1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
From: Thomas Gleixner <tglx@linutronix.de>
Date: Fri, 18 Mar 2011 09:18:52 +0100
Subject: [PATCH 066/354] buffer_head: Replace bh_uptodate_lock for -rt
Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=83ae2e10f64a4ae559245504a71b2afe93d86254
Wrap the bit_spin_lock calls into a separate inline and add the RT
replacements with a real spinlock.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
fs/buffer.c | 21 +++++++--------------
fs/ext4/page-io.c | 6 ++----
fs/ntfs/aops.c | 10 +++-------
include/linux/buffer_head.h | 34 ++++++++++++++++++++++++++++++++++
4 files changed, 46 insertions(+), 25 deletions(-)
diff --git a/fs/buffer.c b/fs/buffer.c
index 5bc0877f223f..85ce01feffe9 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -274,8 +274,7 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate)
* decide that the page is now completely done.
*/
first = page_buffers(page);
- local_irq_save(flags);
- bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
+ flags = bh_uptodate_lock_irqsave(first);
clear_buffer_async_read(bh);
unlock_buffer(bh);
tmp = bh;
@@ -288,8 +287,7 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate)
}
tmp = tmp->b_this_page;
} while (tmp != bh);
- bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
- local_irq_restore(flags);
+ bh_uptodate_unlock_irqrestore(first, flags);
/*
* If none of the buffers had errors and they are all
@@ -301,9 +299,7 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate)
return;
still_busy:
- bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
- local_irq_restore(flags);
- return;
+ bh_uptodate_unlock_irqrestore(first, flags);
}
/*
@@ -330,8 +326,7 @@ void end_buffer_async_write(struct buffer_head *bh, int uptodate)
}
first = page_buffers(page);
- local_irq_save(flags);
- bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
+ flags = bh_uptodate_lock_irqsave(first);
clear_buffer_async_write(bh);
unlock_buffer(bh);
@@ -343,15 +338,12 @@ void end_buffer_async_write(struct buffer_head *bh, int uptodate)
}
tmp = tmp->b_this_page;
}
- bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
- local_irq_restore(flags);
+ bh_uptodate_unlock_irqrestore(first, flags);
end_page_writeback(page);
return;
still_busy:
- bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
- local_irq_restore(flags);
- return;
+ bh_uptodate_unlock_irqrestore(first, flags);
}
EXPORT_SYMBOL(end_buffer_async_write);
@@ -3372,6 +3364,7 @@ struct buffer_head *alloc_buffer_head(gfp_t gfp_flags)
struct buffer_head *ret = kmem_cache_zalloc(bh_cachep, gfp_flags);
if (ret) {
INIT_LIST_HEAD(&ret->b_assoc_buffers);
+ buffer_head_init_locks(ret);
preempt_disable();
__this_cpu_inc(bh_accounting.nr);
recalc_bh_state();
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index bf910f266469..391308566035 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -95,8 +95,7 @@ static void ext4_finish_bio(struct bio *bio)
* We check all buffers in the page under BH_Uptodate_Lock
* to avoid races with other end io clearing async_write flags
*/
- local_irq_save(flags);
- bit_spin_lock(BH_Uptodate_Lock, &head->b_state);
+ flags = bh_uptodate_lock_irqsave(head);
do {
if (bh_offset(bh) < bio_start ||
bh_offset(bh) + bh->b_size > bio_end) {
@@ -110,8 +109,7 @@ static void ext4_finish_bio(struct bio *bio)
buffer_io_error(bh);
}
} while ((bh = bh->b_this_page) != head);
- bit_spin_unlock(BH_Uptodate_Lock, &head->b_state);
- local_irq_restore(flags);
+ bh_uptodate_unlock_irqrestore(head, flags);
if (!under_io) {
#ifdef CONFIG_EXT4_FS_ENCRYPTION
if (data_page)
diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c
index 8946130c87ad..71d0b3ba70f8 100644
--- a/fs/ntfs/aops.c
+++ b/fs/ntfs/aops.c
@@ -106,8 +106,7 @@ static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
"0x%llx.", (unsigned long long)bh->b_blocknr);
}
first = page_buffers(page);
- local_irq_save(flags);
- bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
+ flags = bh_uptodate_lock_irqsave(first);
clear_buffer_async_read(bh);
unlock_buffer(bh);
tmp = bh;
@@ -122,8 +121,7 @@ static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
}
tmp = tmp->b_this_page;
} while (tmp != bh);
- bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
- local_irq_restore(flags);
+ bh_uptodate_unlock_irqrestore(first, flags);
/*
* If none of the buffers had errors then we can set the page uptodate,
* but we first have to perform the post read mst fixups, if the
@@ -156,9 +154,7 @@ static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
unlock_page(page);
return;
still_busy:
- bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
- local_irq_restore(flags);
- return;
+ bh_uptodate_unlock_irqrestore(first, flags);
}
/**
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index 87fbaa84b0df..00028e4f7410 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -76,8 +76,42 @@ struct buffer_head {
struct address_space *b_assoc_map; /* mapping this buffer is
associated with */
atomic_t b_count; /* users using this buffer_head */
+#ifdef CONFIG_PREEMPT_RT_BASE
+ spinlock_t b_uptodate_lock;
+#endif
};
+static inline unsigned long bh_uptodate_lock_irqsave(struct buffer_head *bh)
+{
+ unsigned long flags;
+
+#ifndef CONFIG_PREEMPT_RT_BASE
+ local_irq_save(flags);
+ bit_spin_lock(BH_Uptodate_Lock, &bh->b_state);
+#else
+ spin_lock_irqsave(&bh->b_uptodate_lock, flags);
+#endif
+ return flags;
+}
+
+static inline void
+bh_uptodate_unlock_irqrestore(struct buffer_head *bh, unsigned long flags)
+{
+#ifndef CONFIG_PREEMPT_RT_BASE
+ bit_spin_unlock(BH_Uptodate_Lock, &bh->b_state);
+ local_irq_restore(flags);
+#else
+ spin_unlock_irqrestore(&bh->b_uptodate_lock, flags);
+#endif
+}
+
+static inline void buffer_head_init_locks(struct buffer_head *bh)
+{
+#ifdef CONFIG_PREEMPT_RT_BASE
+ spin_lock_init(&bh->b_uptodate_lock);
+#endif
+}
+
/*
* macro tricks to expand the set_buffer_foo(), clear_buffer_foo()
* and buffer_foo() functions.
|
