diff options
Diffstat (limited to 'fs/reiserfs/file.c')
| -rw-r--r-- | fs/reiserfs/file.c | 1408 |
1 files changed, 1408 insertions, 0 deletions
diff --git a/fs/reiserfs/file.c b/fs/reiserfs/file.c new file mode 100644 index 0000000..2695011 --- /dev/null +++ b/fs/reiserfs/file.c @@ -0,0 +1,1408 @@ +/* + * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README + */ + + +#include <linux/time.h> +#include <linux/reiserfs_fs.h> +#include <linux/reiserfs_acl.h> +#include <linux/reiserfs_xattr.h> +#include <linux/smp_lock.h> +#include <asm/uaccess.h> +#include <linux/pagemap.h> +#include <linux/swap.h> +#include <linux/writeback.h> +#include <linux/blkdev.h> +#include <linux/buffer_head.h> +#include <linux/quotaops.h> + +/* +** We pack the tails of files on file close, not at the time they are written. +** This implies an unnecessary copy of the tail and an unnecessary indirect item +** insertion/balancing, for files that are written in one write. +** It avoids unnecessary tail packings (balances) for files that are written in +** multiple writes and are small enough to have tails. +** +** file_release is called by the VFS layer when the file is closed. If +** this is the last open file descriptor, and the file +** small enough to have a tail, and the tail is currently in an +** unformatted node, the tail is converted back into a direct item. +** +** We use reiserfs_truncate_file to pack the tail, since it already has +** all the conditions coded. +*/ +static int reiserfs_file_release (struct inode * inode, struct file * filp) +{ + + struct reiserfs_transaction_handle th ; + int err; + int jbegin_failure = 0; + + if (!S_ISREG (inode->i_mode)) + BUG (); + + /* fast out for when nothing needs to be done */ + if ((atomic_read(&inode->i_count) > 1 || + !(REISERFS_I(inode)->i_flags & i_pack_on_close_mask) || + !tail_has_to_be_packed(inode)) && + REISERFS_I(inode)->i_prealloc_count <= 0) { + return 0; + } + + reiserfs_write_lock(inode->i_sb); + down (&inode->i_sem); + /* freeing preallocation only involves relogging blocks that + * are already in the current transaction. preallocation gets + * freed at the end of each transaction, so it is impossible for + * us to log any additional blocks (including quota blocks) + */ + err = journal_begin(&th, inode->i_sb, 1); + if (err) { + /* uh oh, we can't allow the inode to go away while there + * is still preallocation blocks pending. Try to join the + * aborted transaction + */ + jbegin_failure = err; + err = journal_join_abort(&th, inode->i_sb, 1); + + if (err) { + /* hmpf, our choices here aren't good. We can pin the inode + * which will disallow unmount from every happening, we can + * do nothing, which will corrupt random memory on unmount, + * or we can forcibly remove the file from the preallocation + * list, which will leak blocks on disk. Lets pin the inode + * and let the admin know what is going on. + */ + igrab(inode); + reiserfs_warning(inode->i_sb, "pinning inode %lu because the " + "preallocation can't be freed"); + goto out; + } + } + reiserfs_update_inode_transaction(inode) ; + +#ifdef REISERFS_PREALLOCATE + reiserfs_discard_prealloc (&th, inode); +#endif + err = journal_end(&th, inode->i_sb, 1); + + /* copy back the error code from journal_begin */ + if (!err) + err = jbegin_failure; + + if (!err && atomic_read(&inode->i_count) <= 1 && + (REISERFS_I(inode)->i_flags & i_pack_on_close_mask) && + tail_has_to_be_packed (inode)) { + /* if regular file is released by last holder and it has been + appended (we append by unformatted node only) or its direct + item(s) had to be converted, then it may have to be + indirect2direct converted */ + err = reiserfs_truncate_file(inode, 0) ; + } +out: + up (&inode->i_sem); + reiserfs_write_unlock(inode->i_sb); + return err; +} + +static void reiserfs_vfs_truncate_file(struct inode *inode) { + reiserfs_truncate_file(inode, 1) ; +} + +/* Sync a reiserfs file. */ + +/* + * FIXME: sync_mapping_buffers() never has anything to sync. Can + * be removed... + */ + +static int reiserfs_sync_file( + struct file * p_s_filp, + struct dentry * p_s_dentry, + int datasync + ) { + struct inode * p_s_inode = p_s_dentry->d_inode; + int n_err; + int barrier_done; + + if (!S_ISREG(p_s_inode->i_mode)) + BUG (); + n_err = sync_mapping_buffers(p_s_inode->i_mapping) ; + reiserfs_write_lock(p_s_inode->i_sb); + barrier_done = reiserfs_commit_for_inode(p_s_inode); + reiserfs_write_unlock(p_s_inode->i_sb); + if (barrier_done != 1) + blkdev_issue_flush(p_s_inode->i_sb->s_bdev, NULL); + if (barrier_done < 0) + return barrier_done; + 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 + __u32 * 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); + + /* 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); // 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 = -ENOSPC; + pathrelse(&path); + goto error_exit; + } + } else { + res = -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 = kmalloc(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; + } + memset ( zeros, 0, to_paste*UNFM_P_SIZE); + 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)) { + 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 + reiserfs_update_sd(th, inode); + err = journal_end(th, inode->i_sb, JOURNAL_PER_BALANCE_CNT * 3 + 1 + 2 * REISERFS_QUOTA_TRANS_BLOCKS); + 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) +{ + unsigned block_start, block_end; + int partial = 0; + unsigned blocksize; + struct buffer_head *bh, *head; + unsigned long i_size_index = inode->i_size >> PAGE_CACHE_SHIFT; + int new; + int logit = reiserfs_file_data_log(inode); + struct super_block *s = inode->i_sb; + int bh_per_page = PAGE_CACHE_SIZE / s->s_blocksize; + struct reiserfs_transaction_handle th; + int ret = 0; + + th.t_trans_id = 0; + blocksize = 1 << inode->i_blkbits; + + if (logit) { + reiserfs_write_lock(s); + ret = journal_begin(&th, s, bh_per_page + 1); + if (ret) + goto drop_write_lock; + reiserfs_update_inode_transaction(inode); + } + for(bh = head = page_buffers(page), block_start = 0; + bh != head || !block_start; + block_start=block_end, bh = bh->b_this_page) + { + + new = buffer_new(bh); + clear_buffer_new(bh); + block_end = block_start + blocksize; + if (block_end <= from || block_start >= to) { + if (!buffer_uptodate(bh)) + partial = 1; + } else { + set_buffer_uptodate(bh); + if (logit) { + reiserfs_prepare_for_journal(s, bh, 1); + journal_mark_dirty(&th, s, bh); + } else if (!buffer_dirty(bh)) { + mark_buffer_dirty(bh); + /* do data=ordered on any page past the end + * of file and any buffer marked BH_New. + */ + if (reiserfs_data_ordered(inode->i_sb) && + (new || page->index >= i_size_index)) { + reiserfs_add_ordered_list(inode, bh); + } + } + } + } + if (logit) { + ret = journal_end(&th, s, bh_per_page + 1); +drop_write_lock: + reiserfs_write_unlock(s); + } + /* + * If this is a partial write which happened to make all buffers + * uptodate then we can optimize away a bogus readpage() for + * the next read(). Here we 'discover' whether the page went + * uptodate as a result of this (potentially partial) write. + */ + if (!partial) + SetPageUptodate(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); + reiserfs_update_sd(th, inode); // And update on-disk metadata + reiserfs_write_unlock(inode->i_sb); + } else + inode->i_sb->s_op->dirty_inode(inode); + + sd_update = 1; + } + if (th->t_trans_id) { + reiserfs_write_lock(inode->i_sb); + if (!sd_update) + reiserfs_update_sd(th, 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. + __u32 * 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 */ + char *kaddr = kmap_atomic(prepared_pages[0], KM_USER0); + memset(kaddr, 0, from); + kunmap_atomic( kaddr, KM_USER0); + } + if ( to != PAGE_CACHE_SIZE ) { /* Last page needs to be partially zeroed */ + char *kaddr = kmap_atomic(prepared_pages[num_pages-1], KM_USER0); + memset(kaddr+to, 0, PAGE_CACHE_SIZE - to); + kunmap_atomic( kaddr, 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 */ + char *kaddr = kmap_atomic(prepared_pages[0], KM_USER0); + memset(kaddr+block_start, 0, from-block_start); + kunmap_atomic( kaddr, 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 */ + char *kaddr = kmap_atomic(prepared_pages[num_pages-1], KM_USER0); + memset(kaddr+to, 0, block_end-to); + kunmap_atomic( kaddr, 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. + + generic_file_write() is only appropriate for filesystems that are not seeking to optimize performance and want + something simple that works. It is not for serious use by general purpose filesystems, excepting the one that it was + written for (ext2/3). This is for several reasons: + + * It has no understanding of any filesystem specific optimizations. + + * It enters the filesystem repeatedly for each page that is written. + + * It depends on reiserfs_get_block() function which if implemented by reiserfs performs costly search_by_key + * operation for each page it is supplied with. By contrast reiserfs_file_write() feeds as much as possible at a time + * to reiserfs which allows for fewer tree traversals. + + * Each indirect pointer insertion takes a lot of cpu, because it involves memory moves inside of blocks. + + * Asking the block allocation code for blocks one at a time is slightly less efficient. + + All of these reasons for not using only generic file write were understood back when reiserfs was first miscoded to + use it, but we were in a hurry to make code freeze, and so it couldn't be revised then. This new code should make + things right finally. + + Future Features: providing search_by_key with hints. + +*/ +static ssize_t reiserfs_file_write( struct file *file, /* the file we are going to write into */ + const char __user *buf, /* pointer to user supplied data +(in userspace) */ + size_t count, /* amount of bytes to write */ + loff_t *ppos /* pointer to position in file that we start writing at. Should be updated to + * 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_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; + + if ( file->f_flags & O_DIRECT) { // Direct IO needs treatment + ssize_t result, after_file_end = 0; + if ( (*ppos + count >= inode->i_size) || (file->f_flags & O_APPEND) ) { + /* If we are appending a file, we need to put this savelink in here. + If we will crash while doing direct io, finish_unfinished will + cut the garbage from the file end. */ + reiserfs_write_lock(inode->i_sb); + err = journal_begin(&th, inode->i_sb, JOURNAL_PER_BALANCE_CNT ); + if (err) { + reiserfs_write_unlock (inode->i_sb); + return err; + } + reiserfs_update_inode_transaction(inode); + add_save_link (&th, inode, 1 /* Truncate */); + after_file_end = 1; + err = journal_end(&th, inode->i_sb, JOURNAL_PER_BALANCE_CNT ); + reiserfs_write_unlock(inode->i_sb); + if (err) + return err; + } + result = generic_file_write(file, buf, count, ppos); + + if ( after_file_end ) { /* Now update i_size and remove the savelink */ + struct reiserfs_transaction_handle th; + reiserfs_write_lock(inode->i_sb); + err = journal_begin(&th, inode->i_sb, 1); + if (err) { + reiserfs_write_unlock (inode->i_sb); + return err; + } + reiserfs_update_inode_transaction(inode); + reiserfs_update_sd(&th, inode); + err = journal_end(&th, inode->i_sb, 1); + if (err) { + reiserfs_write_unlock (inode->i_sb); + return err; + } + err = remove_save_link (inode, 1/* truncate */); + reiserfs_write_unlock(inode->i_sb); + if (err) + return err; + } + + return result; + } + + if ( unlikely((ssize_t) count < 0 )) + return -EINVAL; + + if (unlikely(!access_ok(VERIFY_READ, buf, count))) + return -EFAULT; + + down(&inode->i_sem); // 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_dentry); + if (res) + goto out; + + inode_update_time(inode, 1); /* Both mtime and ctime */ + + // 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 */ + res = -ENOSPC; /* single page, return -ENOSPC */ + if ( pos > (inode->i_size & (inode->i_sb->s_blocksize-1))) + break; // In case we are writing past the file end, 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.*/ + blocks_to_allocate = reiserfs_prepare_file_region_for_write(inode, pos, num_pages, write_bytes, prepared_pages); + if ( blocks_to_allocate < 0 ) { + res = blocks_to_allocate; + reiserfs_release_claimed_blocks(inode->i_sb, num_pages << (PAGE_CACHE_SHIFT - inode->i_blkbits)); + break; + } + + /* 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(inode->i_mapping); + } + + /* 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 ((file->f_flags & O_SYNC) || IS_SYNC(inode)) + res = generic_osync_inode(inode, file->f_mapping, OSYNC_METADATA|OSYNC_DATA); + + up(&inode->i_sem); + reiserfs_async_progress_wait(inode->i_sb); + return (already_written != 0)?already_written:res; + +out: + up(&inode->i_sem); // unlock the file on exit. + return res; +} + +static ssize_t reiserfs_aio_write(struct kiocb *iocb, const char __user *buf, + size_t count, loff_t pos) +{ + return generic_file_aio_write(iocb, buf, count, pos); +} + + + +struct file_operations reiserfs_file_operations = { + .read = generic_file_read, + .write = reiserfs_file_write, + .ioctl = reiserfs_ioctl, + .mmap = generic_file_mmap, + .release = reiserfs_file_release, + .fsync = reiserfs_sync_file, + .sendfile = generic_file_sendfile, + .aio_read = generic_file_aio_read, + .aio_write = reiserfs_aio_write, +}; + + +struct inode_operations reiserfs_file_inode_operations = { + .truncate = reiserfs_vfs_truncate_file, + .setattr = reiserfs_setattr, + .setxattr = reiserfs_setxattr, + .getxattr = reiserfs_getxattr, + .listxattr = reiserfs_listxattr, + .removexattr = reiserfs_removexattr, + .permission = reiserfs_permission, +}; + + |
