diff options
author | Steve French <smfrench@gmail.com> | 2014-10-18 22:01:15 (GMT) |
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committer | Steve French <steve.french@primarydata.com> | 2014-12-08 04:17:19 (GMT) |
commit | 9ccf3216238ca70c0df2ff06494fcf616b62e7dc (patch) | |
tree | b0566fd4fad70693052ceba85582208d03a00160 /fs/cifs/smb2ops.c | |
parent | b2776bf7149bddd1f4161f14f79520f17fc1d71d (diff) | |
download | linux-9ccf3216238ca70c0df2ff06494fcf616b62e7dc.tar.xz |
Add support for original fallocate
In many cases the simple fallocate call is
a no op (since the file is already not sparse) or
can simply be converted from a sparse to a non-sparse
file if we are fallocating the whole file and keeping
the size.
Signed-off-by: Steven French <smfrench@gmail.com>
Diffstat (limited to 'fs/cifs/smb2ops.c')
-rw-r--r-- | fs/cifs/smb2ops.c | 63 |
1 files changed, 62 insertions, 1 deletions
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index c5f521b..568f323 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -1102,6 +1102,64 @@ static long smb3_punch_hole(struct file *file, struct cifs_tcon *tcon, return rc; } +static long smb3_simple_falloc(struct file *file, struct cifs_tcon *tcon, + loff_t off, loff_t len, bool keep_size) +{ + struct inode *inode; + struct cifsInodeInfo *cifsi; + struct cifsFileInfo *cfile = file->private_data; + long rc = -EOPNOTSUPP; + 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; + + /* + * Files are non-sparse by default so falloc may be a no-op + * Must check if file sparse. If not sparse, and not extending + * then no need to do anything since file already allocated + */ + if ((cifsi->cifsAttrs & FILE_ATTRIBUTE_SPARSE_FILE) == 0) { + if (keep_size == true) + return 0; + /* check if extending file */ + else if (i_size_read(inode) >= off + len) + /* not extending file and already not sparse */ + return 0; + /* BB: in future add else clause to extend file */ + else + return -EOPNOTSUPP; + } + + if ((keep_size == true) || (i_size_read(inode) >= off + len)) { + /* + * Check if falloc starts within first few pages of file + * and ends within a few pages of the end of file to + * ensure that most of file is being forced to be + * fallocated now. If so then setting whole file sparse + * ie potentially making a few extra pages at the beginning + * or end of the file non-sparse via set_sparse is harmless. + */ + if ((off > 8192) || (off + len + 8192 < i_size_read(inode))) + return -EOPNOTSUPP; + + rc = smb2_set_sparse(xid, tcon, cfile, inode, false); + } + /* BB: else ... in future add code to extend file and set sparse */ + + + free_xid(xid); + return rc; +} + + static long smb3_fallocate(struct file *file, struct cifs_tcon *tcon, int mode, loff_t off, loff_t len) { @@ -1112,7 +1170,10 @@ static long smb3_fallocate(struct file *file, struct cifs_tcon *tcon, int mode, if (mode & FALLOC_FL_KEEP_SIZE) return smb3_zero_range(file, tcon, off, len, true); return smb3_zero_range(file, tcon, off, len, false); - } + } else if (mode == FALLOC_FL_KEEP_SIZE) + return smb3_simple_falloc(file, tcon, off, len, true); + else if (mode == 0) + return smb3_simple_falloc(file, tcon, off, len, false); return -EOPNOTSUPP; } |