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: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxxxxxx>
---
fs/nilfs2/file.c | 1 +
fs/nilfs2/inode.c | 131 +++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/nilfs2/namei.c | 1 +
fs/nilfs2/nilfs.h | 2 +
fs/nilfs2/page.c | 84 ++++++++++++++++++++++++++++++++++
fs/nilfs2/page.h | 3 +
6 files changed, 222 insertions(+), 0 deletions(-)
diff --git a/fs/nilfs2/file.c b/fs/nilfs2/file.c
index c9a30d7..2f560c9 100644
--- a/fs/nilfs2/file.c
+++ b/fs/nilfs2/file.c
@@ -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 */
diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index 7a18093..e96ef23 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -912,3 +912,134 @@ 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;
+}
diff --git a/fs/nilfs2/namei.c b/fs/nilfs2/namei.c
index 6e9557e..9803427 100644
--- a/fs/nilfs2/namei.c
+++ b/fs/nilfs2/namei.c
@@ -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 = {
diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h
index f7560da..5b10f14 100644
--- a/fs/nilfs2/nilfs.h
+++ b/fs/nilfs2/nilfs.h
@@ -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 *);
diff --git a/fs/nilfs2/page.c b/fs/nilfs2/page.c
index a6c3c2e8..48a775e 100644
--- a/fs/nilfs2/page.c
+++ b/fs/nilfs2/page.c
@@ -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;
+}
diff --git a/fs/nilfs2/page.h b/fs/nilfs2/page.h
index fb9e8a8..622df27 100644
--- a/fs/nilfs2/page.h
+++ b/fs/nilfs2/page.h
@@ -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)
--
1.7.3.2
--
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