diff options
-rw-r--r-- | include/linux/swap.h | 2 | ||||
-rw-r--r-- | mm/swapfile.c | 42 |
2 files changed, 37 insertions, 7 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h index 93f0eca7f916..db3b5de7c92f 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h | |||
@@ -107,6 +107,8 @@ enum { | |||
107 | SWP_USED = (1 << 0), /* is slot in swap_info[] used? */ | 107 | SWP_USED = (1 << 0), /* is slot in swap_info[] used? */ |
108 | SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */ | 108 | SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */ |
109 | SWP_ACTIVE = (SWP_USED | SWP_WRITEOK), | 109 | SWP_ACTIVE = (SWP_USED | SWP_WRITEOK), |
110 | /* add others here before... */ | ||
111 | SWP_SCANNING = (1 << 8), /* refcount in scan_swap_map */ | ||
110 | }; | 112 | }; |
111 | 113 | ||
112 | #define SWAP_CLUSTER_MAX 32 | 114 | #define SWAP_CLUSTER_MAX 32 |
diff --git a/mm/swapfile.c b/mm/swapfile.c index c70248aab536..fdee145afc6f 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c | |||
@@ -98,10 +98,12 @@ static inline unsigned long scan_swap_map(struct swap_info_struct *si) | |||
98 | * But we do now try to find an empty cluster. -Andrea | 98 | * But we do now try to find an empty cluster. -Andrea |
99 | */ | 99 | */ |
100 | 100 | ||
101 | si->flags += SWP_SCANNING; | ||
101 | if (unlikely(!si->cluster_nr)) { | 102 | if (unlikely(!si->cluster_nr)) { |
102 | si->cluster_nr = SWAPFILE_CLUSTER - 1; | 103 | si->cluster_nr = SWAPFILE_CLUSTER - 1; |
103 | if (si->pages - si->inuse_pages < SWAPFILE_CLUSTER) | 104 | if (si->pages - si->inuse_pages < SWAPFILE_CLUSTER) |
104 | goto lowest; | 105 | goto lowest; |
106 | swap_device_unlock(si); | ||
105 | 107 | ||
106 | offset = si->lowest_bit; | 108 | offset = si->lowest_bit; |
107 | last_in_cluster = offset + SWAPFILE_CLUSTER - 1; | 109 | last_in_cluster = offset + SWAPFILE_CLUSTER - 1; |
@@ -111,10 +113,12 @@ static inline unsigned long scan_swap_map(struct swap_info_struct *si) | |||
111 | if (si->swap_map[offset]) | 113 | if (si->swap_map[offset]) |
112 | last_in_cluster = offset + SWAPFILE_CLUSTER; | 114 | last_in_cluster = offset + SWAPFILE_CLUSTER; |
113 | else if (offset == last_in_cluster) { | 115 | else if (offset == last_in_cluster) { |
116 | swap_device_lock(si); | ||
114 | si->cluster_next = offset-SWAPFILE_CLUSTER-1; | 117 | si->cluster_next = offset-SWAPFILE_CLUSTER-1; |
115 | goto cluster; | 118 | goto cluster; |
116 | } | 119 | } |
117 | } | 120 | } |
121 | swap_device_lock(si); | ||
118 | goto lowest; | 122 | goto lowest; |
119 | } | 123 | } |
120 | 124 | ||
@@ -123,10 +127,12 @@ cluster: | |||
123 | offset = si->cluster_next; | 127 | offset = si->cluster_next; |
124 | if (offset > si->highest_bit) | 128 | if (offset > si->highest_bit) |
125 | lowest: offset = si->lowest_bit; | 129 | lowest: offset = si->lowest_bit; |
130 | checks: if (!(si->flags & SWP_WRITEOK)) | ||
131 | goto no_page; | ||
126 | if (!si->highest_bit) | 132 | if (!si->highest_bit) |
127 | goto no_page; | 133 | goto no_page; |
128 | if (!si->swap_map[offset]) { | 134 | if (!si->swap_map[offset]) { |
129 | got_page: if (offset == si->lowest_bit) | 135 | if (offset == si->lowest_bit) |
130 | si->lowest_bit++; | 136 | si->lowest_bit++; |
131 | if (offset == si->highest_bit) | 137 | if (offset == si->highest_bit) |
132 | si->highest_bit--; | 138 | si->highest_bit--; |
@@ -137,16 +143,22 @@ got_page: if (offset == si->lowest_bit) | |||
137 | } | 143 | } |
138 | si->swap_map[offset] = 1; | 144 | si->swap_map[offset] = 1; |
139 | si->cluster_next = offset + 1; | 145 | si->cluster_next = offset + 1; |
146 | si->flags -= SWP_SCANNING; | ||
140 | return offset; | 147 | return offset; |
141 | } | 148 | } |
142 | 149 | ||
150 | swap_device_unlock(si); | ||
143 | while (++offset <= si->highest_bit) { | 151 | while (++offset <= si->highest_bit) { |
144 | if (!si->swap_map[offset]) | 152 | if (!si->swap_map[offset]) { |
145 | goto got_page; | 153 | swap_device_lock(si); |
154 | goto checks; | ||
155 | } | ||
146 | } | 156 | } |
157 | swap_device_lock(si); | ||
147 | goto lowest; | 158 | goto lowest; |
148 | 159 | ||
149 | no_page: | 160 | no_page: |
161 | si->flags -= SWP_SCANNING; | ||
150 | return 0; | 162 | return 0; |
151 | } | 163 | } |
152 | 164 | ||
@@ -1111,10 +1123,6 @@ asmlinkage long sys_swapoff(const char __user * specialfile) | |||
1111 | err = try_to_unuse(type); | 1123 | err = try_to_unuse(type); |
1112 | current->flags &= ~PF_SWAPOFF; | 1124 | current->flags &= ~PF_SWAPOFF; |
1113 | 1125 | ||
1114 | /* wait for any unplug function to finish */ | ||
1115 | down_write(&swap_unplug_sem); | ||
1116 | up_write(&swap_unplug_sem); | ||
1117 | |||
1118 | if (err) { | 1126 | if (err) { |
1119 | /* re-insert swap space back into swap_list */ | 1127 | /* re-insert swap space back into swap_list */ |
1120 | swap_list_lock(); | 1128 | swap_list_lock(); |
@@ -1128,10 +1136,28 @@ asmlinkage long sys_swapoff(const char __user * specialfile) | |||
1128 | swap_info[prev].next = p - swap_info; | 1136 | swap_info[prev].next = p - swap_info; |
1129 | nr_swap_pages += p->pages; | 1137 | nr_swap_pages += p->pages; |
1130 | total_swap_pages += p->pages; | 1138 | total_swap_pages += p->pages; |
1139 | swap_device_lock(p); | ||
1131 | p->flags |= SWP_WRITEOK; | 1140 | p->flags |= SWP_WRITEOK; |
1141 | swap_device_unlock(p); | ||
1132 | swap_list_unlock(); | 1142 | swap_list_unlock(); |
1133 | goto out_dput; | 1143 | goto out_dput; |
1134 | } | 1144 | } |
1145 | |||
1146 | /* wait for any unplug function to finish */ | ||
1147 | down_write(&swap_unplug_sem); | ||
1148 | up_write(&swap_unplug_sem); | ||
1149 | |||
1150 | /* wait for anyone still in scan_swap_map */ | ||
1151 | swap_device_lock(p); | ||
1152 | p->highest_bit = 0; /* cuts scans short */ | ||
1153 | while (p->flags >= SWP_SCANNING) { | ||
1154 | swap_device_unlock(p); | ||
1155 | set_current_state(TASK_UNINTERRUPTIBLE); | ||
1156 | schedule_timeout(1); | ||
1157 | swap_device_lock(p); | ||
1158 | } | ||
1159 | swap_device_unlock(p); | ||
1160 | |||
1135 | destroy_swap_extents(p); | 1161 | destroy_swap_extents(p); |
1136 | down(&swapon_sem); | 1162 | down(&swapon_sem); |
1137 | swap_list_lock(); | 1163 | swap_list_lock(); |
@@ -1431,6 +1457,8 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags) | |||
1431 | } | 1457 | } |
1432 | 1458 | ||
1433 | p->lowest_bit = 1; | 1459 | p->lowest_bit = 1; |
1460 | p->cluster_next = 1; | ||
1461 | |||
1434 | /* | 1462 | /* |
1435 | * Find out how many pages are allowed for a single swap | 1463 | * Find out how many pages are allowed for a single swap |
1436 | * device. There are two limiting factors: 1) the number of | 1464 | * device. There are two limiting factors: 1) the number of |