[PATCH 00/16 v3] pramfs: persistent and protected RAM filesystem
Hi all, third round for the patch series (I hope this is the last one :)). I summarize here the changes to improve the review: v3: - fix a possible memory leak in an error path reported by yidong zhang - fix a warning when using XIP about not used __pram_mmap symbol - fix test module header description and replaced TEST_MODULE with PRAMFS_TEST_MODULE in the Kconfig and Makefile according to the comments done by Randy Dunlap - fix a compilation warning in super.c reported by James Hogan - fix a compilation error when XIP was enabled - removed not used symbol PRAM_XATTR_INDEX_LUSTRE - fix some comment style issue v2: - fix documentation errors reported by Randy Dunlap and Kieran Bingham - reworked memory write protection functions with the suggestions of Andi Kleen v1: - first draft Marco -- To unsubscribe from this list: send the line unsubscribe linux-embedded in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH 01/16 v3] pramfs; documentation
From: Marco Stornelli marco.storne...@gmail.com Documentation for PRAMFS. Signed-off-by: Marco Stornelli marco.storne...@gmail.com --- diff -Nurp linux-2.6.36-orig/Documentation/filesystems/pramfs.txt linux-2.6.36/Documentation/filesystems/pramfs.txt --- linux-2.6.36-orig/Documentation/filesystems/pramfs.txt 1970-01-01 01:00:00.0 +0100 +++ linux-2.6.36/Documentation/filesystems/pramfs.txt 2010-10-23 09:04:32.0 +0200 @@ -0,0 +1,296 @@ + +PRAMFS Overview +=== + +Many embedded systems have a block of non-volatile RAM separate from +normal system memory, i.e. of which the kernel maintains no memory page +descriptors. For such systems it would be beneficial to mount a +fast read/write filesystem over this I/O memory, for storing frequently +accessed data that must survive system reboots and power cycles. An +example usage might be system logs under /var/log, or a user address +book in a cell phone or PDA. + +Linux traditionally had no support for a persistent, non-volatile RAM-based +filesystem, persistent meaning the filesystem survives a system reboot +or power cycle intact. The RAM-based filesystems such as tmpfs and ramfs +have no actual backing store but exist entirely in the page and buffer +caches, hence the filesystem disappears after a system reboot or +power cycle. + +A relatively straightforward solution is to write a simple block driver +for the non-volatile RAM, and mount over it any disk-based filesystem such +as ext2, ext3, ext4, etc. + +But the disk-based fs over non-volatile RAM block driver approach has +some drawbacks: + +1. Complexity of disk-based fs: disk-based filesystems such as ext2/ext3/ext4 + were designed for optimum performance on spinning disk media, so they + implement features such as block groups, which attempts to group inode data + into a contiguous set of data blocks to minimize disk seeking when accessing + files. For RAM there is no such concern; a file's data blocks can be + scattered throughout the media with no access speed penalty at all. So block + groups in a filesystem mounted over RAM just adds unnecessary + complexity. A better approach is to use a filesystem specifically + tailored to RAM media which does away with these disk-based features. + This increases the efficient use of space on the media, i.e. more + space is dedicated to actual file data storage and less to meta-data + needed to maintain that file data. + +2. Different problems between disks and RAM: Because PRAMFS attempts to avoid + filesystem corruption caused by kernel bugs, dirty pages in the page cache + are not allowed to be written back to the backing-store RAM. This way, an + errant write into the page cache will not get written back to the filesystem. + However, if the backing-store RAM is comparable in access speed to system + memory, the penalty of not using caching is minimal. With this consideration + it's better to move file data directly between the user buffers and the backing + store RAM, i.e. use direct I/O. This prevents the unnecessary populating of + the page cache with dirty pages. However direct I/O has to be enabled at + every file open. To enable direct I/O at all times for all regular files + requires either that applications be modified to include the O_DIRECT flag on + all file opens, or that the filesystem used performs direct I/O by default. + +The Persistent/Protected RAM Special Filesystem (PRAMFS) is a read/write +filesystem that has been designed to address these issues. PRAMFS is targeted +to fast I/O memory, and if the memory is non-volatile, the filesystem will be +persistent. + +In PRAMFS, direct I/O is enabled across all files in the filesystem, in other +words the O_DIRECT flag is forced on every open of a PRAMFS file. Also, file +I/O in the PRAMFS is always synchronous. There is no need to block the current +process while the transfer to/from the PRAMFS is in progress, since one of +the requirements of the PRAMFS is that the filesystem exists in fast RAM. So +file I/O in PRAMFS is always direct, synchronous, and never blocks. + +The data organization in PRAMFS can be thought of as an extremely simplified +version of ext2, such that the ratio of data to meta-data is very high. + +PRAMFS supports the execute-in-place. With XIP, instead of keeping data in the +page cache, the need to have a page cache copy is eliminated completely. +Readwrite type operations are performed directly from/to the memory. For file +mappings, the RAM itself is mapped directly into userspace. XIP, in addition, +speed up the applications start-up time because it removes the needs of any +copies. + +PRAMFS is write protected. The page table entries that map the backing-store +RAM are normally marked read-only. Write operations into the filesystem +temporarily mark the affected pages as writeable, the write operation is +carried out with locks held, and then the page table entries is +marked read-only
[PATCH 03/16 v3] pramfs: inode operations
From: Marco Stornelli marco.storne...@gmail.com
Inode methods (allocate/free/read/write).
Signed-off-by: Marco Stornelli marco.storne...@gmail.com
---
diff -Nurp linux-2.6.36-orig/fs/pramfs/inode.c linux-2.6.36/fs/pramfs/inode.c
--- linux-2.6.36-orig/fs/pramfs/inode.c 1970-01-01 01:00:00.0 +0100
+++ linux-2.6.36/fs/pramfs/inode.c 2010-09-26 18:04:38.0 +0200
@@ -0,0 +1,710 @@
+/*
+ * FILE NAME fs/pramfs/inode.c
+ *
+ * BRIEF DESCRIPTION
+ *
+ * Inode methods (allocate/free/read/write).
+ *
+ * Copyright 2009-2010 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.h
+#include xattr.h
+#include xip.h
+#include acl.h
+
+struct backing_dev_info pram_backing_dev_info __read_mostly = {
+ .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, unsigned long *blocknr,
int zero)
+{
+ int errval = pram_new_block(inode-i_sb, blocknr, zero);
+
+ if (!errval) {
+ struct pram_inode *pi = pram_get_inode(inode-i_sb,
+ inode-i_ino);
+ inode-i_blocks++;
+ pram_memunlock_inode(pi);
+ pi-i_blocks = cpu_to_be32(inode-i_blocks);
+ pram_memlock_inode(pi);
+ }
+
+ return errval;
+}
+
+/*
+ * find the offset to the block represented by the given inode's file
+ * relative block number.
+ */
+u64 pram_find_data_block(struct inode *inode, int file_blocknr)
+{
+ struct super_block *sb = inode-i_sb;
+ struct pram_inode *pi;
+ u64 *row; /* ptr to row block */
+ u64 *col; /* ptr to column blocks */
+ u64 bp = 0;
+ int i_row, i_col;
+ int N = sb-s_blocksize 3; /* num block ptrs per block */
+ int Nbits = sb-s_blocksize_bits - 3;
+
+ pi = pram_get_inode(sb, inode-i_ino);
+
+ i_row = file_blocknr Nbits;
+ i_col = file_blocknr (N-1);
+
+ row = pram_get_block(sb, be64_to_cpu(pi-i_type.reg.row_block));
+ if (row) {
+ col = pram_get_block(sb, be64_to_cpu(row[i_row]));
+ if (col)
+ bp = be64_to_cpu(col[i_col]);
+ }
+
+ return bp;
+}
+
+/*
+ * Free data blocks from inode in the range start = end
+ */
+static void __pram_truncate_blocks(struct inode *inode, loff_t start, loff_t
end)
+{
+ struct super_block *sb = inode-i_sb;
+ struct pram_inode *pi = pram_get_inode(sb, inode-i_ino);
+ int N = sb-s_blocksize 3; /* num block ptrs per block */
+ int Nbits = sb-s_blocksize_bits - 3;
+ int first_row_index, last_row_index, i, j;
+ unsigned long blocknr, first_blocknr, last_blocknr;
+ unsigned int freed = 0;
+ u64 *row; /* ptr to row block */
+ u64 *col; /* ptr to column blocks */
+
+ if (start end || !inode-i_blocks || !pi-i_type.reg.row_block)
+ return;
+
+ mutex_lock(PRAM_I(inode)-truncate_mutex);
+
+ first_blocknr = (start + sb-s_blocksize - 1) sb-s_blocksize_bits;
+ last_blocknr = (end + sb-s_blocksize - 1) sb-s_blocksize_bits;
+ first_row_index = first_blocknr Nbits;
+ last_row_index = last_blocknr Nbits;
+
+ row = pram_get_block(sb, be64_to_cpu(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;
+
+ if (unlikely(!row[i]))
+ continue;
+
+ col = pram_get_block(sb, be64_to_cpu(row[i]));
+
+ for (j = first_col_index; j = last_col_index; j++) {
+
+ if (unlikely(!col[j]))
+ continue;
+
+ blocknr = pram_get_blocknr(sb, be64_to_cpu(col[j]));
+ pram_free_block(sb, blocknr);
+ freed++;
+ pram_memunlock_block(sb, col);
+ col[j] = 0;
+ pram_memlock_block(sb, col);
+ }
+
+ if (first_col_index == 0) {
+
[PATCH 04/16 v3] pramfs: file operations
From: Marco Stornelli marco.storne...@gmail.com
File operations.
Signed-off-by: Marco Stornelli marco.storne...@gmail.com
---
diff -Nurp linux-2.6.36-orig/fs/pramfs/file.c linux-2.6.36/fs/pramfs/file.c
--- linux-2.6.36-orig/fs/pramfs/file.c 1970-01-01 01:00:00.0 +0100
+++ linux-2.6.36/fs/pramfs/file.c 2010-09-24 18:34:03.0 +0200
@@ -0,0 +1,166 @@
+/*
+ * FILE NAME fs/pramfs/file.c
+ *
+ * BRIEF DESCRIPTION
+ *
+ * File operations for files.
+ *
+ * Copyright 2009-2010 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/sched.h
+#include linux/slab.h
+#include linux/uio.h
+#include linux/mm.h
+#include linux/uaccess.h
+#include pram.h
+#include acl.h
+#include xip.h
+#include xattr.h
+
+static int pram_open_file(struct inode *inode, struct file *filp)
+{
+#ifndef CONFIG_PRAMFS_XIP
+ /* Without XIP we force to use Direct IO */
+ filp-f_flags |= O_DIRECT;
+#endif
+ return generic_file_open(inode, filp);
+}
+
+ssize_t __pram_direct_IO(int rw, struct kiocb *iocb,
+ const struct iovec *iov,
+ loff_t offset, unsigned long nr_segs)
+{
+ struct file *file = iocb-ki_filp;
+ struct inode *inode = file-f_mapping-host;
+ struct super_block *sb = inode-i_sb;
+ int progress = 0, hole = 0;
+ ssize_t retval = 0;
+ void *tmp = NULL;
+ unsigned long blocknr, blockoff;
+ int num_blocks, blocksize_mask, blocksize, blocksize_bits;
+ char __user *buf = iov-iov_base;
+ size_t length = iov_length(iov, nr_segs);
+
+ if (length 0)
+ return -EINVAL;
+ if ((rw == READ) (offset + length inode-i_size))
+ length = inode-i_size - offset;
+ if (!length)
+ goto out;
+
+ blocksize_bits = inode-i_sb-s_blocksize_bits;
+ blocksize = 1 blocksize_bits;
+ blocksize_mask = blocksize - 1;
+
+ /* find starting block number to access */
+ blocknr = offset blocksize_bits;
+ /* find starting offset within starting block */
+ blockoff = offset blocksize_mask;
+ /* find number of blocks to access */
+ num_blocks = (blockoff + length + blocksize_mask) blocksize_bits;
+
+ if (rw == WRITE) {
+ /* prepare a temporary buffer to hold a user data block
+ for writing. */
+ tmp = kmalloc(blocksize, GFP_KERNEL);
+ if (!tmp)
+ return -ENOMEM;
+ /* now allocate the data blocks we'll need */
+ retval = pram_alloc_blocks(inode, blocknr, num_blocks);
+ if (retval)
+ goto fail1;
+ }
+
+ while (length) {
+ int count;
+ u8 *bp = NULL;
+ u64 block = pram_find_data_block(inode, blocknr++);
+ if (unlikely(!block rw == READ)) {
+ /* We are falling in a hole */
+ hole = 1;
+ } else {
+ bp = (u8 *)pram_get_block(sb, block);
+ if (!bp)
+ goto fail2;
+ }
+
+ count = blockoff + length blocksize ?
+ blocksize - blockoff : length;
+
+ if (rw == READ) {
+ if (unlikely(hole)) {
+ retval = clear_user(buf, count);
+ if (retval) {
+ retval = -EFAULT;
+ goto fail1;
+ }
+ } else {
+ retval = copy_to_user(buf, bp[blockoff],
count);
+ if (retval) {
+ retval = -EFAULT;
+ goto fail1;
+ }
+ }
+ } else {
+ retval = copy_from_user(tmp, buf, count);
+ if (retval) {
+ retval = -EFAULT;
+ goto fail1;
+ }
+
+ pram_memunlock_block(inode-i_sb, bp);
+ memcpy(bp[blockoff], tmp, count);
+ pram_memlock_block(inode-i_sb, bp);
+ }
+
+ progress += count;
+ buf += count;
+ length -= count;
+ blockoff = 0;
+ hole = 0;
+ }
+
+fail2:
+ retval = progress;
+fail1:
+ kfree(tmp);
+out:
+
[PATCH 07/16 v3] pramfs: symbolic links
From: Marco Stornelli marco.storne...@gmail.com
Symlink operations.
Signed-off-by: Marco Stornelli marco.storne...@gmail.com
---
diff -Nurp linux-2.6.36-orig/fs/pramfs/symlink.c
linux-2.6.36/fs/pramfs/symlink.c
--- linux-2.6.36-orig/fs/pramfs/symlink.c 1970-01-01 01:00:00.0
+0100
+++ linux-2.6.36/fs/pramfs/symlink.c2010-09-14 18:49:52.0 +0200
@@ -0,0 +1,78 @@
+/*
+ * FILE NAME fs/pramfs/symlink.c
+ *
+ * BRIEF DESCRIPTION
+ *
+ * Symlink operations
+ *
+ * Copyright 2009-2010 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 pram.h
+#include xattr.h
+
+int pram_block_symlink(struct inode *inode, const char *symname, int len)
+{
+ struct super_block *sb = inode-i_sb;
+ u64 block;
+ char *blockp;
+ int err;
+
+ err = pram_alloc_blocks(inode, 0, 1);
+ if (err)
+ return err;
+
+ block = pram_find_data_block(inode, 0);
+ blockp = pram_get_block(sb, block);
+
+ pram_memunlock_block(sb, blockp);
+ memcpy(blockp, symname, len);
+ blockp[len] = '\0';
+ pram_memlock_block(sb, blockp);
+ return 0;
+}
+
+static int pram_readlink(struct dentry *dentry, char *buffer, int buflen)
+{
+ struct inode *inode = dentry-d_inode;
+ struct super_block *sb = inode-i_sb;
+ u64 block;
+ char *blockp;
+
+ block = pram_find_data_block(inode, 0);
+ blockp = pram_get_block(sb, block);
+ return vfs_readlink(dentry, buffer, buflen, blockp);
+}
+
+static void *pram_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+ struct inode *inode = dentry-d_inode;
+ struct super_block *sb = inode-i_sb;
+ off_t block;
+ int status;
+ char *blockp;
+
+ block = pram_find_data_block(inode, 0);
+ blockp = pram_get_block(sb, block);
+ status = vfs_follow_link(nd, blockp);
+ return ERR_PTR(status);
+}
+
+struct inode_operations pram_symlink_inode_operations = {
+ .readlink = pram_readlink,
+ .follow_link= pram_follow_link,
+ .setattr= pram_notify_change,
+#ifdef CONFIG_PRAMFS_XATTR
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
+ .listxattr = pram_listxattr,
+ .removexattr= generic_removexattr,
+#endif
+};
--
To unsubscribe from this list: send the line unsubscribe linux-embedded in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH 08/16 v3] pramfs: headers
From: Marco Stornelli marco.storne...@gmail.com
Definitions for the PRAMFS filesystem.
Signed-off-by: Marco Stornelli marco.storne...@gmail.com
---
diff -Nurp linux-2.6.36-orig/fs/pramfs/pram.h linux-2.6.36/fs/pramfs/pram.h
--- linux-2.6.36-orig/fs/pramfs/pram.h 1970-01-01 01:00:00.0 +0100
+++ linux-2.6.36/fs/pramfs/pram.h 2010-10-30 12:02:45.0 +0200
@@ -0,0 +1,317 @@
+/*
+ * FILE NAME pram.h
+ *
+ * BRIEF DESCRIPTION
+ *
+ * Definitions for the PRAMFS filesystem.
+ *
+ * Copyright 2009-2010 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.
+ */
+#ifndef __PRAM_H
+#define __PRAM_H
+
+#include linux/buffer_head.h
+#include linux/pram_fs.h
+#include linux/pram_fs_sb.h
+#include linux/crc16.h
+#include linux/mutex.h
+#include linux/types.h
+
+/*
+ * Debug code
+ */
+#define pram_dbg(s, args...) pr_debug(PRAMFS: s, ## args)
+#define pram_err(s, args...) pr_err(PRAMFS: s, ## args)
+#define pram_warn(s, args...) pr_warning(PRAMFS: s, ## args)
+#define pram_info(s, args...) pr_info(PRAMFS: s, ## args)
+
+/* Function Prototypes */
+
+#ifdef CONFIG_PRAMFS_XIP
+
+#define pram_read xip_file_read
+#define pram_write xip_file_write
+#define pram_mmap xip_file_mmap
+#define pram_aio_read NULL
+#define pram_aio_write NULL
+#define pram_readpage NULL
+#define pram_direct_IO NULL
+
+#else
+
+#define pram_read do_sync_read
+#define pram_write do_sync_write
+#define pram_mmap __pram_mmap
+#define pram_aio_read generic_file_aio_read
+#define pram_aio_write generic_file_aio_write
+#define pram_direct_IO __pram_direct_IO
+#define pram_readpage __pram_readpage
+
+extern int pram_get_and_update_block(struct inode *inode, sector_t iblock,
+struct buffer_head *bh, int create);
+
+static inline int __pram_readpage(struct file *file, struct page *page)
+{
+ return block_read_full_page(page, pram_get_and_update_block);
+}
+
+/* file.c */
+extern ssize_t __pram_direct_IO(int rw, struct kiocb *iocb,
+ const struct iovec *iov,
+ loff_t offset, unsigned long nr_segs);
+extern int __pram_mmap(struct file *file, struct vm_area_struct *vma);
+
+#endif /* CONFIG_PRAMFS_XIP */
+
+#define pram_set_bit ext2_set_bit
+#define pram_clear_bit ext2_clear_bit
+#define pram_find_next_zero_bitext2_find_next_zero_bit
+
+/* balloc.c */
+extern void pram_init_bitmap(struct super_block *sb);
+extern void pram_free_block(struct super_block *sb, unsigned long blocknr);
+extern int pram_new_block(struct super_block *sb, unsigned long *blocknr, int
zero);
+extern unsigned long pram_count_free_blocks(struct super_block *sb);
+
+/* dir.c */
+extern int pram_add_link(struct dentry *dentry, struct inode *inode);
+extern int pram_remove_link(struct inode *inode);
+
+/* namei.c */
+extern struct dentry *pram_get_parent(struct dentry *child);
+
+/* inode.c */
+extern int pram_alloc_blocks(struct inode *inode, int file_blocknr, int num);
+extern u64 pram_find_data_block(struct inode *inode,
+int file_blocknr);
+
+extern struct inode *pram_iget(struct super_block *sb, unsigned long ino);
+extern void pram_put_inode(struct inode *inode);
+extern void pram_evict_inode(struct inode *inode);
+extern struct inode *pram_new_inode(struct inode *dir, int mode);
+extern int pram_update_inode(struct inode *inode);
+extern int pram_write_inode(struct inode *inode, struct writeback_control
*wbc);
+extern void pram_dirty_inode(struct inode *inode);
+extern int pram_notify_change(struct dentry *dentry, struct iattr *attr);
+
+
+/* super.c */
+#ifdef CONFIG_PRAMFS_TEST
+extern struct pram_super_block *get_pram_super(void);
+#endif
+extern struct super_block *pram_read_super(struct super_block *sb,
+ void *data,
+ int silent);
+extern int pram_statfs(struct dentry *d, struct kstatfs *buf);
+extern int pram_remount(struct super_block *sb, int *flags, char *data);
+
+/* symlink.c */
+extern int pram_block_symlink(struct inode *inode,
+ const char *symname, int len);
+
+
+#ifdef CONFIG_PRAMFS_WRITE_PROTECT
+extern void pram_writeable(void *vaddr, unsigned long size, int rw);
+
+#define wrprotect(addr, size) pram_writeable(addr, size, 0)
+
+#else
+
+#define wrprotect(addr, size) do {} while (0)
+
+#endif /* CONFIG PRAMFS_WRITE_PROTECT */
+
+/* Inline functions start here */
+
+static inline int pram_calc_checksum(u8 *data, int n)
+{
+ u16 crc = 0;
+ crc = crc16(~0, (__u8 *)data +
[PATCH 09/16 v3] pramfs: dir operations
From: Marco Stornelli marco.storne...@gmail.com
File operations for directories.
Signed-off-by: Marco Stornelli marco.storne...@gmail.com
---
diff -Nurp linux-2.6.36-orig/fs/pramfs/dir.c linux-2.6.36/fs/pramfs/dir.c
--- linux-2.6.36-orig/fs/pramfs/dir.c 1970-01-01 01:00:00.0 +0100
+++ linux-2.6.36/fs/pramfs/dir.c2010-09-17 19:08:54.0 +0200
@@ -0,0 +1,215 @@
+/*
+ * FILE NAME fs/pramfs/dir.c
+ *
+ * BRIEF DESCRIPTION
+ *
+ * File operations for directories.
+ *
+ * Copyright 2009-2010 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/pagemap.h
+#include pram.h
+
+/*
+ * Parent is locked.
+ */
+int pram_add_link(struct dentry *dentry, struct inode *inode)
+{
+ struct inode *dir = dentry-d_parent-d_inode;
+ struct pram_inode *pidir, *pi, *pitail = NULL;
+ u64 tail_ino, prev_ino;
+
+ const char *name = dentry-d_name.name;
+
+ int namelen = dentry-d_name.len PRAM_NAME_LEN ?
+ PRAM_NAME_LEN : dentry-d_name.len;
+
+ pidir = pram_get_inode(dir-i_sb, dir-i_ino);
+ pi = pram_get_inode(dir-i_sb, inode-i_ino);
+
+ dir-i_mtime = dir-i_ctime = CURRENT_TIME;
+
+ tail_ino = be64_to_cpu(pidir-i_type.dir.tail);
+ if (tail_ino != 0) {
+ pitail = pram_get_inode(dir-i_sb, tail_ino);
+ pram_memunlock_inode(pitail);
+ pitail-i_d.d_next = cpu_to_be64(inode-i_ino);
+ pram_memlock_inode(pitail);
+
+ prev_ino = tail_ino;
+
+ pram_memunlock_inode(pidir);
+ pidir-i_type.dir.tail = cpu_to_be64(inode-i_ino);
+ pidir-i_mtime = cpu_to_be32(dir-i_mtime.tv_sec);
+ pidir-i_ctime = cpu_to_be32(dir-i_ctime.tv_sec);
+ pram_memlock_inode(pidir);
+ } else {
+ /* the directory is empty */
+ prev_ino = 0;
+
+ pram_memunlock_inode(pidir);
+ pidir-i_type.dir.tail = cpu_to_be64(inode-i_ino);
+ pidir-i_type.dir.head = cpu_to_be64(inode-i_ino);
+ pidir-i_mtime = cpu_to_be32(dir-i_mtime.tv_sec);
+ pidir-i_ctime = cpu_to_be32(dir-i_ctime.tv_sec);
+ pram_memlock_inode(pidir);
+ }
+
+
+ pram_memunlock_inode(pi);
+ pi-i_d.d_prev = cpu_to_be64(prev_ino);
+ pi-i_d.d_parent = cpu_to_be64(dir-i_ino);
+ memcpy(pi-i_d.d_name, name, namelen);
+ pi-i_d.d_name[namelen] = '\0';
+ pram_memlock_inode(pi);
+ return 0;
+}
+
+int pram_remove_link(struct inode *inode)
+{
+ struct super_block *sb = inode-i_sb;
+ struct pram_inode *prev = NULL;
+ struct pram_inode *next = NULL;
+ struct pram_inode *pidir, *pi;
+
+ pi = pram_get_inode(sb, inode-i_ino);
+ pidir = pram_get_inode(sb, be64_to_cpu(pi-i_d.d_parent));
+ if (!pidir)
+ return -EACCES;
+
+ if (inode-i_ino == be64_to_cpu(pidir-i_type.dir.head)) {
+ /* first inode in directory */
+ next = pram_get_inode(sb, be64_to_cpu(pi-i_d.d_next));
+
+ if (next) {
+ pram_memunlock_inode(next);
+ next-i_d.d_prev = 0;
+ pram_memlock_inode(next);
+
+ pram_memunlock_inode(pidir);
+ pidir-i_type.dir.head = pi-i_d.d_next;
+ } else {
+ pram_memunlock_inode(pidir);
+ pidir-i_type.dir.head = 0;
+ pidir-i_type.dir.tail = 0;
+ }
+ pram_memlock_inode(pidir);
+ } else if (inode-i_ino == be64_to_cpu(pidir-i_type.dir.tail)) {
+ /* last inode in directory */
+ prev = pram_get_inode(sb, be64_to_cpu(pi-i_d.d_prev));
+
+ pram_memunlock_inode(prev);
+ prev-i_d.d_next = 0;
+ pram_memlock_inode(prev);
+
+ pram_memunlock_inode(pidir);
+ pidir-i_type.dir.tail = pi-i_d.d_prev;
+ pram_memlock_inode(pidir);
+ } else {
+ /* somewhere in the middle */
+ prev = pram_get_inode(sb, be64_to_cpu(pi-i_d.d_prev));
+ next = pram_get_inode(sb, be64_to_cpu(pi-i_d.d_next));
+
+ if (prev next) {
+ pram_memunlock_inode(prev);
+ prev-i_d.d_next = pi-i_d.d_next;
+ pram_memlock_inode(prev);
+
+ pram_memunlock_inode(next);
+ next-i_d.d_prev = pi-i_d.d_prev;
+
[PATCH 10/16 v3] pramfs: XIP operations
From: Marco Stornelli marco.storne...@gmail.com
XIP operations.
Signed-off-by: Marco Stornelli marco.storne...@gmail.com
---
diff -Nurp linux-2.6.36-orig/fs/pramfs/xip.c linux-2.6.36/fs/pramfs/xip.c
--- linux-2.6.36-orig/fs/pramfs/xip.c 1970-01-01 01:00:00.0 +0100
+++ linux-2.6.36/fs/pramfs/xip.c2010-09-14 18:49:52.0 +0200
@@ -0,0 +1,90 @@
+/*
+ * FILE NAME fs/pramfs/xip.c
+ *
+ * BRIEF DESCRIPTION
+ *
+ * XIP operations.
+ *
+ * Copyright 2009-2010 Marco Stornelli marco.storne...@gmail.com
+ * 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/mm.h
+#include linux/fs.h
+#include linux/genhd.h
+#include linux/buffer_head.h
+#include pram.h
+#include xip.h
+
+static int pram_find_and_alloc_blocks(struct inode *inode, sector_t iblock,
+sector_t *data_block, int create)
+{
+ int err = -EIO;
+ u64 block;
+
+ mutex_lock(PRAM_I(inode)-truncate_mutex);
+
+ block = pram_find_data_block(inode, iblock);
+
+ if (!block) {
+ if (!create) {
+ err = -ENODATA;
+ goto err;
+ }
+
+ err = pram_alloc_blocks(inode, iblock, 1);
+ if (err)
+ goto err;
+
+ block = pram_find_data_block(inode, iblock);
+ if (!block) {
+ err = -ENODATA;
+ goto err;
+ }
+ }
+
+ *data_block = block;
+ err = 0;
+
+ err:
+ mutex_unlock(PRAM_I(inode)-truncate_mutex);
+ return err;
+}
+
+
+static int __pram_get_block(struct inode *inode, pgoff_t pgoff, int create,
+ sector_t *result)
+{
+ int rc = 0;
+ sector_t iblock;
+
+ /* find starting block number to access */
+ iblock = (sector_t)pgoff (PAGE_CACHE_SHIFT - inode-i_blkbits);
+
+ rc = pram_find_and_alloc_blocks(inode, iblock, result, create);
+
+ if (rc == -ENODATA)
+ BUG_ON(create);
+
+ return rc;
+}
+
+int pram_get_xip_mem(struct address_space *mapping, pgoff_t pgoff, int create,
+ void **kmem, unsigned long *pfn)
+{
+ int rc;
+ sector_t block;
+
+ /* first, retrieve the block */
+ rc = __pram_get_block(mapping-host, pgoff, create, block);
+ if (rc)
+ goto exit;
+
+ *kmem = pram_get_block(mapping-host-i_sb, block);
+ *pfn = page_to_pfn(virt_to_page((unsigned long)*kmem));
+
+exit:
+ return rc;
+}
diff -Nurp linux-2.6.36-orig/fs/pramfs/xip.h linux-2.6.36/fs/pramfs/xip.h
--- linux-2.6.36-orig/fs/pramfs/xip.h 1970-01-01 01:00:00.0 +0100
+++ linux-2.6.36/fs/pramfs/xip.h2010-09-14 18:49:52.0 +0200
@@ -0,0 +1,24 @@
+/*
+ * FILE NAME fs/pramfs/xip.h
+ *
+ * BRIEF DESCRIPTION
+ *
+ * XIP operations.
+ *
+ * Copyright 2009-2010 Marco Stornelli marco.storne...@gmail.com
+ * 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.
+ */
+
+#ifdef CONFIG_PRAMFS_XIP
+
+int pram_get_xip_mem(struct address_space *, pgoff_t, int, void **,
+ unsigned long *);
+
+#else
+
+#define pram_get_xip_mem NULL
+
+#endif
+
--
To unsubscribe from this list: send the line unsubscribe linux-embedded in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH 12/16 v3] pramfs: extended attributes
From: Marco Stornelli marco.storne...@gmail.com
Extended attributes operations.
Signed-off-by: Marco Stornelli marco.storne...@gmail.com
---
diff -Nurp linux-2.6.36-orig/fs/pramfs/xattr.c linux-2.6.36/fs/pramfs/xattr.c
--- linux-2.6.36-orig/fs/pramfs/xattr.c 1970-01-01 01:00:00.0 +0100
+++ linux-2.6.36/fs/pramfs/xattr.c 2010-09-14 19:45:40.0 +0200
@@ -0,0 +1,1108 @@
+/*
+ * FILE NAME fs/pramfs/xattr.c
+ *
+ * BRIEF DESCRIPTION
+ *
+ * Extended attributes operations.
+ *
+ * Copyright 2010 Marco Stornelli marco.storne...@gmail.com
+ *
+ * based on fs/ext2/xattr.c with the following copyright:
+ *
+ * Fix by Harrison Xing harri...@mountainviewdata.com.
+ * Extended attributes for symlinks and special files added per
+ * suggestion of Luka Renko luka.re...@hermes.si.
+ * xattr consolidation Copyright (c) 2004 James Morris jmor...@redhat.com,
+ * Red Hat Inc.
+ *
+ * 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.
+ */
+
+/*
+ * Extended attributes are stored in blocks allocated outside of
+ * any inode. The i_xattr field is then made to point to this allocated
+ * block. If all extended attributes of an inode are identical, these
+ * inodes may share the same extended attribute block. Such situations
+ * are automatically detected by keeping a cache of recent attribute block
+ * numbers and hashes over the block's contents in memory.
+ *
+ *
+ * Extended attribute block layout:
+ *
+ * +--+
+ * | header |
+ * | entry 1 | |
+ * | entry 2 | | growing downwards
+ * | entry 3 | v
+ * | four null bytes |
+ * | . . .|
+ * | value 1 | ^
+ * | value 3 | | growing upwards
+ * | value 2 | |
+ * +--+
+ *
+ * The block header is followed by multiple entry descriptors. These entry
+ * descriptors are variable in size, and alligned to PRAM_XATTR_PAD
+ * byte boundaries. The entry descriptors are sorted by attribute name,
+ * so that two extended attribute blocks can be compared efficiently.
+ *
+ * Attribute values are aligned to the end of the block, stored in
+ * no specific order. They are also padded to PRAM_XATTR_PAD byte
+ * boundaries. No additional gaps are left between them.
+ *
+ * Locking strategy
+ *
+ * pi-i_xattr is protected by PRAM_I(inode)-xattr_sem.
+ * EA blocks are only changed if they are exclusive to an inode, so
+ * holding xattr_sem also means that nothing but the EA block's reference
+ * count will change. Multiple writers to an EA block are synchronized
+ * by the mutex in each block descriptor. Block descriptors are kept in a
+ * red black tree and the key is the absolute block number.
+ */
+
+#include linux/module.h
+#include linux/init.h
+#include linux/mbcache.h
+#include linux/rwsem.h
+#include linux/security.h
+#include pram.h
+#include xattr.h
+#include acl.h
+#include desctree.h
+
+#define HDR(bp) ((struct pram_xattr_header *)(bp))
+#define ENTRY(ptr) ((struct pram_xattr_entry *)(ptr))
+#define FIRST_ENTRY(bh) ENTRY(HDR(bh)+1)
+#define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
+#define GET_DESC(sbi, blocknr) lookup_xblock_desc(sbi, blocknr,
pram_xblock_desc_cache, 1)
+#define LOOKUP_DESC(sbi, blocknr) lookup_xblock_desc(sbi, blocknr, NULL, 0)
+
+#ifdef PRAM_XATTR_DEBUG
+# define ea_idebug(inode, f...) do { \
+ printk(KERN_DEBUG inode %ld: , inode-i_ino); \
+ printk(f); \
+ printk(\n); \
+ } while (0)
+# define ea_bdebug(blocknr, f...) do { \
+ printk(KERN_DEBUG block %lu: , blocknr); \
+ printk(f); \
+ printk(\n); \
+ } while (0)
+#else
+# define ea_idebug(f...)
+# define ea_bdebug(f...)
+#endif
+
+static int pram_xattr_set2(struct inode *, char *, struct pram_xblock_desc *,
struct pram_xattr_header *);
+
+static int pram_xattr_cache_insert(struct super_block *sb, unsigned long
blocknr, u32 xhash);
+static struct pram_xblock_desc *pram_xattr_cache_find(struct inode *,
+struct pram_xattr_header *);
+static void pram_xattr_rehash(struct pram_xattr_header *,
+ struct pram_xattr_entry *);
+
+static struct mb_cache *pram_xattr_cache;
+static struct kmem_cache *pram_xblock_desc_cache;
+
+static const struct xattr_handler *pram_xattr_handler_map[] = {
+ [PRAM_XATTR_INDEX_USER] = pram_xattr_user_handler,
+#ifdef CONFIG_PRAMFS_POSIX_ACL
+ [PRAM_XATTR_INDEX_POSIX_ACL_ACCESS] = pram_xattr_acl_access_handler,
+ [PRAM_XATTR_INDEX_POSIX_ACL_DEFAULT] = pram_xattr_acl_default_handler,
+#endif
+ [PRAM_XATTR_INDEX_TRUSTED] = pram_xattr_trusted_handler,
+#ifdef CONFIG_PRAMFS_SECURITY
+ [PRAM_XATTR_INDEX_SECURITY] = pram_xattr_security_handler,
+#endif
+};
+
+const
[PATCH 13/16 v3] pramfs: xattr attributes block descriptors tree
From: Marco Stornelli marco.storne...@gmail.com
Extended attributes block descriptors tree.
Signed-off-by: Marco Stornelli marco.storne...@gmail.com
---
diff -Nurp linux-2.6.36-orig/fs/pramfs/desctree.c
linux-2.6.36/fs/pramfs/desctree.c
--- linux-2.6.36-orig/fs/pramfs/desctree.c 1970-01-01 01:00:00.0
+0100
+++ linux-2.6.36/fs/pramfs/desctree.c 2010-09-14 18:49:52.0 +0200
@@ -0,0 +1,183 @@
+/*
+ * FILE NAME fs/pramfs/desctree.c
+ *
+ * BRIEF DESCRIPTION
+ *
+ * Extended attributes block descriptors tree.
+ *
+ * Copyright 2010 Marco Stornelli marco.storne...@gmail.com
+ *
+ * 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/spinlock.h
+#include desctree.h
+#include pram.h
+
+/* xblock_desc_init_always()
+ *
+ * These are initializations that need to be done on every
+ * descriptor allocation as the fields are not initialised
+ * by slab allocation.
+ */
+void xblock_desc_init_always(struct pram_xblock_desc *desc)
+{
+ atomic_set(desc-refcount, 0);
+ desc-blocknr = 0;
+ desc-flags = 0;
+}
+
+/* xblock_desc_init_once()
+ *
+ * These are initializations that only need to be done
+ * once, because the fields are idempotent across use
+ * of the descriptor, so let the slab aware of that.
+ */
+void xblock_desc_init_once(struct pram_xblock_desc *desc)
+{
+ mutex_init(desc-lock);
+}
+
+/* __insert_xblock_desc()
+ *
+ * Insert a new descriptor in the tree.
+ */
+static void __insert_xblock_desc(struct pram_sb_info *sbi,
+unsigned long blocknr, struct rb_node *node)
+{
+ struct rb_node **p = (sbi-desc_tree.rb_node);
+ struct rb_node *parent = NULL;
+ struct pram_xblock_desc *desc;
+
+ while (*p) {
+ parent = *p;
+ desc = rb_entry(parent, struct pram_xblock_desc, node);
+
+ if (blocknr desc-blocknr)
+ p = (*p)-rb_left;
+ else if (blocknr desc-blocknr)
+ p = (*p)-rb_right;
+ else
+ /* Oops...an other descriptor for the same block ? */
+ BUG();
+ }
+
+ rb_link_node(node, parent, p);
+ rb_insert_color(node, sbi-desc_tree);
+}
+
+void insert_xblock_desc(struct pram_sb_info *sbi, struct pram_xblock_desc
*desc)
+{
+ spin_lock(sbi-desc_tree_lock);
+ __insert_xblock_desc(sbi, desc-blocknr, desc-node);
+ spin_unlock(sbi-desc_tree_lock);
+};
+
+/* __lookup_xblock_desc()
+ *
+ * Search an extended attribute descriptor in the tree via the
+ * block number. It returns the descriptor if it's found or
+ * NULL. If not found it creates a new descriptor if create is not 0.
+ */
+static struct pram_xblock_desc *__lookup_xblock_desc(struct pram_sb_info *sbi,
+ unsigned long blocknr,
+ struct kmem_cache *cache,
+ int create)
+{
+ struct rb_node *n = sbi-desc_tree.rb_node;
+ struct pram_xblock_desc *desc = NULL;
+
+ while (n) {
+ desc = rb_entry(n, struct pram_xblock_desc, node);
+
+ if (blocknr desc-blocknr)
+ n = n-rb_left;
+ else if (blocknr desc-blocknr)
+ n = n-rb_right;
+ else {
+ atomic_inc(desc-refcount);
+ goto out;
+ }
+ }
+
+ /* not found */
+ if (create) {
+ desc = kmem_cache_alloc(cache, GFP_NOFS);
+ if (!desc)
+ return ERR_PTR(-ENOMEM);
+ xblock_desc_init_always(desc);
+ atomic_set(desc-refcount, 1);
+ desc-blocknr = blocknr;
+ __insert_xblock_desc(sbi, desc-blocknr, desc-node);
+ }
+out:
+ return desc;
+}
+
+struct pram_xblock_desc *lookup_xblock_desc(struct pram_sb_info *sbi,
+ unsigned long blocknr,
+ struct kmem_cache *cache,
+ int create)
+{
+ struct pram_xblock_desc *desc = NULL;
+
+ spin_lock(sbi-desc_tree_lock);
+ desc = __lookup_xblock_desc(sbi, blocknr, cache, create);
+ spin_unlock(sbi-desc_tree_lock);
+ return desc;
+}
+
+/* put_xblock_desc()
+ *
+ * Decrement the reference count and if it reaches zero and the
+ * desciptor has been marked to be free, then we free it.
+ * It returns 0 if the descriptor has been deleted and 1 otherwise.
+ */
+int put_xblock_desc(struct pram_sb_info *sbi, struct pram_xblock_desc *desc)
+{
+ int ret = 1;
+ if (!desc)
+ return ret;
+
+ if (atomic_dec_and_lock(desc-refcount, sbi-desc_tree_lock)) {
+
[PATCH 14/16 v3] pramfs: memory protection
From: Marco Stornelli marco.storne...@gmail.com
Memory write protection.
Signed-off-by: Marco Stornelli marco.storne...@gmail.com
---
diff -Nurp linux-2.6.36-orig/fs/pramfs/wprotect.c
linux-2.6.36/fs/pramfs/wprotect.c
--- linux-2.6.36-orig/fs/pramfs/wprotect.c 1970-01-01 01:00:00.0
+0100
+++ linux-2.6.36/fs/pramfs/wprotect.c 2010-10-30 11:59:54.0 +0200
@@ -0,0 +1,41 @@
+/*
+ * FILE NAME fs/pramfs/wprotect.c
+ *
+ * BRIEF DESCRIPTION
+ *
+ * Write protection for the filesystem pages.
+ *
+ * Copyright 2009-2010 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/module.h
+#include linux/fs.h
+#include linux/mm.h
+#include linux/io.h
+#include pram.h
+
+void pram_writeable(void *vaddr, unsigned long size, int rw)
+{
+ int ret = 0;
+ unsigned long nrpages = size PAGE_SHIFT;
+ unsigned long addr = (unsigned long)vaddr;
+
+ /* Page aligned */
+ addr = PAGE_MASK;
+
+ if (size (PAGE_SIZE - 1))
+ nrpages++;
+
+ if (rw)
+ ret = set_memory_rw(addr, nrpages);
+ else
+ ret = set_memory_ro(addr, nrpages);
+
+ BUG_ON(ret);
+}
--
To unsubscribe from this list: send the line unsubscribe linux-embedded in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH 16/16 v3] pramfs: makefile and Kconfig
From: Marco Stornelli marco.storne...@gmail.com Makefile and Kconfig. Signed-off-by: Marco Stornelli marco.storne...@gmail.com --- diff -Nurp linux-2.6.36-orig/fs/Makefile linux-2.6.36/fs/Makefile --- linux-2.6.36-orig/fs/Makefile 2010-09-13 01:07:37.0 +0200 +++ linux-2.6.36/fs/Makefile2010-09-14 18:49:52.0 +0200 @@ -126,3 +126,4 @@ obj-$(CONFIG_BTRFS_FS) += btrfs/ obj-$(CONFIG_GFS2_FS) += gfs2/ obj-$(CONFIG_EXOFS_FS) += exofs/ obj-$(CONFIG_CEPH_FS) += ceph/ +obj-$(CONFIG_PRAMFS) += pramfs/ diff -Nurp linux-2.6.36-orig/fs/Kconfig linux-2.6.36/fs/Kconfig --- linux-2.6.36-orig/fs/Kconfig2010-09-13 01:07:37.0 +0200 +++ linux-2.6.36/fs/Kconfig 2010-09-14 18:49:52.0 +0200 @@ -13,7 +13,7 @@ source fs/ext4/Kconfig config FS_XIP # execute in place bool - depends on EXT2_FS_XIP + depends on EXT2_FS_XIP || PRAMFS_XIP default y source fs/jbd/Kconfig @@ -25,13 +25,14 @@ config FS_MBCACHE default y if EXT2_FS=y EXT2_FS_XATTR default y if EXT3_FS=y EXT3_FS_XATTR default y if EXT4_FS=y EXT4_FS_XATTR - default m if EXT2_FS_XATTR || EXT3_FS_XATTR || EXT4_FS_XATTR + default y if PRAMFS=y PRAMFS_XATTR + default m if EXT2_FS_XATTR || EXT3_FS_XATTR || EXT4_FS_XATTR || PRAMFS_XATTR source fs/reiserfs/Kconfig source fs/jfs/Kconfig config FS_POSIX_ACL -# Posix ACL utility routines (for now, only ext2/ext3/jfs/reiserfs/nfs4) +# Posix ACL utility routines (for now, only ext2/ext3/jfs/reiserfs/nfs4/pramfs) # # NOTE: you can implement Posix ACLs without these helpers (XFS does). # Never use this symbol for ifdefs. @@ -189,6 +190,7 @@ source fs/romfs/Kconfig source fs/sysv/Kconfig source fs/ufs/Kconfig source fs/exofs/Kconfig +source fs/pramfs/Kconfig endif # MISC_FILESYSTEMS diff -Nurp linux-2.6.36-orig/fs/pramfs/Kconfig linux-2.6.36/fs/pramfs/Kconfig --- linux-2.6.36-orig/fs/pramfs/Kconfig 1970-01-01 01:00:00.0 +0100 +++ linux-2.6.36/fs/pramfs/Kconfig 2010-10-30 10:30:19.0 +0200 @@ -0,0 +1,72 @@ +config PRAMFS + tristate Persistent and Protected RAM file system support + depends on HAS_IOMEM EXPERIMENTAL + select CRC16 + help + If your system has a block of fast (comparable in access speed to + system memory) and non-volatile RAM and you wish to mount a + light-weight, full-featured, and space-efficient filesystem over it, + say Y here, and read file:Documentation/filesystems/pramfs.txt. + + To compile this as a module, choose M here: the module will be + called pramfs. + +config PRAMFS_XIP + bool Enable Execute-in-place in PRAMFS + depends on PRAMFS !PRAMFS_WRITE_PROTECT + help + Say Y here to enable XIP feature of PRAMFS. + +config PRAMFS_WRITE_PROTECT + bool Enable PRAMFS write protection + depends on PRAMFS MMU HAVE_SET_MEMORY_RO + default y + help + Say Y here to enable the write protect feature of PRAMFS. + +config PRAMFS_XATTR + bool PRAMFS extended attributes + depends on PRAMFS + help + Extended attributes are name:value pairs associated with inodes by + the kernel or by users (see the attr(5) manual page, or visit + http://acl.bestbits.at/ for details). + + If unsure, say N. + +config PRAMFS_POSIX_ACL + bool PRAMFS POSIX Access Control Lists + depends on PRAMFS_XATTR + select FS_POSIX_ACL + help + Posix Access Control Lists (ACLs) support permissions for users and + groups beyond the owner/group/world scheme. + + To learn more about Access Control Lists, visit the Posix ACLs for + Linux website http://acl.bestbits.at/. + + If you don't know what Access Control Lists are, say N. + +config PRAMFS_SECURITY + bool PRAMFS Security Labels + depends on PRAMFS_XATTR + help + Security labels support alternative access control models + implemented by security modules like SELinux. This option + enables an extended attribute handler for file security + labels in the pram filesystem. + + If you are not using a security module that requires using + extended attributes for file security labels, say N. + +config PRAMFS_TEST + boolean + depends on PRAMFS + +config PRAMFS_TEST_MODULE + tristate PRAMFS Test + depends on PRAMFS m + select PRAMFS_TEST + help + Say Y here to build a simple module to test the protection of + PRAMFS. The module will be called pramfs_test. diff -Nurp linux-2.6.36-orig/fs/pramfs/Makefile linux-2.6.36/fs/pramfs/Makefile --- linux-2.6.36-orig/fs/pramfs/Makefile1970-01-01 01:00:00.0 +0100 +++ linux-2.6.36/fs/pramfs/Makefile 2010-09-14 18:49:52.0 +0200 @@ -0,0 +1,14 @@ +# +# Makefile for the
[PATCH 15/16 v3] pramfs: test module
From: Marco Stornelli marco.storne...@gmail.com
Test module.
Signed-off-by: Marco Stornelli marco.storne...@gmail.com
---
diff -Nurp linux-2.6.36-orig/fs/pramfs/pramfs_test.c
linux-2.6.36/fs/pramfs/pramfs_test.c
--- linux-2.6.36-orig/fs/pramfs/pramfs_test.c 1970-01-01 01:00:00.0
+0100
+++ linux-2.6.36/fs/pramfs/pramfs_test.c2010-09-14 18:49:52.0
+0200
@@ -0,0 +1,49 @@
+/*
+ * FILE NAME fs/pramfs/pramfs_test.c
+ *
+ * BRIEF DESCRIPTION
+ *
+ * Pramfs test module.
+ *
+ * Copyright 2009-2010 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/module.h
+#include linux/version.h
+#include linux/init.h
+#include linux/fs.h
+#include pram.h
+
+int __init test_pramfs_write(void)
+{
+ struct pram_super_block *psb;
+
+ psb = get_pram_super();
+ if (!psb) {
+ printk(KERN_ERR
+ %s: PRAMFS super block not found (not mounted?)\n,
+ __func__);
+ return 1;
+ }
+
+ /*
+* Attempt an unprotected clear of checksum information in the
+* superblock, this should cause a kernel page protection fault.
+*/
+ printk(%s: writing to kernel VA %p\n, __func__, psb);
+ psb-s_sum = 0;
+
+ return 0;
+}
+
+void test_pramfs_write_cleanup(void) {}
+
+/* Module information */
+MODULE_LICENSE(GPL);
+module_init(test_pramfs_write);
+module_exit(test_pramfs_write_cleanup);
--
To unsubscribe from this list: send the line unsubscribe linux-embedded in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
