kernel-ark/fs/quota_v2.c
Valdis.Kletnieks@vt.edu 3135806358 [PATCH] quota: make useless quota error message informative
fs/quota_v2.c can, under some conditions, issue a kernel message that says,
in totality, 'failed read'.  This patch does the following:

1) Gives a hint who issued the error message, so people reading the logs
   don't have to go grepping the entire kernel tree (with 11 false
   positives).

2) Say what amount of data we expected, and actually got.

Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Cc: Jan Kara <jack@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-14 18:27:12 -08:00

696 lines
20 KiB
C

/*
* 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=%d got=%d\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_sem */
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);