From: Marco Stornelli <marco.storne...@gmail.com>
Inode operations.
Signed-off-by: Marco Stornelli <marco.storne...@gmail.com>
---
diff -uprN linux-2.6.30-orig/fs/pramfs/inode.c linux-2.6.30/fs/pramfs/inode.c
--- linux-2.6.30-orig/fs/pramfs/inode.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.30/fs/pramfs/inode.c 2009-06-13 12:58:27.000000000 +0200
@@ -0,0 +1,620 @@
+/*
+ * FILE NAME fs/pramfs/inode.c
+ *
+ * BRIEF DESCRIPTION
+ *
+ * Inode methods (allocate/free/read/write).
+ *
+ * Copyright 2009 Marco Stornelli <marco.storne...@gmail.com>
+ * Copyright 2003 Sony Corporation
+ * Copyright 2003 Matsushita Electric Industrial Co., Ltd.
+ * 2003-2004 (c) MontaVista Software, Inc. , Steve Longerbeam
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+#include <linux/fs.h>
+#include <linux/smp_lock.h>
+#include <linux/sched.h>
+#include <linux/highuid.h>
+#include <linux/quotaops.h>
+#include <linux/module.h>
+#include <linux/mpage.h>
+#include <linux/backing-dev.h>
+#include "pram_fs.h"
+#include "xip.h"
+
+static struct backing_dev_info pram_backing_dev_info = {
+ .ra_pages = 0, /* No readahead */
+ .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
+};
+
+/*
+ * allocate a data block for inode and return it's absolute blocknr.
+ * Zeroes out the block if zero set. Increments inode->i_blocks.
+ */
+static int
+pram_new_data_block(struct inode *inode, int *blocknr, int zero)
+{
+ unsigned long flags;
+
+ int errval = pram_new_block(inode->i_sb, blocknr, zero);
+
+ flags = 0;
+
+ if (!errval) {
+ struct pram_inode *pi = pram_get_inode(inode->i_sb,
+ inode->i_ino);
+ inode->i_blocks++;
+ pram_lock_inode(pi, flags);
+ pi->i_blocks = inode->i_blocks;
+ pram_unlock_inode(pi, flags);
+ }
+
+ return errval;
+}
+
+/*
+ * find the offset to the block represented by the given inode's file
+ * relative block number.
+ */
+off_t pram_find_data_block(struct inode *inode, int file_blocknr)
+{
+ struct super_block *sb = inode->i_sb;
+ struct pram_inode *pi;
+ off_t *row; /* ptr to row block */
+ off_t *col; /* ptr to column blocks */
+ off_t bp = 0;
+ int i_row, i_col;
+ int N = sb->s_blocksize >> 2; /* num block ptrs per block */
+ int Nbits = sb->s_blocksize_bits - 2;
+
+ pi = pram_get_inode(sb, inode->i_ino);
+
+ i_row = file_blocknr >> Nbits;
+ i_col = file_blocknr & (N-1);
+
+ row = pram_get_block(sb, pi->i_type.reg.row_block);
+ if (row) {
+ col = pram_get_block(sb, row[i_row]);
+ if (col)
+ bp = col[i_col];
+ }
+
+ return bp;
+}
+
+
+/*
+ * Free data blocks from inode starting at first_trunc_block.
+ */
+static void
+pram_truncate_blocks(struct inode *inode, int first_trunc_block)
+{
+ struct super_block *sb = inode->i_sb;
+ struct pram_inode *pi = pram_get_inode(sb, inode->i_ino);
+ int N = sb->s_blocksize >> 2; /* num block ptrs per block */
+ int Nbits = sb->s_blocksize_bits - 2;
+ int first_row_index, last_row_index;
+ int i, j, first_blocknr, last_blocknr, blocknr;
+ unsigned long flags;
+ off_t *row; /* ptr to row block */
+ off_t *col; /* ptr to column blocks */
+
+ flags = 0;
+
+ if (first_trunc_block >= inode->i_blocks ||
+ !inode->i_blocks || !pi->i_type.reg.row_block) {
+ return;
+ }
+
+ first_blocknr = first_trunc_block;
+ last_blocknr = inode->i_blocks - 1;
+ first_row_index = first_blocknr >> Nbits;
+ last_row_index = last_blocknr >> Nbits;
+
+ row = pram_get_block(sb, pi->i_type.reg.row_block);
+
+ for (i = first_row_index; i <= last_row_index; i++) {
+ int first_col_index = (i == first_row_index) ?
+ first_blocknr & (N-1) : 0;
+ int last_col_index = (i == last_row_index) ?
+ last_blocknr & (N-1) : N-1;
+
+ col = pram_get_block(sb, row[i]);
+ for (j = first_col_index; j <= last_col_index; j++) {
+ blocknr = pram_get_blocknr(sb, col[j]);
+ pram_free_block(sb, blocknr);
+ pram_lock_block(sb, col, flags);
+ col[j] = 0;
+ pram_unlock_block(sb, col, flags);
+ }
+
+ if (first_col_index == 0) {
+ blocknr = pram_get_blocknr(sb, row[i]);
+ pram_free_block(sb, blocknr);
+ pram_lock_block(sb, row, flags);
+ row[i] = 0;
+ pram_unlock_block(sb, row, flags);
+ }
+ }
+
+ inode->i_blocks -= (last_blocknr - first_blocknr + 1);
+
+ if (first_row_index == 0) {
+ blocknr = pram_get_blocknr(sb, pi->i_type.reg.row_block);
+ pram_free_block(sb, blocknr);
+ pram_lock_inode(pi, flags);
+ pi->i_type.reg.row_block = 0;
+ pram_unlock_inode(pi, flags);
+ }
+ pram_lock_inode(pi, flags);
+ pi->i_blocks = inode->i_blocks;
+ pram_unlock_inode(pi, flags);
+}
+
+/*
+ * Allocate num data blocks for inode, starting at given file-relative
+ * block number. Any unallocated file blocks before file_blocknr
+ * are allocated. All blocks except the last are zeroed out.
+ */
+int pram_alloc_blocks(struct inode *inode, int file_blocknr, int num)
+{
+ struct super_block *sb = inode->i_sb;
+ struct pram_inode *pi = pram_get_inode(sb, inode->i_ino);
+ int N = sb->s_blocksize >> 2; /* num block ptrs per block */
+ int Nbits = sb->s_blocksize_bits - 2;
+ int first_file_blocknr;
+ int last_file_blocknr;
+ int first_row_index, last_row_index;
+ int i, j, blocknr, errval;
+ unsigned long flags;
+ off_t *row;
+ off_t *col;
+
+ flags = 0;
+
+ if (!pi->i_type.reg.row_block) {
+ /* alloc the 2nd order array block */
+ errval = pram_new_block(sb, &blocknr, 1);
+ if (errval) {
+ pram_err("failed to alloc 2nd order array block\n");
+ goto fail;
+ }
+ pram_lock_inode(pi, flags);
+ pi->i_type.reg.row_block = pram_get_block_off(sb, blocknr);
+ pram_unlock_inode(pi, flags);
+ }
+
+ row = pram_get_block(sb, pi->i_type.reg.row_block);
+
+ first_file_blocknr = (file_blocknr > inode->i_blocks) ?
+ inode->i_blocks : file_blocknr;
+ last_file_blocknr = file_blocknr + num - 1;
+
+ first_row_index = first_file_blocknr >> Nbits;
+ last_row_index = last_file_blocknr >> Nbits;
+
+ for (i = first_row_index; i <= last_row_index; i++) {
+ int first_col_index, last_col_index;
+ /*
+ * we are starting a new row, so make sure
+ * there is a block allocated for the row.
+ */
+ if (!row[i]) {
+ /* allocate the row block */
+ errval = pram_new_block(sb, &blocknr, 1);
+ if (errval) {
+ pram_err("failed to alloc row block\n");
+ goto fail;
+ }
+ pram_lock_block(sb, row, flags);
+ row[i] = pram_get_block_off(sb, blocknr);
+ pram_unlock_block(sb, row, flags);
+ }
+ col = pram_get_block(sb, row[i]);
+
+ first_col_index = (i == first_row_index) ?
+ first_file_blocknr & (N-1) : 0;
+
+ last_col_index = (i == last_row_index) ?
+ last_file_blocknr & (N-1) : N-1;
+
+ for (j = first_col_index; j <= last_col_index; j++) {
+ int last_block =
+ (i == last_row_index) && (j == last_col_index);
+ if (!col[j]) {
+ errval = pram_new_data_block(inode,
+ &blocknr,
+ !last_block);
+ if (errval) {
+ pram_err("failed to alloc "
+ "data block\n");
+ goto fail;
+ }
+ pram_lock_block(sb, col, flags);
+ col[j] = pram_get_block_off(sb, blocknr);
+ pram_unlock_block(sb, col, flags);
+ }
+ }
+ }
+
+ errval = 0;
+ fail:
+ return errval;
+}
+
+static int
+pram_fill_inode(struct inode *inode, struct pram_inode *pi)
+{
+ int ret = -EIO;
+
+ if (pram_calc_checksum((u32 *)pi, PRAM_INODE_SIZE>>2)) {
+ pram_err("checksum error in inode %08x\n",
+ (u32)inode->i_ino);
+ goto bad_inode;
+ }
+
+ inode->i_mode = pi->i_mode;
+ inode->i_uid = pi->i_uid;
+ inode->i_gid = pi->i_gid;
+ inode->i_nlink = pi->i_links_count;
+ inode->i_size = pi->i_size;
+ inode->i_atime.tv_sec = pi->i_atime;
+ inode->i_ctime.tv_sec = pi->i_ctime;
+ inode->i_mtime.tv_sec = pi->i_mtime;
+ inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec =
+ inode->i_ctime.tv_nsec = 0;
+
+ /* check if the inode is active. */
+ if (inode->i_nlink == 0 && (inode->i_mode == 0 || pi->i_dtime)) {
+ /* this inode is deleted */
+ ret = -EINVAL;
+ goto bad_inode;
+ }
+
+ inode->i_blocks = pi->i_blocks;
+ inode->i_ino = pram_get_inodenr(inode->i_sb, pi);
+ inode->i_mapping->a_ops = &pram_aops;
+ inode->i_mapping->backing_dev_info = &pram_backing_dev_info;
+
+ insert_inode_hash(inode);
+ switch (inode->i_mode & S_IFMT) {
+ case S_IFREG:
+ inode->i_op = &pram_file_inode_operations;
+ inode->i_fop = &pram_file_operations;
+ break;
+ case S_IFDIR:
+ inode->i_op = &pram_dir_inode_operations;
+ inode->i_fop = &pram_dir_operations;
+ break;
+ case S_IFLNK:
+ inode->i_op = &pram_symlink_inode_operations;
+ break;
+ default:
+ inode->i_size = 0;
+ init_special_inode(inode, inode->i_mode,
+ pi->i_type.dev.rdev);
+ break;
+ }
+
+ return 0;
+
+ bad_inode:
+ make_bad_inode(inode);
+ return ret;
+}
+
+static int pram_update_inode(struct inode *inode)
+{
+ struct pram_inode *pi;
+ int retval = 0;
+ unsigned long flags;
+
+ flags = 0;
+
+ pi = pram_get_inode(inode->i_sb, inode->i_ino);
+
+ pram_lock_inode(pi, flags);
+ pi->i_mode = inode->i_mode;
+ pi->i_uid = inode->i_uid;
+ pi->i_gid = inode->i_gid;
+ pi->i_links_count = inode->i_nlink;
+ pi->i_size = inode->i_size;
+ pi->i_blocks = inode->i_blocks;
+ pi->i_atime = inode->i_atime.tv_sec;
+ pi->i_ctime = inode->i_ctime.tv_sec;
+ pi->i_mtime = inode->i_mtime.tv_sec;
+
+ if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
+ pi->i_type.dev.rdev = inode->i_rdev;
+
+ pram_unlock_inode(pi, flags);
+ return retval;
+}
+
+/*
+ * NOTE! When we get the inode, we're the only people
+ * that have access to it, and as such there are no
+ * race conditions we have to worry about. The inode
+ * is not on the hash-lists, and it cannot be reached
+ * through the filesystem because the directory entry
+ * has been deleted earlier.
+ */
+static void pram_free_inode(struct inode *inode)
+{
+ struct super_block *sb = inode->i_sb;
+ struct pram_super_block *ps;
+ struct pram_inode *pi;
+ unsigned long inode_nr;
+ unsigned long flags;
+
+ flags = 0;
+
+ /*
+ * Note: we must free any quota before locking the superblock,
+ * as writing the quota to disk may need the lock as well.
+ */
+ if (!is_bad_inode(inode)) {
+ /* Quota is already initialized in iput() */
+ vfs_dq_free_inode(inode);
+ vfs_dq_drop(inode);
+ }
+
+ lock_super(sb);
+ clear_inode(inode);
+
+ inode_nr = (inode->i_ino - PRAM_ROOT_INO) >> PRAM_INODE_BITS;
+
+ pi = pram_get_inode(sb, inode->i_ino);
+ pram_lock_inode(pi, flags);
+ pi->i_dtime = get_seconds();
+ pi->i_type.reg.row_block = 0;
+ pram_unlock_inode(pi, flags);
+
+ /* increment s_free_inodes_count */
+ ps = pram_get_super(sb);
+ pram_lock_super(ps, flags);
+ if (inode_nr < ps->s_free_inode_hint)
+ ps->s_free_inode_hint = inode_nr;
+ ps->s_free_inodes_count++;
+ if (ps->s_free_inodes_count == ps->s_inodes_count - 1) {
+ /* filesystem is empty */
+ pram_dbg("fs is empty!\n");
+ ps->s_free_inode_hint = 1;
+ }
+ pram_unlock_super(ps, flags);
+
+ unlock_super(sb);
+}
+
+
+struct inode *
+pram_fill_new_inode(struct super_block *sb,
+ struct pram_inode *pi)
+{
+ struct inode *inode = new_inode(sb);
+
+ if (inode)
+ pram_fill_inode(inode, pi);
+
+ return inode;
+}
+
+
+/*
+ * Called at the last iput() if i_nlink is zero.
+ */
+void pram_delete_inode(struct inode *inode)
+{
+ lock_kernel();
+
+ if (is_bad_inode(inode))
+ goto no_delete;
+
+ /* unlink from chain in the inode's directory */
+ pram_remove_link(inode);
+ inode->i_size = 0;
+ if (inode->i_blocks)
+ pram_truncate(inode);
+ pram_free_inode(inode);
+
+ unlock_kernel();
+ return;
+ no_delete:
+ unlock_kernel();
+ clear_inode(inode); /* We must guarantee clearing of inode... */
+}
+
+
+struct inode *pram_new_inode(const struct inode *dir, int mode)
+{
+ struct super_block *sb;
+ struct pram_super_block *ps;
+ struct inode *inode;
+ struct pram_inode *pi = NULL;
+ int i, errval;
+ ino_t ino = 0;
+ unsigned long flags;
+
+ flags = 0;
+
+ sb = dir->i_sb;
+ inode = new_inode(sb);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+
+ lock_super(sb);
+ ps = pram_get_super(sb);
+
+ if (ps->s_free_inodes_count) {
+ /* find the oldest unused pram inode */
+ for (i = ps->s_free_inode_hint; i < ps->s_inodes_count; i++) {
+ ino = PRAM_ROOT_INO + (i << PRAM_INODE_BITS);
+ pi = pram_get_inode(sb, ino);
+ /* check if the inode is active. */
+ if (pi->i_links_count == 0 && (pi->i_mode == 0 ||
+ pi->i_dtime)) {
+ /* this inode is deleted */
+ break;
+ }
+ }
+
+ if (i >= ps->s_inodes_count) {
+ pram_err("s_free_inodes_count!=0 but none free!?\n");
+ errval = -ENOSPC;
+ goto fail;
+ }
+
+ pram_dbg("allocating inode %lu\n", ino);
+ pram_lock_super(ps, flags);
+ ps->s_free_inodes_count--;
+ ps->s_free_inode_hint = (i < ps->s_inodes_count-1) ? i+1 : 0;
+ pram_unlock_super(ps, flags);
+ } else {
+ pram_err("no space left to create new inode!\n");
+ errval = -ENOSPC;
+ goto fail;
+ }
+
+ /* chosen inode is in ino */
+
+ inode->i_ino = ino;
+ inode->i_uid = current_fsuid();
+
+ if (dir->i_mode & S_ISGID) {
+ inode->i_gid = dir->i_gid;
+ if (S_ISDIR(mode))
+ mode |= S_ISGID;
+ } else
+ inode->i_gid = current_fsgid();
+ inode->i_mode = mode;
+
+ inode->i_blocks = inode->i_size = 0;
+ inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
+
+ pram_lock_inode(pi, flags);
+ pi->i_d.d_next = 0;
+ pi->i_d.d_prev = 0;
+ pram_unlock_inode(pi, flags);
+
+ insert_inode_hash(inode);
+ pram_write_inode(inode, 0);
+
+ unlock_super(sb);
+
+ if (vfs_dq_alloc_inode(inode)) {
+ vfs_dq_drop(inode);
+ inode->i_flags |= S_NOQUOTA;
+ inode->i_nlink = 0;
+ iput(inode);
+ return ERR_PTR(-EDQUOT);
+ }
+ return inode;
+
+fail:
+ unlock_super(sb);
+ make_bad_inode(inode);
+ iput(inode);
+ return ERR_PTR(errval);
+}
+
+void pram_truncate(struct inode *inode)
+{
+ int blocksize, blocksize_bits;
+ int blocknr;
+
+ if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+ S_ISLNK(inode->i_mode)))
+ return;
+ if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+ return;
+
+ blocksize_bits = inode->i_sb->s_blocksize_bits;
+ blocksize = 1 << blocksize_bits;
+ blocknr = (inode->i_size + blocksize-1) >> blocksize_bits;
+
+ lock_kernel();
+ pram_truncate_blocks(inode, blocknr);
+ inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ pram_update_inode(inode);
+ unlock_kernel();
+}
+
+int pram_write_inode(struct inode *inode, int wait)
+{
+ int ret = 0;
+
+ lock_kernel();
+ ret = pram_update_inode(inode);
+ unlock_kernel();
+
+ return ret;
+}
+
+/*
+ * dirty_inode() is called from __mark_inode_dirty()
+ */
+void pram_dirty_inode(struct inode *inode)
+{
+ pram_write_inode(inode, 0);
+}
+
+int pram_get_and_update_block(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh, int create)
+{
+ struct super_block *sb = inode->i_sb;
+ unsigned int blocksize = 1 << inode->i_blkbits;
+ int err = -EIO;
+ off_t block;
+ void *bp;
+ unsigned long flags;
+
+ flags = 0;
+
+ lock_kernel();
+
+ block = pram_find_data_block(inode, iblock);
+
+ if (!block) {
+ if (!create)
+ goto out;
+
+ err = pram_alloc_blocks(inode, iblock, 1);
+ if (err)
+ goto out;
+ block = pram_find_data_block(inode, iblock);
+ if (!block) {
+ err = -EIO;
+ goto out;
+ }
+ set_buffer_new(bh);
+ }
+
+ bh->b_blocknr = block;
+ set_buffer_mapped(bh);
+
+ /* now update the buffer synchronously */
+ bp = pram_get_block(sb, block);
+ if (buffer_new(bh)) {
+ pram_lock_block(sb, bp, flags);
+ memset(bp, 0, blocksize);
+ pram_unlock_block(sb, bp, flags);
+ memset(bh->b_data, 0, blocksize);
+ } else {
+ memcpy(bh->b_data, bp, blocksize);
+ }
+
+ set_buffer_uptodate(bh);
+ err = 0;
+
+ out:
+ unlock_kernel();
+ return err;
+}
+
+struct address_space_operations pram_aops = {
+ .readpage = pram_readpage,
+ .direct_IO = pram_direct_IO,
+ .get_xip_mem = pram_get_xip_mem,
+};
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