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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/reiserfs/file.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'fs/reiserfs/file.c')
-rw-r--r--fs/reiserfs/file.c1408
1 files changed, 1408 insertions, 0 deletions
diff --git a/fs/reiserfs/file.c b/fs/reiserfs/file.c
new file mode 100644
index 00000000000..26950113af8
--- /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,
+};
+
+