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linux/fs/gfs2/bmap.c
Steven Whitehouse 71b86f562b [GFS2] Further updates to dir and logging code 
This reduces the size of the directory code by about 3k and gets
readdir() to use the functions which were introduced in the previous
directory code update.

Two memory allocations are merged into one. Eliminates zeroing of some
buffers which were never used before they were initialised by
other data.

There is still scope for further improvement in the directory code.

On the logging side, a hand created mutex has been replaced by a
standard Linux mutex in the log allocation code.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-03-28 14:14:04 -05:00

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/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU General Public License v.2.
*/
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/gfs2_ondisk.h>
#include <linux/crc32.h>
#include <asm/semaphore.h>
#include "gfs2.h"
#include "lm_interface.h"
#include "incore.h"
#include "bmap.h"
#include "glock.h"
#include "inode.h"
#include "meta_io.h"
#include "page.h"
#include "quota.h"
#include "rgrp.h"
#include "trans.h"
#include "dir.h"
#include "util.h"
/* This doesn't need to be that large as max 64 bit pointers in a 4k
* block is 512, so __u16 is fine for that. It saves stack space to
* keep it small.
*/
struct metapath {
__u16 mp_list[GFS2_MAX_META_HEIGHT];
};
typedef int (*block_call_t) (struct gfs2_inode *ip, struct buffer_head *dibh,
struct buffer_head *bh, uint64_t *top,
uint64_t *bottom, unsigned int height,
void *data);
struct strip_mine {
int sm_first;
unsigned int sm_height;
};
/**
* @gfs2_unstuffer_sync - Synchronously unstuff a dinode
* @ip:
* @dibh:
* @block:
* @private:
*
* Cheat and use a metadata buffer instead of a data page.
*
* Returns: errno
*/
int gfs2_unstuffer_sync(struct gfs2_inode *ip, struct buffer_head *dibh,
uint64_t block, void *private)
{
struct buffer_head *bh;
int error;
bh = gfs2_meta_new(ip->i_gl, block);
gfs2_buffer_copy_tail(bh, 0, dibh, sizeof(struct gfs2_dinode));
set_buffer_dirty(bh);
error = sync_dirty_buffer(bh);
brelse(bh);
return error;
}
/**
* gfs2_unstuff_dinode - Unstuff a dinode when the data has grown too big
* @ip: The GFS2 inode to unstuff
* @unstuffer: the routine that handles unstuffing a non-zero length file
* @private: private data for the unstuffer
*
* This routine unstuffs a dinode and returns it to a "normal" state such
* that the height can be grown in the traditional way.
*
* Returns: errno
*/
int gfs2_unstuff_dinode(struct gfs2_inode *ip, gfs2_unstuffer_t unstuffer,
void *private)
{
struct buffer_head *bh, *dibh;
uint64_t block = 0;
int isdir = gfs2_is_dir(ip);
int error;
down_write(&ip->i_rw_mutex);
error = gfs2_meta_inode_buffer(ip, &dibh);
if (error)
goto out;
if (ip->i_di.di_size) {
/* Get a free block, fill it with the stuffed data,
and write it out to disk */
if (isdir) {
block = gfs2_alloc_meta(ip);
error = gfs2_dir_get_buffer(ip, block, 1, &bh);
if (error)
goto out_brelse;
gfs2_buffer_copy_tail(bh,
sizeof(struct gfs2_meta_header),
dibh, sizeof(struct gfs2_dinode));
brelse(bh);
} else {
block = gfs2_alloc_data(ip);
error = unstuffer(ip, dibh, block, private);
if (error)
goto out_brelse;
}
}
/* Set up the pointer to the new block */
gfs2_trans_add_bh(ip->i_gl, dibh, 1);
gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
if (ip->i_di.di_size) {
*(uint64_t *)(dibh->b_data + sizeof(struct gfs2_dinode)) =
cpu_to_be64(block);
ip->i_di.di_blocks++;
}
ip->i_di.di_height = 1;
gfs2_dinode_out(&ip->i_di, dibh->b_data);
out_brelse:
brelse(dibh);
out:
up_write(&ip->i_rw_mutex);
return error;
}
/**
* calc_tree_height - Calculate the height of a metadata tree
* @ip: The GFS2 inode
* @size: The proposed size of the file
*
* Work out how tall a metadata tree needs to be in order to accommodate a
* file of a particular size. If size is less than the current size of
* the inode, then the current size of the inode is used instead of the
* supplied one.
*
* Returns: the height the tree should be
*/
static unsigned int calc_tree_height(struct gfs2_inode *ip, uint64_t size)
{
struct gfs2_sbd *sdp = ip->i_sbd;
uint64_t *arr;
unsigned int max, height;
if (ip->i_di.di_size > size)
size = ip->i_di.di_size;
if (gfs2_is_dir(ip)) {
arr = sdp->sd_jheightsize;
max = sdp->sd_max_jheight;
} else {
arr = sdp->sd_heightsize;
max = sdp->sd_max_height;
}
for (height = 0; height < max; height++)
if (arr[height] >= size)
break;
return height;
}
/**
* build_height - Build a metadata tree of the requested height
* @ip: The GFS2 inode
* @height: The height to build to
*
* This routine makes sure that the metadata tree is tall enough to hold
* "size" bytes of data.
*
* Returns: errno
*/
static int build_height(struct gfs2_inode *ip, int height)
{
struct gfs2_sbd *sdp = ip->i_sbd;
struct buffer_head *bh, *dibh;
uint64_t block = 0, *bp;
unsigned int x;
int new_block;
int error;
while (ip->i_di.di_height < height) {
error = gfs2_meta_inode_buffer(ip, &dibh);
if (error)
return error;
new_block = 0;
bp = (uint64_t *)(dibh->b_data + sizeof(struct gfs2_dinode));
for (x = 0; x < sdp->sd_diptrs; x++, bp++)
if (*bp) {
new_block = 1;
break;
}
if (new_block) {
/* Get a new block, fill it with the old direct
pointers, and write it out */
block = gfs2_alloc_meta(ip);
bh = gfs2_meta_new(ip->i_gl, block);
gfs2_trans_add_bh(ip->i_gl, bh, 1);
gfs2_metatype_set(bh,
GFS2_METATYPE_IN,
GFS2_FORMAT_IN);
gfs2_buffer_copy_tail(bh,
sizeof(struct gfs2_meta_header),
dibh, sizeof(struct gfs2_dinode));
brelse(bh);
}
/* Set up the new direct pointer and write it out to disk */
gfs2_trans_add_bh(ip->i_gl, dibh, 1);
gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
if (new_block) {
*(uint64_t *)(dibh->b_data +
sizeof(struct gfs2_dinode)) =
cpu_to_be64(block);
ip->i_di.di_blocks++;
}
ip->i_di.di_height++;
gfs2_dinode_out(&ip->i_di, dibh->b_data);
brelse(dibh);
}
return 0;
}
/**
* find_metapath - Find path through the metadata tree
* @ip: The inode pointer
* @mp: The metapath to return the result in
* @block: The disk block to look up
*
* This routine returns a struct metapath structure that defines a path
* through the metadata of inode "ip" to get to block "block".
*
* Example:
* Given: "ip" is a height 3 file, "offset" is 101342453, and this is a
* filesystem with a blocksize of 4096.
*
* find_metapath() would return a struct metapath structure set to:
* mp_offset = 101342453, mp_height = 3, mp_list[0] = 0, mp_list[1] = 48,
* and mp_list[2] = 165.
*
* That means that in order to get to the block containing the byte at
* offset 101342453, we would load the indirect block pointed to by pointer
* 0 in the dinode. We would then load the indirect block pointed to by
* pointer 48 in that indirect block. We would then load the data block
* pointed to by pointer 165 in that indirect block.
*
* ----------------------------------------
* | Dinode | |
* | | 4|
* | |0 1 2 3 4 5 9|
* | | 6|
* ----------------------------------------
* |
* |
* V
* ----------------------------------------
* | Indirect Block |
* | 5|
* | 4 4 4 4 4 5 5 1|
* |0 5 6 7 8 9 0 1 2|
* ----------------------------------------
* |
* |
* V
* ----------------------------------------
* | Indirect Block |
* | 1 1 1 1 1 5|
* | 6 6 6 6 6 1|
* |0 3 4 5 6 7 2|
* ----------------------------------------
* |
* |
* V
* ----------------------------------------
* | Data block containing offset |
* | 101342453 |
* | |
* | |
* ----------------------------------------
*
*/
static void find_metapath(struct gfs2_inode *ip, uint64_t block,
struct metapath *mp)
{
struct gfs2_sbd *sdp = ip->i_sbd;
uint64_t b = block;
unsigned int i;
for (i = ip->i_di.di_height; i--;)
mp->mp_list[i] = (__u16)do_div(b, sdp->sd_inptrs);
}
/**
* metapointer - Return pointer to start of metadata in a buffer
* @bh: The buffer
* @height: The metadata height (0 = dinode)
* @mp: The metapath
*
* Return a pointer to the block number of the next height of the metadata
* tree given a buffer containing the pointer to the current height of the
* metadata tree.
*/
static inline uint64_t *metapointer(struct buffer_head *bh,
unsigned int height, struct metapath *mp)
{
unsigned int head_size = (height > 0) ?
sizeof(struct gfs2_meta_header) : sizeof(struct gfs2_dinode);
return ((uint64_t *)(bh->b_data + head_size)) + mp->mp_list[height];
}
/**
* lookup_block - Get the next metadata block in metadata tree
* @ip: The GFS2 inode
* @bh: Buffer containing the pointers to metadata blocks
* @height: The height of the tree (0 = dinode)
* @mp: The metapath
* @create: Non-zero if we may create a new meatdata block
* @new: Used to indicate if we did create a new metadata block
* @block: the returned disk block number
*
* Given a metatree, complete to a particular height, checks to see if the next
* height of the tree exists. If not the next height of the tree is created.
* The block number of the next height of the metadata tree is returned.
*
*/
static void lookup_block(struct gfs2_inode *ip, struct buffer_head *bh,
unsigned int height, struct metapath *mp, int create,
int *new, uint64_t *block)
{
uint64_t *ptr = metapointer(bh, height, mp);
if (*ptr) {
*block = be64_to_cpu(*ptr);
return;
}
*block = 0;
if (!create)
return;
if (height == ip->i_di.di_height - 1 &&
!gfs2_is_dir(ip))
*block = gfs2_alloc_data(ip);
else
*block = gfs2_alloc_meta(ip);
gfs2_trans_add_bh(ip->i_gl, bh, 1);
*ptr = cpu_to_be64(*block);
ip->i_di.di_blocks++;
*new = 1;
}
/**
* gfs2_block_map - Map a block from an inode to a disk block
* @ip: The GFS2 inode
* @lblock: The logical block number
* @new: Value/Result argument (1 = may create/did create new blocks)
* @dblock: the disk block number of the start of an extent
* @extlen: the size of the extent
*
* Find the block number on the current device which corresponds to an
* inode's block. If the block had to be created, "new" will be set.
*
* Returns: errno
*/
int gfs2_block_map(struct gfs2_inode *ip, uint64_t lblock, int *new,
uint64_t *dblock, uint32_t *extlen)
{
struct gfs2_sbd *sdp = ip->i_sbd;
struct buffer_head *bh;
struct metapath mp;
int create = *new;
unsigned int bsize;
unsigned int height;
unsigned int end_of_metadata;
unsigned int x;
int error = 0;
*new = 0;
*dblock = 0;
if (extlen)
*extlen = 0;
if (create)
down_write(&ip->i_rw_mutex);
else
down_read(&ip->i_rw_mutex);
if (gfs2_assert_warn(sdp, !gfs2_is_stuffed(ip)))
goto out;
bsize = (gfs2_is_dir(ip)) ? sdp->sd_jbsize : sdp->sd_sb.sb_bsize;
height = calc_tree_height(ip, (lblock + 1) * bsize);
if (ip->i_di.di_height < height) {
if (!create)
goto out;
error = build_height(ip, height);
if (error)
goto out;
}
find_metapath(ip, lblock, &mp);
end_of_metadata = ip->i_di.di_height - 1;
error = gfs2_meta_inode_buffer(ip, &bh);
if (error)
goto out;
for (x = 0; x < end_of_metadata; x++) {
lookup_block(ip, bh, x, &mp, create, new, dblock);
brelse(bh);
if (!*dblock)
goto out;
error = gfs2_meta_indirect_buffer(ip, x+1, *dblock, *new, &bh);
if (error)
goto out;
}
lookup_block(ip, bh, end_of_metadata, &mp, create, new, dblock);
if (extlen && *dblock) {
*extlen = 1;
if (!*new) {
uint64_t tmp_dblock;
int tmp_new;
unsigned int nptrs;
nptrs = (end_of_metadata) ? sdp->sd_inptrs :
sdp->sd_diptrs;
while (++mp.mp_list[end_of_metadata] < nptrs) {
lookup_block(ip, bh, end_of_metadata, &mp,
0, &tmp_new, &tmp_dblock);
if (*dblock + *extlen != tmp_dblock)
break;
(*extlen)++;
}
}
}
brelse(bh);
if (*new) {
error = gfs2_meta_inode_buffer(ip, &bh);
if (!error) {
gfs2_trans_add_bh(ip->i_gl, bh, 1);
gfs2_dinode_out(&ip->i_di, bh->b_data);
brelse(bh);
}
}
out:
if (create)
up_write(&ip->i_rw_mutex);
else
up_read(&ip->i_rw_mutex);
return error;
}
/**
* recursive_scan - recursively scan through the end of a file
* @ip: the inode
* @dibh: the dinode buffer
* @mp: the path through the metadata to the point to start
* @height: the height the recursion is at
* @block: the indirect block to look at
* @first: 1 if this is the first block
* @bc: the call to make for each piece of metadata
* @data: data opaque to this function to pass to @bc
*
* When this is first called @height and @block should be zero and
* @first should be 1.
*
* Returns: errno
*/
static int recursive_scan(struct gfs2_inode *ip, struct buffer_head *dibh,
struct metapath *mp, unsigned int height,
uint64_t block, int first, block_call_t bc,
void *data)
{
struct gfs2_sbd *sdp = ip->i_sbd;
struct buffer_head *bh = NULL;
uint64_t *top, *bottom;
uint64_t bn;
int error;
int mh_size = sizeof(struct gfs2_meta_header);
if (!height) {
error = gfs2_meta_inode_buffer(ip, &bh);
if (error)
return error;
dibh = bh;
top = (uint64_t *)(bh->b_data + sizeof(struct gfs2_dinode)) +
mp->mp_list[0];
bottom = (uint64_t *)(bh->b_data + sizeof(struct gfs2_dinode)) +
sdp->sd_diptrs;
} else {
error = gfs2_meta_indirect_buffer(ip, height, block, 0, &bh);
if (error)
return error;
top = (uint64_t *)(bh->b_data + mh_size) +
((first) ? mp->mp_list[height] : 0);
bottom = (uint64_t *)(bh->b_data + mh_size) + sdp->sd_inptrs;
}
error = bc(ip, dibh, bh, top, bottom, height, data);
if (error)
goto out;
if (height < ip->i_di.di_height - 1)
for (; top < bottom; top++, first = 0) {
if (!*top)
continue;
bn = be64_to_cpu(*top);
error = recursive_scan(ip, dibh, mp, height + 1, bn,
first, bc, data);
if (error)
break;
}
out:
brelse(bh);
return error;
}
/**
* do_strip - Look for a layer a particular layer of the file and strip it off
* @ip: the inode
* @dibh: the dinode buffer
* @bh: A buffer of pointers
* @top: The first pointer in the buffer
* @bottom: One more than the last pointer
* @height: the height this buffer is at
* @data: a pointer to a struct strip_mine
*
* Returns: errno
*/
static int do_strip(struct gfs2_inode *ip, struct buffer_head *dibh,
struct buffer_head *bh, uint64_t *top, uint64_t *bottom,
unsigned int height, void *data)
{
struct strip_mine *sm = (struct strip_mine *)data;
struct gfs2_sbd *sdp = ip->i_sbd;
struct gfs2_rgrp_list rlist;
uint64_t bn, bstart;
uint32_t blen;
uint64_t *p;
unsigned int rg_blocks = 0;
int metadata;
unsigned int revokes = 0;
int x;
int error;
if (!*top)
sm->sm_first = 0;
if (height != sm->sm_height)
return 0;
if (sm->sm_first) {
top++;
sm->sm_first = 0;
}
metadata = (height != ip->i_di.di_height - 1);
if (metadata)
revokes = (height) ? sdp->sd_inptrs : sdp->sd_diptrs;
error = gfs2_rindex_hold(sdp, &ip->i_alloc.al_ri_gh);
if (error)
return error;
memset(&rlist, 0, sizeof(struct gfs2_rgrp_list));
bstart = 0;
blen = 0;
for (p = top; p < bottom; p++) {
if (!*p)
continue;
bn = be64_to_cpu(*p);
if (bstart + blen == bn)
blen++;
else {
if (bstart)
gfs2_rlist_add(sdp, &rlist, bstart);
bstart = bn;
blen = 1;
}
}
if (bstart)
gfs2_rlist_add(sdp, &rlist, bstart);
else
goto out; /* Nothing to do */
gfs2_rlist_alloc(&rlist, LM_ST_EXCLUSIVE, 0);
for (x = 0; x < rlist.rl_rgrps; x++) {
struct gfs2_rgrpd *rgd;
rgd = rlist.rl_ghs[x].gh_gl->gl_object;
rg_blocks += rgd->rd_ri.ri_length;
}
error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs);
if (error)
goto out_rlist;
error = gfs2_trans_begin(sdp, rg_blocks + RES_DINODE +
RES_INDIRECT + RES_STATFS + RES_QUOTA,
revokes);
if (error)
goto out_rg_gunlock;
down_write(&ip->i_rw_mutex);
gfs2_trans_add_bh(ip->i_gl, dibh, 1);
gfs2_trans_add_bh(ip->i_gl, bh, 1);
bstart = 0;
blen = 0;
for (p = top; p < bottom; p++) {
if (!*p)
continue;
bn = be64_to_cpu(*p);
if (bstart + blen == bn)
blen++;
else {
if (bstart) {
if (metadata)
gfs2_free_meta(ip, bstart, blen);
else
gfs2_free_data(ip, bstart, blen);
}
bstart = bn;
blen = 1;
}
*p = 0;
if (!ip->i_di.di_blocks)
gfs2_consist_inode(ip);
ip->i_di.di_blocks--;
}
if (bstart) {
if (metadata)
gfs2_free_meta(ip, bstart, blen);
else
gfs2_free_data(ip, bstart, blen);
}
ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();
gfs2_dinode_out(&ip->i_di, dibh->b_data);
up_write(&ip->i_rw_mutex);
gfs2_trans_end(sdp);
out_rg_gunlock:
gfs2_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs);
out_rlist:
gfs2_rlist_free(&rlist);
out:
gfs2_glock_dq_uninit(&ip->i_alloc.al_ri_gh);
return error;
}
/**
* do_grow - Make a file look bigger than it is
* @ip: the inode
* @size: the size to set the file to
*
* Called with an exclusive lock on @ip.
*
* Returns: errno
*/
static int do_grow(struct gfs2_inode *ip, uint64_t size)
{
struct gfs2_sbd *sdp = ip->i_sbd;
struct gfs2_alloc *al;
struct buffer_head *dibh;
unsigned int h;
int error;
al = gfs2_alloc_get(ip);
error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
if (error)
goto out;
error = gfs2_quota_check(ip, ip->i_di.di_uid, ip->i_di.di_gid);
if (error)
goto out_gunlock_q;
al->al_requested = sdp->sd_max_height + RES_DATA;
error = gfs2_inplace_reserve(ip);
if (error)
goto out_gunlock_q;
error = gfs2_trans_begin(sdp,
sdp->sd_max_height + al->al_rgd->rd_ri.ri_length +
RES_JDATA + RES_DINODE + RES_STATFS + RES_QUOTA, 0);
if (error)
goto out_ipres;
if (size > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
if (gfs2_is_stuffed(ip)) {
error = gfs2_unstuff_dinode(ip, gfs2_unstuffer_page,
NULL);
if (error)
goto out_end_trans;
}
h = calc_tree_height(ip, size);
if (ip->i_di.di_height < h) {
down_write(&ip->i_rw_mutex);
error = build_height(ip, h);
up_write(&ip->i_rw_mutex);
if (error)
goto out_end_trans;
}
}
ip->i_di.di_size = size;
ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();
error = gfs2_meta_inode_buffer(ip, &dibh);
if (error)
goto out_end_trans;
gfs2_trans_add_bh(ip->i_gl, dibh, 1);
gfs2_dinode_out(&ip->i_di, dibh->b_data);
brelse(dibh);
out_end_trans:
gfs2_trans_end(sdp);
out_ipres:
gfs2_inplace_release(ip);
out_gunlock_q:
gfs2_quota_unlock(ip);
out:
gfs2_alloc_put(ip);
return error;
}
static int trunc_start(struct gfs2_inode *ip, uint64_t size)
{
struct gfs2_sbd *sdp = ip->i_sbd;
struct buffer_head *dibh;
int journaled = gfs2_is_jdata(ip);
int error;
error = gfs2_trans_begin(sdp,
RES_DINODE + ((journaled) ? RES_JDATA : 0), 0);
if (error)
return error;
error = gfs2_meta_inode_buffer(ip, &dibh);
if (error)
goto out;
if (gfs2_is_stuffed(ip)) {
ip->i_di.di_size = size;
ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();
gfs2_trans_add_bh(ip->i_gl, dibh, 1);
gfs2_dinode_out(&ip->i_di, dibh->b_data);
gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode) + size);
error = 1;
} else {
if (size & (uint64_t)(sdp->sd_sb.sb_bsize - 1))
error = gfs2_block_truncate_page(ip->i_vnode->i_mapping);
if (!error) {
ip->i_di.di_size = size;
ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();
ip->i_di.di_flags |= GFS2_DIF_TRUNC_IN_PROG;
gfs2_trans_add_bh(ip->i_gl, dibh, 1);
gfs2_dinode_out(&ip->i_di, dibh->b_data);
}
}
brelse(dibh);
out:
gfs2_trans_end(sdp);
return error;
}
static int trunc_dealloc(struct gfs2_inode *ip, uint64_t size)
{
unsigned int height = ip->i_di.di_height;
uint64_t lblock;
struct metapath mp;
int error;
if (!size)
lblock = 0;
else
lblock = (size - 1) >> ip->i_sbd->sd_sb.sb_bsize_shift;
find_metapath(ip, lblock, &mp);
gfs2_alloc_get(ip);
error = gfs2_quota_hold(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
if (error)
goto out;
while (height--) {
struct strip_mine sm;
sm.sm_first = !!size;
sm.sm_height = height;
error = recursive_scan(ip, NULL, &mp, 0, 0, 1, do_strip, &sm);
if (error)
break;
}
gfs2_quota_unhold(ip);
out:
gfs2_alloc_put(ip);
return error;
}
static int trunc_end(struct gfs2_inode *ip)
{
struct gfs2_sbd *sdp = ip->i_sbd;
struct buffer_head *dibh;
int error;
error = gfs2_trans_begin(sdp, RES_DINODE, 0);
if (error)
return error;
down_write(&ip->i_rw_mutex);
error = gfs2_meta_inode_buffer(ip, &dibh);
if (error)
goto out;
if (!ip->i_di.di_size) {
ip->i_di.di_height = 0;
ip->i_di.di_goal_meta =
ip->i_di.di_goal_data =
ip->i_num.no_addr;
gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
}
ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();
ip->i_di.di_flags &= ~GFS2_DIF_TRUNC_IN_PROG;
gfs2_trans_add_bh(ip->i_gl, dibh, 1);
gfs2_dinode_out(&ip->i_di, dibh->b_data);
brelse(dibh);
out:
up_write(&ip->i_rw_mutex);
gfs2_trans_end(sdp);
return error;
}
/**
* do_shrink - make a file smaller
* @ip: the inode
* @size: the size to make the file
* @truncator: function to truncate the last partial block
*
* Called with an exclusive lock on @ip.
*
* Returns: errno
*/
static int do_shrink(struct gfs2_inode *ip, uint64_t size)
{
int error;
error = trunc_start(ip, size);
if (error < 0)
return error;
if (error > 0)
return 0;
error = trunc_dealloc(ip, size);
if (!error)
error = trunc_end(ip);
return error;
}
/**
* gfs2_truncatei - make a file a given size
* @ip: the inode
* @size: the size to make the file
* @truncator: function to truncate the last partial block
*
* The file size can grow, shrink, or stay the same size.
*
* Returns: errno
*/
int gfs2_truncatei(struct gfs2_inode *ip, uint64_t size)
{
int error;
if (gfs2_assert_warn(ip->i_sbd, S_ISREG(ip->i_di.di_mode)))
return -EINVAL;
if (size > ip->i_di.di_size)
error = do_grow(ip, size);
else
error = do_shrink(ip, size);
return error;
}
int gfs2_truncatei_resume(struct gfs2_inode *ip)
{
int error;
error = trunc_dealloc(ip, ip->i_di.di_size);
if (!error)
error = trunc_end(ip);
return error;
}
int gfs2_file_dealloc(struct gfs2_inode *ip)
{
return trunc_dealloc(ip, 0);
}
/**
* gfs2_write_calc_reserv - calculate number of blocks needed to write to a file
* @ip: the file
* @len: the number of bytes to be written to the file
* @data_blocks: returns the number of data blocks required
* @ind_blocks: returns the number of indirect blocks required
*
*/
void gfs2_write_calc_reserv(struct gfs2_inode *ip, unsigned int len,
unsigned int *data_blocks, unsigned int *ind_blocks)
{
struct gfs2_sbd *sdp = ip->i_sbd;
unsigned int tmp;
if (gfs2_is_dir(ip)) {
*data_blocks = DIV_ROUND_UP(len, sdp->sd_jbsize) + 2;
*ind_blocks = 3 * (sdp->sd_max_jheight - 1);
} else {
*data_blocks = (len >> sdp->sd_sb.sb_bsize_shift) + 3;
*ind_blocks = 3 * (sdp->sd_max_height - 1);
}
for (tmp = *data_blocks; tmp > sdp->sd_diptrs;) {
tmp = DIV_ROUND_UP(tmp, sdp->sd_inptrs);
*ind_blocks += tmp;
}
}
/**
* gfs2_write_alloc_required - figure out if a write will require an allocation
* @ip: the file being written to
* @offset: the offset to write to
* @len: the number of bytes being written
* @alloc_required: set to 1 if an alloc is required, 0 otherwise
*
* Returns: errno
*/
int gfs2_write_alloc_required(struct gfs2_inode *ip, uint64_t offset,
unsigned int len, int *alloc_required)
{
struct gfs2_sbd *sdp = ip->i_sbd;
uint64_t lblock, lblock_stop, dblock;
uint32_t extlen;
int new = 0;
int error = 0;
*alloc_required = 0;
if (!len)
return 0;
if (gfs2_is_stuffed(ip)) {
if (offset + len >
sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode))
*alloc_required = 1;
return 0;
}
if (gfs2_is_dir(ip)) {
unsigned int bsize = sdp->sd_jbsize;
lblock = offset;
do_div(lblock, bsize);
lblock_stop = offset + len + bsize - 1;
do_div(lblock_stop, bsize);
} else {
unsigned int shift = sdp->sd_sb.sb_bsize_shift;
lblock = offset >> shift;
lblock_stop = (offset + len + sdp->sd_sb.sb_bsize - 1) >> shift;
}
for (; lblock < lblock_stop; lblock += extlen) {
error = gfs2_block_map(ip, lblock, &new, &dblock, &extlen);
if (error)
return error;
if (!dblock) {
*alloc_required = 1;
return 0;
}
}
return 0;
}
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