Commit 622daaff authored by Ryusuke Konishi's avatar Ryusuke Konishi
Browse files

nilfs2: fiemap support



This adds fiemap to nilfs.  Two new functions, nilfs_fiemap and
nilfs_find_uncommitted_extent are added.

nilfs_fiemap() implements the fiemap inode operation, and
nilfs_find_uncommitted_extent() helps to get a range of data blocks
whose physical location has not been determined.

nilfs_fiemap() collects extent information by looping through
nilfs_bmap_lookup_contig and nilfs_find_uncommitted_extent routines.
Signed-off-by: default avatarRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
parent 27e6c7a3
......@@ -155,6 +155,7 @@ const struct inode_operations nilfs_file_inode_operations = {
.truncate = nilfs_truncate,
.setattr = nilfs_setattr,
.permission = nilfs_permission,
.fiemap = nilfs_fiemap,
};
/* end of file */
......@@ -916,3 +916,134 @@ void nilfs_dirty_inode(struct inode *inode)
nilfs_mark_inode_dirty(inode);
nilfs_transaction_commit(inode->i_sb); /* never fails */
}
int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
__u64 start, __u64 len)
{
struct the_nilfs *nilfs = NILFS_I_NILFS(inode);
__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;
}
......@@ -577,6 +577,7 @@ const struct inode_operations nilfs_dir_inode_operations = {
.rename = nilfs_rename,
.setattr = nilfs_setattr,
.permission = nilfs_permission,
.fiemap = nilfs_fiemap,
};
const struct inode_operations nilfs_special_inode_operations = {
......
......@@ -264,6 +264,8 @@ extern int nilfs_set_file_dirty(struct nilfs_sb_info *, struct inode *,
unsigned);
extern int nilfs_mark_inode_dirty(struct inode *);
extern void nilfs_dirty_inode(struct inode *);
int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
__u64 start, __u64 len);
/* super.c */
extern struct inode *nilfs_alloc_inode(struct super_block *);
......
......@@ -546,3 +546,87 @@ int __nilfs_clear_page_dirty(struct page *page)
}
return TestClearPageDirty(page);
}
/**
* nilfs_find_uncommitted_extent - find extent of uncommitted data
* @inode: inode
* @start_blk: start block offset (in)
* @blkoff: start offset of the found extent (out)
*
* This function searches an extent of buffers marked "delayed" which
* starts from a block offset equal to or larger than @start_blk. If
* such an extent was found, this will store the start offset in
* @blkoff and return its length in blocks. Otherwise, zero is
* returned.
*/
unsigned long nilfs_find_uncommitted_extent(struct inode *inode,
sector_t start_blk,
sector_t *blkoff)
{
unsigned int i;
pgoff_t index;
unsigned int nblocks_in_page;
unsigned long length = 0;
sector_t b;
struct pagevec pvec;
struct page *page;
if (inode->i_mapping->nrpages == 0)
return 0;
index = start_blk >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
nblocks_in_page = 1U << (PAGE_CACHE_SHIFT - inode->i_blkbits);
pagevec_init(&pvec, 0);
repeat:
pvec.nr = find_get_pages_contig(inode->i_mapping, index, PAGEVEC_SIZE,
pvec.pages);
if (pvec.nr == 0)
return length;
if (length > 0 && pvec.pages[0]->index > index)
goto out;
b = pvec.pages[0]->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
i = 0;
do {
page = pvec.pages[i];
lock_page(page);
if (page_has_buffers(page)) {
struct buffer_head *bh, *head;
bh = head = page_buffers(page);
do {
if (b < start_blk)
continue;
if (buffer_delay(bh)) {
if (length == 0)
*blkoff = b;
length++;
} else if (length > 0) {
goto out_locked;
}
} while (++b, bh = bh->b_this_page, bh != head);
} else {
if (length > 0)
goto out_locked;
b += nblocks_in_page;
}
unlock_page(page);
} while (++i < pagevec_count(&pvec));
index = page->index + 1;
pagevec_release(&pvec);
cond_resched();
goto repeat;
out_locked:
unlock_page(page);
out:
pagevec_release(&pvec);
return length;
}
......@@ -66,6 +66,9 @@ void nilfs_mapping_init(struct address_space *mapping,
struct backing_dev_info *bdi,
const struct address_space_operations *aops);
unsigned nilfs_page_count_clean_buffers(struct page *, unsigned, unsigned);
unsigned long nilfs_find_uncommitted_extent(struct inode *inode,
sector_t start_blk,
sector_t *blkoff);
#define NILFS_PAGE_BUG(page, m, a...) \
do { nilfs_page_bug(page); BUG(); } while (0)
......
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