fs/ntfs3: Refactoring of ntfs_set_ea

Make code more readable.
Don't try to read zero bytes.
Add warning when size of exteneded attribute exceeds limit.

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

diff --git a/fs/ntfs3/xattr.c b/fs/ntfs3/xattr.c
index 29f571b..cdc0187 100644 (file)
--- a/fs/ntfs3/xattr.c
+++ b/fs/ntfs3/xattr.c
@@ -75,6 +75,7 @@ static int ntfs_read_ea(struct ntfs_inode *ni, struct EA_FULL **ea,
                        size_t add_bytes, const struct EA_INFO **info)
 {
        int err;
+       struct ntfs_sb_info *sbi = ni->mi.sbi;
        struct ATTR_LIST_ENTRY *le = NULL;
        struct ATTRIB *attr_info, *attr_ea;
        void *ea_p;
@@ -99,10 +100,10 @@ static int ntfs_read_ea(struct ntfs_inode *ni, struct EA_FULL **ea,
 
        /* Check Ea limit. */
        size = le32_to_cpu((*info)->size);
-       if (size > ni->mi.sbi->ea_max_size)
+       if (size > sbi->ea_max_size)
                return -EFBIG;
 
-       if (attr_size(attr_ea) > ni->mi.sbi->ea_max_size)
+       if (attr_size(attr_ea) > sbi->ea_max_size)
                return -EFBIG;
 
        /* Allocate memory for packed Ea. */
@@ -110,15 +111,16 @@ static int ntfs_read_ea(struct ntfs_inode *ni, struct EA_FULL **ea,
        if (!ea_p)
                return -ENOMEM;
 
-       if (attr_ea->non_res) {
+       if (!size) {
+               ;
+       } else if (attr_ea->non_res) {
                struct runs_tree run;
 
                run_init(&run);
 
                err = attr_load_runs(attr_ea, ni, &run, NULL);
                if (!err)
-                       err = ntfs_read_run_nb(ni->mi.sbi, &run, 0, ea_p, size,
-                                              NULL);
+                       err = ntfs_read_run_nb(sbi, &run, 0, ea_p, size, NULL);
                run_close(&run);
 
                if (err)
@@ -366,21 +368,22 @@ static noinline int ntfs_set_ea(struct inode *inode, const char *name,
        new_ea->name[name_len] = 0;
        memcpy(new_ea->name + name_len + 1, value, val_size);
        new_pack = le16_to_cpu(ea_info.size_pack) + packed_ea_size(new_ea);
-
-       /* Should fit into 16 bits. */
-       if (new_pack > 0xffff) {
-               err = -EFBIG; // -EINVAL?
-               goto out;
-       }
        ea_info.size_pack = cpu_to_le16(new_pack);
-
        /* New size of ATTR_EA. */
        size += add;
-       if (size > sbi->ea_max_size) {
+       ea_info.size = cpu_to_le32(size);
+
+       /*
+        * 1. Check ea_info.size_pack for overflow.
+        * 2. New attibute size must fit value from $AttrDef
+        */
+       if (new_pack > 0xffff || size > sbi->ea_max_size) {
+               ntfs_inode_warn(
+                       inode,
+                       "The size of extended attributes must not exceed 64KiB");
                err = -EFBIG; // -EINVAL?
                goto out;
        }
-       ea_info.size = cpu_to_le32(size);
 
 update_ea: