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);
struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
__u64 blknum = 0;
int err = 0, ret;
unsigned maxblocks = bh_result->b_size >> inode->i_blkbits;
down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
ret = nilfs_bmap_lookup_contig(ii->i_bmap, blkoff, &blknum, maxblocks);
up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
if (ret >= 0) {
map_bh(bh_result, inode->i_sb, blknum);
if (ret > 0)
bh_result->b_size = (ret << inode->i_blkbits);
goto out;
}
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) {
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;
}
nilfs_transaction_abort(inode->i_sb);
goto out;
}
nilfs_mark_inode_dirty(inode);
nilfs_transaction_commit(inode->i_sb);
set_buffer_new(bh_result);
set_buffer_delay(bh_result);
map_bh(bh_result, inode->i_sb, 0);
} else if (ret == -ENOENT) {
;
} else {
err = ret;
}
out:
return err;
}
int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
__u64 start, __u64 len)
{
struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
__u64 logical = 0, phys = 0, size = 0;
__u32 flags = 0;
loff_t isize;
sector_t blkoff, end_blkoff;
sector_t delalloc_blkoff;
unsigned long delalloc_blklen;
unsigned int blkbits = inode->i_blkbits;
int ret, n;
ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
if (ret)
return ret;
mutex_lock(&inode->i_mutex);
isize = i_size_read(inode);
blkoff = start >> blkbits;
end_blkoff = (start + len - 1) >> blkbits;
delalloc_blklen = nilfs_find_uncommitted_extent(inode, blkoff,
&delalloc_blkoff);
do {
__u64 blkphy;
unsigned int maxblocks;
if (delalloc_blklen && blkoff == delalloc_blkoff) {
if (size) {
/* End of the current extent */
ret = fiemap_fill_next_extent(
fieinfo, logical, phys, size, flags);
if (ret)
break;
}
if (blkoff > end_blkoff)
break;
flags = FIEMAP_EXTENT_MERGED | FIEMAP_EXTENT_DELALLOC;
logical = blkoff << blkbits;
phys = 0;
size = delalloc_blklen << blkbits;
blkoff = delalloc_blkoff + delalloc_blklen;
delalloc_blklen = nilfs_find_uncommitted_extent(
inode, blkoff, &delalloc_blkoff);
continue;
}
/*
* Limit the number of blocks that we look up so as
* not to get into the next delayed allocation extent.
*/
maxblocks = INT_MAX;
if (delalloc_blklen)
maxblocks = min_t(sector_t, delalloc_blkoff - blkoff,
maxblocks);
blkphy = 0;
down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
n = nilfs_bmap_lookup_contig(
NILFS_I(inode)->i_bmap, blkoff, &blkphy, maxblocks);
up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
if (n < 0) {
int past_eof;
if (unlikely(n != -ENOENT))
break; /* error */
/* HOLE */
blkoff++;
past_eof = ((blkoff << blkbits) >= isize);
if (size) {
/* End of the current extent */
if (past_eof)
flags |= FIEMAP_EXTENT_LAST;
ret = fiemap_fill_next_extent(
fieinfo, logical, phys, size, flags);
if (ret)
break;
size = 0;
}
if (blkoff > end_blkoff || past_eof)
break;
} else {
if (size) {
if (phys && blkphy << blkbits == phys + size) {
/* The current extent goes on */
size += n << blkbits;
} else {
/* Terminate the current extent */
ret = fiemap_fill_next_extent(
fieinfo, logical, phys, size,
flags);
if (ret || blkoff > end_blkoff)
break;
/* Start another extent */
flags = FIEMAP_EXTENT_MERGED;
logical = blkoff << blkbits;
phys = blkphy << blkbits;
size = n << blkbits;
}
} else {
/* Start a new extent */
flags = FIEMAP_EXTENT_MERGED;
logical = blkoff << blkbits;
phys = blkphy << blkbits;
size = n << blkbits;
}
blkoff += n;
}
cond_resched();
} while (true);
/* If ret is 1 then we just hit the end of the extent array */
if (ret == 1)
ret = 0;
mutex_unlock(&inode->i_mutex);
return ret;
}
/**
* 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);
struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
__u64 blknum = 0;
int err = 0, ret;
unsigned maxblocks = bh_result->b_size >> inode->i_blkbits;
down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
ret = nilfs_bmap_lookup_contig(ii->i_bmap, blkoff, &blknum, maxblocks);
up_read(&NILFS_MDT(nilfs->ns_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;
}
nilfs_transaction_abort(inode->i_sb);
goto out;
}
nilfs_mark_inode_dirty(inode);
nilfs_transaction_commit(inode->i_sb); /* never fails */
/* Error handling should be detailed */
set_buffer_new(bh_result);
set_buffer_delay(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;
}