ext4: add sanity checking to count_overhead()
[pandora-kernel.git] / fs / ext4 / ext4_jbd2.c
1 /*
2  * Interface between ext4 and JBD
3  */
4
5 #include "ext4_jbd2.h"
6
7 #include <trace/events/ext4.h>
8
9 int __ext4_journal_get_write_access(const char *where, unsigned int line,
10                                     handle_t *handle, struct buffer_head *bh)
11 {
12         int err = 0;
13
14         if (ext4_handle_valid(handle)) {
15                 err = jbd2_journal_get_write_access(handle, bh);
16                 if (err)
17                         ext4_journal_abort_handle(where, line, __func__, bh,
18                                                   handle, err);
19         }
20         return err;
21 }
22
23 /*
24  * The ext4 forget function must perform a revoke if we are freeing data
25  * which has been journaled.  Metadata (eg. indirect blocks) must be
26  * revoked in all cases.
27  *
28  * "bh" may be NULL: a metadata block may have been freed from memory
29  * but there may still be a record of it in the journal, and that record
30  * still needs to be revoked.
31  *
32  * If the handle isn't valid we're not journaling, but we still need to
33  * call into ext4_journal_revoke() to put the buffer head.
34  */
35 int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
36                   int is_metadata, struct inode *inode,
37                   struct buffer_head *bh, ext4_fsblk_t blocknr)
38 {
39         int err;
40
41         might_sleep();
42
43         trace_ext4_forget(inode, is_metadata, blocknr);
44         BUFFER_TRACE(bh, "enter");
45
46         jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
47                   "data mode %x\n",
48                   bh, is_metadata, inode->i_mode,
49                   test_opt(inode->i_sb, DATA_FLAGS));
50
51         /* In the no journal case, we can just do a bforget and return */
52         if (!ext4_handle_valid(handle)) {
53                 bforget(bh);
54                 return 0;
55         }
56
57         /* Never use the revoke function if we are doing full data
58          * journaling: there is no need to, and a V1 superblock won't
59          * support it.  Otherwise, only skip the revoke on un-journaled
60          * data blocks. */
61
62         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
63             (!is_metadata && !ext4_should_journal_data(inode))) {
64                 if (bh) {
65                         BUFFER_TRACE(bh, "call jbd2_journal_forget");
66                         err = jbd2_journal_forget(handle, bh);
67                         if (err)
68                                 ext4_journal_abort_handle(where, line, __func__,
69                                                           bh, handle, err);
70                         return err;
71                 }
72                 return 0;
73         }
74
75         /*
76          * data!=journal && (is_metadata || should_journal_data(inode))
77          */
78         BUFFER_TRACE(bh, "call jbd2_journal_revoke");
79         err = jbd2_journal_revoke(handle, blocknr, bh);
80         if (err) {
81                 ext4_journal_abort_handle(where, line, __func__,
82                                           bh, handle, err);
83                 __ext4_abort(inode->i_sb, where, line,
84                            "error %d when attempting revoke", err);
85         }
86         BUFFER_TRACE(bh, "exit");
87         return err;
88 }
89
90 int __ext4_journal_get_create_access(const char *where, unsigned int line,
91                                 handle_t *handle, struct buffer_head *bh)
92 {
93         int err = 0;
94
95         if (ext4_handle_valid(handle)) {
96                 err = jbd2_journal_get_create_access(handle, bh);
97                 if (err)
98                         ext4_journal_abort_handle(where, line, __func__,
99                                                   bh, handle, err);
100         }
101         return err;
102 }
103
104 int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
105                                  handle_t *handle, struct inode *inode,
106                                  struct buffer_head *bh)
107 {
108         int err = 0;
109
110         if (ext4_handle_valid(handle)) {
111                 err = jbd2_journal_dirty_metadata(handle, bh);
112                 /* Errors can only happen if there is a bug */
113                 if (WARN_ON_ONCE(err)) {
114                         ext4_journal_abort_handle(where, line, __func__, bh,
115                                                   handle, err);
116                         ext4_error_inode(inode, where, line,
117                                          bh->b_blocknr,
118                                          "journal_dirty_metadata failed: "
119                                          "errcode %d", err);
120                 }
121         } else {
122                 if (inode)
123                         mark_buffer_dirty_inode(bh, inode);
124                 else
125                         mark_buffer_dirty(bh);
126                 if (inode && inode_needs_sync(inode)) {
127                         sync_dirty_buffer(bh);
128                         if (buffer_req(bh) && !buffer_uptodate(bh)) {
129                                 struct ext4_super_block *es;
130
131                                 es = EXT4_SB(inode->i_sb)->s_es;
132                                 es->s_last_error_block =
133                                         cpu_to_le64(bh->b_blocknr);
134                                 ext4_error_inode(inode, where, line,
135                                                  bh->b_blocknr,
136                                         "IO error syncing itable block");
137                                 err = -EIO;
138                         }
139                 }
140         }
141         return err;
142 }
143
144 int __ext4_handle_dirty_super(const char *where, unsigned int line,
145                               handle_t *handle, struct super_block *sb)
146 {
147         struct buffer_head *bh = EXT4_SB(sb)->s_sbh;
148         int err = 0;
149
150         if (ext4_handle_valid(handle)) {
151                 err = jbd2_journal_dirty_metadata(handle, bh);
152                 if (err)
153                         ext4_journal_abort_handle(where, line, __func__,
154                                                   bh, handle, err);
155         } else
156                 sb->s_dirt = 1;
157         return err;
158 }