Re: 2.4.22-pre4+ build error with CONFIG_QFMT_V2=y.

From: Christoph Hellwig (hch@infradead.org)
Date: Wed Jul 09 2003 - 12:26:54 EST


On Wed, Jul 09, 2003 at 11:16:10AM -0600, Steven Cole wrote:
> Kernel is 2.4.22-pre4+ pulled one hour ago with:
> bk pull bk://linux.bkbits.net/linux-2.4
>
> This builds fine with only CONFIG_QUOTA=y.

Looks like I didn't check in quota_v2.c.

Marcelo, can you add the file below to the tree as fs/quota_v2.c?

------- snip --------
/*
 * vfsv0 quota IO operations on file
 */

#include <linux/errno.h>
#include <linux/fs.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>
#include <asm/uaccess.h>

#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;
        struct file *f = sb_dqopt(sb)->files[type];
        mm_segment_t fs;
        ssize_t size;
        loff_t offset = 0;
        static const uint quota_magics[] = V2_INITQMAGICS;
        static const uint quota_versions[] = V2_INITQVERSIONS;
 
        fs = get_fs();
        set_fs(KERNEL_DS);
        size = f->f_op->read(f, (char *)&dqhead, sizeof(struct v2_disk_dqheader), &offset);
        set_fs(fs);
        if (size != sizeof(struct v2_disk_dqheader))
                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)
{
        mm_segment_t fs;
        struct v2_disk_dqinfo dinfo;
        struct mem_dqinfo *info = sb_dqopt(sb)->info+type;
        struct file *f = sb_dqopt(sb)->files[type];
        ssize_t size;
        loff_t offset = V2_DQINFOOFF;

        fs = get_fs();
        set_fs(KERNEL_DS);
        size = f->f_op->read(f, (char *)&dinfo, sizeof(struct v2_disk_dqinfo), &offset);
        set_fs(fs);
        if (size != sizeof(struct v2_disk_dqinfo)) {
                printk(KERN_WARNING "Can't read info structure on device %s.\n",
                        kdevname(f->f_dentry->d_sb->s_dev));
                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)
{
        mm_segment_t fs;
        struct v2_disk_dqinfo dinfo;
        struct mem_dqinfo *info = sb_dqopt(sb)->info+type;
        struct file *f = sb_dqopt(sb)->files[type];
        ssize_t size;
        loff_t offset = V2_DQINFOOFF;

        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);
        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);
        fs = get_fs();
        set_fs(KERNEL_DS);
        size = f->f_op->write(f, (char *)&dinfo, sizeof(struct v2_disk_dqinfo), &offset);
        set_fs(fs);
        if (size != sizeof(struct v2_disk_dqinfo)) {
                printk(KERN_WARNING "Can't write info structure on device %s.\n",
                        kdevname(f->f_dentry->d_sb->s_dev));
                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_KERNEL);
        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 ssize_t read_blk(struct file *filp, uint blk, dqbuf_t buf)
{
        mm_segment_t fs;
        ssize_t ret;
        loff_t offset = blk<<V2_DQBLKSIZE_BITS;

        memset(buf, 0, V2_DQBLKSIZE);
        fs = get_fs();
        set_fs(KERNEL_DS);
        ret = filp->f_op->read(filp, (char *)buf, V2_DQBLKSIZE, &offset);
        set_fs(fs);
        return ret;
}

static ssize_t write_blk(struct file *filp, uint blk, dqbuf_t buf)
{
        mm_segment_t fs;
        ssize_t ret;
        loff_t offset = blk<<V2_DQBLKSIZE_BITS;

        fs = get_fs();
        set_fs(KERNEL_DS);
        ret = filp->f_op->write(filp, (char *)buf, V2_DQBLKSIZE, &offset);
        set_fs(fs);
        return ret;

}

/* Remove empty block from list and return it */
static int get_free_dqblk(struct file *filp, struct mem_dqinfo *info)
{
        dqbuf_t buf = getdqbuf();
        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(filp, 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);
                if ((ret = write_blk(filp, info->u.v2_i.dqi_blocks, buf)) < 0) /* Assure block allocation... */
                        goto out_buf;
                blk = info->u.v2_i.dqi_blocks++;
        }
        mark_info_dirty(info);
        ret = blk;
out_buf:
        freedqbuf(buf);
        return ret;
}

/* Insert empty block to the list */
static int put_free_dqblk(struct file *filp, struct mem_dqinfo *info, dqbuf_t buf, uint blk)
{
        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(info);
        if ((err = write_blk(filp, blk, buf)) < 0) /* Some strange block. We had better leave it... */
                return err;
        return 0;
}

/* Remove given block from the list of blocks with free entries */
static int remove_free_dqentry(struct file *filp, struct mem_dqinfo *info, dqbuf_t buf, uint blk)
{
        dqbuf_t tmpbuf = getdqbuf();
        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(filp, nextblk, tmpbuf)) < 0)
                        goto out_buf;
                ((struct v2_disk_dqdbheader *)tmpbuf)->dqdh_prev_free = dh->dqdh_prev_free;
                if ((err = write_blk(filp, nextblk, tmpbuf)) < 0)
                        goto out_buf;
        }
        if (prevblk) {
                if ((err = read_blk(filp, prevblk, tmpbuf)) < 0)
                        goto out_buf;
                ((struct v2_disk_dqdbheader *)tmpbuf)->dqdh_next_free = dh->dqdh_next_free;
                if ((err = write_blk(filp, prevblk, tmpbuf)) < 0)
                        goto out_buf;
        }
        else {
                info->u.v2_i.dqi_free_entry = nextblk;
                mark_info_dirty(info);
        }
        freedqbuf(tmpbuf);
        dh->dqdh_next_free = dh->dqdh_prev_free = cpu_to_le32(0);
        if (write_blk(filp, blk, buf) < 0) /* No matter whether write succeeds block is out of list */
                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 file *filp, struct mem_dqinfo *info, dqbuf_t buf, uint blk)
{
        dqbuf_t tmpbuf = getdqbuf();
        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(filp, blk, buf)) < 0)
                goto out_buf;
        if (info->u.v2_i.dqi_free_entry) {
                if ((err = read_blk(filp, 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(filp, 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(info);
        return 0;
out_buf:
        freedqbuf(tmpbuf);
        return err;
}

/* Find space for dquot */
static uint find_free_dqentry(struct dquot *dquot, int *err)
{
        struct file *filp = sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
        struct mem_dqinfo *info = sb_dqopt(dquot->dq_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(filp, blk, buf)) < 0)
                        goto out_buf;
        }
        else {
                blk = get_free_dqblk(filp, info);
                if ((int)blk < 0) {
                        *err = blk;
                        return 0;
                }
                memset(buf, 0, V2_DQBLKSIZE);
                info->u.v2_i.dqi_free_entry = blk; /* This is enough as block is already zeroed and entry list is empty... */
                mark_info_dirty(info);
        }
        if (le16_to_cpu(dh->dqdh_entries)+1 >= V2_DQSTRINBLK) /* Block will be full? */
                if ((*err = remove_free_dqentry(filp, info, 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(filp, 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 file *filp = sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
        struct mem_dqinfo *info = sb_dqopt(dquot->dq_sb)->info + dquot->dq_type;
        dqbuf_t buf;
        int ret = 0, newson = 0, newact = 0;
        u32 *ref;
        uint newblk;

        if (!(buf = getdqbuf()))
                return -ENOMEM;
        if (!*treeblk) {
                ret = get_free_dqblk(filp, info);
                if (ret < 0)
                        goto out_buf;
                *treeblk = ret;
                memset(buf, 0, V2_DQBLKSIZE);
                newact = 1;
        }
        else {
                if ((ret = read_blk(filp, *treeblk, buf)) < 0) {
                        printk(KERN_ERR "VFS: Can't read tree quota block %u.\n", *treeblk);
                        goto out_buf;
                }
        }
        ref = (u32 *)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", 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(filp, *treeblk, buf);
        }
        else if (newact && ret < 0)
                put_free_dqblk(filp, info, 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;
        struct file *filp;
        mm_segment_t fs;
        loff_t offset;
        ssize_t ret;
        struct v2_disk_dqblk ddquot;

        if (!dquot->dq_off)
                if ((ret = dq_insert_tree(dquot)) < 0) {
                        printk(KERN_ERR "VFS: Error %d occured while creating quota.\n", ret);
                        return ret;
                }
        filp = sb_dqopt(dquot->dq_sb)->files[type];
        offset = dquot->dq_off;
        mem2diskdqb(&ddquot, &dquot->dq_dqb, dquot->dq_id);
        fs = get_fs();
        set_fs(KERNEL_DS);
        ret = filp->f_op->write(filp, (char *)&ddquot, sizeof(struct v2_disk_dqblk), &offset);
        set_fs(fs);
        if (ret != sizeof(struct v2_disk_dqblk)) {
                printk(KERN_WARNING "VFS: dquota write failed on dev %s\n", kdevname(dquot->dq_dev));
                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 file *filp = sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
        struct mem_dqinfo *info = sb_dqopt(dquot->dq_sb)->info + 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(filp, 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(filp, info, buf, blk)) < 0 ||
                    (ret = put_free_dqblk(filp, info, 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(filp, info, 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(filp, 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 file *filp = sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
        struct mem_dqinfo *info = sb_dqopt(dquot->dq_sb)->info + dquot->dq_type;
        dqbuf_t buf = getdqbuf();
        int ret = 0;
        uint newblk;
        u32 *ref = (u32 *)buf;
        
        if (!buf)
                return -ENOMEM;
        if ((ret = read_blk(filp, *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? */
                if (i == V2_DQBLKSIZE) {
                        put_free_dqblk(filp, info, buf, *blk);
                        *blk = 0;
                }
                else
                        if ((ret = write_blk(filp, *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)
{
        struct file *filp = sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
        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(filp, 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)
{
        struct file *filp = sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
        dqbuf_t buf = getdqbuf();
        loff_t ret = 0;
        u32 *ref = (u32 *)buf;

        if (!buf)
                return -ENOMEM;
        if ((ret = read_blk(filp, 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;
        struct file *filp;
        mm_segment_t fs;
        loff_t offset;
        struct v2_disk_dqblk ddquot;
        int ret = 0;

        filp = sb_dqopt(dquot->dq_sb)->files[type];

#ifdef __QUOTA_V2_PARANOIA
        if (!filp || !dquot->dq_sb) { /* Invalidated quota? */
                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;
                dquot->dq_flags |= DQ_FAKE;
                memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));
                ret = offset;
        }
        else {
                dquot->dq_off = offset;
                fs = get_fs();
                set_fs(KERNEL_DS);
                if ((ret = filp->f_op->read(filp, (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;
                set_fs(fs);
                disk2memdqb(&dquot->dq_dqb, &ddquot);
        }
        dqstats.reads++;
        return ret;
}

/* Commit changes of dquot to disk - it might also mean deleting it when quota became fake one and user has no blocks... */
static int v2_commit_dquot(struct dquot *dquot)
{
        /* We clear the flag everytime so we don't loop when there was an IO error... */
        dquot->dq_flags &= ~DQ_MOD;
        if (dquot->dq_flags & DQ_FAKE && !(dquot->dq_dqb.dqb_curinodes | dquot->dq_dqb.dqb_curspace))
                return v2_delete_dquot(dquot);
        else
                return v2_write_dquot(dquot);
}

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_commit_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);
}

EXPORT_NO_SYMBOLS;

module_init(init_v2_quota_format);
module_exit(exit_v2_quota_format);
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This archive was generated by hypermail 2b29 : Tue Jul 15 2003 - 22:00:31 EST