| /* |
| * 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 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.*/ |
| 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, |
| }; |
| |
| |