diff options
Diffstat (limited to 'fs/overlayfs/copy_up.c')
| -rw-r--r-- | fs/overlayfs/copy_up.c | 96 |
1 files changed, 65 insertions, 31 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index b801c6353100..9fc47c2e078d 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -24,7 +24,7 @@ static int ovl_ccup_set(const char *buf, const struct kernel_param *param) { - pr_warn("overlayfs: \"check_copy_up\" module option is obsolete\n"); + pr_warn("\"check_copy_up\" module option is obsolete\n"); return 0; } @@ -123,6 +123,9 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len) loff_t old_pos = 0; loff_t new_pos = 0; loff_t cloned; + loff_t data_pos = -1; + loff_t hole_len; + bool skip_hole = false; int error = 0; if (len == 0) @@ -144,7 +147,11 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len) goto out; /* Couldn't clone, so now we try to copy the data */ - /* FIXME: copy up sparse files efficiently */ + /* Check if lower fs supports seek operation */ + if (old_file->f_mode & FMODE_LSEEK && + old_file->f_op->llseek) + skip_hole = true; + while (len) { size_t this_len = OVL_COPY_UP_CHUNK_SIZE; long bytes; @@ -157,6 +164,36 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len) break; } + /* + * Fill zero for hole will cost unnecessary disk space + * and meanwhile slow down the copy-up speed, so we do + * an optimization for hole during copy-up, it relies + * on SEEK_DATA implementation in lower fs so if lower + * fs does not support it, copy-up will behave as before. + * + * Detail logic of hole detection as below: + * When we detect next data position is larger than current + * position we will skip that hole, otherwise we copy + * data in the size of OVL_COPY_UP_CHUNK_SIZE. Actually, + * it may not recognize all kind of holes and sometimes + * only skips partial of hole area. However, it will be + * enough for most of the use cases. + */ + + if (skip_hole && data_pos < old_pos) { + data_pos = vfs_llseek(old_file, old_pos, SEEK_DATA); + if (data_pos > old_pos) { + hole_len = data_pos - old_pos; + len -= hole_len; + old_pos = new_pos = data_pos; + continue; + } else if (data_pos == -ENXIO) { + break; + } else if (data_pos < 0) { + skip_hole = false; + } + } + bytes = do_splice_direct(old_file, &old_pos, new_file, &new_pos, this_len, SPLICE_F_MOVE); @@ -227,13 +264,17 @@ int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat) struct ovl_fh *ovl_encode_real_fh(struct dentry *real, bool is_upper) { struct ovl_fh *fh; - int fh_type, fh_len, dwords; - void *buf; + int fh_type, dwords; int buflen = MAX_HANDLE_SZ; uuid_t *uuid = &real->d_sb->s_uuid; + int err; - buf = kmalloc(buflen, GFP_KERNEL); - if (!buf) + /* Make sure the real fid stays 32bit aligned */ + BUILD_BUG_ON(OVL_FH_FID_OFFSET % 4); + BUILD_BUG_ON(MAX_HANDLE_SZ + OVL_FH_FID_OFFSET > 255); + + fh = kzalloc(buflen + OVL_FH_FID_OFFSET, GFP_KERNEL); + if (!fh) return ERR_PTR(-ENOMEM); /* @@ -242,27 +283,19 @@ struct ovl_fh *ovl_encode_real_fh(struct dentry *real, bool is_upper) * the price or reconnecting the dentry. */ dwords = buflen >> 2; - fh_type = exportfs_encode_fh(real, buf, &dwords, 0); + fh_type = exportfs_encode_fh(real, (void *)fh->fb.fid, &dwords, 0); buflen = (dwords << 2); - fh = ERR_PTR(-EIO); + err = -EIO; if (WARN_ON(fh_type < 0) || WARN_ON(buflen > MAX_HANDLE_SZ) || WARN_ON(fh_type == FILEID_INVALID)) - goto out; - - BUILD_BUG_ON(MAX_HANDLE_SZ + offsetof(struct ovl_fh, fid) > 255); - fh_len = offsetof(struct ovl_fh, fid) + buflen; - fh = kmalloc(fh_len, GFP_KERNEL); - if (!fh) { - fh = ERR_PTR(-ENOMEM); - goto out; - } + goto out_err; - fh->version = OVL_FH_VERSION; - fh->magic = OVL_FH_MAGIC; - fh->type = fh_type; - fh->flags = OVL_FH_FLAG_CPU_ENDIAN; + fh->fb.version = OVL_FH_VERSION; + fh->fb.magic = OVL_FH_MAGIC; + fh->fb.type = fh_type; + fh->fb.flags = OVL_FH_FLAG_CPU_ENDIAN; /* * When we will want to decode an overlay dentry from this handle * and all layers are on the same fs, if we get a disconncted real @@ -270,14 +303,15 @@ struct ovl_fh *ovl_encode_real_fh(struct dentry *real, bool is_upper) * it to upperdentry or to lowerstack is by checking this flag. */ if (is_upper) - fh->flags |= OVL_FH_FLAG_PATH_UPPER; - fh->len = fh_len; - fh->uuid = *uuid; - memcpy(fh->fid, buf, buflen); + fh->fb.flags |= OVL_FH_FLAG_PATH_UPPER; + fh->fb.len = sizeof(fh->fb) + buflen; + fh->fb.uuid = *uuid; -out: - kfree(buf); return fh; + +out_err: + kfree(fh); + return ERR_PTR(err); } int ovl_set_origin(struct dentry *dentry, struct dentry *lower, @@ -300,8 +334,8 @@ int ovl_set_origin(struct dentry *dentry, struct dentry *lower, /* * Do not fail when upper doesn't support xattrs. */ - err = ovl_check_setxattr(dentry, upper, OVL_XATTR_ORIGIN, fh, - fh ? fh->len : 0, 0); + err = ovl_check_setxattr(dentry, upper, OVL_XATTR_ORIGIN, fh->buf, + fh ? fh->fb.len : 0, 0); kfree(fh); return err; @@ -317,7 +351,7 @@ static int ovl_set_upper_fh(struct dentry *upper, struct dentry *index) if (IS_ERR(fh)) return PTR_ERR(fh); - err = ovl_do_setxattr(index, OVL_XATTR_UPPER, fh, fh->len, 0); + err = ovl_do_setxattr(index, OVL_XATTR_UPPER, fh->buf, fh->fb.len, 0); kfree(fh); return err; @@ -483,7 +517,7 @@ static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp) } inode_lock(temp->d_inode); - if (c->metacopy) + if (S_ISREG(c->stat.mode)) err = ovl_set_size(temp, &c->stat); if (!err) err = ovl_set_attr(temp, &c->stat); |