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gfs2: Implement fallocate(FALLOC_FL_PUNCH_HOLE)

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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>
This commit is contained in:
Andreas Gruenbacher 2017-12-14 17:11:03 +01:00
parent 10d2cf94c2
commit 4e56a6411f
3 changed files with 134 additions and 8 deletions
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122
fs/gfs2/bmap.c
View File

@ -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;
}

1
fs/gfs2/bmap.h
View File

@ -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__ */

19
fs/gfs2/file.c
View File

@ -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);