| Message ID | 20180614151236.26814-4-rgoldwyn@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Very interesting patch, but as I was looking at this, it brought up a key missing feature in cifs.ko. Looking at generic_file_llseek (which many fs end up calling) - seek hole returns the end of file. Looks like I need to see if I can code SEEK_HOLE support in cifs, at least for SMB3 (and also need to add .fiemap while I am at it - the protocol supports it). On Thu, Jun 14, 2018 at 10:14 AM Goldwyn Rodrigues <rgoldwyn@suse.de> wrote: > > From: Goldwyn Rodrigues <rgoldwyn@suse.com> > > copy_file_range calls do_splice_direct() if fs->clone_file_range > or fs->copy_file_range() is not available. However, do_splice_direct() > converts holes to zeros. Detect holes in the file_in range, and > create them in the corresponding file_out range. > > If there is already data present at the offset in file_out, attempt > to punch a hole there. If the operation is not supported, fall > back to performing splice on the whole range. > > Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> > Reviewed-by: Amir Goldstein <amir73il@gmail.com> > --- > fs/read_write.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++++---- > 1 file changed, 56 insertions(+), 4 deletions(-) > > diff --git a/fs/read_write.c b/fs/read_write.c > index 1b8fc9eada69..3c6a13101e6e 100644 > --- a/fs/read_write.c > +++ b/fs/read_write.c > @@ -20,6 +20,7 @@ > #include <linux/compat.h> > #include <linux/mount.h> > #include <linux/fs.h> > +#include <linux/falloc.h> > #include "internal.h" > > #include <linux/uaccess.h> > @@ -1547,7 +1548,8 @@ static ssize_t do_copy_file_range(struct file *file_in, loff_t pos_in, > { > struct inode *inode_in = file_inode(file_in); > struct inode *inode_out = file_inode(file_out); > - ssize_t ret = 0; > + ssize_t ret = 0, total = 0; > + loff_t size, end; > > if (len == 0) > return 0; > @@ -1572,10 +1574,60 @@ static ssize_t do_copy_file_range(struct file *file_in, loff_t pos_in, > if (ret != -EOPNOTSUPP) > return ret; > } > + > splice: > - ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out, > - len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0); > - return ret; > + while (total < len) { > + end = vfs_llseek(file_in, pos_in, SEEK_HOLE); > + > + /* Starting position is already in a hole */ > + if (end == pos_in) > + goto hole; > + size = end - pos_in; > +do_splice: > + if (size > len - total) > + size = len - total; > + ret = do_splice_direct(file_in, &pos_in, file_out, > + &pos_out, size, 0); > + if (ret < 0) > + goto out; > + total += ret; > + if (total == len) > + break; > +hole: > + end = vfs_llseek(file_in, pos_in, SEEK_DATA); > + if (end < 0) { > + ret = end; > + goto out; > + } > + size = end - pos_in; > + if (size > len - total) > + size = len - total; > + /* Data on offset, punch holes */ > + if (size && (i_size_read(file_out->f_inode) > pos_out)) { > + int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE; > + ret = -EOPNOTSUPP; > + if (file_out->f_op->fallocate) > + ret = file_out->f_op->fallocate(file_out, mode, > + pos_out, size); > + if (ret < 0) { > + /* > + * The filesystem does not support punching > + * holes. Perform splice on the remaining range. > + */ > + if (ret == -EOPNOTSUPP) { > + size = len - total; > + goto do_splice; > + } > + goto out; > + } > + } > + pos_out += size; > + pos_in = end; > + total += size; > + } > + > +out: > + return total ? total : ret; > } > > /* > -- > 2.16.3 >
diff --git a/fs/read_write.c b/fs/read_write.c index 1b8fc9eada69..3c6a13101e6e 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -20,6 +20,7 @@ #include <linux/compat.h> #include <linux/mount.h> #include <linux/fs.h> +#include <linux/falloc.h> #include "internal.h" #include <linux/uaccess.h> @@ -1547,7 +1548,8 @@ static ssize_t do_copy_file_range(struct file *file_in, loff_t pos_in, { struct inode *inode_in = file_inode(file_in); struct inode *inode_out = file_inode(file_out); - ssize_t ret = 0; + ssize_t ret = 0, total = 0; + loff_t size, end; if (len == 0) return 0; @@ -1572,10 +1574,60 @@ static ssize_t do_copy_file_range(struct file *file_in, loff_t pos_in, if (ret != -EOPNOTSUPP) return ret; } + splice: - ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out, - len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0); - return ret; + while (total < len) { + end = vfs_llseek(file_in, pos_in, SEEK_HOLE); + + /* Starting position is already in a hole */ + if (end == pos_in) + goto hole; + size = end - pos_in; +do_splice: + if (size > len - total) + size = len - total; + ret = do_splice_direct(file_in, &pos_in, file_out, + &pos_out, size, 0); + if (ret < 0) + goto out; + total += ret; + if (total == len) + break; +hole: + end = vfs_llseek(file_in, pos_in, SEEK_DATA); + if (end < 0) { + ret = end; + goto out; + } + size = end - pos_in; + if (size > len - total) + size = len - total; + /* Data on offset, punch holes */ + if (size && (i_size_read(file_out->f_inode) > pos_out)) { + int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE; + ret = -EOPNOTSUPP; + if (file_out->f_op->fallocate) + ret = file_out->f_op->fallocate(file_out, mode, + pos_out, size); + if (ret < 0) { + /* + * The filesystem does not support punching + * holes. Perform splice on the remaining range. + */ + if (ret == -EOPNOTSUPP) { + size = len - total; + goto do_splice; + } + goto out; + } + } + pos_out += size; + pos_in = end; + total += size; + } + +out: + return total ? total : ret; } /*