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authorAmir Goldstein <amir73il@gmail.com>2019-11-15 13:33:04 +0200
committerMiklos Szeredi <mszeredi@redhat.com>2019-12-10 16:00:55 +0100
commitec7bbb53d339250df7d4b042ff93c468535c0a90 (patch)
tree32152e73d4bc54dadf062f7c11f91ab060a382d6 /fs/overlayfs/copy_up.c
parentcbe7fba8edfc8cb8e621599e376f8ac5c224fa72 (diff)
downloadlinux-ec7bbb53d339250df7d4b042ff93c468535c0a90.tar.bz2
ovl: don't use a temp buf for encoding real fh
We can allocate maximum fh size and encode into it directly. Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs/copy_up.c')
-rw-r--r--fs/overlayfs/copy_up.c37
1 files changed, 16 insertions, 21 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 7f744a9541e5..6220642fe113 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -227,13 +227,17 @@ 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);
/*
@@ -242,24 +246,14 @@ 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;
-
- /* 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_len = OVL_FH_FID_OFFSET + buflen;
- fh = kzalloc(fh_len, GFP_KERNEL);
- if (!fh) {
- fh = ERR_PTR(-ENOMEM);
- goto out;
- }
+ goto out_err;
fh->fb.version = OVL_FH_VERSION;
fh->fb.magic = OVL_FH_MAGIC;
@@ -273,13 +267,14 @@ struct ovl_fh *ovl_encode_real_fh(struct dentry *real, bool is_upper)
*/
if (is_upper)
fh->fb.flags |= OVL_FH_FLAG_PATH_UPPER;
- fh->fb.len = fh_len - OVL_FH_WIRE_OFFSET;
+ fh->fb.len = sizeof(fh->fb) + buflen;
fh->fb.uuid = *uuid;
- memcpy(fh->fb.fid, buf, buflen);
-out:
- kfree(buf);
return fh;
+
+out_err:
+ kfree(fh);
+ return ERR_PTR(err);
}
int ovl_set_origin(struct dentry *dentry, struct dentry *lower,