_transaction_should_end - (th, th->t_blocks_allocated)) { - inode->i_size = cpu_key_k_offset(&key) + - (to_paste << inode->i_blkbits); - res = - restart_transaction(th, inode, - &path); - if (res) { - pathrelse(&path); - kfree(zeros); - goto error_exit; - } - } - - /* Well, need to recalculate path and stuff */ - set_cpu_key_k_offset(&key, - cpu_key_k_offset(&key) + - (to_paste << inode-> - i_blkbits)); - res = - search_for_position_by_key(inode->i_sb, - &key, &path); - if (res == IO_ERROR) { - res = -EIO; - kfree(zeros); - goto error_exit_free_blocks; - } - bh = get_last_bh(&path); - ih = get_ih(&path); - item = get_item(&path); - hole_size -= to_paste; - } while (hole_size); - kfree(zeros); - } - } - // Go through existing indirect items first - // replace all zeroes with blocknumbers from list - // Note that if no corresponding item was found, by previous search, - // it means there are no existing in-tree representation for file area - // we are going to overwrite, so there is nothing to scan through for holes. - for (curr_block = 0, itempos = path.pos_in_item; - curr_block < blocks_to_allocate && res == POSITION_FOUND;) { - retry: - - if (itempos >= ih_item_len(ih) / UNFM_P_SIZE) { - /* We run out of data in this indirect item, let's look for another - one. */ - /* First if we are already modifying current item, log it */ - if (modifying_this_item) { - journal_mark_dirty(th, inode->i_sb, bh); - modifying_this_item = 0; - } - /* Then set the key to look for a new indirect item (offset of old - item is added to old item length */ - set_cpu_key_k_offset(&key, - le_key_k_offset - (get_inode_item_key_version(inode), - &(ih->ih_key)) + - op_bytes_number(ih, - inode->i_sb-> - s_blocksize)); - /* Search ofor position of new key in the tree. */ - res = - search_for_position_by_key(inode->i_sb, &key, - &path); - if (res == IO_ERROR) { - res = -EIO; - goto error_exit_free_blocks; - } - bh = get_last_bh(&path); - ih = get_ih(&path); - item = get_item(&path); - itempos = path.pos_in_item; - continue; // loop to check all kinds of conditions and so on. - } - /* Ok, we have correct position in item now, so let's see if it is - representing file hole (blocknumber is zero) and fill it if needed */ - if (!item[itempos]) { - /* Ok, a hole. Now we need to check if we already prepared this - block to be journaled */ - while (!modifying_this_item) { // loop until succeed - /* Well, this item is not journaled yet, so we must prepare - it for journal first, before we can change it */ - struct item_head tmp_ih; // We copy item head of found item, - // here to detect if fs changed under - // us while we were preparing for - // journal. - int fs_gen; // We store fs generation here to find if someone - // changes fs under our feet - - copy_item_head(&tmp_ih, ih); // Remember itemhead - fs_gen = get_generation(inode->i_sb); // remember fs generation - reiserfs_prepare_for_journal(inode->i_sb, bh, 1); // Prepare a buffer within which indirect item is stored for changing. - if (fs_changed(fs_gen, inode->i_sb) - && item_moved(&tmp_ih, &path)) { - // Sigh, fs was changed under us, we need to look for new - // location of item we are working with - - /* unmark prepaerd area as journaled and search for it's - new position */ - reiserfs_restore_prepared_buffer(inode-> - i_sb, - bh); - res = - search_for_position_by_key(inode-> - i_sb, - &key, - &path); - if (res == IO_ERROR) { - res = -EIO; - goto error_exit_free_blocks; - } - bh = get_last_bh(&path); - ih = get_ih(&path); - item = get_item(&path); - itempos = path.pos_in_item; - goto retry; - } - modifying_this_item = 1; - } - item[itempos] = allocated_blocks[curr_block]; // Assign new block - curr_block++; - } - itempos++; - } - - if (modifying_this_item) { // We need to log last-accessed block, if it - // was modified, but not logged yet. - journal_mark_dirty(th, inode->i_sb, bh); - } - - if (curr_block < blocks_to_allocate) { - // Oh, well need to append to indirect item, or to create indirect item - // if there weren't any - if (is_indirect_le_ih(ih)) { - // Existing indirect item - append. First calculate key for append - // position. We do not need to recalculate path as it should - // already point to correct place. - make_cpu_key(&key, inode, - le_key_k_offset(get_inode_item_key_version - (inode), - &(ih->ih_key)) + - op_bytes_number(ih, - inode->i_sb->s_blocksize), - TYPE_INDIRECT, 3); - res = - reiserfs_paste_into_item(th, &path, &key, inode, - (char *)(allocated_blocks + - curr_block), - UNFM_P_SIZE * - (blocks_to_allocate - - curr_block)); - if (res) { - goto error_exit_free_blocks; - } - } else if (is_statdata_le_ih(ih)) { - // Last found item was statdata. That means we need to create indirect item. - struct item_head ins_ih; /* itemhead for new item */ - - /* create a key for our new item */ - make_cpu_key(&key, inode, 1, TYPE_INDIRECT, 3); // Position one, - // because that's - // where first - // indirect item - // begins - /* Create new item head for our new item */ - make_le_item_head(&ins_ih, &key, key.version, 1, - TYPE_INDIRECT, - (blocks_to_allocate - - curr_block) * UNFM_P_SIZE, - 0 /* free space */ ); - /* Find where such item should live in the tree */ - res = search_item(inode->i_sb, &key, &path); - if (res != ITEM_NOT_FOUND) { - /* Well, if we have found such item already, or some error - occured, we need to warn user and return error */ - if (res != -ENOSPC) { - reiserfs_warning(inode->i_sb, - "green-9009: search_by_key (%K) " - "returned %d", &key, - res); - } - res = -EIO; - goto error_exit_free_blocks; - } - /* Insert item into the tree with the data as its body */ - res = - reiserfs_insert_item(th, &path, &key, &ins_ih, - inode, - (char *)(allocated_blocks + - curr_block)); - } else { - reiserfs_panic(inode->i_sb, - "green-9010: unexpected item type for key %K\n", - &key); - } - } - // the caller is responsible for closing the transaction - // unless we return an error, they are also responsible for logging - // the inode. - // - pathrelse(&path); - /* - * cleanup prellocation from previous writes - * if this is a partial block write - */ - if (write_bytes & (inode->i_sb->s_blocksize - 1)) - reiserfs_discard_prealloc(th, inode); - reiserfs_write_unlock(inode->i_sb); - - // go through all the pages/buffers and map the buffers to newly allocated - // blocks (so that system knows where to write these pages later). - curr_block = 0; - for (i = 0; i < num_pages; i++) { - struct page *page = prepared_pages[i]; //current page - struct buffer_head *head = page_buffers(page); // first buffer for a page - int block_start, block_end; // in-page offsets for buffers. - - if (!page_buffers(page)) - reiserfs_panic(inode->i_sb, - "green-9005: No buffers for prepared page???"); - - /* For each buffer in page */ - for (bh = head, block_start = 0; bh != head || !block_start; - block_start = block_end, bh = bh->b_this_page) { - if (!bh) - reiserfs_panic(inode->i_sb, - "green-9006: Allocated but absent buffer for a page?"); - block_end = block_start + inode->i_sb->s_blocksize; - if (i == 0 && block_end <= from) - /* if this buffer is before requested data to map, skip it */ - continue; - if (i == num_pages - 1 && block_start >= to) - /* If this buffer is after requested data to map, abort - processing of current page */ - break; - - if (!buffer_mapped(bh)) { // Ok, unmapped buffer, need to map it - map_bh(bh, inode->i_sb, - le32_to_cpu(allocated_blocks - [curr_block])); - curr_block++; - set_buffer_new(bh); - } - } - } - - RFALSE(curr_block > blocks_to_allocate, - "green-9007: Used too many blocks? weird"); - - kfree(allocated_blocks); - return 0; - -// Need to deal with transaction here. - error_exit_free_blocks: - pathrelse(&path); - // free blocks - for (i = 0; i < blocks_to_allocate; i++) - reiserfs_free_block(th, inode, le32_to_cpu(allocated_blocks[i]), - 1); - - error_exit: - if (th->t_trans_id) { - int err; - // update any changes we made to blk count - mark_inode_dirty(inode); - err = - journal_end(th, inode->i_sb, - JOURNAL_PER_BALANCE_CNT * 3 + 1 + - 2 * REISERFS_QUOTA_TRANS_BLOCKS(inode->i_sb)); - if (err) - res = err; - } - reiserfs_write_unlock(inode->i_sb); - kfree(allocated_blocks); - - return res; -} - -/* Unlock pages prepared by reiserfs_prepare_file_region_for_write */ -static void reiserfs_unprepare_pages(struct page **prepared_pages, /* list of locked pages */ - size_t num_pages /* amount of pages */ ) -{ - int i; // loop counter - - for (i = 0; i < num_pages; i++) { - struct page *page = prepared_pages[i]; - - try_to_free_buffers(page); - unlock_page(page); - page_cache_release(page); - } -} - -/* This function will copy data from userspace to specified pages within - supplied byte range */ -static int reiserfs_copy_from_user_to_file_region(loff_t pos, /* In-file position */ - int num_pages, /* Number of pages affected */ - int write_bytes, /* Amount of bytes to write */ - struct page **prepared_pages, /* pointer to - array to - prepared pages - */ - const char __user * buf /* Pointer to user-supplied - data */ - ) -{ - long page_fault = 0; // status of copy_from_user. - int i; // loop counter. - int offset; // offset in page - - for (i = 0, offset = (pos & (PAGE_CACHE_SIZE - 1)); i < num_pages; - i++, offset = 0) { - size_t count = min_t(size_t, PAGE_CACHE_SIZE - offset, write_bytes); // How much of bytes to write to this page - struct page *page = prepared_pages[i]; // Current page we process. - - fault_in_pages_readable(buf, count); - - /* Copy data from userspace to the current page */ - kmap(page); - page_fault = __copy_from_user(page_address(page) + offset, buf, count); // Copy the data. - /* Flush processor's dcache for this page */ - flush_dcache_page(page); - kunmap(page); - buf += count; - write_bytes -= count; - - if (page_fault) - break; // Was there a fault? abort. - } - - return page_fault ? -EFAULT : 0; -} - /* taken fs/buffer.c:__block_commit_write */ int reiserfs_commit_page(struct inode *inode, struct page *page, unsigned from, unsigned to) @@ -824,432 +222,6 @@ int reiserfs_commit_page(struct inode *inode, struct page *page, return ret; } -/* Submit pages for write. This was separated from actual file copying - because we might want to allocate block numbers in-between. - This function assumes that caller will adjust file size to correct value. */ -static int reiserfs_submit_file_region_for_write(struct reiserfs_transaction_handle *th, struct inode *inode, loff_t pos, /* Writing position offset */ - size_t num_pages, /* Number of pages to write */ - size_t write_bytes, /* number of bytes to write */ - struct page **prepared_pages /* list of pages */ - ) -{ - int status; // return status of block_commit_write. - int retval = 0; // Return value we are going to return. - int i; // loop counter - int offset; // Writing offset in page. - int orig_write_bytes = write_bytes; - int sd_update = 0; - - for (i = 0, offset = (pos & (PAGE_CACHE_SIZE - 1)); i < num_pages; - i++, offset = 0) { - int count = min_t(int, PAGE_CACHE_SIZE - offset, write_bytes); // How much of bytes to write to this page - struct page *page = prepared_pages[i]; // Current page we process. - - status = - reiserfs_commit_page(inode, page, offset, offset + count); - if (status) - retval = status; // To not overcomplicate matters We are going to - // submit all the pages even if there was error. - // we only remember error status to report it on - // exit. - write_bytes -= count; - } - /* now that we've gotten all the ordered buffers marked dirty, - * we can safely update i_size and close any running transaction - */ - if (pos + orig_write_bytes > inode->i_size) { - inode->i_size = pos + orig_write_bytes; // Set new size - /* If the file have grown so much that tail packing is no - * longer possible, reset "need to pack" flag */ - if ((have_large_tails(inode->i_sb) && - inode->i_size > i_block_size(inode) * 4) || - (have_small_tails(inode->i_sb) && - inode->i_size > i_block_size(inode))) - REISERFS_I(inode)->i_flags &= ~i_pack_on_close_mask; - else if ((have_large_tails(inode->i_sb) && - inode->i_size < i_block_size(inode) * 4) || - (have_small_tails(inode->i_sb) && - inode->i_size < i_block_size(inode))) - REISERFS_I(inode)->i_flags |= i_pack_on_close_mask; - - if (th->t_trans_id) { - reiserfs_write_lock(inode->i_sb); - // this sets the proper flags for O_SYNC to trigger a commit - mark_inode_dirty(inode); - reiserfs_write_unlock(inode->i_sb); - } else { - reiserfs_write_lock(inode->i_sb); - reiserfs_update_inode_transaction(inode); - mark_inode_dirty(inode); - reiserfs_write_unlock(inode->i_sb); - } - - sd_update = 1; - } - if (th->t_trans_id) { - reiserfs_write_lock(inode->i_sb); - if (!sd_update) - mark_inode_dirty(inode); - status = journal_end(th, th->t_super, th->t_blocks_allocated); - if (status) - retval = status; - reiserfs_write_unlock(inode->i_sb); - } - th->t_trans_id = 0; - - /* - * we have to unlock the pages after updating i_size, otherwise - * we race with writepage - */ - for (i = 0; i < num_pages; i++) { - struct page *page = prepared_pages[i]; - unlock_page(page); - mark_page_accessed(page); - page_cache_release(page); - } - return retval; -} - -/* Look if passed writing region is going to touch file's tail - (if it is present). And if it is, convert the tail to unformatted node */ -static int reiserfs_check_for_tail_and_convert(struct inode *inode, /* inode to deal with */ - loff_t pos, /* Writing position */ - int write_bytes /* amount of bytes to write */ - ) -{ - INITIALIZE_PATH(path); // needed for search_for_position - struct cpu_key key; // Key that would represent last touched writing byte. - struct item_head *ih; // item header of found block; - int res; // Return value of various functions we call. - int cont_expand_offset; // We will put offset for generic_cont_expand here - // This can be int just because tails are created - // only for small files. - -/* this embodies a dependency on a particular tail policy */ - if (inode->i_size >= inode->i_sb->s_blocksize * 4) { - /* such a big files do not have tails, so we won't bother ourselves - to look for tails, simply return */ - return 0; - } - - reiserfs_write_lock(inode->i_sb); - /* find the item containing the last byte to be written, or if - * writing past the end of the file then the last item of the - * file (and then we check its type). */ - make_cpu_key(&key, inode, pos + write_bytes + 1, TYPE_ANY, - 3 /*key length */ ); - res = search_for_position_by_key(inode->i_sb, &key, &path); - if (res == IO_ERROR) { - reiserfs_write_unlock(inode->i_sb); - return -EIO; - } - ih = get_ih(&path); - res = 0; - if (is_direct_le_ih(ih)) { - /* Ok, closest item is file tail (tails are stored in "direct" - * items), so we need to unpack it. */ - /* To not overcomplicate matters, we just call generic_cont_expand - which will in turn call other stuff and finally will boil down to - reiserfs_get_block() that would do necessary conversion. */ - cont_expand_offset = - le_key_k_offset(get_inode_item_key_version(inode), - &(ih->ih_key)); - pathrelse(&path); - res = generic_cont_expand(inode, cont_expand_offset); - } else - pathrelse(&path); - - reiserfs_write_unlock(inode->i_sb); - return res; -} - -/* This function locks pages starting from @pos for @inode. - @num_pages pages are locked and stored in - @prepared_pages array. Also buffers are allocated for these pages. - First and last page of the region is read if it is overwritten only - partially. If last page did not exist before write (file hole or file - append), it is zeroed, then. - Returns number of unallocated blocks that should be allocated to cover - new file data.*/ -static int reiserfs_prepare_file_region_for_write(struct inode *inode - /* Inode of the file */ , - loff_t pos, /* position in the file */ - size_t num_pages, /* number of pages to - prepare */ - size_t write_bytes, /* Amount of bytes to be - overwritten from - @pos */ - struct page **prepared_pages /* pointer to array - where to store - prepared pages */ - ) -{ - int res = 0; // Return values of different functions we call. - unsigned long index = pos >> PAGE_CACHE_SHIFT; // Offset in file in pages. - int from = (pos & (PAGE_CACHE_SIZE - 1)); // Writing offset in first page - int to = ((pos + write_bytes - 1) & (PAGE_CACHE_SIZE - 1)) + 1; - /* offset of last modified byte in last - page */ - struct address_space *mapping = inode->i_mapping; // Pages are mapped here. - int i; // Simple counter - int blocks = 0; /* Return value (blocks that should be allocated) */ - struct buffer_head *bh, *head; // Current bufferhead and first bufferhead - // of a page. - unsigned block_start, block_end; // Starting and ending offsets of current - // buffer in the page. - struct buffer_head *wait[2], **wait_bh = wait; // Buffers for page, if - // Page appeared to be not up - // to date. Note how we have - // at most 2 buffers, this is - // because we at most may - // partially overwrite two - // buffers for one page. One at // the beginning of write area - // and one at the end. - // Everything inthe middle gets // overwritten totally. - - struct cpu_key key; // cpu key of item that we are going to deal with - struct item_head *ih = NULL; // pointer to item head that we are going to deal with - struct buffer_head *itembuf = NULL; // Buffer head that contains items that we are going to deal with - INITIALIZE_PATH(path); // path to item, that we are going to deal with. - __le32 *item = NULL; // pointer to item we are going to deal with - int item_pos = -1; /* Position in indirect item */ - - if (num_pages < 1) { - reiserfs_warning(inode->i_sb, - "green-9001: reiserfs_prepare_file_region_for_write " - "called with zero number of pages to process"); - return -EFAULT; - } - - /* We have 2 loops for pages. In first loop we grab and lock the pages, so - that nobody would touch these until we release the pages. Then - we'd start to deal with mapping buffers to blocks. */ - for (i = 0; i < num_pages; i++) { - prepared_pages[i] = grab_cache_page(mapping, index + i); // locks the page - if (!prepared_pages[i]) { - res = -ENOMEM; - goto failed_page_grabbing; - } - if (!page_has_buffers(prepared_pages[i])) - create_empty_buffers(prepared_pages[i], - inode->i_sb->s_blocksize, 0); - } - - /* Let's count amount of blocks for a case where all the blocks - overwritten are new (we will substract already allocated blocks later) */ - if (num_pages > 2) - /* These are full-overwritten pages so we count all the blocks in - these pages are counted as needed to be allocated */ - blocks = - (num_pages - 2) << (PAGE_CACHE_SHIFT - inode->i_blkbits); - - /* count blocks needed for first page (possibly partially written) */ - blocks += ((PAGE_CACHE_SIZE - from) >> inode->i_blkbits) + !!(from & (inode->i_sb->s_blocksize - 1)); /* roundup */ - - /* Now we account for last page. If last page == first page (we - overwrite only one page), we substract all the blocks past the - last writing position in a page out of already calculated number - of blocks */ - blocks += ((num_pages > 1) << (PAGE_CACHE_SHIFT - inode->i_blkbits)) - - ((PAGE_CACHE_SIZE - to) >> inode->i_blkbits); - /* Note how we do not roundup here since partial blocks still - should be allocated */ - - /* Now if all the write area lies past the file end, no point in - maping blocks, since there is none, so we just zero out remaining - parts of first and last pages in write area (if needed) */ - if ((pos & ~((loff_t) PAGE_CACHE_SIZE - 1)) > inode->i_size) { - if (from != 0) /* First page needs to be partially zeroed */ - zero_user_page(prepared_pages[0], 0, from, KM_USER0); - - if (to != PAGE_CACHE_SIZE) /* Last page needs to be partially zeroed */ - zero_user_page(prepared_pages[num_pages-1], to, - PAGE_CACHE_SIZE - to, KM_USER0); - - /* Since all blocks are new - use already calculated value */ - return blocks; - } - - /* Well, since we write somewhere into the middle of a file, there is - possibility we are writing over some already allocated blocks, so - let's map these blocks and substract number of such blocks out of blocks - we need to allocate (calculated above) */ - /* Mask write position to start on blocksize, we do it out of the - loop for performance reasons */ - pos &= ~((loff_t) inode->i_sb->s_blocksize - 1); - /* Set cpu key to the starting position in a file (on left block boundary) */ - make_cpu_key(&key, inode, - 1 + ((pos) & ~((loff_t) inode->i_sb->s_blocksize - 1)), - TYPE_ANY, 3 /*key length */ ); - - reiserfs_write_lock(inode->i_sb); // We need that for at least search_by_key() - for (i = 0; i < num_pages; i++) { - - head = page_buffers(prepared_pages[i]); - /* For each buffer in the page */ - for (bh = head, block_start = 0; bh != head || !block_start; - block_start = block_end, bh = bh->b_this_page) { - if (!bh) - reiserfs_panic(inode->i_sb, - "green-9002: Allocated but absent buffer for a page?"); - /* Find where this buffer ends */ - block_end = block_start + inode->i_sb->s_blocksize; - if (i == 0 && block_end <= from) - /* if this buffer is before requested data to map, skip it */ - continue; - - if (i == num_pages - 1 && block_start >= to) { - /* If this buffer is after requested data to map, abort - processing of current page */ - break; - } - - if (buffer_mapped(bh) && bh->b_blocknr != 0) { - /* This is optimisation for a case where buffer is mapped - and have blocknumber assigned. In case significant amount - of such buffers are present, we may avoid some amount - of search_by_key calls. - Probably it would be possible to move parts of this code - out of BKL, but I afraid that would overcomplicate code - without any noticeable benefit. - */ - item_pos++; - /* Update the key */ - set_cpu_key_k_offset(&key, - cpu_key_k_offset(&key) + - inode->i_sb->s_blocksize); - blocks--; // Decrease the amount of blocks that need to be - // allocated - continue; // Go to the next buffer - } - - if (!itembuf || /* if first iteration */ - item_pos >= ih_item_len(ih) / UNFM_P_SIZE) { /* or if we progressed past the - current unformatted_item */ - /* Try to find next item */ - res = - search_for_position_by_key(inode->i_sb, - &key, &path); - /* Abort if no more items */ - if (res != POSITION_FOUND) { - /* make sure later loops don't use this item */ - itembuf = NULL; - item = NULL; - break; - } - - /* Update information about current indirect item */ - itembuf = get_last_bh(&path); - ih = get_ih(&path); - item = get_item(&path); - item_pos = path.pos_in_item; - - RFALSE(!is_indirect_le_ih(ih), - "green-9003: indirect item expected"); - } - - /* See if there is some block associated with the file - at that position, map the buffer to this block */ - if (get_block_num(item, item_pos)) { - map_bh(bh, inode->i_sb, - get_block_num(item, item_pos)); - blocks--; // Decrease the amount of blocks that need to be - // allocated - } - item_pos++; - /* Update the key */ - set_cpu_key_k_offset(&key, - cpu_key_k_offset(&key) + - inode->i_sb->s_blocksize); - } - } - pathrelse(&path); // Free the path - reiserfs_write_unlock(inode->i_sb); - - /* Now zero out unmappend buffers for the first and last pages of - write area or issue read requests if page is mapped. */ - /* First page, see if it is not uptodate */ - if (!PageUptodate(prepared_pages[0])) { - head = page_buffers(prepared_pages[0]); - - /* For each buffer in page */ - for (bh = head, block_start = 0; bh != head || !block_start; - block_start = block_end, bh = bh->b_this_page) { - - if (!bh) - reiserfs_panic(inode->i_sb, - "green-9002: Allocated but absent buffer for a page?"); - /* Find where this buffer ends */ - block_end = block_start + inode->i_sb->s_blocksize; - if (block_end <= from) - /* if this buffer is before requested data to map, skip it */ - continue; - if (block_start < from) { /* Aha, our partial buffer */ - if (buffer_mapped(bh)) { /* If it is mapped, we need to - issue READ request for it to - not loose data */ - ll_rw_block(READ, 1, &bh); - *wait_bh++ = bh; - } else { /* Not mapped, zero it */ - zero_user_page(prepared_pages[0], - block_start, - from - block_start, KM_USER0); - set_buffer_uptodate(bh); - } - } - } - } - - /* Last page, see if it is not uptodate, or if the last page is past the end of the file. */ - if (!PageUptodate(prepared_pages[num_pages - 1]) || - ((pos + write_bytes) >> PAGE_CACHE_SHIFT) > - (inode->i_size >> PAGE_CACHE_SHIFT)) { - head = page_buffers(prepared_pages[num_pages - 1]); - - /* for each buffer in page */ - for (bh = head, block_start = 0; bh != head || !block_start; - block_start = block_end, bh = bh->b_this_page) { - - if (!bh) - reiserfs_panic(inode->i_sb, - "green-9002: Allocated but absent buffer for a page?"); - /* Find where this buffer ends */ - block_end = block_start + inode->i_sb->s_blocksize; - if (block_start >= to) - /* if this buffer is after requested data to map, skip it */ - break; - if (block_end > to) { /* Aha, our partial buffer */ - if (buffer_mapped(bh)) { /* If it is mapped, we need to - issue READ request for it to - not loose data */ - ll_rw_block(READ, 1, &bh); - *wait_bh++ = bh; - } else { /* Not mapped, zero it */ - zero_user_page(prepared_pages[num_pages-1], - to, block_end - to, KM_USER0); - set_buffer_uptodate(bh); - } - } - } - } - - /* Wait for read requests we made to happen, if necessary */ - while (wait_bh > wait) { - wait_on_buffer(*--wait_bh); - if (!buffer_uptodate(*wait_bh)) { - res = -EIO; - goto failed_read; - } - } - - return blocks; - failed_page_grabbing: - num_pages = i; - failed_read: - reiserfs_unprepare_pages(prepared_pages, num_pages); - return res; -} - /* Write @count bytes at position @ppos in a file indicated by @file from the buffer @buf. @@ -1284,14 +256,9 @@ static ssize_t reiserfs_file_write(struct file *file, /* the file we are going t * new current position before returning. */ ) { - size_t already_written = 0; // Number of bytes already written to the file. - loff_t pos; // Current position in the file. - ssize_t res; // return value of various functions that we call. - int err = 0; struct inode *inode = file->f_path.dentry->d_inode; // Inode of the file that we are writing to. /* To simplify coding at this time, we store locked pages in array for now */ - struct page *prepared_pages[REISERFS_WRITE_PAGES_AT_A_TIME]; struct reiserfs_transaction_handle th; th.t_trans_id = 0; @@ -1311,212 +278,7 @@ static ssize_t reiserfs_file_write(struct file *file, /* the file we are going t count = MAX_NON_LFS - (unsigned long)*ppos; } - if (file->f_flags & O_DIRECT) - return do_sync_write(file, buf, count, ppos); - - if (unlikely((ssize_t) count < 0)) - return -EINVAL; - - if (unlikely(!access_ok(VERIFY_READ, buf, count))) - return -EFAULT; - - mutex_lock(&inode->i_mutex); // locks the entire file for just us - - pos = *ppos; - - /* Check if we can write to specified region of file, file - is not overly big and this kind of stuff. Adjust pos and - count, if needed */ - res = generic_write_checks(file, &pos, &count, 0); - if (res) - goto out; - - if (count == 0) - goto out; - - res = remove_suid(file->f_path.dentry); - if (res) - goto out; - - file_update_time(file); - - // Ok, we are done with all the checks. - - // Now we should start real work - - /* If we are going to write past the file's packed tail or if we are going - to overwrite part of the tail, we need that tail to be converted into - unformatted node */ - res = reiserfs_check_for_tail_and_convert(inode, pos, count); - if (res) - goto out; - - while (count > 0) { - /* This is the main loop in which we running until some error occures - or until we write all of the data. */ - size_t num_pages; /* amount of pages we are going to write this iteration */ - size_t write_bytes; /* amount of bytes to write during this iteration */ - size_t blocks_to_allocate; /* how much blocks we need to allocate for this iteration */ - - /* (pos & (PAGE_CACHE_SIZE-1)) is an idiom for offset into a page of pos */ - num_pages = !!((pos + count) & (PAGE_CACHE_SIZE - 1)) + /* round up partial - pages */ - ((count + - (pos & (PAGE_CACHE_SIZE - 1))) >> PAGE_CACHE_SHIFT); - /* convert size to amount of - pages */ - reiserfs_write_lock(inode->i_sb); - if (num_pages > REISERFS_WRITE_PAGES_AT_A_TIME - || num_pages > reiserfs_can_fit_pages(inode->i_sb)) { - /* If we were asked to write more data than we want to or if there - is not that much space, then we shorten amount of data to write - for this iteration. */ - num_pages = - min_t(size_t, REISERFS_WRITE_PAGES_AT_A_TIME, - reiserfs_can_fit_pages(inode->i_sb)); - /* Also we should not forget to set size in bytes accordingly */ - write_bytes = (num_pages << PAGE_CACHE_SHIFT) - - (pos & (PAGE_CACHE_SIZE - 1)); - /* If position is not on the - start of the page, we need - to substract the offset - within page */ - } else - write_bytes = count; - - /* reserve the blocks to be allocated later, so that later on - we still have the space to write the blocks to */ - reiserfs_claim_blocks_to_be_allocated(inode->i_sb, - num_pages << - (PAGE_CACHE_SHIFT - - inode->i_blkbits)); - reiserfs_write_unlock(inode->i_sb); - - if (!num_pages) { /* If we do not have enough space even for a single page... */ - if (pos > - inode->i_size + inode->i_sb->s_blocksize - - (pos & (inode->i_sb->s_blocksize - 1))) { - res = -ENOSPC; - break; // In case we are writing past the end of the last file block, break. - } - // Otherwise we are possibly overwriting the file, so - // let's set write size to be equal or less than blocksize. - // This way we get it correctly for file holes. - // But overwriting files on absolutelly full volumes would not - // be very efficient. Well, people are not supposed to fill - // 100% of disk space anyway. - write_bytes = - min_t(size_t, count, - inode->i_sb->s_blocksize - - (pos & (inode->i_sb->s_blocksize - 1))); - num_pages = 1; - // No blocks were claimed before, so do it now. - reiserfs_claim_blocks_to_be_allocated(inode->i_sb, - 1 << - (PAGE_CACHE_SHIFT - - - inode-> - i_blkbits)); - } - - /* Prepare for writing into the region, read in all the - partially overwritten pages, if needed. And lock the pages, - so that nobody else can access these until we are done. - We get number of actual blocks needed as a result. */ - res = reiserfs_prepare_file_region_for_write(inode, pos, - num_pages, - write_bytes, - prepared_pages); - if (res < 0) { - reiserfs_release_claimed_blocks(inode->i_sb, - num_pages << - (PAGE_CACHE_SHIFT - - inode->i_blkbits)); - break; - } - - blocks_to_allocate = res; - - /* First we correct our estimate of how many blocks we need */ - reiserfs_release_claimed_blocks(inode->i_sb, - (num_pages << - (PAGE_CACHE_SHIFT - - inode->i_sb-> - s_blocksize_bits)) - - blocks_to_allocate); - - if (blocks_to_allocate > 0) { /*We only allocate blocks if we need to */ - /* Fill in all the possible holes and append the file if needed */ - res = - reiserfs_allocate_blocks_for_region(&th, inode, pos, - num_pages, - write_bytes, - prepared_pages, - blocks_to_allocate); - } - - /* well, we have allocated the blocks, so it is time to free - the reservation we made earlier. */ - reiserfs_release_claimed_blocks(inode->i_sb, - blocks_to_allocate); - if (res) { - reiserfs_unprepare_pages(prepared_pages, num_pages); - break; - } - -/* NOTE that allocating blocks and filling blocks can be done in reverse order - and probably we would do that just to get rid of garbage in files after a - crash */ - - /* Copy data from user-supplied buffer to file's pages */ - res = - reiserfs_copy_from_user_to_file_region(pos, num_pages, - write_bytes, - prepared_pages, buf); - if (res) { - reiserfs_unprepare_pages(prepared_pages, num_pages); - break; - } - - /* Send the pages to disk and unlock them. */ - res = - reiserfs_submit_file_region_for_write(&th, inode, pos, - num_pages, - write_bytes, - prepared_pages); - if (res) - break; - - already_written += write_bytes; - buf += write_bytes; - *ppos = pos += write_bytes; - count -= write_bytes; - balance_dirty_pages_ratelimited_nr(inode->i_mapping, num_pages); - } - - /* this is only true on error */ - if (th.t_trans_id) { - reiserfs_write_lock(inode->i_sb); - err = journal_end(&th, th.t_super, th.t_blocks_allocated); - reiserfs_write_unlock(inode->i_sb); - if (err) { - res = err; - goto out; - } - } - - if (likely(res >= 0) && - (unlikely((file->f_flags & O_SYNC) || IS_SYNC(inode)))) - res = generic_osync_inode(inode, file->f_mapping, - OSYNC_METADATA | OSYNC_DATA); - - mutex_unlock(&inode->i_mutex); - reiserfs_async_progress_wait(inode->i_sb); - return (already_written != 0) ? already_written : res; - - out: - mutex_unlock(&inode->i_mutex); // unlock the file on exit. - return res; + return do_sync_write(file, buf, count, ppos); } const struct file_operations reiserfs_file_operations = { |
