 8ab22b9abb
			
		
	
	
	8ab22b9abb
	
	
	
		
			
			When we read some part of a file through pagecache, if there is a
pagecache of corresponding index but this page is not uptodate, read IO
is issued and this page will be uptodate.
I think this is good for pagesize == blocksize environment but there is
room for improvement on pagesize != blocksize environment.  Because in
this case a page can have multiple buffers and even if a page is not
uptodate, some buffers can be uptodate.
So I suggest that when all buffers which correspond to a part of a file
that we want to read are uptodate, use this pagecache and copy data from
this pagecache to user buffer even if a page is not uptodate.  This can
reduce read IO and improve system throughput.
I wrote a benchmark program and got result number with this program.
This benchmark do:
  1: mount and open a test file.
  2: create a 512MB file.
  3: close a file and umount.
  4: mount and again open a test file.
  5: pwrite randomly 300000 times on a test file.  offset is aligned
     by IO size(1024bytes).
  6: measure time of preading randomly 100000 times on a test file.
The result was:
	2.6.26
        330 sec
	2.6.26-patched
        226 sec
Arch:i386
Filesystem:ext3
Blocksize:1024 bytes
Memory: 1GB
On ext3/4, a file is written through buffer/block.  So random read/write
mixed workloads or random read after random write workloads are optimized
with this patch under pagesize != blocksize environment.  This test result
showed this.
The benchmark program is as follows:
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <time.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mount.h>
#define LEN 1024
#define LOOP 1024*512 /* 512MB */
main(void)
{
	unsigned long i, offset, filesize;
	int fd;
	char buf[LEN];
	time_t t1, t2;
	if (mount("/dev/sda1", "/root/test1/", "ext3", 0, 0) < 0) {
		perror("cannot mount\n");
		exit(1);
	}
	memset(buf, 0, LEN);
	fd = open("/root/test1/testfile", O_CREAT|O_RDWR|O_TRUNC);
	if (fd < 0) {
		perror("cannot open file\n");
		exit(1);
	}
	for (i = 0; i < LOOP; i++)
		write(fd, buf, LEN);
	close(fd);
	if (umount("/root/test1/") < 0) {
		perror("cannot umount\n");
		exit(1);
	}
	if (mount("/dev/sda1", "/root/test1/", "ext3", 0, 0) < 0) {
		perror("cannot mount\n");
		exit(1);
	}
	fd = open("/root/test1/testfile", O_RDWR);
	if (fd < 0) {
		perror("cannot open file\n");
		exit(1);
	}
	filesize = LEN * LOOP;
	for (i = 0; i < 300000; i++){
		offset = (random() % filesize) & (~(LEN - 1));
		pwrite(fd, buf, LEN, offset);
	}
	printf("start test\n");
	time(&t1);
	for (i = 0; i < 100000; i++){
		offset = (random() % filesize) & (~(LEN - 1));
		pread(fd, buf, LEN, offset);
	}
	time(&t2);
	printf("%ld sec\n", t2-t1);
	close(fd);
	if (umount("/root/test1/") < 0) {
		perror("cannot umount\n");
		exit(1);
	}
}
Signed-off-by: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jan Kara <jack@ucw.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
		
	
			
		
			
				
	
	
		
			1446 lines
		
	
	
	
		
			42 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			1446 lines
		
	
	
	
		
			42 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  *  linux/fs/ext2/inode.c
 | |
|  *
 | |
|  * Copyright (C) 1992, 1993, 1994, 1995
 | |
|  * Remy Card (card@masi.ibp.fr)
 | |
|  * Laboratoire MASI - Institut Blaise Pascal
 | |
|  * Universite Pierre et Marie Curie (Paris VI)
 | |
|  *
 | |
|  *  from
 | |
|  *
 | |
|  *  linux/fs/minix/inode.c
 | |
|  *
 | |
|  *  Copyright (C) 1991, 1992  Linus Torvalds
 | |
|  *
 | |
|  *  Goal-directed block allocation by Stephen Tweedie
 | |
|  * 	(sct@dcs.ed.ac.uk), 1993, 1998
 | |
|  *  Big-endian to little-endian byte-swapping/bitmaps by
 | |
|  *        David S. Miller (davem@caip.rutgers.edu), 1995
 | |
|  *  64-bit file support on 64-bit platforms by Jakub Jelinek
 | |
|  * 	(jj@sunsite.ms.mff.cuni.cz)
 | |
|  *
 | |
|  *  Assorted race fixes, rewrite of ext2_get_block() by Al Viro, 2000
 | |
|  */
 | |
| 
 | |
| #include <linux/smp_lock.h>
 | |
| #include <linux/time.h>
 | |
| #include <linux/highuid.h>
 | |
| #include <linux/pagemap.h>
 | |
| #include <linux/quotaops.h>
 | |
| #include <linux/module.h>
 | |
| #include <linux/writeback.h>
 | |
| #include <linux/buffer_head.h>
 | |
| #include <linux/mpage.h>
 | |
| #include "ext2.h"
 | |
| #include "acl.h"
 | |
| #include "xip.h"
 | |
| 
 | |
| MODULE_AUTHOR("Remy Card and others");
 | |
| MODULE_DESCRIPTION("Second Extended Filesystem");
 | |
| MODULE_LICENSE("GPL");
 | |
| 
 | |
| static int ext2_update_inode(struct inode * inode, int do_sync);
 | |
| 
 | |
| /*
 | |
|  * Test whether an inode is a fast symlink.
 | |
|  */
 | |
| static inline int ext2_inode_is_fast_symlink(struct inode *inode)
 | |
| {
 | |
| 	int ea_blocks = EXT2_I(inode)->i_file_acl ?
 | |
| 		(inode->i_sb->s_blocksize >> 9) : 0;
 | |
| 
 | |
| 	return (S_ISLNK(inode->i_mode) &&
 | |
| 		inode->i_blocks - ea_blocks == 0);
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Called at the last iput() if i_nlink is zero.
 | |
|  */
 | |
| void ext2_delete_inode (struct inode * inode)
 | |
| {
 | |
| 	truncate_inode_pages(&inode->i_data, 0);
 | |
| 
 | |
| 	if (is_bad_inode(inode))
 | |
| 		goto no_delete;
 | |
| 	EXT2_I(inode)->i_dtime	= get_seconds();
 | |
| 	mark_inode_dirty(inode);
 | |
| 	ext2_update_inode(inode, inode_needs_sync(inode));
 | |
| 
 | |
| 	inode->i_size = 0;
 | |
| 	if (inode->i_blocks)
 | |
| 		ext2_truncate (inode);
 | |
| 	ext2_free_inode (inode);
 | |
| 
 | |
| 	return;
 | |
| no_delete:
 | |
| 	clear_inode(inode);	/* We must guarantee clearing of inode... */
 | |
| }
 | |
| 
 | |
| typedef struct {
 | |
| 	__le32	*p;
 | |
| 	__le32	key;
 | |
| 	struct buffer_head *bh;
 | |
| } Indirect;
 | |
| 
 | |
| static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
 | |
| {
 | |
| 	p->key = *(p->p = v);
 | |
| 	p->bh = bh;
 | |
| }
 | |
| 
 | |
| static inline int verify_chain(Indirect *from, Indirect *to)
 | |
| {
 | |
| 	while (from <= to && from->key == *from->p)
 | |
| 		from++;
 | |
| 	return (from > to);
 | |
| }
 | |
| 
 | |
| /**
 | |
|  *	ext2_block_to_path - parse the block number into array of offsets
 | |
|  *	@inode: inode in question (we are only interested in its superblock)
 | |
|  *	@i_block: block number to be parsed
 | |
|  *	@offsets: array to store the offsets in
 | |
|  *      @boundary: set this non-zero if the referred-to block is likely to be
 | |
|  *             followed (on disk) by an indirect block.
 | |
|  *	To store the locations of file's data ext2 uses a data structure common
 | |
|  *	for UNIX filesystems - tree of pointers anchored in the inode, with
 | |
|  *	data blocks at leaves and indirect blocks in intermediate nodes.
 | |
|  *	This function translates the block number into path in that tree -
 | |
|  *	return value is the path length and @offsets[n] is the offset of
 | |
|  *	pointer to (n+1)th node in the nth one. If @block is out of range
 | |
|  *	(negative or too large) warning is printed and zero returned.
 | |
|  *
 | |
|  *	Note: function doesn't find node addresses, so no IO is needed. All
 | |
|  *	we need to know is the capacity of indirect blocks (taken from the
 | |
|  *	inode->i_sb).
 | |
|  */
 | |
| 
 | |
| /*
 | |
|  * Portability note: the last comparison (check that we fit into triple
 | |
|  * indirect block) is spelled differently, because otherwise on an
 | |
|  * architecture with 32-bit longs and 8Kb pages we might get into trouble
 | |
|  * if our filesystem had 8Kb blocks. We might use long long, but that would
 | |
|  * kill us on x86. Oh, well, at least the sign propagation does not matter -
 | |
|  * i_block would have to be negative in the very beginning, so we would not
 | |
|  * get there at all.
 | |
|  */
 | |
| 
 | |
| static int ext2_block_to_path(struct inode *inode,
 | |
| 			long i_block, int offsets[4], int *boundary)
 | |
| {
 | |
| 	int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb);
 | |
| 	int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb);
 | |
| 	const long direct_blocks = EXT2_NDIR_BLOCKS,
 | |
| 		indirect_blocks = ptrs,
 | |
| 		double_blocks = (1 << (ptrs_bits * 2));
 | |
| 	int n = 0;
 | |
| 	int final = 0;
 | |
| 
 | |
| 	if (i_block < 0) {
 | |
| 		ext2_warning (inode->i_sb, "ext2_block_to_path", "block < 0");
 | |
| 	} else if (i_block < direct_blocks) {
 | |
| 		offsets[n++] = i_block;
 | |
| 		final = direct_blocks;
 | |
| 	} else if ( (i_block -= direct_blocks) < indirect_blocks) {
 | |
| 		offsets[n++] = EXT2_IND_BLOCK;
 | |
| 		offsets[n++] = i_block;
 | |
| 		final = ptrs;
 | |
| 	} else if ((i_block -= indirect_blocks) < double_blocks) {
 | |
| 		offsets[n++] = EXT2_DIND_BLOCK;
 | |
| 		offsets[n++] = i_block >> ptrs_bits;
 | |
| 		offsets[n++] = i_block & (ptrs - 1);
 | |
| 		final = ptrs;
 | |
| 	} else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
 | |
| 		offsets[n++] = EXT2_TIND_BLOCK;
 | |
| 		offsets[n++] = i_block >> (ptrs_bits * 2);
 | |
| 		offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
 | |
| 		offsets[n++] = i_block & (ptrs - 1);
 | |
| 		final = ptrs;
 | |
| 	} else {
 | |
| 		ext2_warning (inode->i_sb, "ext2_block_to_path", "block > big");
 | |
| 	}
 | |
| 	if (boundary)
 | |
| 		*boundary = final - 1 - (i_block & (ptrs - 1));
 | |
| 
 | |
| 	return n;
 | |
| }
 | |
| 
 | |
| /**
 | |
|  *	ext2_get_branch - read the chain of indirect blocks leading to data
 | |
|  *	@inode: inode in question
 | |
|  *	@depth: depth of the chain (1 - direct pointer, etc.)
 | |
|  *	@offsets: offsets of pointers in inode/indirect blocks
 | |
|  *	@chain: place to store the result
 | |
|  *	@err: here we store the error value
 | |
|  *
 | |
|  *	Function fills the array of triples <key, p, bh> and returns %NULL
 | |
|  *	if everything went OK or the pointer to the last filled triple
 | |
|  *	(incomplete one) otherwise. Upon the return chain[i].key contains
 | |
|  *	the number of (i+1)-th block in the chain (as it is stored in memory,
 | |
|  *	i.e. little-endian 32-bit), chain[i].p contains the address of that
 | |
|  *	number (it points into struct inode for i==0 and into the bh->b_data
 | |
|  *	for i>0) and chain[i].bh points to the buffer_head of i-th indirect
 | |
|  *	block for i>0 and NULL for i==0. In other words, it holds the block
 | |
|  *	numbers of the chain, addresses they were taken from (and where we can
 | |
|  *	verify that chain did not change) and buffer_heads hosting these
 | |
|  *	numbers.
 | |
|  *
 | |
|  *	Function stops when it stumbles upon zero pointer (absent block)
 | |
|  *		(pointer to last triple returned, *@err == 0)
 | |
|  *	or when it gets an IO error reading an indirect block
 | |
|  *		(ditto, *@err == -EIO)
 | |
|  *	or when it notices that chain had been changed while it was reading
 | |
|  *		(ditto, *@err == -EAGAIN)
 | |
|  *	or when it reads all @depth-1 indirect blocks successfully and finds
 | |
|  *	the whole chain, all way to the data (returns %NULL, *err == 0).
 | |
|  */
 | |
| static Indirect *ext2_get_branch(struct inode *inode,
 | |
| 				 int depth,
 | |
| 				 int *offsets,
 | |
| 				 Indirect chain[4],
 | |
| 				 int *err)
 | |
| {
 | |
| 	struct super_block *sb = inode->i_sb;
 | |
| 	Indirect *p = chain;
 | |
| 	struct buffer_head *bh;
 | |
| 
 | |
| 	*err = 0;
 | |
| 	/* i_data is not going away, no lock needed */
 | |
| 	add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets);
 | |
| 	if (!p->key)
 | |
| 		goto no_block;
 | |
| 	while (--depth) {
 | |
| 		bh = sb_bread(sb, le32_to_cpu(p->key));
 | |
| 		if (!bh)
 | |
| 			goto failure;
 | |
| 		read_lock(&EXT2_I(inode)->i_meta_lock);
 | |
| 		if (!verify_chain(chain, p))
 | |
| 			goto changed;
 | |
| 		add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
 | |
| 		read_unlock(&EXT2_I(inode)->i_meta_lock);
 | |
| 		if (!p->key)
 | |
| 			goto no_block;
 | |
| 	}
 | |
| 	return NULL;
 | |
| 
 | |
| changed:
 | |
| 	read_unlock(&EXT2_I(inode)->i_meta_lock);
 | |
| 	brelse(bh);
 | |
| 	*err = -EAGAIN;
 | |
| 	goto no_block;
 | |
| failure:
 | |
| 	*err = -EIO;
 | |
| no_block:
 | |
| 	return p;
 | |
| }
 | |
| 
 | |
| /**
 | |
|  *	ext2_find_near - find a place for allocation with sufficient locality
 | |
|  *	@inode: owner
 | |
|  *	@ind: descriptor of indirect block.
 | |
|  *
 | |
|  *	This function returns the preferred place for block allocation.
 | |
|  *	It is used when heuristic for sequential allocation fails.
 | |
|  *	Rules are:
 | |
|  *	  + if there is a block to the left of our position - allocate near it.
 | |
|  *	  + if pointer will live in indirect block - allocate near that block.
 | |
|  *	  + if pointer will live in inode - allocate in the same cylinder group.
 | |
|  *
 | |
|  * In the latter case we colour the starting block by the callers PID to
 | |
|  * prevent it from clashing with concurrent allocations for a different inode
 | |
|  * in the same block group.   The PID is used here so that functionally related
 | |
|  * files will be close-by on-disk.
 | |
|  *
 | |
|  *	Caller must make sure that @ind is valid and will stay that way.
 | |
|  */
 | |
| 
 | |
| static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind)
 | |
| {
 | |
| 	struct ext2_inode_info *ei = EXT2_I(inode);
 | |
| 	__le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
 | |
| 	__le32 *p;
 | |
| 	ext2_fsblk_t bg_start;
 | |
| 	ext2_fsblk_t colour;
 | |
| 
 | |
| 	/* Try to find previous block */
 | |
| 	for (p = ind->p - 1; p >= start; p--)
 | |
| 		if (*p)
 | |
| 			return le32_to_cpu(*p);
 | |
| 
 | |
| 	/* No such thing, so let's try location of indirect block */
 | |
| 	if (ind->bh)
 | |
| 		return ind->bh->b_blocknr;
 | |
| 
 | |
| 	/*
 | |
| 	 * It is going to be refered from inode itself? OK, just put it into
 | |
| 	 * the same cylinder group then.
 | |
| 	 */
 | |
| 	bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group);
 | |
| 	colour = (current->pid % 16) *
 | |
| 			(EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16);
 | |
| 	return bg_start + colour;
 | |
| }
 | |
| 
 | |
| /**
 | |
|  *	ext2_find_goal - find a preferred place for allocation.
 | |
|  *	@inode: owner
 | |
|  *	@block:  block we want
 | |
|  *	@partial: pointer to the last triple within a chain
 | |
|  *
 | |
|  *	Returns preferred place for a block (the goal).
 | |
|  */
 | |
| 
 | |
| static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block,
 | |
| 					  Indirect *partial)
 | |
| {
 | |
| 	struct ext2_block_alloc_info *block_i;
 | |
| 
 | |
| 	block_i = EXT2_I(inode)->i_block_alloc_info;
 | |
| 
 | |
| 	/*
 | |
| 	 * try the heuristic for sequential allocation,
 | |
| 	 * failing that at least try to get decent locality.
 | |
| 	 */
 | |
| 	if (block_i && (block == block_i->last_alloc_logical_block + 1)
 | |
| 		&& (block_i->last_alloc_physical_block != 0)) {
 | |
| 		return block_i->last_alloc_physical_block + 1;
 | |
| 	}
 | |
| 
 | |
| 	return ext2_find_near(inode, partial);
 | |
| }
 | |
| 
 | |
| /**
 | |
|  *	ext2_blks_to_allocate: Look up the block map and count the number
 | |
|  *	of direct blocks need to be allocated for the given branch.
 | |
|  *
 | |
|  * 	@branch: chain of indirect blocks
 | |
|  *	@k: number of blocks need for indirect blocks
 | |
|  *	@blks: number of data blocks to be mapped.
 | |
|  *	@blocks_to_boundary:  the offset in the indirect block
 | |
|  *
 | |
|  *	return the total number of blocks to be allocate, including the
 | |
|  *	direct and indirect blocks.
 | |
|  */
 | |
| static int
 | |
| ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks,
 | |
| 		int blocks_to_boundary)
 | |
| {
 | |
| 	unsigned long count = 0;
 | |
| 
 | |
| 	/*
 | |
| 	 * Simple case, [t,d]Indirect block(s) has not allocated yet
 | |
| 	 * then it's clear blocks on that path have not allocated
 | |
| 	 */
 | |
| 	if (k > 0) {
 | |
| 		/* right now don't hanel cross boundary allocation */
 | |
| 		if (blks < blocks_to_boundary + 1)
 | |
| 			count += blks;
 | |
| 		else
 | |
| 			count += blocks_to_boundary + 1;
 | |
| 		return count;
 | |
| 	}
 | |
| 
 | |
| 	count++;
 | |
| 	while (count < blks && count <= blocks_to_boundary
 | |
| 		&& le32_to_cpu(*(branch[0].p + count)) == 0) {
 | |
| 		count++;
 | |
| 	}
 | |
| 	return count;
 | |
| }
 | |
| 
 | |
| /**
 | |
|  *	ext2_alloc_blocks: multiple allocate blocks needed for a branch
 | |
|  *	@indirect_blks: the number of blocks need to allocate for indirect
 | |
|  *			blocks
 | |
|  *
 | |
|  *	@new_blocks: on return it will store the new block numbers for
 | |
|  *	the indirect blocks(if needed) and the first direct block,
 | |
|  *	@blks:	on return it will store the total number of allocated
 | |
|  *		direct blocks
 | |
|  */
 | |
| static int ext2_alloc_blocks(struct inode *inode,
 | |
| 			ext2_fsblk_t goal, int indirect_blks, int blks,
 | |
| 			ext2_fsblk_t new_blocks[4], int *err)
 | |
| {
 | |
| 	int target, i;
 | |
| 	unsigned long count = 0;
 | |
| 	int index = 0;
 | |
| 	ext2_fsblk_t current_block = 0;
 | |
| 	int ret = 0;
 | |
| 
 | |
| 	/*
 | |
| 	 * Here we try to allocate the requested multiple blocks at once,
 | |
| 	 * on a best-effort basis.
 | |
| 	 * To build a branch, we should allocate blocks for
 | |
| 	 * the indirect blocks(if not allocated yet), and at least
 | |
| 	 * the first direct block of this branch.  That's the
 | |
| 	 * minimum number of blocks need to allocate(required)
 | |
| 	 */
 | |
| 	target = blks + indirect_blks;
 | |
| 
 | |
| 	while (1) {
 | |
| 		count = target;
 | |
| 		/* allocating blocks for indirect blocks and direct blocks */
 | |
| 		current_block = ext2_new_blocks(inode,goal,&count,err);
 | |
| 		if (*err)
 | |
| 			goto failed_out;
 | |
| 
 | |
| 		target -= count;
 | |
| 		/* allocate blocks for indirect blocks */
 | |
| 		while (index < indirect_blks && count) {
 | |
| 			new_blocks[index++] = current_block++;
 | |
| 			count--;
 | |
| 		}
 | |
| 
 | |
| 		if (count > 0)
 | |
| 			break;
 | |
| 	}
 | |
| 
 | |
| 	/* save the new block number for the first direct block */
 | |
| 	new_blocks[index] = current_block;
 | |
| 
 | |
| 	/* total number of blocks allocated for direct blocks */
 | |
| 	ret = count;
 | |
| 	*err = 0;
 | |
| 	return ret;
 | |
| failed_out:
 | |
| 	for (i = 0; i <index; i++)
 | |
| 		ext2_free_blocks(inode, new_blocks[i], 1);
 | |
| 	return ret;
 | |
| }
 | |
| 
 | |
| /**
 | |
|  *	ext2_alloc_branch - allocate and set up a chain of blocks.
 | |
|  *	@inode: owner
 | |
|  *	@num: depth of the chain (number of blocks to allocate)
 | |
|  *	@offsets: offsets (in the blocks) to store the pointers to next.
 | |
|  *	@branch: place to store the chain in.
 | |
|  *
 | |
|  *	This function allocates @num blocks, zeroes out all but the last one,
 | |
|  *	links them into chain and (if we are synchronous) writes them to disk.
 | |
|  *	In other words, it prepares a branch that can be spliced onto the
 | |
|  *	inode. It stores the information about that chain in the branch[], in
 | |
|  *	the same format as ext2_get_branch() would do. We are calling it after
 | |
|  *	we had read the existing part of chain and partial points to the last
 | |
|  *	triple of that (one with zero ->key). Upon the exit we have the same
 | |
|  *	picture as after the successful ext2_get_block(), excpet that in one
 | |
|  *	place chain is disconnected - *branch->p is still zero (we did not
 | |
|  *	set the last link), but branch->key contains the number that should
 | |
|  *	be placed into *branch->p to fill that gap.
 | |
|  *
 | |
|  *	If allocation fails we free all blocks we've allocated (and forget
 | |
|  *	their buffer_heads) and return the error value the from failed
 | |
|  *	ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain
 | |
|  *	as described above and return 0.
 | |
|  */
 | |
| 
 | |
| static int ext2_alloc_branch(struct inode *inode,
 | |
| 			int indirect_blks, int *blks, ext2_fsblk_t goal,
 | |
| 			int *offsets, Indirect *branch)
 | |
| {
 | |
| 	int blocksize = inode->i_sb->s_blocksize;
 | |
| 	int i, n = 0;
 | |
| 	int err = 0;
 | |
| 	struct buffer_head *bh;
 | |
| 	int num;
 | |
| 	ext2_fsblk_t new_blocks[4];
 | |
| 	ext2_fsblk_t current_block;
 | |
| 
 | |
| 	num = ext2_alloc_blocks(inode, goal, indirect_blks,
 | |
| 				*blks, new_blocks, &err);
 | |
| 	if (err)
 | |
| 		return err;
 | |
| 
 | |
| 	branch[0].key = cpu_to_le32(new_blocks[0]);
 | |
| 	/*
 | |
| 	 * metadata blocks and data blocks are allocated.
 | |
| 	 */
 | |
| 	for (n = 1; n <= indirect_blks;  n++) {
 | |
| 		/*
 | |
| 		 * Get buffer_head for parent block, zero it out
 | |
| 		 * and set the pointer to new one, then send
 | |
| 		 * parent to disk.
 | |
| 		 */
 | |
| 		bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
 | |
| 		branch[n].bh = bh;
 | |
| 		lock_buffer(bh);
 | |
| 		memset(bh->b_data, 0, blocksize);
 | |
| 		branch[n].p = (__le32 *) bh->b_data + offsets[n];
 | |
| 		branch[n].key = cpu_to_le32(new_blocks[n]);
 | |
| 		*branch[n].p = branch[n].key;
 | |
| 		if ( n == indirect_blks) {
 | |
| 			current_block = new_blocks[n];
 | |
| 			/*
 | |
| 			 * End of chain, update the last new metablock of
 | |
| 			 * the chain to point to the new allocated
 | |
| 			 * data blocks numbers
 | |
| 			 */
 | |
| 			for (i=1; i < num; i++)
 | |
| 				*(branch[n].p + i) = cpu_to_le32(++current_block);
 | |
| 		}
 | |
| 		set_buffer_uptodate(bh);
 | |
| 		unlock_buffer(bh);
 | |
| 		mark_buffer_dirty_inode(bh, inode);
 | |
| 		/* We used to sync bh here if IS_SYNC(inode).
 | |
| 		 * But we now rely upon generic_osync_inode()
 | |
| 		 * and b_inode_buffers.  But not for directories.
 | |
| 		 */
 | |
| 		if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode))
 | |
| 			sync_dirty_buffer(bh);
 | |
| 	}
 | |
| 	*blks = num;
 | |
| 	return err;
 | |
| }
 | |
| 
 | |
| /**
 | |
|  * ext2_splice_branch - splice the allocated branch onto inode.
 | |
|  * @inode: owner
 | |
|  * @block: (logical) number of block we are adding
 | |
|  * @chain: chain of indirect blocks (with a missing link - see
 | |
|  *	ext2_alloc_branch)
 | |
|  * @where: location of missing link
 | |
|  * @num:   number of indirect blocks we are adding
 | |
|  * @blks:  number of direct blocks we are adding
 | |
|  *
 | |
|  * This function fills the missing link and does all housekeeping needed in
 | |
|  * inode (->i_blocks, etc.). In case of success we end up with the full
 | |
|  * chain to new block and return 0.
 | |
|  */
 | |
| static void ext2_splice_branch(struct inode *inode,
 | |
| 			long block, Indirect *where, int num, int blks)
 | |
| {
 | |
| 	int i;
 | |
| 	struct ext2_block_alloc_info *block_i;
 | |
| 	ext2_fsblk_t current_block;
 | |
| 
 | |
| 	block_i = EXT2_I(inode)->i_block_alloc_info;
 | |
| 
 | |
| 	/* XXX LOCKING probably should have i_meta_lock ?*/
 | |
| 	/* That's it */
 | |
| 
 | |
| 	*where->p = where->key;
 | |
| 
 | |
| 	/*
 | |
| 	 * Update the host buffer_head or inode to point to more just allocated
 | |
| 	 * direct blocks blocks
 | |
| 	 */
 | |
| 	if (num == 0 && blks > 1) {
 | |
| 		current_block = le32_to_cpu(where->key) + 1;
 | |
| 		for (i = 1; i < blks; i++)
 | |
| 			*(where->p + i ) = cpu_to_le32(current_block++);
 | |
| 	}
 | |
| 
 | |
| 	/*
 | |
| 	 * update the most recently allocated logical & physical block
 | |
| 	 * in i_block_alloc_info, to assist find the proper goal block for next
 | |
| 	 * allocation
 | |
| 	 */
 | |
| 	if (block_i) {
 | |
| 		block_i->last_alloc_logical_block = block + blks - 1;
 | |
| 		block_i->last_alloc_physical_block =
 | |
| 				le32_to_cpu(where[num].key) + blks - 1;
 | |
| 	}
 | |
| 
 | |
| 	/* We are done with atomic stuff, now do the rest of housekeeping */
 | |
| 
 | |
| 	/* had we spliced it onto indirect block? */
 | |
| 	if (where->bh)
 | |
| 		mark_buffer_dirty_inode(where->bh, inode);
 | |
| 
 | |
| 	inode->i_ctime = CURRENT_TIME_SEC;
 | |
| 	mark_inode_dirty(inode);
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Allocation strategy is simple: if we have to allocate something, we will
 | |
|  * have to go the whole way to leaf. So let's do it before attaching anything
 | |
|  * to tree, set linkage between the newborn blocks, write them if sync is
 | |
|  * required, recheck the path, free and repeat if check fails, otherwise
 | |
|  * set the last missing link (that will protect us from any truncate-generated
 | |
|  * removals - all blocks on the path are immune now) and possibly force the
 | |
|  * write on the parent block.
 | |
|  * That has a nice additional property: no special recovery from the failed
 | |
|  * allocations is needed - we simply release blocks and do not touch anything
 | |
|  * reachable from inode.
 | |
|  *
 | |
|  * `handle' can be NULL if create == 0.
 | |
|  *
 | |
|  * return > 0, # of blocks mapped or allocated.
 | |
|  * return = 0, if plain lookup failed.
 | |
|  * return < 0, error case.
 | |
|  */
 | |
| static int ext2_get_blocks(struct inode *inode,
 | |
| 			   sector_t iblock, unsigned long maxblocks,
 | |
| 			   struct buffer_head *bh_result,
 | |
| 			   int create)
 | |
| {
 | |
| 	int err = -EIO;
 | |
| 	int offsets[4];
 | |
| 	Indirect chain[4];
 | |
| 	Indirect *partial;
 | |
| 	ext2_fsblk_t goal;
 | |
| 	int indirect_blks;
 | |
| 	int blocks_to_boundary = 0;
 | |
| 	int depth;
 | |
| 	struct ext2_inode_info *ei = EXT2_I(inode);
 | |
| 	int count = 0;
 | |
| 	ext2_fsblk_t first_block = 0;
 | |
| 
 | |
| 	depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
 | |
| 
 | |
| 	if (depth == 0)
 | |
| 		return (err);
 | |
| reread:
 | |
| 	partial = ext2_get_branch(inode, depth, offsets, chain, &err);
 | |
| 
 | |
| 	/* Simplest case - block found, no allocation needed */
 | |
| 	if (!partial) {
 | |
| 		first_block = le32_to_cpu(chain[depth - 1].key);
 | |
| 		clear_buffer_new(bh_result); /* What's this do? */
 | |
| 		count++;
 | |
| 		/*map more blocks*/
 | |
| 		while (count < maxblocks && count <= blocks_to_boundary) {
 | |
| 			ext2_fsblk_t blk;
 | |
| 
 | |
| 			if (!verify_chain(chain, partial)) {
 | |
| 				/*
 | |
| 				 * Indirect block might be removed by
 | |
| 				 * truncate while we were reading it.
 | |
| 				 * Handling of that case: forget what we've
 | |
| 				 * got now, go to reread.
 | |
| 				 */
 | |
| 				count = 0;
 | |
| 				goto changed;
 | |
| 			}
 | |
| 			blk = le32_to_cpu(*(chain[depth-1].p + count));
 | |
| 			if (blk == first_block + count)
 | |
| 				count++;
 | |
| 			else
 | |
| 				break;
 | |
| 		}
 | |
| 		goto got_it;
 | |
| 	}
 | |
| 
 | |
| 	/* Next simple case - plain lookup or failed read of indirect block */
 | |
| 	if (!create || err == -EIO)
 | |
| 		goto cleanup;
 | |
| 
 | |
| 	mutex_lock(&ei->truncate_mutex);
 | |
| 
 | |
| 	/*
 | |
| 	 * Okay, we need to do block allocation.  Lazily initialize the block
 | |
| 	 * allocation info here if necessary
 | |
| 	*/
 | |
| 	if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
 | |
| 		ext2_init_block_alloc_info(inode);
 | |
| 
 | |
| 	goal = ext2_find_goal(inode, iblock, partial);
 | |
| 
 | |
| 	/* the number of blocks need to allocate for [d,t]indirect blocks */
 | |
| 	indirect_blks = (chain + depth) - partial - 1;
 | |
| 	/*
 | |
| 	 * Next look up the indirect map to count the totoal number of
 | |
| 	 * direct blocks to allocate for this branch.
 | |
| 	 */
 | |
| 	count = ext2_blks_to_allocate(partial, indirect_blks,
 | |
| 					maxblocks, blocks_to_boundary);
 | |
| 	/*
 | |
| 	 * XXX ???? Block out ext2_truncate while we alter the tree
 | |
| 	 */
 | |
| 	err = ext2_alloc_branch(inode, indirect_blks, &count, goal,
 | |
| 				offsets + (partial - chain), partial);
 | |
| 
 | |
| 	if (err) {
 | |
| 		mutex_unlock(&ei->truncate_mutex);
 | |
| 		goto cleanup;
 | |
| 	}
 | |
| 
 | |
| 	if (ext2_use_xip(inode->i_sb)) {
 | |
| 		/*
 | |
| 		 * we need to clear the block
 | |
| 		 */
 | |
| 		err = ext2_clear_xip_target (inode,
 | |
| 			le32_to_cpu(chain[depth-1].key));
 | |
| 		if (err) {
 | |
| 			mutex_unlock(&ei->truncate_mutex);
 | |
| 			goto cleanup;
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
| 	ext2_splice_branch(inode, iblock, partial, indirect_blks, count);
 | |
| 	mutex_unlock(&ei->truncate_mutex);
 | |
| 	set_buffer_new(bh_result);
 | |
| got_it:
 | |
| 	map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
 | |
| 	if (count > blocks_to_boundary)
 | |
| 		set_buffer_boundary(bh_result);
 | |
| 	err = count;
 | |
| 	/* Clean up and exit */
 | |
| 	partial = chain + depth - 1;	/* the whole chain */
 | |
| cleanup:
 | |
| 	while (partial > chain) {
 | |
| 		brelse(partial->bh);
 | |
| 		partial--;
 | |
| 	}
 | |
| 	return err;
 | |
| changed:
 | |
| 	while (partial > chain) {
 | |
| 		brelse(partial->bh);
 | |
| 		partial--;
 | |
| 	}
 | |
| 	goto reread;
 | |
| }
 | |
| 
 | |
| int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
 | |
| {
 | |
| 	unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
 | |
| 	int ret = ext2_get_blocks(inode, iblock, max_blocks,
 | |
| 			      bh_result, create);
 | |
| 	if (ret > 0) {
 | |
| 		bh_result->b_size = (ret << inode->i_blkbits);
 | |
| 		ret = 0;
 | |
| 	}
 | |
| 	return ret;
 | |
| 
 | |
| }
 | |
| 
 | |
| static int ext2_writepage(struct page *page, struct writeback_control *wbc)
 | |
| {
 | |
| 	return block_write_full_page(page, ext2_get_block, wbc);
 | |
| }
 | |
| 
 | |
| static int ext2_readpage(struct file *file, struct page *page)
 | |
| {
 | |
| 	return mpage_readpage(page, ext2_get_block);
 | |
| }
 | |
| 
 | |
| static int
 | |
| ext2_readpages(struct file *file, struct address_space *mapping,
 | |
| 		struct list_head *pages, unsigned nr_pages)
 | |
| {
 | |
| 	return mpage_readpages(mapping, pages, nr_pages, ext2_get_block);
 | |
| }
 | |
| 
 | |
| int __ext2_write_begin(struct file *file, struct address_space *mapping,
 | |
| 		loff_t pos, unsigned len, unsigned flags,
 | |
| 		struct page **pagep, void **fsdata)
 | |
| {
 | |
| 	return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
 | |
| 							ext2_get_block);
 | |
| }
 | |
| 
 | |
| static int
 | |
| ext2_write_begin(struct file *file, struct address_space *mapping,
 | |
| 		loff_t pos, unsigned len, unsigned flags,
 | |
| 		struct page **pagep, void **fsdata)
 | |
| {
 | |
| 	*pagep = NULL;
 | |
| 	return __ext2_write_begin(file, mapping, pos, len, flags, pagep,fsdata);
 | |
| }
 | |
| 
 | |
| static int
 | |
| ext2_nobh_write_begin(struct file *file, struct address_space *mapping,
 | |
| 		loff_t pos, unsigned len, unsigned flags,
 | |
| 		struct page **pagep, void **fsdata)
 | |
| {
 | |
| 	/*
 | |
| 	 * Dir-in-pagecache still uses ext2_write_begin. Would have to rework
 | |
| 	 * directory handling code to pass around offsets rather than struct
 | |
| 	 * pages in order to make this work easily.
 | |
| 	 */
 | |
| 	return nobh_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
 | |
| 							ext2_get_block);
 | |
| }
 | |
| 
 | |
| static int ext2_nobh_writepage(struct page *page,
 | |
| 			struct writeback_control *wbc)
 | |
| {
 | |
| 	return nobh_writepage(page, ext2_get_block, wbc);
 | |
| }
 | |
| 
 | |
| static sector_t ext2_bmap(struct address_space *mapping, sector_t block)
 | |
| {
 | |
| 	return generic_block_bmap(mapping,block,ext2_get_block);
 | |
| }
 | |
| 
 | |
| static ssize_t
 | |
| ext2_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;
 | |
| 
 | |
| 	return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
 | |
| 				offset, nr_segs, ext2_get_block, NULL);
 | |
| }
 | |
| 
 | |
| static int
 | |
| ext2_writepages(struct address_space *mapping, struct writeback_control *wbc)
 | |
| {
 | |
| 	return mpage_writepages(mapping, wbc, ext2_get_block);
 | |
| }
 | |
| 
 | |
| const struct address_space_operations ext2_aops = {
 | |
| 	.readpage		= ext2_readpage,
 | |
| 	.readpages		= ext2_readpages,
 | |
| 	.writepage		= ext2_writepage,
 | |
| 	.sync_page		= block_sync_page,
 | |
| 	.write_begin		= ext2_write_begin,
 | |
| 	.write_end		= generic_write_end,
 | |
| 	.bmap			= ext2_bmap,
 | |
| 	.direct_IO		= ext2_direct_IO,
 | |
| 	.writepages		= ext2_writepages,
 | |
| 	.migratepage		= buffer_migrate_page,
 | |
| 	.is_partially_uptodate	= block_is_partially_uptodate,
 | |
| };
 | |
| 
 | |
| const struct address_space_operations ext2_aops_xip = {
 | |
| 	.bmap			= ext2_bmap,
 | |
| 	.get_xip_mem		= ext2_get_xip_mem,
 | |
| };
 | |
| 
 | |
| const struct address_space_operations ext2_nobh_aops = {
 | |
| 	.readpage		= ext2_readpage,
 | |
| 	.readpages		= ext2_readpages,
 | |
| 	.writepage		= ext2_nobh_writepage,
 | |
| 	.sync_page		= block_sync_page,
 | |
| 	.write_begin		= ext2_nobh_write_begin,
 | |
| 	.write_end		= nobh_write_end,
 | |
| 	.bmap			= ext2_bmap,
 | |
| 	.direct_IO		= ext2_direct_IO,
 | |
| 	.writepages		= ext2_writepages,
 | |
| 	.migratepage		= buffer_migrate_page,
 | |
| };
 | |
| 
 | |
| /*
 | |
|  * Probably it should be a library function... search for first non-zero word
 | |
|  * or memcmp with zero_page, whatever is better for particular architecture.
 | |
|  * Linus?
 | |
|  */
 | |
| static inline int all_zeroes(__le32 *p, __le32 *q)
 | |
| {
 | |
| 	while (p < q)
 | |
| 		if (*p++)
 | |
| 			return 0;
 | |
| 	return 1;
 | |
| }
 | |
| 
 | |
| /**
 | |
|  *	ext2_find_shared - find the indirect blocks for partial truncation.
 | |
|  *	@inode:	  inode in question
 | |
|  *	@depth:	  depth of the affected branch
 | |
|  *	@offsets: offsets of pointers in that branch (see ext2_block_to_path)
 | |
|  *	@chain:	  place to store the pointers to partial indirect blocks
 | |
|  *	@top:	  place to the (detached) top of branch
 | |
|  *
 | |
|  *	This is a helper function used by ext2_truncate().
 | |
|  *
 | |
|  *	When we do truncate() we may have to clean the ends of several indirect
 | |
|  *	blocks but leave the blocks themselves alive. Block is partially
 | |
|  *	truncated if some data below the new i_size is refered from it (and
 | |
|  *	it is on the path to the first completely truncated data block, indeed).
 | |
|  *	We have to free the top of that path along with everything to the right
 | |
|  *	of the path. Since no allocation past the truncation point is possible
 | |
|  *	until ext2_truncate() finishes, we may safely do the latter, but top
 | |
|  *	of branch may require special attention - pageout below the truncation
 | |
|  *	point might try to populate it.
 | |
|  *
 | |
|  *	We atomically detach the top of branch from the tree, store the block
 | |
|  *	number of its root in *@top, pointers to buffer_heads of partially
 | |
|  *	truncated blocks - in @chain[].bh and pointers to their last elements
 | |
|  *	that should not be removed - in @chain[].p. Return value is the pointer
 | |
|  *	to last filled element of @chain.
 | |
|  *
 | |
|  *	The work left to caller to do the actual freeing of subtrees:
 | |
|  *		a) free the subtree starting from *@top
 | |
|  *		b) free the subtrees whose roots are stored in
 | |
|  *			(@chain[i].p+1 .. end of @chain[i].bh->b_data)
 | |
|  *		c) free the subtrees growing from the inode past the @chain[0].p
 | |
|  *			(no partially truncated stuff there).
 | |
|  */
 | |
| 
 | |
| static Indirect *ext2_find_shared(struct inode *inode,
 | |
| 				int depth,
 | |
| 				int offsets[4],
 | |
| 				Indirect chain[4],
 | |
| 				__le32 *top)
 | |
| {
 | |
| 	Indirect *partial, *p;
 | |
| 	int k, err;
 | |
| 
 | |
| 	*top = 0;
 | |
| 	for (k = depth; k > 1 && !offsets[k-1]; k--)
 | |
| 		;
 | |
| 	partial = ext2_get_branch(inode, k, offsets, chain, &err);
 | |
| 	if (!partial)
 | |
| 		partial = chain + k-1;
 | |
| 	/*
 | |
| 	 * If the branch acquired continuation since we've looked at it -
 | |
| 	 * fine, it should all survive and (new) top doesn't belong to us.
 | |
| 	 */
 | |
| 	write_lock(&EXT2_I(inode)->i_meta_lock);
 | |
| 	if (!partial->key && *partial->p) {
 | |
| 		write_unlock(&EXT2_I(inode)->i_meta_lock);
 | |
| 		goto no_top;
 | |
| 	}
 | |
| 	for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
 | |
| 		;
 | |
| 	/*
 | |
| 	 * OK, we've found the last block that must survive. The rest of our
 | |
| 	 * branch should be detached before unlocking. However, if that rest
 | |
| 	 * of branch is all ours and does not grow immediately from the inode
 | |
| 	 * it's easier to cheat and just decrement partial->p.
 | |
| 	 */
 | |
| 	if (p == chain + k - 1 && p > chain) {
 | |
| 		p->p--;
 | |
| 	} else {
 | |
| 		*top = *p->p;
 | |
| 		*p->p = 0;
 | |
| 	}
 | |
| 	write_unlock(&EXT2_I(inode)->i_meta_lock);
 | |
| 
 | |
| 	while(partial > p)
 | |
| 	{
 | |
| 		brelse(partial->bh);
 | |
| 		partial--;
 | |
| 	}
 | |
| no_top:
 | |
| 	return partial;
 | |
| }
 | |
| 
 | |
| /**
 | |
|  *	ext2_free_data - free a list of data blocks
 | |
|  *	@inode:	inode we are dealing with
 | |
|  *	@p:	array of block numbers
 | |
|  *	@q:	points immediately past the end of array
 | |
|  *
 | |
|  *	We are freeing all blocks refered from that array (numbers are
 | |
|  *	stored as little-endian 32-bit) and updating @inode->i_blocks
 | |
|  *	appropriately.
 | |
|  */
 | |
| static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q)
 | |
| {
 | |
| 	unsigned long block_to_free = 0, count = 0;
 | |
| 	unsigned long nr;
 | |
| 
 | |
| 	for ( ; p < q ; p++) {
 | |
| 		nr = le32_to_cpu(*p);
 | |
| 		if (nr) {
 | |
| 			*p = 0;
 | |
| 			/* accumulate blocks to free if they're contiguous */
 | |
| 			if (count == 0)
 | |
| 				goto free_this;
 | |
| 			else if (block_to_free == nr - count)
 | |
| 				count++;
 | |
| 			else {
 | |
| 				mark_inode_dirty(inode);
 | |
| 				ext2_free_blocks (inode, block_to_free, count);
 | |
| 			free_this:
 | |
| 				block_to_free = nr;
 | |
| 				count = 1;
 | |
| 			}
 | |
| 		}
 | |
| 	}
 | |
| 	if (count > 0) {
 | |
| 		mark_inode_dirty(inode);
 | |
| 		ext2_free_blocks (inode, block_to_free, count);
 | |
| 	}
 | |
| }
 | |
| 
 | |
| /**
 | |
|  *	ext2_free_branches - free an array of branches
 | |
|  *	@inode:	inode we are dealing with
 | |
|  *	@p:	array of block numbers
 | |
|  *	@q:	pointer immediately past the end of array
 | |
|  *	@depth:	depth of the branches to free
 | |
|  *
 | |
|  *	We are freeing all blocks refered from these branches (numbers are
 | |
|  *	stored as little-endian 32-bit) and updating @inode->i_blocks
 | |
|  *	appropriately.
 | |
|  */
 | |
| static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth)
 | |
| {
 | |
| 	struct buffer_head * bh;
 | |
| 	unsigned long nr;
 | |
| 
 | |
| 	if (depth--) {
 | |
| 		int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
 | |
| 		for ( ; p < q ; p++) {
 | |
| 			nr = le32_to_cpu(*p);
 | |
| 			if (!nr)
 | |
| 				continue;
 | |
| 			*p = 0;
 | |
| 			bh = sb_bread(inode->i_sb, nr);
 | |
| 			/*
 | |
| 			 * A read failure? Report error and clear slot
 | |
| 			 * (should be rare).
 | |
| 			 */ 
 | |
| 			if (!bh) {
 | |
| 				ext2_error(inode->i_sb, "ext2_free_branches",
 | |
| 					"Read failure, inode=%ld, block=%ld",
 | |
| 					inode->i_ino, nr);
 | |
| 				continue;
 | |
| 			}
 | |
| 			ext2_free_branches(inode,
 | |
| 					   (__le32*)bh->b_data,
 | |
| 					   (__le32*)bh->b_data + addr_per_block,
 | |
| 					   depth);
 | |
| 			bforget(bh);
 | |
| 			ext2_free_blocks(inode, nr, 1);
 | |
| 			mark_inode_dirty(inode);
 | |
| 		}
 | |
| 	} else
 | |
| 		ext2_free_data(inode, p, q);
 | |
| }
 | |
| 
 | |
| void ext2_truncate(struct inode *inode)
 | |
| {
 | |
| 	__le32 *i_data = EXT2_I(inode)->i_data;
 | |
| 	struct ext2_inode_info *ei = EXT2_I(inode);
 | |
| 	int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
 | |
| 	int offsets[4];
 | |
| 	Indirect chain[4];
 | |
| 	Indirect *partial;
 | |
| 	__le32 nr = 0;
 | |
| 	int n;
 | |
| 	long iblock;
 | |
| 	unsigned blocksize;
 | |
| 
 | |
| 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 | |
| 	    S_ISLNK(inode->i_mode)))
 | |
| 		return;
 | |
| 	if (ext2_inode_is_fast_symlink(inode))
 | |
| 		return;
 | |
| 	if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
 | |
| 		return;
 | |
| 
 | |
| 	blocksize = inode->i_sb->s_blocksize;
 | |
| 	iblock = (inode->i_size + blocksize-1)
 | |
| 					>> EXT2_BLOCK_SIZE_BITS(inode->i_sb);
 | |
| 
 | |
| 	if (mapping_is_xip(inode->i_mapping))
 | |
| 		xip_truncate_page(inode->i_mapping, inode->i_size);
 | |
| 	else if (test_opt(inode->i_sb, NOBH))
 | |
| 		nobh_truncate_page(inode->i_mapping,
 | |
| 				inode->i_size, ext2_get_block);
 | |
| 	else
 | |
| 		block_truncate_page(inode->i_mapping,
 | |
| 				inode->i_size, ext2_get_block);
 | |
| 
 | |
| 	n = ext2_block_to_path(inode, iblock, offsets, NULL);
 | |
| 	if (n == 0)
 | |
| 		return;
 | |
| 
 | |
| 	/*
 | |
| 	 * From here we block out all ext2_get_block() callers who want to
 | |
| 	 * modify the block allocation tree.
 | |
| 	 */
 | |
| 	mutex_lock(&ei->truncate_mutex);
 | |
| 
 | |
| 	if (n == 1) {
 | |
| 		ext2_free_data(inode, i_data+offsets[0],
 | |
| 					i_data + EXT2_NDIR_BLOCKS);
 | |
| 		goto do_indirects;
 | |
| 	}
 | |
| 
 | |
| 	partial = ext2_find_shared(inode, n, offsets, chain, &nr);
 | |
| 	/* Kill the top of shared branch (already detached) */
 | |
| 	if (nr) {
 | |
| 		if (partial == chain)
 | |
| 			mark_inode_dirty(inode);
 | |
| 		else
 | |
| 			mark_buffer_dirty_inode(partial->bh, inode);
 | |
| 		ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial);
 | |
| 	}
 | |
| 	/* Clear the ends of indirect blocks on the shared branch */
 | |
| 	while (partial > chain) {
 | |
| 		ext2_free_branches(inode,
 | |
| 				   partial->p + 1,
 | |
| 				   (__le32*)partial->bh->b_data+addr_per_block,
 | |
| 				   (chain+n-1) - partial);
 | |
| 		mark_buffer_dirty_inode(partial->bh, inode);
 | |
| 		brelse (partial->bh);
 | |
| 		partial--;
 | |
| 	}
 | |
| do_indirects:
 | |
| 	/* Kill the remaining (whole) subtrees */
 | |
| 	switch (offsets[0]) {
 | |
| 		default:
 | |
| 			nr = i_data[EXT2_IND_BLOCK];
 | |
| 			if (nr) {
 | |
| 				i_data[EXT2_IND_BLOCK] = 0;
 | |
| 				mark_inode_dirty(inode);
 | |
| 				ext2_free_branches(inode, &nr, &nr+1, 1);
 | |
| 			}
 | |
| 		case EXT2_IND_BLOCK:
 | |
| 			nr = i_data[EXT2_DIND_BLOCK];
 | |
| 			if (nr) {
 | |
| 				i_data[EXT2_DIND_BLOCK] = 0;
 | |
| 				mark_inode_dirty(inode);
 | |
| 				ext2_free_branches(inode, &nr, &nr+1, 2);
 | |
| 			}
 | |
| 		case EXT2_DIND_BLOCK:
 | |
| 			nr = i_data[EXT2_TIND_BLOCK];
 | |
| 			if (nr) {
 | |
| 				i_data[EXT2_TIND_BLOCK] = 0;
 | |
| 				mark_inode_dirty(inode);
 | |
| 				ext2_free_branches(inode, &nr, &nr+1, 3);
 | |
| 			}
 | |
| 		case EXT2_TIND_BLOCK:
 | |
| 			;
 | |
| 	}
 | |
| 
 | |
| 	ext2_discard_reservation(inode);
 | |
| 
 | |
| 	mutex_unlock(&ei->truncate_mutex);
 | |
| 	inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
 | |
| 	if (inode_needs_sync(inode)) {
 | |
| 		sync_mapping_buffers(inode->i_mapping);
 | |
| 		ext2_sync_inode (inode);
 | |
| 	} else {
 | |
| 		mark_inode_dirty(inode);
 | |
| 	}
 | |
| }
 | |
| 
 | |
| static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino,
 | |
| 					struct buffer_head **p)
 | |
| {
 | |
| 	struct buffer_head * bh;
 | |
| 	unsigned long block_group;
 | |
| 	unsigned long block;
 | |
| 	unsigned long offset;
 | |
| 	struct ext2_group_desc * gdp;
 | |
| 
 | |
| 	*p = NULL;
 | |
| 	if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) ||
 | |
| 	    ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 | |
| 		goto Einval;
 | |
| 
 | |
| 	block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb);
 | |
| 	gdp = ext2_get_group_desc(sb, block_group, NULL);
 | |
| 	if (!gdp)
 | |
| 		goto Egdp;
 | |
| 	/*
 | |
| 	 * Figure out the offset within the block group inode table
 | |
| 	 */
 | |
| 	offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb);
 | |
| 	block = le32_to_cpu(gdp->bg_inode_table) +
 | |
| 		(offset >> EXT2_BLOCK_SIZE_BITS(sb));
 | |
| 	if (!(bh = sb_bread(sb, block)))
 | |
| 		goto Eio;
 | |
| 
 | |
| 	*p = bh;
 | |
| 	offset &= (EXT2_BLOCK_SIZE(sb) - 1);
 | |
| 	return (struct ext2_inode *) (bh->b_data + offset);
 | |
| 
 | |
| Einval:
 | |
| 	ext2_error(sb, "ext2_get_inode", "bad inode number: %lu",
 | |
| 		   (unsigned long) ino);
 | |
| 	return ERR_PTR(-EINVAL);
 | |
| Eio:
 | |
| 	ext2_error(sb, "ext2_get_inode",
 | |
| 		   "unable to read inode block - inode=%lu, block=%lu",
 | |
| 		   (unsigned long) ino, block);
 | |
| Egdp:
 | |
| 	return ERR_PTR(-EIO);
 | |
| }
 | |
| 
 | |
| void ext2_set_inode_flags(struct inode *inode)
 | |
| {
 | |
| 	unsigned int flags = EXT2_I(inode)->i_flags;
 | |
| 
 | |
| 	inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
 | |
| 	if (flags & EXT2_SYNC_FL)
 | |
| 		inode->i_flags |= S_SYNC;
 | |
| 	if (flags & EXT2_APPEND_FL)
 | |
| 		inode->i_flags |= S_APPEND;
 | |
| 	if (flags & EXT2_IMMUTABLE_FL)
 | |
| 		inode->i_flags |= S_IMMUTABLE;
 | |
| 	if (flags & EXT2_NOATIME_FL)
 | |
| 		inode->i_flags |= S_NOATIME;
 | |
| 	if (flags & EXT2_DIRSYNC_FL)
 | |
| 		inode->i_flags |= S_DIRSYNC;
 | |
| }
 | |
| 
 | |
| /* Propagate flags from i_flags to EXT2_I(inode)->i_flags */
 | |
| void ext2_get_inode_flags(struct ext2_inode_info *ei)
 | |
| {
 | |
| 	unsigned int flags = ei->vfs_inode.i_flags;
 | |
| 
 | |
| 	ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL|
 | |
| 			EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL);
 | |
| 	if (flags & S_SYNC)
 | |
| 		ei->i_flags |= EXT2_SYNC_FL;
 | |
| 	if (flags & S_APPEND)
 | |
| 		ei->i_flags |= EXT2_APPEND_FL;
 | |
| 	if (flags & S_IMMUTABLE)
 | |
| 		ei->i_flags |= EXT2_IMMUTABLE_FL;
 | |
| 	if (flags & S_NOATIME)
 | |
| 		ei->i_flags |= EXT2_NOATIME_FL;
 | |
| 	if (flags & S_DIRSYNC)
 | |
| 		ei->i_flags |= EXT2_DIRSYNC_FL;
 | |
| }
 | |
| 
 | |
| struct inode *ext2_iget (struct super_block *sb, unsigned long ino)
 | |
| {
 | |
| 	struct ext2_inode_info *ei;
 | |
| 	struct buffer_head * bh;
 | |
| 	struct ext2_inode *raw_inode;
 | |
| 	struct inode *inode;
 | |
| 	long ret = -EIO;
 | |
| 	int n;
 | |
| 
 | |
| 	inode = iget_locked(sb, ino);
 | |
| 	if (!inode)
 | |
| 		return ERR_PTR(-ENOMEM);
 | |
| 	if (!(inode->i_state & I_NEW))
 | |
| 		return inode;
 | |
| 
 | |
| 	ei = EXT2_I(inode);
 | |
| #ifdef CONFIG_EXT2_FS_POSIX_ACL
 | |
| 	ei->i_acl = EXT2_ACL_NOT_CACHED;
 | |
| 	ei->i_default_acl = EXT2_ACL_NOT_CACHED;
 | |
| #endif
 | |
| 	ei->i_block_alloc_info = NULL;
 | |
| 
 | |
| 	raw_inode = ext2_get_inode(inode->i_sb, ino, &bh);
 | |
| 	if (IS_ERR(raw_inode)) {
 | |
| 		ret = PTR_ERR(raw_inode);
 | |
|  		goto bad_inode;
 | |
| 	}
 | |
| 
 | |
| 	inode->i_mode = le16_to_cpu(raw_inode->i_mode);
 | |
| 	inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
 | |
| 	inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
 | |
| 	if (!(test_opt (inode->i_sb, NO_UID32))) {
 | |
| 		inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
 | |
| 		inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
 | |
| 	}
 | |
| 	inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
 | |
| 	inode->i_size = le32_to_cpu(raw_inode->i_size);
 | |
| 	inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime);
 | |
| 	inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime);
 | |
| 	inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime);
 | |
| 	inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0;
 | |
| 	ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
 | |
| 	/* We now have enough fields to check if the inode was active or not.
 | |
| 	 * This is needed because nfsd might try to access dead inodes
 | |
| 	 * the test is that same one that e2fsck uses
 | |
| 	 * NeilBrown 1999oct15
 | |
| 	 */
 | |
| 	if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) {
 | |
| 		/* this inode is deleted */
 | |
| 		brelse (bh);
 | |
| 		ret = -ESTALE;
 | |
| 		goto bad_inode;
 | |
| 	}
 | |
| 	inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
 | |
| 	ei->i_flags = le32_to_cpu(raw_inode->i_flags);
 | |
| 	ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
 | |
| 	ei->i_frag_no = raw_inode->i_frag;
 | |
| 	ei->i_frag_size = raw_inode->i_fsize;
 | |
| 	ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
 | |
| 	ei->i_dir_acl = 0;
 | |
| 	if (S_ISREG(inode->i_mode))
 | |
| 		inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
 | |
| 	else
 | |
| 		ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
 | |
| 	ei->i_dtime = 0;
 | |
| 	inode->i_generation = le32_to_cpu(raw_inode->i_generation);
 | |
| 	ei->i_state = 0;
 | |
| 	ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
 | |
| 	ei->i_dir_start_lookup = 0;
 | |
| 
 | |
| 	/*
 | |
| 	 * NOTE! The in-memory inode i_data array is in little-endian order
 | |
| 	 * even on big-endian machines: we do NOT byteswap the block numbers!
 | |
| 	 */
 | |
| 	for (n = 0; n < EXT2_N_BLOCKS; n++)
 | |
| 		ei->i_data[n] = raw_inode->i_block[n];
 | |
| 
 | |
| 	if (S_ISREG(inode->i_mode)) {
 | |
| 		inode->i_op = &ext2_file_inode_operations;
 | |
| 		if (ext2_use_xip(inode->i_sb)) {
 | |
| 			inode->i_mapping->a_ops = &ext2_aops_xip;
 | |
| 			inode->i_fop = &ext2_xip_file_operations;
 | |
| 		} else if (test_opt(inode->i_sb, NOBH)) {
 | |
| 			inode->i_mapping->a_ops = &ext2_nobh_aops;
 | |
| 			inode->i_fop = &ext2_file_operations;
 | |
| 		} else {
 | |
| 			inode->i_mapping->a_ops = &ext2_aops;
 | |
| 			inode->i_fop = &ext2_file_operations;
 | |
| 		}
 | |
| 	} else if (S_ISDIR(inode->i_mode)) {
 | |
| 		inode->i_op = &ext2_dir_inode_operations;
 | |
| 		inode->i_fop = &ext2_dir_operations;
 | |
| 		if (test_opt(inode->i_sb, NOBH))
 | |
| 			inode->i_mapping->a_ops = &ext2_nobh_aops;
 | |
| 		else
 | |
| 			inode->i_mapping->a_ops = &ext2_aops;
 | |
| 	} else if (S_ISLNK(inode->i_mode)) {
 | |
| 		if (ext2_inode_is_fast_symlink(inode))
 | |
| 			inode->i_op = &ext2_fast_symlink_inode_operations;
 | |
| 		else {
 | |
| 			inode->i_op = &ext2_symlink_inode_operations;
 | |
| 			if (test_opt(inode->i_sb, NOBH))
 | |
| 				inode->i_mapping->a_ops = &ext2_nobh_aops;
 | |
| 			else
 | |
| 				inode->i_mapping->a_ops = &ext2_aops;
 | |
| 		}
 | |
| 	} else {
 | |
| 		inode->i_op = &ext2_special_inode_operations;
 | |
| 		if (raw_inode->i_block[0])
 | |
| 			init_special_inode(inode, inode->i_mode,
 | |
| 			   old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
 | |
| 		else 
 | |
| 			init_special_inode(inode, inode->i_mode,
 | |
| 			   new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
 | |
| 	}
 | |
| 	brelse (bh);
 | |
| 	ext2_set_inode_flags(inode);
 | |
| 	unlock_new_inode(inode);
 | |
| 	return inode;
 | |
| 	
 | |
| bad_inode:
 | |
| 	iget_failed(inode);
 | |
| 	return ERR_PTR(ret);
 | |
| }
 | |
| 
 | |
| static int ext2_update_inode(struct inode * inode, int do_sync)
 | |
| {
 | |
| 	struct ext2_inode_info *ei = EXT2_I(inode);
 | |
| 	struct super_block *sb = inode->i_sb;
 | |
| 	ino_t ino = inode->i_ino;
 | |
| 	uid_t uid = inode->i_uid;
 | |
| 	gid_t gid = inode->i_gid;
 | |
| 	struct buffer_head * bh;
 | |
| 	struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh);
 | |
| 	int n;
 | |
| 	int err = 0;
 | |
| 
 | |
| 	if (IS_ERR(raw_inode))
 | |
|  		return -EIO;
 | |
| 
 | |
| 	/* For fields not not tracking in the in-memory inode,
 | |
| 	 * initialise them to zero for new inodes. */
 | |
| 	if (ei->i_state & EXT2_STATE_NEW)
 | |
| 		memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size);
 | |
| 
 | |
| 	ext2_get_inode_flags(ei);
 | |
| 	raw_inode->i_mode = cpu_to_le16(inode->i_mode);
 | |
| 	if (!(test_opt(sb, NO_UID32))) {
 | |
| 		raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid));
 | |
| 		raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid));
 | |
| /*
 | |
|  * Fix up interoperability with old kernels. Otherwise, old inodes get
 | |
|  * re-used with the upper 16 bits of the uid/gid intact
 | |
|  */
 | |
| 		if (!ei->i_dtime) {
 | |
| 			raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid));
 | |
| 			raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid));
 | |
| 		} else {
 | |
| 			raw_inode->i_uid_high = 0;
 | |
| 			raw_inode->i_gid_high = 0;
 | |
| 		}
 | |
| 	} else {
 | |
| 		raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid));
 | |
| 		raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid));
 | |
| 		raw_inode->i_uid_high = 0;
 | |
| 		raw_inode->i_gid_high = 0;
 | |
| 	}
 | |
| 	raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
 | |
| 	raw_inode->i_size = cpu_to_le32(inode->i_size);
 | |
| 	raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
 | |
| 	raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
 | |
| 	raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
 | |
| 
 | |
| 	raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
 | |
| 	raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
 | |
| 	raw_inode->i_flags = cpu_to_le32(ei->i_flags);
 | |
| 	raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
 | |
| 	raw_inode->i_frag = ei->i_frag_no;
 | |
| 	raw_inode->i_fsize = ei->i_frag_size;
 | |
| 	raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
 | |
| 	if (!S_ISREG(inode->i_mode))
 | |
| 		raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
 | |
| 	else {
 | |
| 		raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32);
 | |
| 		if (inode->i_size > 0x7fffffffULL) {
 | |
| 			if (!EXT2_HAS_RO_COMPAT_FEATURE(sb,
 | |
| 					EXT2_FEATURE_RO_COMPAT_LARGE_FILE) ||
 | |
| 			    EXT2_SB(sb)->s_es->s_rev_level ==
 | |
| 					cpu_to_le32(EXT2_GOOD_OLD_REV)) {
 | |
| 			       /* If this is the first large file
 | |
| 				* created, add a flag to the superblock.
 | |
| 				*/
 | |
| 				lock_kernel();
 | |
| 				ext2_update_dynamic_rev(sb);
 | |
| 				EXT2_SET_RO_COMPAT_FEATURE(sb,
 | |
| 					EXT2_FEATURE_RO_COMPAT_LARGE_FILE);
 | |
| 				unlock_kernel();
 | |
| 				ext2_write_super(sb);
 | |
| 			}
 | |
| 		}
 | |
| 	}
 | |
| 	
 | |
| 	raw_inode->i_generation = cpu_to_le32(inode->i_generation);
 | |
| 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
 | |
| 		if (old_valid_dev(inode->i_rdev)) {
 | |
| 			raw_inode->i_block[0] =
 | |
| 				cpu_to_le32(old_encode_dev(inode->i_rdev));
 | |
| 			raw_inode->i_block[1] = 0;
 | |
| 		} else {
 | |
| 			raw_inode->i_block[0] = 0;
 | |
| 			raw_inode->i_block[1] =
 | |
| 				cpu_to_le32(new_encode_dev(inode->i_rdev));
 | |
| 			raw_inode->i_block[2] = 0;
 | |
| 		}
 | |
| 	} else for (n = 0; n < EXT2_N_BLOCKS; n++)
 | |
| 		raw_inode->i_block[n] = ei->i_data[n];
 | |
| 	mark_buffer_dirty(bh);
 | |
| 	if (do_sync) {
 | |
| 		sync_dirty_buffer(bh);
 | |
| 		if (buffer_req(bh) && !buffer_uptodate(bh)) {
 | |
| 			printk ("IO error syncing ext2 inode [%s:%08lx]\n",
 | |
| 				sb->s_id, (unsigned long) ino);
 | |
| 			err = -EIO;
 | |
| 		}
 | |
| 	}
 | |
| 	ei->i_state &= ~EXT2_STATE_NEW;
 | |
| 	brelse (bh);
 | |
| 	return err;
 | |
| }
 | |
| 
 | |
| int ext2_write_inode(struct inode *inode, int wait)
 | |
| {
 | |
| 	return ext2_update_inode(inode, wait);
 | |
| }
 | |
| 
 | |
| int ext2_sync_inode(struct inode *inode)
 | |
| {
 | |
| 	struct writeback_control wbc = {
 | |
| 		.sync_mode = WB_SYNC_ALL,
 | |
| 		.nr_to_write = 0,	/* sys_fsync did this */
 | |
| 	};
 | |
| 	return sync_inode(inode, &wbc);
 | |
| }
 | |
| 
 | |
| int ext2_setattr(struct dentry *dentry, struct iattr *iattr)
 | |
| {
 | |
| 	struct inode *inode = dentry->d_inode;
 | |
| 	int error;
 | |
| 
 | |
| 	error = inode_change_ok(inode, iattr);
 | |
| 	if (error)
 | |
| 		return error;
 | |
| 	if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) ||
 | |
| 	    (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) {
 | |
| 		error = DQUOT_TRANSFER(inode, iattr) ? -EDQUOT : 0;
 | |
| 		if (error)
 | |
| 			return error;
 | |
| 	}
 | |
| 	error = inode_setattr(inode, iattr);
 | |
| 	if (!error && (iattr->ia_valid & ATTR_MODE))
 | |
| 		error = ext2_acl_chmod(inode);
 | |
| 	return error;
 | |
| }
 |