static void nilfs_truncate_bmap(struct nilfs_inode_info *ii,
unsigned long from)
{
unsigned long b;
int ret;
if (!test_bit(NILFS_I_BMAP, &ii->i_state))
return;
repeat:
ret = nilfs_bmap_last_key(ii->i_bmap, &b);
if (ret == -ENOENT)
return;
else if (ret < 0)
goto failed;
if (b < from)
return;
b -= min_t(unsigned long, NILFS_MAX_TRUNCATE_BLOCKS, b - from);
ret = nilfs_bmap_truncate(ii->i_bmap, b);
nilfs_relax_pressure_in_lock(ii->vfs_inode.i_sb);
if (!ret || (ret == -ENOMEM &&
nilfs_bmap_truncate(ii->i_bmap, b) == 0))
goto repeat;
failed:
if (ret == -EINVAL)
nilfs_error(ii->vfs_inode.i_sb, __func__,
"bmap is broken (ino=%lu)", ii->vfs_inode.i_ino);
else
nilfs_warning(ii->vfs_inode.i_sb, __func__,
"failed to truncate bmap (ino=%lu, err=%d)",
ii->vfs_inode.i_ino, ret);
}
static int nilfs_bmap_convert_error(struct nilfs_bmap *bmap,
const char *fname, int err)
{
struct inode *inode = bmap->b_inode;
if (err == -EINVAL) {
nilfs_error(inode->i_sb, fname,
"broken bmap (inode number=%lu)\n", inode->i_ino);
err = -EIO;
}
return err;
}
int nilfs_ifile_get_inode_block(struct inode *ifile, ino_t ino,
struct buffer_head **out_bh)
{
struct super_block *sb = ifile->i_sb;
int err;
if (unlikely(!NILFS_VALID_INODE(sb, ino))) {
nilfs_error(sb, __func__, "bad inode number: %lu",
(unsigned long) ino);
return -EINVAL;
}
err = nilfs_palloc_get_entry_block(ifile, ino, 0, out_bh);
if (unlikely(err)) {
if (err == -EINVAL)
nilfs_error(sb, __func__, "ifile is broken");
else
nilfs_warning(sb, __func__,
"unable to read inode: %lu",
(unsigned long) ino);
}
return err;
}
int nilfs_ifile_get_inode_block(struct inode *ifile, ino_t ino,
struct buffer_head **out_bh)
{
struct super_block *sb = ifile->i_sb;
int err;
if (unlikely(!NILFS_VALID_INODE(sb, ino))) {
nilfs_error(sb, "bad inode number: %lu", (unsigned long)ino);
return -EINVAL;
}
err = nilfs_palloc_get_entry_block(ifile, ino, 0, out_bh);
if (unlikely(err))
nilfs_msg(sb, KERN_WARNING, "error %d reading inode: ino=%lu",
err, (unsigned long)ino);
return err;
}
/**
* nilfs_get_block() - get a file block on the filesystem (callback function)
* @inode - inode struct of the target file
* @blkoff - file block number
* @bh_result - buffer head to be mapped on
* @create - indicate whether allocating the block or not when it has not
* been allocated yet.
*
* This function does not issue actual read request of the specified data
* block. It is done by VFS.
*/
int nilfs_get_block(struct inode *inode, sector_t blkoff,
struct buffer_head *bh_result, int create)
{
struct nilfs_inode_info *ii = NILFS_I(inode);
__u64 blknum = 0;
int err = 0, ret;
struct inode *dat = nilfs_dat_inode(NILFS_I_NILFS(inode));
unsigned maxblocks = bh_result->b_size >> inode->i_blkbits;
down_read(&NILFS_MDT(dat)->mi_sem);
ret = nilfs_bmap_lookup_contig(ii->i_bmap, blkoff, &blknum, maxblocks);
up_read(&NILFS_MDT(dat)->mi_sem);
if (ret >= 0) { /* found */
map_bh(bh_result, inode->i_sb, blknum);
if (ret > 0)
bh_result->b_size = (ret << inode->i_blkbits);
goto out;
}
/* data block was not found */
if (ret == -ENOENT && create) {
struct nilfs_transaction_info ti;
bh_result->b_blocknr = 0;
err = nilfs_transaction_begin(inode->i_sb, &ti, 1);
if (unlikely(err))
goto out;
err = nilfs_bmap_insert(ii->i_bmap, (unsigned long)blkoff,
(unsigned long)bh_result);
if (unlikely(err != 0)) {
if (err == -EEXIST) {
/*
* The get_block() function could be called
* from multiple callers for an inode.
* However, the page having this block must
* be locked in this case.
*/
printk(KERN_WARNING
"nilfs_get_block: a race condition "
"while inserting a data block. "
"(inode number=%lu, file block "
"offset=%llu)\n",
inode->i_ino,
(unsigned long long)blkoff);
err = 0;
} else if (err == -EINVAL) {
nilfs_error(inode->i_sb, __func__,
"broken bmap (inode=%lu)\n",
inode->i_ino);
err = -EIO;
}
nilfs_transaction_abort(inode->i_sb);
goto out;
}
nilfs_transaction_commit(inode->i_sb); /* never fails */
/* Error handling should be detailed */
set_buffer_new(bh_result);
map_bh(bh_result, inode->i_sb, 0); /* dbn must be changed
to proper value */
} else if (ret == -ENOENT) {
/* not found is not error (e.g. hole); must return without
the mapped state flag. */
;
} else {
err = ret;
}
out:
return err;
}
