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/******************************************************************************
*******************************************************************************
**
** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
** Copyright (C) 2004-2006 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/smp_lock.h>
#include <linux/spinlock.h>
#include <asm/semaphore.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include "gfs.h"
#include "bmap.h"
#include "dio.h"
#include "glock.h"
#include "inode.h"
#include "quota.h"
#include "rgrp.h"
#include "trans.h"
struct metapath {
unsigned int mp_list[GFS_MAX_META_HEIGHT];
};
typedef int (*block_call_t) (struct gfs_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;
};
/**
* gfs_unstuffer_sync - unstuff a dinode synchronously
* @ip: the inode
* @dibh: the dinode buffer
* @block: the block number that was allocated
* @private: not used
*
* Returns: errno
*/
int
gfs_unstuffer_sync(struct gfs_inode *ip, struct buffer_head *dibh,
uint64_t block, void *private)
{
struct gfs_sbd *sdp = ip->i_sbd;
struct buffer_head *bh;
int error;
error = gfs_get_data_buffer(ip, block, TRUE, &bh);
if (error)
return error;
gfs_buffer_copy_tail(bh, 0, dibh, sizeof(struct gfs_dinode));
error = gfs_dwrite(sdp, bh, DIO_DIRTY | DIO_START | DIO_WAIT);
brelse(bh);
return error;
}
/**
* gfs_unstuffer_async - unstuff a dinode asynchronously
* @ip: the inode
* @dibh: the dinode buffer
* @block: the block number that was allocated
* @private: not used
*
* Returns: errno
*/
int
gfs_unstuffer_async(struct gfs_inode *ip, struct buffer_head *dibh,
uint64_t block, void *private)
{
struct gfs_sbd *sdp = ip->i_sbd;
struct buffer_head *bh;
int error;
error = gfs_get_data_buffer(ip, block, TRUE, &bh);
if (error)
return error;
gfs_buffer_copy_tail(bh, 0, dibh, sizeof(struct gfs_dinode));
error = gfs_dwrite(sdp, bh, DIO_DIRTY);
brelse(bh);
return error;
}
/**
* gfs_unstuff_dinode - Unstuff a dinode when the data has grown too big
* @ip: The GFS 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
gfs_unstuff_dinode(struct gfs_inode *ip, gfs_unstuffer_t unstuffer,
void *private)
{
struct buffer_head *bh, *dibh;
uint64_t block = 0;
int journaled = gfs_is_jdata(ip);
int error;
down_write(&ip->i_rw_mutex);
error = gfs_get_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 (journaled) {
error = gfs_metaalloc(ip, &block);
if (error)
goto out_brelse;
error = gfs_get_data_buffer(ip, block, TRUE, &bh);
if (error)
goto out_brelse;
gfs_buffer_copy_tail(bh, sizeof(struct gfs_meta_header),
dibh, sizeof(struct gfs_dinode));
brelse(bh);
} else {
gfs_blkalloc(ip, &block);
error = unstuffer(ip, dibh, block, private);
if (error)
goto out_brelse;
}
}
/* Set up the pointer to the new block */
gfs_trans_add_bh(ip->i_gl, dibh);
gfs_buffer_clear_tail(dibh, sizeof(struct gfs_dinode));
if (ip->i_di.di_size) {
*(uint64_t *)(dibh->b_data + sizeof(struct gfs_dinode)) = cpu_to_gfs64(block);
ip->i_di.di_blocks++;
}
ip->i_di.di_height = 1;
gfs_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 GFS 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 gfs_inode *ip, uint64_t size)
{
struct gfs_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 (gfs_is_jdata(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 GFS 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 gfs_inode *ip, int height)
{
struct gfs_sbd *sdp = ip->i_sbd;
struct buffer_head *bh, *dibh;
uint64_t block, *bp;
unsigned int x;
int new_block;
int error;
while (ip->i_di.di_height < height) {
error = gfs_get_inode_buffer(ip, &dibh);
if (error)
return error;
new_block = FALSE;
bp = (uint64_t *)(dibh->b_data + sizeof(struct gfs_dinode));
for (x = 0; x < sdp->sd_diptrs; x++, bp++)
if (*bp) {
new_block = TRUE;
break;
}
if (new_block) {
/* Get a new block, fill it with the old direct pointers,
and write it out */
error = gfs_metaalloc(ip, &block);
if (error)
goto fail;
error = gfs_dread(ip->i_gl, block,
DIO_NEW | DIO_START | DIO_WAIT, &bh);
if (error)
goto fail;
gfs_trans_add_bh(ip->i_gl, bh);
gfs_metatype_set(bh,
GFS_METATYPE_IN,
GFS_FORMAT_IN);
memset(bh->b_data + sizeof(struct gfs_meta_header),
0,
sizeof(struct gfs_indirect) -
sizeof(struct gfs_meta_header));
gfs_buffer_copy_tail(bh, sizeof(struct gfs_indirect),
dibh, sizeof(struct gfs_dinode));
brelse(bh);
}
/* Set up the new direct pointer and write it out to disk */
gfs_trans_add_bh(ip->i_gl, dibh);
gfs_buffer_clear_tail(dibh, sizeof(struct gfs_dinode));
if (new_block) {
*(uint64_t *)(dibh->b_data + sizeof(struct gfs_dinode)) = cpu_to_gfs64(block);
ip->i_di.di_blocks++;
}
ip->i_di.di_height++;
gfs_dinode_out(&ip->i_di, dibh->b_data);
brelse(dibh);
}
return 0;
fail:
brelse(dibh);
return error;
}
/**
* 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 struct metapath *
find_metapath(struct gfs_inode *ip, uint64_t block)
{
struct gfs_sbd *sdp = ip->i_sbd;
struct metapath *mp;
uint64_t b = block;
unsigned int i;
mp = gmalloc(sizeof(struct metapath));
memset(mp, 0, sizeof(struct metapath));
for (i = ip->i_di.di_height; i--;)
mp->mp_list[i] = do_div(b, sdp->sd_inptrs);
return mp;
}
/**
* 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 gfs_indirect) : sizeof(struct gfs_dinode);
return ((uint64_t *)(bh->b_data + head_size)) + mp->mp_list[height];
}
/**
* get_metablock - Get the next metadata block in metadata tree
* @ip: The GFS 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.
*
* Returns: errno
*/
static int
get_metablock(struct gfs_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);
int error;
if (*ptr) {
*block = gfs64_to_cpu(*ptr);
return 0;
}
*block = 0;
if (!create)
return 0;
error = gfs_metaalloc(ip, block);
if (error)
return error;
gfs_trans_add_bh(ip->i_gl, bh);
*ptr = cpu_to_gfs64(*block);
ip->i_di.di_blocks++;
*new = 1;
return 0;
}
/**
* get_datablock - Get datablock number from metadata block
* @ip: The GFS inode
* @bh: The buffer containing pointers to datablocks
* @mp: The metapath
* @create: Non-zero if we may create a new data block
* @new: Used to indicate if we created a new data block
* @block: the returned disk block number
*
* Given a fully built metadata tree, checks to see if a particular data
* block exists. It is created if it does not exist and the block number
* on disk is returned.
*
* Returns: errno
*/
static int
get_datablock(struct gfs_inode *ip,
struct buffer_head *bh, struct metapath *mp,
int create, int *new, uint64_t *block)
{
uint64_t *ptr = metapointer(bh, ip->i_di.di_height - 1, mp);
if (*ptr) {
*block = gfs64_to_cpu(*ptr);
return 0;
}
*block = 0;
if (!create)
return 0;
if (gfs_is_jdata(ip)) {
int error;
error = gfs_metaalloc(ip, block);
if (error)
return error;
} else
gfs_blkalloc(ip, block);
gfs_trans_add_bh(ip->i_gl, bh);
*ptr = cpu_to_gfs64(*block);
ip->i_di.di_blocks++;
*new = 1;
return 0;
}
/**
* gfs_block_map - Map a block from an inode to a disk block
* @ip: The GFS 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
gfs_block_map(struct gfs_inode *ip,
uint64_t lblock, int *new,
uint64_t *dblock, uint32_t *extlen)
{
struct gfs_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 (gfs_assert_warn(sdp, !gfs_is_stuffed(ip)))
goto out;
bsize = (gfs_is_jdata(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;
}
mp = find_metapath(ip, lblock);
end_of_metadata = ip->i_di.di_height - 1;
error = gfs_get_inode_buffer(ip, &bh);
if (error)
goto out_kfree;
for (x = 0; x < end_of_metadata; x++) {
error = get_metablock(ip, bh, x, mp, create, new, dblock);
brelse(bh);
if (error || !*dblock)
goto out_kfree;
error = gfs_get_meta_buffer(ip, x + 1, *dblock, *new, &bh);
if (error)
goto out_kfree;
}
error = get_datablock(ip, bh, mp, create, new, dblock);
if (error) {
brelse(bh);
goto out_kfree;
}
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) {
get_datablock(ip, bh, mp,
FALSE, &tmp_new,
&tmp_dblock);
if (*dblock + *extlen != tmp_dblock)
break;
(*extlen)++;
}
}
}
brelse(bh);
if (*new) {
error = gfs_get_inode_buffer(ip, &bh);
if (!error) {
gfs_trans_add_bh(ip->i_gl, bh);
gfs_dinode_out(&ip->i_di, bh->b_data);
brelse(bh);
}
}
out_kfree:
kfree(mp);
out:
if (create)
up_write(&ip->i_rw_mutex);
else
up_read(&ip->i_rw_mutex);
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 gfs_inode *ip, uint64_t size)
{
struct gfs_sbd *sdp = ip->i_sbd;
struct gfs_alloc *al;
struct buffer_head *dibh;
unsigned int h;
int journaled = gfs_is_jdata(ip);
int error;
al = gfs_alloc_get(ip);
error = gfs_quota_lock_m(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
if (error)
goto out;
error = gfs_quota_check(ip, ip->i_di.di_uid, ip->i_di.di_gid);
if (error)
goto out_gunlock_q;
if (journaled)
al->al_requested_meta = sdp->sd_max_height + 1;
else {
al->al_requested_meta = sdp->sd_max_height;
al->al_requested_data = 1;
}
error = gfs_inplace_reserve(ip);
if (error)
goto out_gunlock_q;
/* Trans may require:
Full extention of the metadata tree, block allocation,
a dinode modification, and a quota change */
error = gfs_trans_begin(sdp,
sdp->sd_max_height + al->al_rgd->rd_ri.ri_length +
1 + !!journaled,
1);
if (error)
goto out_ipres;
if (size > sdp->sd_sb.sb_bsize - sizeof(struct gfs_dinode)) {
if (gfs_is_stuffed(ip)) {
error = gfs_unstuff_dinode(ip, gfs_unstuffer_sync, 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 = gfs_get_inode_buffer(ip, &dibh);
if (error)
goto out_end_trans;
gfs_trans_add_bh(ip->i_gl, dibh);
gfs_dinode_out(&ip->i_di, dibh->b_data);
brelse(dibh);
out_end_trans:
gfs_trans_end(sdp);
out_ipres:
gfs_inplace_release(ip);
out_gunlock_q:
gfs_quota_unlock_m(ip);
out:
gfs_alloc_put(ip);
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: TRUE 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 TRUE.
*
* Returns: errno
*/
static int
recursive_scan(struct gfs_inode *ip, struct buffer_head *dibh,
struct metapath *mp, unsigned int height, uint64_t block,
int first, block_call_t bc, void *data)
{
struct gfs_sbd *sdp = ip->i_sbd;
struct buffer_head *bh = NULL;
uint64_t *top, *bottom;
uint64_t bn;
int error;
if (!height) {
error = gfs_get_inode_buffer(ip, &bh);
if (error)
goto fail;
dibh = bh;
top = (uint64_t *)(bh->b_data + sizeof(struct gfs_dinode)) +
mp->mp_list[0];
bottom = (uint64_t *)(bh->b_data + sizeof(struct gfs_dinode)) +
sdp->sd_diptrs;
} else {
error = gfs_get_meta_buffer(ip, height, block, FALSE, &bh);
if (error)
goto fail;
top = (uint64_t *)(bh->b_data + sizeof(struct gfs_indirect)) +
((first) ? mp->mp_list[height] : 0);
bottom = (uint64_t *)(bh->b_data + sizeof(struct gfs_indirect)) +
sdp->sd_inptrs;
}
error = bc(ip, dibh, bh, top, bottom, height, data);
if (error)
goto fail;
if (height < ip->i_di.di_height - 1)
for (; top < bottom; top++, first = FALSE) {
if (!*top)
continue;
bn = gfs64_to_cpu(*top);
error = recursive_scan(ip, dibh, mp,
height + 1, bn, first,
bc, data);
if (error)
goto fail;
}
brelse(bh);
return 0;
fail:
if (bh)
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 gfs_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 gfs_sbd *sdp = ip->i_sbd;
struct gfs_rgrp_list rlist;
uint64_t bn, bstart;
uint32_t blen;
uint64_t *p;
unsigned int rg_blocks = 0;
int metadata;
int x;
int error;
if (!*top)
sm->sm_first = FALSE;
if (height != sm->sm_height)
return 0;
if (sm->sm_first) {
top++;
sm->sm_first = FALSE;
}
metadata = (height != ip->i_di.di_height - 1) || gfs_is_jdata(ip);
error = gfs_rindex_hold(sdp, &ip->i_alloc->al_ri_gh);
if (error)
return error;
memset(&rlist, 0, sizeof(struct gfs_rgrp_list));
bstart = 0;
blen = 0;
for (p = top; p < bottom; p++) {
if (!*p)
continue;
bn = gfs64_to_cpu(*p);
if (bstart + blen == bn)
blen++;
else {
if (bstart)
gfs_rlist_add(sdp, &rlist, bstart);
bstart = bn;
blen = 1;
}
}
if (bstart)
gfs_rlist_add(sdp, &rlist, bstart);
else
goto out; /* Nothing to do */
gfs_rlist_alloc(&rlist, LM_ST_EXCLUSIVE, 0);
for (x = 0; x < rlist.rl_rgrps; x++) {
struct gfs_rgrpd *rgd;
rgd = get_gl2rgd(rlist.rl_ghs[x].gh_gl);
rg_blocks += rgd->rd_ri.ri_length;
}
error = gfs_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs);
if (error)
goto out_rlist;
/* Trans may require:
All the bitmaps that were reserved.
One block for the dinode.
One block for the indirect block being cleared.
One block for a quota change. */
error = gfs_trans_begin(sdp, rg_blocks + 2, 1);
if (error)
goto out_rg_gunlock;
down_write(&ip->i_rw_mutex);
gfs_trans_add_bh(ip->i_gl, dibh);
gfs_trans_add_bh(ip->i_gl, bh);
bstart = 0;
blen = 0;
for (p = top; p < bottom; p++) {
if (!*p)
continue;
bn = gfs64_to_cpu(*p);
if (bstart + blen == bn)
blen++;
else {
if (bstart) {
if (metadata)
gfs_metafree(ip, bstart, blen);
else
gfs_blkfree(ip, bstart, blen);
}
bstart = bn;
blen = 1;
}
*p = 0;
if (!ip->i_di.di_blocks)
gfs_consist_inode(ip);
ip->i_di.di_blocks--;
}
if (bstart) {
if (metadata)
gfs_metafree(ip, bstart, blen);
else
gfs_blkfree(ip, bstart, blen);
}
ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();
gfs_dinode_out(&ip->i_di, dibh->b_data);
up_write(&ip->i_rw_mutex);
gfs_trans_end(sdp);
out_rg_gunlock:
gfs_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs);
out_rlist:
gfs_rlist_free(&rlist);
out:
gfs_glock_dq_uninit(&ip->i_alloc->al_ri_gh);
return error;
}
/**
* gfs_truncator_default - truncate a partial data block
* @ip: the inode
* @size: the size the file should be
*
* Returns: errno
*/
int
gfs_truncator_default(struct gfs_inode *ip, uint64_t size)
{
struct gfs_sbd *sdp = ip->i_sbd;
struct buffer_head *bh;
uint64_t bn;
int not_new = 0;
int error;
error = gfs_block_map(ip, size >> sdp->sd_sb.sb_bsize_shift, &not_new,
&bn, NULL);
if (error)
return error;
if (!bn)
return 0;
error = gfs_get_data_buffer(ip, bn, FALSE, &bh);
if (error)
return error;
gfs_buffer_clear_tail(bh, size & (sdp->sd_sb.sb_bsize - 1));
error = gfs_dwrite(sdp, bh, DIO_DIRTY);
brelse(bh);
return error;
}
/**
* truncator_journaled - truncate a partial data block
* @ip: the inode
* @size: the size the file should be
*
* Returns: errno
*/
static int
truncator_journaled(struct gfs_inode *ip, uint64_t size)
{
struct gfs_sbd *sdp = ip->i_sbd;
struct buffer_head *bh;
uint64_t lbn, dbn;
uint32_t off;
int not_new = 0;
int error;
lbn = size;
off = do_div(lbn, sdp->sd_jbsize);
error = gfs_block_map(ip, lbn, &not_new, &dbn, NULL);
if (error)
return error;
if (!dbn)
return 0;
error = gfs_trans_begin(sdp, 1, 0);
if (error)
return error;
error = gfs_get_data_buffer(ip, dbn, FALSE, &bh);
if (!error) {
gfs_trans_add_bh(ip->i_gl, bh);
gfs_buffer_clear_tail(bh,
sizeof(struct gfs_meta_header) +
off);
brelse(bh);
}
gfs_trans_end(sdp);
return error;
}
/**
* gfs_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
*/
int
gfs_shrink(struct gfs_inode *ip, uint64_t size, gfs_truncator_t truncator)
{
struct gfs_sbd *sdp = ip->i_sbd;
struct gfs_holder ri_gh;
struct gfs_rgrpd *rgd;
struct buffer_head *dibh;
uint64_t block;
unsigned int height;
int journaled = gfs_is_jdata(ip);
int error;
if (!size)
block = 0;
else if (journaled) {
block = size - 1;
do_div(block, sdp->sd_jbsize);
}
else
block = (size - 1) >> sdp->sd_sb.sb_bsize_shift;
/* Get rid of all the data/metadata blocks */
height = ip->i_di.di_height;
if (height) {
struct metapath *mp = find_metapath(ip, block);
gfs_alloc_get(ip);
error = gfs_quota_hold_m(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
if (error) {
gfs_alloc_put(ip);
kfree(mp);
return error;
}
while (height--) {
struct strip_mine sm;
sm.sm_first = (size) ? TRUE : FALSE;
sm.sm_height = height;
error = recursive_scan(ip, NULL, mp, 0, 0, TRUE,
do_strip, &sm);
if (error) {
gfs_quota_unhold_m(ip);
gfs_alloc_put(ip);
kfree(mp);
return error;
}
}
gfs_quota_unhold_m(ip);
gfs_alloc_put(ip);
kfree(mp);
}
/* If we truncated in the middle of a block, zero out the leftovers. */
if (gfs_is_stuffed(ip)) {
/* Do nothing */
} else if (journaled) {
if (do_mod(size, sdp->sd_jbsize)) {
error = truncator_journaled(ip, size);
if (error)
return error;
}
} else if (size & (uint64_t)(sdp->sd_sb.sb_bsize - 1)) {
error = truncator(ip, size);
if (error)
return error;
}
/* Set the new size (and possibly the height) */
if (!size) {
error = gfs_rindex_hold(sdp, &ri_gh);
if (error)
return error;
}
error = gfs_trans_begin(sdp, 1, 0);
if (error)
goto out;
down_write(&ip->i_rw_mutex);
error = gfs_get_inode_buffer(ip, &dibh);
if (error)
goto out_end_trans;
if (!size) {
ip->i_di.di_height = 0;
rgd = gfs_blk2rgrpd(sdp, ip->i_num.no_addr);
if (!rgd) {
gfs_consist_inode(ip);
error = -EIO;
goto out_end_trans;
}
ip->i_di.di_goal_rgrp = rgd->rd_ri.ri_addr;
ip->i_di.di_goal_dblk =
ip->i_di.di_goal_mblk =
ip->i_num.no_addr - rgd->rd_ri.ri_data1;
}
ip->i_di.di_size = size;
ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();
gfs_trans_add_bh(ip->i_gl, dibh);
if (!ip->i_di.di_height &&
size < sdp->sd_sb.sb_bsize - sizeof(struct gfs_dinode))
gfs_buffer_clear_tail(dibh, sizeof(struct gfs_dinode) + size);
gfs_dinode_out(&ip->i_di, dibh->b_data);
brelse(dibh);
out_end_trans:
up_write(&ip->i_rw_mutex);
gfs_trans_end(sdp);
out:
if (!size)
gfs_glock_dq_uninit(&ri_gh);
return error;
}
/**
* do_same - truncate to same size (update time stamps)
* @ip:
*
* Returns: errno
*/
static int
do_same(struct gfs_inode *ip)
{
struct gfs_sbd *sdp = ip->i_sbd;
struct buffer_head *dibh;
int error;
error = gfs_trans_begin(sdp, 1, 0);
if (error)
return error;
error = gfs_get_inode_buffer(ip, &dibh);
if (error)
goto out;
ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();
gfs_trans_add_bh(ip->i_gl, dibh);
gfs_dinode_out(&ip->i_di, dibh->b_data);
brelse(dibh);
out:
gfs_trans_end(sdp);
return error;
}
/**
* gfs_truncatei - make a file a give 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
gfs_truncatei(struct gfs_inode *ip, uint64_t size,
gfs_truncator_t truncator)
{
if (gfs_assert_warn(ip->i_sbd, ip->i_di.di_type == GFS_FILE_REG))
return -EINVAL;
if (size == ip->i_di.di_size)
return do_same(ip);
else if (size > ip->i_di.di_size)
return do_grow(ip, size);
else
return gfs_shrink(ip, size, truncator);
}
/**
* gfs_write_calc_reserv - calculate the 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
gfs_write_calc_reserv(struct gfs_inode *ip, unsigned int len,
unsigned int *data_blocks, unsigned int *ind_blocks)
{
struct gfs_sbd *sdp = ip->i_sbd;
unsigned int tmp;
if (gfs_is_jdata(ip)) {
*data_blocks = DIV_RU(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_RU(tmp, sdp->sd_inptrs);
*ind_blocks += tmp;
}
}
/**
* gfs_write_alloc_required - figure out if a write is going to require an allocation
* @ip: the file being written to
* @offset: the offset to write to
* @len: the number of bytes being written
* @alloc_required: the int is set to TRUE if an alloc is required, FALSE otherwise
*
* Returns: errno
*/
int
gfs_write_alloc_required(struct gfs_inode *ip,
uint64_t offset, unsigned int len,
int *alloc_required)
{
struct gfs_sbd *sdp = ip->i_sbd;
uint64_t lblock, lblock_stop, dblock;
uint32_t extlen;
int not_new = FALSE;
int error = 0;
*alloc_required = FALSE;
if (!len)
return 0;
if (gfs_is_stuffed(ip)) {
if (offset + len > sdp->sd_sb.sb_bsize - sizeof(struct gfs_dinode))
*alloc_required = TRUE;
return 0;
}
if (gfs_is_jdata(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 = gfs_block_map(ip, lblock, &not_new, &dblock, &extlen);
if (error)
return error;
if (!dblock) {
*alloc_required = TRUE;
return 0;
}
}
return 0;
}
/**
* do_gfm - Copy out the dinode/indirect blocks of a file
* @ip: the file
* @dibh: the dinode buffer
* @bh: the indirect buffer we're looking at
* @top: the first pointer in the block
* @bottom: one more than the last pointer in the block
* @height: the height the block is at
* @data: a pointer to a struct gfs_user_buffer structure
*
* If this is a journaled file, copy out the data too.
*
* Returns: errno
*/
static int
do_gfm(struct gfs_inode *ip, struct buffer_head *dibh,
struct buffer_head *bh, uint64_t *top, uint64_t *bottom,
unsigned int height, void *data)
{
struct gfs_user_buffer *ub = (struct gfs_user_buffer *)data;
int error;
error = gfs_add_bh_to_ub(ub, bh);
if (error)
return error;
if (ip->i_di.di_type != GFS_FILE_DIR ||
height + 1 != ip->i_di.di_height)
return 0;
for (; top < bottom; top++)
if (*top) {
struct buffer_head *data_bh;
error = gfs_dread(ip->i_gl, gfs64_to_cpu(*top),
DIO_START | DIO_WAIT,
&data_bh);
if (error)
return error;
error = gfs_add_bh_to_ub(ub, data_bh);
brelse(data_bh);
if (error)
return error;
}
return 0;
}
/**
* gfs_get_file_meta - return all the metadata for a file
* @ip: the file
* @ub: the structure representing the meta
*
* Returns: errno
*/
int
gfs_get_file_meta(struct gfs_inode *ip, struct gfs_user_buffer *ub)
{
int error;
if (gfs_is_stuffed(ip)) {
struct buffer_head *dibh;
error = gfs_get_inode_buffer(ip, &dibh);
if (!error) {
error = gfs_add_bh_to_ub(ub, dibh);
brelse(dibh);
}
} else {
struct metapath *mp = find_metapath(ip, 0);
error = recursive_scan(ip, NULL, mp, 0, 0, TRUE, do_gfm, ub);
kfree(mp);
}
return error;
}

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