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acrn-kernel/fs/quota_v2.c

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/*
* vfsv0 quota IO operations on file
*/
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/dqblk_v2.h>
#include <linux/quotaio_v2.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <asm/byteorder.h>
MODULE_AUTHOR("Jan Kara");
MODULE_DESCRIPTION("Quota format v2 support");
MODULE_LICENSE("GPL");
#define __QUOTA_V2_PARANOIA
typedef char *dqbuf_t;
#define GETIDINDEX(id, depth) (((id) >> ((V2_DQTREEDEPTH-(depth)-1)*8)) & 0xff)
#define GETENTRIES(buf) ((struct v2_disk_dqblk *)(((char *)buf)+sizeof(struct v2_disk_dqdbheader)))
/* Check whether given file is really vfsv0 quotafile */
static int v2_check_quota_file(struct super_block *sb, int type)
{
struct v2_disk_dqheader dqhead;
ssize_t size;
static const uint quota_magics[] = V2_INITQMAGICS;
static const uint quota_versions[] = V2_INITQVERSIONS;
size = sb->s_op->quota_read(sb, type, (char *)&dqhead, sizeof(struct v2_disk_dqheader), 0);
if (size != sizeof(struct v2_disk_dqheader)) {
printk("quota_v2: failed read expected=%zd got=%zd\n",
sizeof(struct v2_disk_dqheader), size);
return 0;
}
if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type] ||
le32_to_cpu(dqhead.dqh_version) != quota_versions[type])
return 0;
return 1;
}
/* Read information header from quota file */
static int v2_read_file_info(struct super_block *sb, int type)
{
struct v2_disk_dqinfo dinfo;
struct mem_dqinfo *info = sb_dqopt(sb)->info+type;
ssize_t size;
size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
if (size != sizeof(struct v2_disk_dqinfo)) {
printk(KERN_WARNING "Can't read info structure on device %s.\n",
sb->s_id);
return -1;
}
info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
info->dqi_flags = le32_to_cpu(dinfo.dqi_flags);
info->u.v2_i.dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
info->u.v2_i.dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
info->u.v2_i.dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
return 0;
}
/* Write information header to quota file */
static int v2_write_file_info(struct super_block *sb, int type)
{
struct v2_disk_dqinfo dinfo;
struct mem_dqinfo *info = sb_dqopt(sb)->info+type;
ssize_t size;
spin_lock(&dq_data_lock);
info->dqi_flags &= ~DQF_INFO_DIRTY;
dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
dinfo.dqi_flags = cpu_to_le32(info->dqi_flags & DQF_MASK);
spin_unlock(&dq_data_lock);
dinfo.dqi_blocks = cpu_to_le32(info->u.v2_i.dqi_blocks);
dinfo.dqi_free_blk = cpu_to_le32(info->u.v2_i.dqi_free_blk);
dinfo.dqi_free_entry = cpu_to_le32(info->u.v2_i.dqi_free_entry);
size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
if (size != sizeof(struct v2_disk_dqinfo)) {
printk(KERN_WARNING "Can't write info structure on device %s.\n",
sb->s_id);
return -1;
}
return 0;
}
static void disk2memdqb(struct mem_dqblk *m, struct v2_disk_dqblk *d)
{
m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
m->dqb_itime = le64_to_cpu(d->dqb_itime);
m->dqb_bhardlimit = le32_to_cpu(d->dqb_bhardlimit);
m->dqb_bsoftlimit = le32_to_cpu(d->dqb_bsoftlimit);
m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
m->dqb_btime = le64_to_cpu(d->dqb_btime);
}
static void mem2diskdqb(struct v2_disk_dqblk *d, struct mem_dqblk *m, qid_t id)
{
d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
d->dqb_itime = cpu_to_le64(m->dqb_itime);
d->dqb_bhardlimit = cpu_to_le32(m->dqb_bhardlimit);
d->dqb_bsoftlimit = cpu_to_le32(m->dqb_bsoftlimit);
d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
d->dqb_btime = cpu_to_le64(m->dqb_btime);
d->dqb_id = cpu_to_le32(id);
}
static dqbuf_t getdqbuf(void)
{
dqbuf_t buf = kmalloc(V2_DQBLKSIZE, GFP_NOFS);
if (!buf)
printk(KERN_WARNING "VFS: Not enough memory for quota buffers.\n");
return buf;
}
static inline void freedqbuf(dqbuf_t buf)
{
kfree(buf);
}
static inline ssize_t read_blk(struct super_block *sb, int type, uint blk, dqbuf_t buf)
{
memset(buf, 0, V2_DQBLKSIZE);
return sb->s_op->quota_read(sb, type, (char *)buf,
V2_DQBLKSIZE, blk << V2_DQBLKSIZE_BITS);
}
static inline ssize_t write_blk(struct super_block *sb, int type, uint blk, dqbuf_t buf)
{
return sb->s_op->quota_write(sb, type, (char *)buf,
V2_DQBLKSIZE, blk << V2_DQBLKSIZE_BITS);
}
/* Remove empty block from list and return it */
static int get_free_dqblk(struct super_block *sb, int type)
{
dqbuf_t buf = getdqbuf();
struct mem_dqinfo *info = sb_dqinfo(sb, type);
struct v2_disk_dqdbheader *dh = (struct v2_disk_dqdbheader *)buf;
int ret, blk;
if (!buf)
return -ENOMEM;
if (info->u.v2_i.dqi_free_blk) {
blk = info->u.v2_i.dqi_free_blk;
if ((ret = read_blk(sb, type, blk, buf)) < 0)
goto out_buf;
info->u.v2_i.dqi_free_blk = le32_to_cpu(dh->dqdh_next_free);
}
else {
memset(buf, 0, V2_DQBLKSIZE);
/* Assure block allocation... */
if ((ret = write_blk(sb, type, info->u.v2_i.dqi_blocks, buf)) < 0)
goto out_buf;
blk = info->u.v2_i.dqi_blocks++;
}
mark_info_dirty(sb, type);
ret = blk;
out_buf:
freedqbuf(buf);
return ret;
}
/* Insert empty block to the list */
static int put_free_dqblk(struct super_block *sb, int type, dqbuf_t buf, uint blk)
{
struct mem_dqinfo *info = sb_dqinfo(sb, type);
struct v2_disk_dqdbheader *dh = (struct v2_disk_dqdbheader *)buf;
int err;
dh->dqdh_next_free = cpu_to_le32(info->u.v2_i.dqi_free_blk);
dh->dqdh_prev_free = cpu_to_le32(0);
dh->dqdh_entries = cpu_to_le16(0);
info->u.v2_i.dqi_free_blk = blk;
mark_info_dirty(sb, type);
/* Some strange block. We had better leave it... */
if ((err = write_blk(sb, type, blk, buf)) < 0)
return err;
return 0;
}
/* Remove given block from the list of blocks with free entries */
static int remove_free_dqentry(struct super_block *sb, int type, dqbuf_t buf, uint blk)
{
dqbuf_t tmpbuf = getdqbuf();
struct mem_dqinfo *info = sb_dqinfo(sb, type);
struct v2_disk_dqdbheader *dh = (struct v2_disk_dqdbheader *)buf;
uint nextblk = le32_to_cpu(dh->dqdh_next_free), prevblk = le32_to_cpu(dh->dqdh_prev_free);
int err;
if (!tmpbuf)
return -ENOMEM;
if (nextblk) {
if ((err = read_blk(sb, type, nextblk, tmpbuf)) < 0)
goto out_buf;
((struct v2_disk_dqdbheader *)tmpbuf)->dqdh_prev_free = dh->dqdh_prev_free;
if ((err = write_blk(sb, type, nextblk, tmpbuf)) < 0)
goto out_buf;
}
if (prevblk) {
if ((err = read_blk(sb, type, prevblk, tmpbuf)) < 0)
goto out_buf;
((struct v2_disk_dqdbheader *)tmpbuf)->dqdh_next_free = dh->dqdh_next_free;
if ((err = write_blk(sb, type, prevblk, tmpbuf)) < 0)
goto out_buf;
}
else {
info->u.v2_i.dqi_free_entry = nextblk;
mark_info_dirty(sb, type);
}
freedqbuf(tmpbuf);
dh->dqdh_next_free = dh->dqdh_prev_free = cpu_to_le32(0);
/* No matter whether write succeeds block is out of list */
if (write_blk(sb, type, blk, buf) < 0)
printk(KERN_ERR "VFS: Can't write block (%u) with free entries.\n", blk);
return 0;
out_buf:
freedqbuf(tmpbuf);
return err;
}
/* Insert given block to the beginning of list with free entries */
static int insert_free_dqentry(struct super_block *sb, int type, dqbuf_t buf, uint blk)
{
dqbuf_t tmpbuf = getdqbuf();
struct mem_dqinfo *info = sb_dqinfo(sb, type);
struct v2_disk_dqdbheader *dh = (struct v2_disk_dqdbheader *)buf;
int err;
if (!tmpbuf)
return -ENOMEM;
dh->dqdh_next_free = cpu_to_le32(info->u.v2_i.dqi_free_entry);
dh->dqdh_prev_free = cpu_to_le32(0);
if ((err = write_blk(sb, type, blk, buf)) < 0)
goto out_buf;
if (info->u.v2_i.dqi_free_entry) {
if ((err = read_blk(sb, type, info->u.v2_i.dqi_free_entry, tmpbuf)) < 0)
goto out_buf;
((struct v2_disk_dqdbheader *)tmpbuf)->dqdh_prev_free = cpu_to_le32(blk);
if ((err = write_blk(sb, type, info->u.v2_i.dqi_free_entry, tmpbuf)) < 0)
goto out_buf;
}
freedqbuf(tmpbuf);
info->u.v2_i.dqi_free_entry = blk;
mark_info_dirty(sb, type);
return 0;
out_buf:
freedqbuf(tmpbuf);
return err;
}
/* Find space for dquot */
static uint find_free_dqentry(struct dquot *dquot, int *err)
{
struct super_block *sb = dquot->dq_sb;
struct mem_dqinfo *info = sb_dqopt(sb)->info+dquot->dq_type;
uint blk, i;
struct v2_disk_dqdbheader *dh;
struct v2_disk_dqblk *ddquot;
struct v2_disk_dqblk fakedquot;
dqbuf_t buf;
*err = 0;
if (!(buf = getdqbuf())) {
*err = -ENOMEM;
return 0;
}
dh = (struct v2_disk_dqdbheader *)buf;
ddquot = GETENTRIES(buf);
if (info->u.v2_i.dqi_free_entry) {
blk = info->u.v2_i.dqi_free_entry;
if ((*err = read_blk(sb, dquot->dq_type, blk, buf)) < 0)
goto out_buf;
}
else {
blk = get_free_dqblk(sb, dquot->dq_type);
if ((int)blk < 0) {
*err = blk;
freedqbuf(buf);
return 0;
}
memset(buf, 0, V2_DQBLKSIZE);
/* This is enough as block is already zeroed and entry list is empty... */
info->u.v2_i.dqi_free_entry = blk;
mark_info_dirty(sb, dquot->dq_type);
}
if (le16_to_cpu(dh->dqdh_entries)+1 >= V2_DQSTRINBLK) /* Block will be full? */
if ((*err = remove_free_dqentry(sb, dquot->dq_type, buf, blk)) < 0) {
printk(KERN_ERR "VFS: find_free_dqentry(): Can't remove block (%u) from entry free list.\n", blk);
goto out_buf;
}
dh->dqdh_entries = cpu_to_le16(le16_to_cpu(dh->dqdh_entries)+1);
memset(&fakedquot, 0, sizeof(struct v2_disk_dqblk));
/* Find free structure in block */
for (i = 0; i < V2_DQSTRINBLK && memcmp(&fakedquot, ddquot+i, sizeof(struct v2_disk_dqblk)); i++);
#ifdef __QUOTA_V2_PARANOIA
if (i == V2_DQSTRINBLK) {
printk(KERN_ERR "VFS: find_free_dqentry(): Data block full but it shouldn't.\n");
*err = -EIO;
goto out_buf;
}
#endif
if ((*err = write_blk(sb, dquot->dq_type, blk, buf)) < 0) {
printk(KERN_ERR "VFS: find_free_dqentry(): Can't write quota data block %u.\n", blk);
goto out_buf;
}
dquot->dq_off = (blk<<V2_DQBLKSIZE_BITS)+sizeof(struct v2_disk_dqdbheader)+i*sizeof(struct v2_disk_dqblk);
freedqbuf(buf);
return blk;
out_buf:
freedqbuf(buf);
return 0;
}
/* Insert reference to structure into the trie */
static int do_insert_tree(struct dquot *dquot, uint *treeblk, int depth)
{
struct super_block *sb = dquot->dq_sb;
dqbuf_t buf;
int ret = 0, newson = 0, newact = 0;
__le32 *ref;
uint newblk;
if (!(buf = getdqbuf()))
return -ENOMEM;
if (!*treeblk) {
ret = get_free_dqblk(sb, dquot->dq_type);
if (ret < 0)
goto out_buf;
*treeblk = ret;
memset(buf, 0, V2_DQBLKSIZE);
newact = 1;
}
else {
if ((ret = read_blk(sb, dquot->dq_type, *treeblk, buf)) < 0) {
printk(KERN_ERR "VFS: Can't read tree quota block %u.\n", *treeblk);
goto out_buf;
}
}
ref = (__le32 *)buf;
newblk = le32_to_cpu(ref[GETIDINDEX(dquot->dq_id, depth)]);
if (!newblk)
newson = 1;
if (depth == V2_DQTREEDEPTH-1) {
#ifdef __QUOTA_V2_PARANOIA
if (newblk) {
printk(KERN_ERR "VFS: Inserting already present quota entry (block %u).\n", le32_to_cpu(ref[GETIDINDEX(dquot->dq_id, depth)]));
ret = -EIO;
goto out_buf;
}
#endif
newblk = find_free_dqentry(dquot, &ret);
}
else
ret = do_insert_tree(dquot, &newblk, depth+1);
if (newson && ret >= 0) {
ref[GETIDINDEX(dquot->dq_id, depth)] = cpu_to_le32(newblk);
ret = write_blk(sb, dquot->dq_type, *treeblk, buf);
}
else if (newact && ret < 0)
put_free_dqblk(sb, dquot->dq_type, buf, *treeblk);
out_buf:
freedqbuf(buf);
return ret;
}
/* Wrapper for inserting quota structure into tree */
static inline int dq_insert_tree(struct dquot *dquot)
{
int tmp = V2_DQTREEOFF;
return do_insert_tree(dquot, &tmp, 0);
}
/*
* We don't have to be afraid of deadlocks as we never have quotas on quota files...
*/
static int v2_write_dquot(struct dquot *dquot)
{
int type = dquot->dq_type;
ssize_t ret;
struct v2_disk_dqblk ddquot, empty;
/* dq_off is guarded by dqio_mutex */
if (!dquot->dq_off)
if ((ret = dq_insert_tree(dquot)) < 0) {
printk(KERN_ERR "VFS: Error %zd occurred while creating quota.\n", ret);
return ret;
}
spin_lock(&dq_data_lock);
mem2diskdqb(&ddquot, &dquot->dq_dqb, dquot->dq_id);
/* Argh... We may need to write structure full of zeroes but that would be
* treated as an empty place by the rest of the code. Format change would
* be definitely cleaner but the problems probably are not worth it */
memset(&empty, 0, sizeof(struct v2_disk_dqblk));
if (!memcmp(&empty, &ddquot, sizeof(struct v2_disk_dqblk)))
ddquot.dqb_itime = cpu_to_le64(1);
spin_unlock(&dq_data_lock);
ret = dquot->dq_sb->s_op->quota_write(dquot->dq_sb, type,
(char *)&ddquot, sizeof(struct v2_disk_dqblk), dquot->dq_off);
if (ret != sizeof(struct v2_disk_dqblk)) {
printk(KERN_WARNING "VFS: dquota write failed on dev %s\n", dquot->dq_sb->s_id);
if (ret >= 0)
ret = -ENOSPC;
}
else
ret = 0;
dqstats.writes++;
return ret;
}
/* Free dquot entry in data block */
static int free_dqentry(struct dquot *dquot, uint blk)
{
struct super_block *sb = dquot->dq_sb;
int type = dquot->dq_type;
struct v2_disk_dqdbheader *dh;
dqbuf_t buf = getdqbuf();
int ret = 0;
if (!buf)
return -ENOMEM;
if (dquot->dq_off >> V2_DQBLKSIZE_BITS != blk) {
printk(KERN_ERR "VFS: Quota structure has offset to other "
"block (%u) than it should (%u).\n", blk,
(uint)(dquot->dq_off >> V2_DQBLKSIZE_BITS));
goto out_buf;
}
if ((ret = read_blk(sb, type, blk, buf)) < 0) {
printk(KERN_ERR "VFS: Can't read quota data block %u\n", blk);
goto out_buf;
}
dh = (struct v2_disk_dqdbheader *)buf;
dh->dqdh_entries = cpu_to_le16(le16_to_cpu(dh->dqdh_entries)-1);
if (!le16_to_cpu(dh->dqdh_entries)) { /* Block got free? */
if ((ret = remove_free_dqentry(sb, type, buf, blk)) < 0 ||
(ret = put_free_dqblk(sb, type, buf, blk)) < 0) {
printk(KERN_ERR "VFS: Can't move quota data block (%u) "
"to free list.\n", blk);
goto out_buf;
}
}
else {
memset(buf+(dquot->dq_off & ((1 << V2_DQBLKSIZE_BITS)-1)), 0,
sizeof(struct v2_disk_dqblk));
if (le16_to_cpu(dh->dqdh_entries) == V2_DQSTRINBLK-1) {
/* Insert will write block itself */
if ((ret = insert_free_dqentry(sb, type, buf, blk)) < 0) {
printk(KERN_ERR "VFS: Can't insert quota data block (%u) to free entry list.\n", blk);
goto out_buf;
}
}
else
if ((ret = write_blk(sb, type, blk, buf)) < 0) {
printk(KERN_ERR "VFS: Can't write quota data "
"block %u\n", blk);
goto out_buf;
}
}
dquot->dq_off = 0; /* Quota is now unattached */
out_buf:
freedqbuf(buf);
return ret;
}
/* Remove reference to dquot from tree */
static int remove_tree(struct dquot *dquot, uint *blk, int depth)
{
struct super_block *sb = dquot->dq_sb;
int type = dquot->dq_type;
dqbuf_t buf = getdqbuf();
int ret = 0;
uint newblk;
__le32 *ref = (__le32 *)buf;
if (!buf)
return -ENOMEM;
if ((ret = read_blk(sb, type, *blk, buf)) < 0) {
printk(KERN_ERR "VFS: Can't read quota data block %u\n", *blk);
goto out_buf;
}
newblk = le32_to_cpu(ref[GETIDINDEX(dquot->dq_id, depth)]);
if (depth == V2_DQTREEDEPTH-1) {
ret = free_dqentry(dquot, newblk);
newblk = 0;
}
else
ret = remove_tree(dquot, &newblk, depth+1);
if (ret >= 0 && !newblk) {
int i;
ref[GETIDINDEX(dquot->dq_id, depth)] = cpu_to_le32(0);
for (i = 0; i < V2_DQBLKSIZE && !buf[i]; i++); /* Block got empty? */
/* Don't put the root block into the free block list */
if (i == V2_DQBLKSIZE && *blk != V2_DQTREEOFF) {
put_free_dqblk(sb, type, buf, *blk);
*blk = 0;
}
else
if ((ret = write_blk(sb, type, *blk, buf)) < 0)
printk(KERN_ERR "VFS: Can't write quota tree "
"block %u.\n", *blk);
}
out_buf:
freedqbuf(buf);
return ret;
}
/* Delete dquot from tree */
static int v2_delete_dquot(struct dquot *dquot)
{
uint tmp = V2_DQTREEOFF;
if (!dquot->dq_off) /* Even not allocated? */
return 0;
return remove_tree(dquot, &tmp, 0);
}
/* Find entry in block */
static loff_t find_block_dqentry(struct dquot *dquot, uint blk)
{
dqbuf_t buf = getdqbuf();
loff_t ret = 0;
int i;
struct v2_disk_dqblk *ddquot = GETENTRIES(buf);
if (!buf)
return -ENOMEM;
if ((ret = read_blk(dquot->dq_sb, dquot->dq_type, blk, buf)) < 0) {
printk(KERN_ERR "VFS: Can't read quota tree block %u.\n", blk);
goto out_buf;
}
if (dquot->dq_id)
for (i = 0; i < V2_DQSTRINBLK &&
le32_to_cpu(ddquot[i].dqb_id) != dquot->dq_id; i++);
else { /* ID 0 as a bit more complicated searching... */
struct v2_disk_dqblk fakedquot;
memset(&fakedquot, 0, sizeof(struct v2_disk_dqblk));
for (i = 0; i < V2_DQSTRINBLK; i++)
if (!le32_to_cpu(ddquot[i].dqb_id) &&
memcmp(&fakedquot, ddquot+i, sizeof(struct v2_disk_dqblk)))
break;
}
if (i == V2_DQSTRINBLK) {
printk(KERN_ERR "VFS: Quota for id %u referenced "
"but not present.\n", dquot->dq_id);
ret = -EIO;
goto out_buf;
}
else
ret = (blk << V2_DQBLKSIZE_BITS) + sizeof(struct
v2_disk_dqdbheader) + i * sizeof(struct v2_disk_dqblk);
out_buf:
freedqbuf(buf);
return ret;
}
/* Find entry for given id in the tree */
static loff_t find_tree_dqentry(struct dquot *dquot, uint blk, int depth)
{
dqbuf_t buf = getdqbuf();
loff_t ret = 0;
__le32 *ref = (__le32 *)buf;
if (!buf)
return -ENOMEM;
if ((ret = read_blk(dquot->dq_sb, dquot->dq_type, blk, buf)) < 0) {
printk(KERN_ERR "VFS: Can't read quota tree block %u.\n", blk);
goto out_buf;
}
ret = 0;
blk = le32_to_cpu(ref[GETIDINDEX(dquot->dq_id, depth)]);
if (!blk) /* No reference? */
goto out_buf;
if (depth < V2_DQTREEDEPTH-1)
ret = find_tree_dqentry(dquot, blk, depth+1);
else
ret = find_block_dqentry(dquot, blk);
out_buf:
freedqbuf(buf);
return ret;
}
/* Find entry for given id in the tree - wrapper function */
static inline loff_t find_dqentry(struct dquot *dquot)
{
return find_tree_dqentry(dquot, V2_DQTREEOFF, 0);
}
static int v2_read_dquot(struct dquot *dquot)
{
int type = dquot->dq_type;
loff_t offset;
struct v2_disk_dqblk ddquot, empty;
int ret = 0;
#ifdef __QUOTA_V2_PARANOIA
/* Invalidated quota? */
if (!dquot->dq_sb || !sb_dqopt(dquot->dq_sb)->files[type]) {
printk(KERN_ERR "VFS: Quota invalidated while reading!\n");
return -EIO;
}
#endif
offset = find_dqentry(dquot);
if (offset <= 0) { /* Entry not present? */
if (offset < 0)
printk(KERN_ERR "VFS: Can't read quota "
"structure for id %u.\n", dquot->dq_id);
dquot->dq_off = 0;
set_bit(DQ_FAKE_B, &dquot->dq_flags);
memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));
ret = offset;
}
else {
dquot->dq_off = offset;
if ((ret = dquot->dq_sb->s_op->quota_read(dquot->dq_sb, type,
(char *)&ddquot, sizeof(struct v2_disk_dqblk), offset))
!= sizeof(struct v2_disk_dqblk)) {
if (ret >= 0)
ret = -EIO;
printk(KERN_ERR "VFS: Error while reading quota "
"structure for id %u.\n", dquot->dq_id);
memset(&ddquot, 0, sizeof(struct v2_disk_dqblk));
}
else {
ret = 0;
/* We need to escape back all-zero structure */
memset(&empty, 0, sizeof(struct v2_disk_dqblk));
empty.dqb_itime = cpu_to_le64(1);
if (!memcmp(&empty, &ddquot, sizeof(struct v2_disk_dqblk)))
ddquot.dqb_itime = 0;
}
disk2memdqb(&dquot->dq_dqb, &ddquot);
if (!dquot->dq_dqb.dqb_bhardlimit &&
!dquot->dq_dqb.dqb_bsoftlimit &&
!dquot->dq_dqb.dqb_ihardlimit &&
!dquot->dq_dqb.dqb_isoftlimit)
set_bit(DQ_FAKE_B, &dquot->dq_flags);
}
dqstats.reads++;
return ret;
}
/* Check whether dquot should not be deleted. We know we are
* the only one operating on dquot (thanks to dq_lock) */
static int v2_release_dquot(struct dquot *dquot)
{
if (test_bit(DQ_FAKE_B, &dquot->dq_flags) && !(dquot->dq_dqb.dqb_curinodes | dquot->dq_dqb.dqb_curspace))
return v2_delete_dquot(dquot);
return 0;
}
static struct quota_format_ops v2_format_ops = {
.check_quota_file = v2_check_quota_file,
.read_file_info = v2_read_file_info,
.write_file_info = v2_write_file_info,
.free_file_info = NULL,
.read_dqblk = v2_read_dquot,
.commit_dqblk = v2_write_dquot,
.release_dqblk = v2_release_dquot,
};
static struct quota_format_type v2_quota_format = {
.qf_fmt_id = QFMT_VFS_V0,
.qf_ops = &v2_format_ops,
.qf_owner = THIS_MODULE
};
static int __init init_v2_quota_format(void)
{
return register_quota_format(&v2_quota_format);
}
static void __exit exit_v2_quota_format(void)
{
unregister_quota_format(&v2_quota_format);
}
module_init(init_v2_quota_format);
module_exit(exit_v2_quota_format);
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