1 From aa282f628e4ad75eea7f8ee1b26dea920c238241 Mon Sep 17 00:00:00 2001
2 From: Shaun Tancheff <stancheff@cray.com>
3 Date: Tue, 6 Aug 2019 17:00:55 -0500
4 Subject: [PATCH] + linux-5.3/ext4-kill-dx-root
7 fs/ext4/namei.c | 111 +++++++++++++++++++++++++-----------------------
8 1 file changed, 58 insertions(+), 53 deletions(-)
10 diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
11 index a1db7ce..b0291ed 100644
14 @@ -212,22 +212,13 @@ struct dx_entry
15 * hash version mod 4 should never be 0. Sincerely, the paranoia department.
21 - struct fake_dirent dot;
23 - struct fake_dirent dotdot;
24 - char dotdot_name[4];
27 - __le32 reserved_zero;
29 - u8 info_length; /* 8 */
34 - struct dx_entry entries[0];
35 + __le32 reserved_zero;
37 + u8 info_length; /* 8 */
43 @@ -529,6 +520,16 @@ ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
44 * Future: use high four bits of block for coalesce-on-delete flags
45 * Mask them off for now.
47 +struct dx_root_info *dx_get_dx_info(struct ext4_dir_entry_2 *de)
49 + /* get dotdot first */
50 + de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(1));
52 + /* dx root info is after dotdot entry */
53 + de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(2));
55 + return (struct dx_root_info *)de;
58 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
60 @@ -753,7 +754,7 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
62 unsigned count, indirect;
63 struct dx_entry *at, *entries, *p, *q, *m;
64 - struct dx_root *root;
65 + struct dx_root_info *info;
66 struct dx_frame *frame = frame_in;
67 struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
69 @@ -762,18 +763,17 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
70 frame->bh = ext4_read_dirblock(dir, 0, INDEX);
71 if (IS_ERR(frame->bh))
72 return (struct dx_frame *) frame->bh;
74 - root = (struct dx_root *) frame->bh->b_data;
75 - if (root->info.hash_version != DX_HASH_TEA &&
76 - root->info.hash_version != DX_HASH_HALF_MD4 &&
77 - root->info.hash_version != DX_HASH_LEGACY) {
78 - ext4_warning_inode(dir, "Unrecognised inode hash code %u for directory "
79 - "%lu", root->info.hash_version, dir->i_ino);
80 + info = dx_get_dx_info((struct ext4_dir_entry_2 *)frame->bh->b_data);
81 + if (info->hash_version != DX_HASH_TEA &&
82 + info->hash_version != DX_HASH_HALF_MD4 &&
83 + info->hash_version != DX_HASH_LEGACY) {
84 + ext4_warning(dir->i_sb, "Unrecognised inode hash code %d for directory "
85 + "#%lu", info->hash_version, dir->i_ino);
89 hinfo = &fname->hinfo;
90 - hinfo->hash_version = root->info.hash_version;
91 + hinfo->hash_version = info->hash_version;
92 if (hinfo->hash_version <= DX_HASH_TEA)
93 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
94 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
95 @@ -781,13 +781,13 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
96 ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), hinfo);
99 - if (root->info.unused_flags & 1) {
100 + if (info->unused_flags & 1) {
101 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
102 - root->info.unused_flags);
103 + info->unused_flags);
107 - indirect = root->info.indirect_levels;
108 + indirect = info->indirect_levels;
109 if (indirect >= ext4_dir_htree_level(dir->i_sb)) {
110 ext4_warning(dir->i_sb,
111 "Directory (ino: %lu) htree depth %#06x exceed"
112 @@ -800,14 +800,13 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
116 - entries = (struct dx_entry *)(((char *)&root->info) +
117 - root->info.info_length);
118 + entries = (struct dx_entry *)(((char *)info) + info->info_length);
120 if (dx_get_limit(entries) != dx_root_limit(dir,
121 - root->info.info_length)) {
122 + info->info_length)) {
123 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
124 dx_get_limit(entries),
125 - dx_root_limit(dir, root->info.info_length));
126 + dx_root_limit(dir, info->info_length));
130 @@ -892,7 +891,7 @@ static void dx_release(struct dx_frame *frames)
131 if (frames[0].bh == NULL)
134 - info = &((struct dx_root *)frames[0].bh->b_data)->info;
135 + info = dx_get_dx_info((struct ext4_dir_entry_2 *)frames[0].bh->b_data);
136 /* save local copy, "info" may be freed after brelse() */
137 indirect_levels = info->indirect_levels;
138 for (i = 0; i <= indirect_levels; i++) {
139 @@ -2065,16 +2064,15 @@ static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
140 struct inode *inode, struct buffer_head *bh)
142 struct buffer_head *bh2;
143 - struct dx_root *root;
144 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
145 struct dx_entry *entries;
146 - struct ext4_dir_entry_2 *de, *de2;
147 + struct ext4_dir_entry_2 *de, *de2, *dot_de, *dotdot_de;
153 - struct fake_dirent *fde;
154 + struct dx_root_info *dx_info;
157 if (ext4_has_metadata_csum(inode->i_sb))
158 @@ -2089,18 +2087,19 @@ static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
162 - root = (struct dx_root *) bh->b_data;
164 + dot_de = (struct ext4_dir_entry_2 *)bh->b_data;
165 + dotdot_de = ext4_next_entry(dot_de, blocksize);
167 /* The 0th block becomes the root, move the dirents out */
168 - fde = &root->dotdot;
169 - de = (struct ext4_dir_entry_2 *)((char *)fde +
170 - ext4_rec_len_from_disk(fde->rec_len, blocksize));
171 - if ((char *) de >= (((char *) root) + blocksize)) {
172 + de = (struct ext4_dir_entry_2 *)((char *)dotdot_de +
173 + ext4_rec_len_from_disk(dotdot_de->rec_len, blocksize));
174 + if ((char *)de >= (((char *)dot_de) + blocksize)) {
175 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
177 return -EFSCORRUPTED;
179 - len = ((char *) root) + (blocksize - csum_size) - (char *) de;
180 + len = ((char *)dot_de) + (blocksize - csum_size) - (char *)de;
182 /* Allocate new block for the 0th block's dirents */
183 bh2 = ext4_append(handle, dir, &block);
184 @@ -2123,19 +2122,24 @@ static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
185 ext4_initialize_dirent_tail(bh2, blocksize);
187 /* Initialize the root; the dot dirents already exist */
188 - de = (struct ext4_dir_entry_2 *) (&root->dotdot);
189 - de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
191 - memset (&root->info, 0, sizeof(root->info));
192 - root->info.info_length = sizeof(root->info);
193 - root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
194 - entries = root->entries;
195 + dotdot_de->rec_len =
196 + ext4_rec_len_to_disk(blocksize - le16_to_cpu(dot_de->rec_len),
199 + /* initialize hashing info */
200 + dx_info = dx_get_dx_info(dot_de);
201 + memset(dx_info, 0, sizeof(*dx_info));
202 + dx_info->info_length = sizeof(*dx_info);
203 + dx_info->hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
205 + entries = (void *)dx_info + sizeof(*dx_info);
207 dx_set_block(entries, 1);
208 dx_set_count(entries, 1);
209 - dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
210 + dx_set_limit(entries, dx_root_limit(dir, sizeof(*dx_info)));
212 /* Initialize as for dx_probe */
213 - fname->hinfo.hash_version = root->info.hash_version;
214 + fname->hinfo.hash_version = dx_info->hash_version;
215 if (fname->hinfo.hash_version <= DX_HASH_TEA)
216 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
217 fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
218 @@ -2488,7 +2492,7 @@ again:
222 - struct dx_root *dxroot;
223 + struct dx_root_info *info;
224 memcpy((char *) entries2, (char *) entries,
225 icount * sizeof(struct dx_entry));
226 dx_set_limit(entries2, dx_node_limit(dir));
227 @@ -2496,8 +2500,9 @@ again:
229 dx_set_count(entries, 1);
230 dx_set_block(entries + 0, newblock);
231 - dxroot = (struct dx_root *)frames[0].bh->b_data;
232 - dxroot->info.indirect_levels += 1;
233 + info = dx_get_dx_info((struct ext4_dir_entry_2 *)
234 + frames[0].bh->b_data);
235 + info->indirect_levels = 1;
236 dxtrace(printk(KERN_DEBUG
237 "Creating %d level index...\n",
238 dxroot->info.indirect_levels));