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[SMB3] Enable fallocate -z support for SMB3 mounts

fallocate -z (FALLOC_FL_ZERO_RANGE) can map to SMB3
FSCTL_SET_ZERO_DATA SMB3 FSCTL but FALLOC_FL_ZERO_RANGE
when called without the FALLOC_FL_KEEPSIZE flag set could want
the file size changed so we can not support that subcase unless
the file is cached (and thus we know the file size).

Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org>
This commit is contained in:
Steve French 2014-08-17 18:16:40 -05:00
parent 31742c5a33
commit 30175628bf

View File

@ -1015,6 +1015,56 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon,
return rc;
}
static long smb3_zero_range(struct file *file, struct cifs_tcon *tcon,
loff_t offset, loff_t len, bool keep_size)
{
struct inode *inode;
struct cifsInodeInfo *cifsi;
struct cifsFileInfo *cfile = file->private_data;
struct file_zero_data_information fsctl_buf;
long rc;
unsigned int xid;
xid = get_xid();
inode = cfile->dentry->d_inode;
cifsi = CIFS_I(inode);
/* if file not oplocked can't be sure whether asking to extend size */
if (!CIFS_CACHE_READ(cifsi))
if (keep_size == false)
return -EOPNOTSUPP;
/*
* Must check if file sparse since fallocate -z (zero range) assumes
* non-sparse allocation
*/
if (!(cifsi->cifsAttrs & FILE_ATTRIBUTE_SPARSE_FILE))
return -EOPNOTSUPP;
/*
* need to make sure we are not asked to extend the file since the SMB3
* fsctl does not change the file size. In the future we could change
* this to zero the first part of the range then set the file size
* which for a non sparse file would zero the newly extended range
*/
if (keep_size == false)
if (i_size_read(inode) < offset + len)
return -EOPNOTSUPP;
cifs_dbg(FYI, "offset %lld len %lld", offset, len);
fsctl_buf.FileOffset = cpu_to_le64(offset);
fsctl_buf.BeyondFinalZero = cpu_to_le64(offset + len);
rc = SMB2_ioctl(xid, tcon, cfile->fid.persistent_fid,
cfile->fid.volatile_fid, FSCTL_SET_ZERO_DATA,
true /* is_fctl */, (char *)&fsctl_buf,
sizeof(struct file_zero_data_information), NULL, NULL);
free_xid(xid);
return rc;
}
static long smb3_punch_hole(struct file *file, struct cifs_tcon *tcon,
loff_t offset, loff_t len)
{
@ -1055,6 +1105,11 @@ static long smb3_fallocate(struct file *file, struct cifs_tcon *tcon, int mode,
/* KEEP_SIZE already checked for by do_fallocate */
if (mode & FALLOC_FL_PUNCH_HOLE)
return smb3_punch_hole(file, tcon, off, len);
else if (mode & FALLOC_FL_ZERO_RANGE) {
if (mode & FALLOC_FL_KEEP_SIZE)
return smb3_zero_range(file, tcon, off, len, true);
return smb3_zero_range(file, tcon, off, len, false);
}
return -EOPNOTSUPP;
}