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authorAndreas Gruenbacher <agruenba@redhat.com>2017-12-14 19:11:03 +0300
committerAndreas Gruenbacher <agruenba@redhat.com>2018-01-18 23:15:58 +0300
commit4e56a6411fbce6f859566e17298114c2434391a4 (patch)
tree9619a913d0176f33b2dae824439a94e74cf50693 /fs/gfs2/bmap.c
parent10d2cf94c23d48ef1b141084216e7580011e4790 (diff)
downloadlinux-4e56a6411fbce6f859566e17298114c2434391a4.tar.xz
gfs2: Implement fallocate(FALLOC_FL_PUNCH_HOLE)
Implement the top-level bits of punching a hole into a file. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Diffstat (limited to 'fs/gfs2/bmap.c')
-rw-r--r--fs/gfs2/bmap.c122
1 files changed, 121 insertions, 1 deletions
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index f6dbd2f400cc..2ec11981e694 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -1351,7 +1351,7 @@ static int punch_hole(struct gfs2_inode *ip, u64 offset, u64 length)
u64 lblock = (offset + (1 << bsize_shift) - 1) >> bsize_shift;
__u16 start_list[GFS2_MAX_META_HEIGHT];
__u16 __end_list[GFS2_MAX_META_HEIGHT], *end_list = NULL;
- unsigned int start_aligned, end_aligned;
+ unsigned int start_aligned, uninitialized_var(end_aligned);
unsigned int strip_h = ip->i_height - 1;
u32 btotal = 0;
int ret, state;
@@ -1956,3 +1956,123 @@ 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;
+
+ tr = current->journal_info;
+ if (!test_bit(TR_TOUCHED, &tr->tr_flags))
+ 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);
+
+out:
+ if (current->journal_info)
+ gfs2_trans_end(sdp);
+ return error;
+}