Implement the top-level bits of punching a hole into a file.
Signed-off-by: Andreas Gruenbacher <[email protected]>
---
fs/gfs2/bmap.c | 124 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/gfs2/bmap.h | 1 +
fs/gfs2/file.c | 19 +++++----
3 files changed, 137 insertions(+), 7 deletions(-)
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index da7e04b9973e..819e86a73560 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -1956,3 +1956,127 @@ int gfs2_write_alloc_required(struct gfs2_inode *ip,
u64 offset,
return 0;
}
+static int stuffed_zero_range(struct inode *inode, loff_t offset, loff_t
length)
+{
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct buffer_head *dibh;
+ int error;
+
+ if (offset >= inode->i_size)
+ return 0;
+ if (offset + length > inode->i_size)
+ length = inode->i_size - offset;
+
+ error = gfs2_meta_inode_buffer(ip, &dibh);
+ if (error)
+ return error;
+ gfs2_trans_add_meta(ip->i_gl, dibh);
+ memset(dibh->b_data + sizeof(struct gfs2_dinode) + offset, 0,
+ length);
+ brelse(dibh);
+ return 0;
+}
+
+static int gfs2_journaled_truncate_range(struct inode *inode, loff_t offset,
+ loff_t length)
+{
+ struct gfs2_sbd *sdp = GFS2_SB(inode);
+ loff_t max_chunk = GFS2_JTRUNC_REVOKES * sdp->sd_vfs->s_blocksize;
+ int error;
+
+ while (length) {
+ struct gfs2_trans *tr;
+ loff_t chunk;
+ unsigned int offs;
+
+ chunk = length;
+ if (chunk > max_chunk)
+ chunk = max_chunk;
+
+ offs = offset & ~PAGE_MASK;
+ if (offs && chunk > PAGE_SIZE)
+ chunk = offs + ((chunk - offs) & PAGE_MASK);
+
+ truncate_pagecache_range(inode, offset, chunk);
+ offset += chunk;
+ length -= chunk;
+
+ /* XXX Is this check sufficient? */
+ tr = current->journal_info;
+ if (!tr->tr_num_revoke)
+ continue;
+
+ gfs2_trans_end(sdp);
+ error = gfs2_trans_begin(sdp, RES_DINODE, GFS2_JTRUNC_REVOKES);
+ if (error)
+ return error;
+ }
+ return 0;
+}
+
+int __gfs2_punch_hole(struct file *file, loff_t offset, loff_t length)
+{
+ struct inode *inode = file_inode(file);
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_sbd *sdp = GFS2_SB(inode);
+ int error;
+
+ if (gfs2_is_jdata(ip))
+ error = gfs2_trans_begin(sdp, RES_DINODE + 2 * RES_JDATA,
+ GFS2_JTRUNC_REVOKES);
+ else
+ error = gfs2_trans_begin(sdp, RES_DINODE, 0);
+ if (error)
+ return error;
+
+ if (gfs2_is_stuffed(ip)) {
+ error = stuffed_zero_range(inode, offset, length);
+ if (error)
+ goto out;
+ } else {
+ unsigned int start_off, end_off, blocksize;
+
+ blocksize = i_blocksize(inode);
+ start_off = offset & (blocksize - 1);
+ end_off = (offset + length) & (blocksize - 1);
+ if (start_off) {
+ unsigned int len = length;
+ if (length > blocksize - start_off)
+ len = blocksize - start_off;
+ error = gfs2_block_zero_range(inode, offset, len);
+ if (error)
+ goto out;
+ if (start_off + length < blocksize)
+ end_off = 0;
+ }
+ if (end_off) {
+ error = gfs2_block_zero_range(inode,
+ offset + length - end_off, end_off);
+ if (error)
+ goto out;
+ }
+ }
+
+ if (gfs2_is_jdata(ip)) {
+ BUG_ON(!current->journal_info);
+ gfs2_journaled_truncate_range(inode, offset, length);
+ } else
+ truncate_pagecache_range(inode, offset, offset + length - 1);
+
+ file_update_time(file);
+ mark_inode_dirty(inode);
+
+ if (current->journal_info)
+ gfs2_trans_end(sdp);
+
+ if (!gfs2_is_stuffed(ip)) {
+ error = punch_hole(ip, offset, length);
+ if (error)
+ goto out;
+ }
+
+out:
+ if (current->journal_info)
+ gfs2_trans_end(sdp);
+ return error;
+}
diff --git a/fs/gfs2/bmap.h b/fs/gfs2/bmap.h
index 443cc182cf18..c3402fe00653 100644
--- a/fs/gfs2/bmap.h
+++ b/fs/gfs2/bmap.h
@@ -61,5 +61,6 @@ extern int gfs2_write_alloc_required(struct gfs2_inode *ip,
u64 offset,
unsigned int len);
extern int gfs2_map_journal_extents(struct gfs2_sbd *sdp, struct gfs2_jdesc
*jd);
extern void gfs2_free_journal_extents(struct gfs2_jdesc *jd);
+extern int __gfs2_punch_hole(struct file *file, loff_t offset, loff_t length);
#endif /* __BMAP_DOT_H__ */
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 58705ef8643a..bd60dc682676 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -924,7 +924,7 @@ static long gfs2_fallocate(struct file *file, int mode,
loff_t offset, loff_t le
struct gfs2_holder gh;
int ret;
- if (mode & ~FALLOC_FL_KEEP_SIZE)
+ if (mode & ~(FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE))
return -EOPNOTSUPP;
/* fallocate is needed by gfs2_grow to reserve space in the rindex */
if (gfs2_is_jdata(ip) && inode != sdp->sd_rindex)
@@ -948,13 +948,18 @@ static long gfs2_fallocate(struct file *file, int mode,
loff_t offset, loff_t le
if (ret)
goto out_unlock;
- ret = gfs2_rsqa_alloc(ip);
- if (ret)
- goto out_putw;
+ if (mode & FALLOC_FL_PUNCH_HOLE) {
+ ret = __gfs2_punch_hole(file, offset, len);
+ } else {
+ ret = gfs2_rsqa_alloc(ip);
+ if (ret)
+ goto out_putw;
- ret = __gfs2_fallocate(file, mode, offset, len);
- if (ret)
- gfs2_rs_deltree(&ip->i_res);
+ ret = __gfs2_fallocate(file, mode, offset, len);
+
+ if (ret)
+ gfs2_rs_deltree(&ip->i_res);
+ }
out_putw:
put_write_access(inode);
--
2.14.3
