]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Macros for manipulating and testing page->flags | |
3 | */ | |
4 | ||
5 | #ifndef PAGE_FLAGS_H | |
6 | #define PAGE_FLAGS_H | |
7 | ||
f886ed44 AM |
8 | #include <linux/types.h> |
9 | ||
1da177e4 LT |
10 | /* |
11 | * Various page->flags bits: | |
12 | * | |
13 | * PG_reserved is set for special pages, which can never be swapped out. Some | |
14 | * of them might not even exist (eg empty_bad_page)... | |
15 | * | |
da6052f7 NP |
16 | * The PG_private bitflag is set on pagecache pages if they contain filesystem |
17 | * specific data (which is normally at page->private). It can be used by | |
18 | * private allocations for its own usage. | |
1da177e4 | 19 | * |
da6052f7 NP |
20 | * During initiation of disk I/O, PG_locked is set. This bit is set before I/O |
21 | * and cleared when writeback _starts_ or when read _completes_. PG_writeback | |
22 | * is set before writeback starts and cleared when it finishes. | |
23 | * | |
24 | * PG_locked also pins a page in pagecache, and blocks truncation of the file | |
25 | * while it is held. | |
26 | * | |
27 | * page_waitqueue(page) is a wait queue of all tasks waiting for the page | |
28 | * to become unlocked. | |
1da177e4 LT |
29 | * |
30 | * PG_uptodate tells whether the page's contents is valid. When a read | |
31 | * completes, the page becomes uptodate, unless a disk I/O error happened. | |
32 | * | |
da6052f7 NP |
33 | * PG_referenced, PG_reclaim are used for page reclaim for anonymous and |
34 | * file-backed pagecache (see mm/vmscan.c). | |
1da177e4 LT |
35 | * |
36 | * PG_error is set to indicate that an I/O error occurred on this page. | |
37 | * | |
38 | * PG_arch_1 is an architecture specific page state bit. The generic code | |
39 | * guarantees that this bit is cleared for a page when it first is entered into | |
40 | * the page cache. | |
41 | * | |
42 | * PG_highmem pages are not permanently mapped into the kernel virtual address | |
43 | * space, they need to be kmapped separately for doing IO on the pages. The | |
44 | * struct page (these bits with information) are always mapped into kernel | |
45 | * address space... | |
da6052f7 NP |
46 | * |
47 | * PG_buddy is set to indicate that the page is free and in the buddy system | |
48 | * (see mm/page_alloc.c). | |
49 | * | |
1da177e4 LT |
50 | */ |
51 | ||
52 | /* | |
53 | * Don't use the *_dontuse flags. Use the macros. Otherwise you'll break | |
91fc8ab3 AW |
54 | * locked- and dirty-page accounting. |
55 | * | |
56 | * The page flags field is split into two parts, the main flags area | |
57 | * which extends from the low bits upwards, and the fields area which | |
58 | * extends from the high bits downwards. | |
59 | * | |
60 | * | FIELD | ... | FLAGS | | |
61 | * N-1 ^ 0 | |
62 | * (N-FLAGS_RESERVED) | |
63 | * | |
64 | * The fields area is reserved for fields mapping zone, node and SPARSEMEM | |
65 | * section. The boundry between these two areas is defined by | |
66 | * FLAGS_RESERVED which defines the width of the fields section | |
67 | * (see linux/mmzone.h). New flags must _not_ overlap with this area. | |
1da177e4 LT |
68 | */ |
69 | #define PG_locked 0 /* Page is locked. Don't touch. */ | |
70 | #define PG_error 1 | |
71 | #define PG_referenced 2 | |
72 | #define PG_uptodate 3 | |
73 | ||
74 | #define PG_dirty 4 | |
75 | #define PG_lru 5 | |
76 | #define PG_active 6 | |
77 | #define PG_slab 7 /* slab debug (Suparna wants this) */ | |
78 | ||
5409bae0 | 79 | #define PG_owner_priv_1 8 /* Owner use. If pagecache, fs may use*/ |
cbe37d09 BP |
80 | #define PG_arch_1 9 |
81 | #define PG_reserved 10 | |
da6052f7 | 82 | #define PG_private 11 /* If pagecache, has fs-private data */ |
cbe37d09 BP |
83 | |
84 | #define PG_writeback 12 /* Page is under writeback */ | |
85 | #define PG_nosave 13 /* Used for system suspend/resume */ | |
86 | #define PG_compound 14 /* Part of a compound page */ | |
87 | #define PG_swapcache 15 /* Swap page: swp_entry_t in private */ | |
88 | ||
89 | #define PG_mappedtodisk 16 /* Has blocks allocated on-disk */ | |
90 | #define PG_reclaim 17 /* To be reclaimed asap */ | |
da6052f7 | 91 | #define PG_nosave_free 18 /* Used for system suspend/resume */ |
676165a8 NP |
92 | #define PG_buddy 19 /* Page is free, on buddy lists */ |
93 | ||
5409bae0 NP |
94 | /* PG_owner_priv_1 users should have descriptive aliases */ |
95 | #define PG_checked PG_owner_priv_1 /* Used by some filesystems */ | |
f886ed44 | 96 | |
d85f3385 CL |
97 | /* |
98 | * Marks tail portion of a compound page. We currently do not reclaim | |
99 | * compound pages so we can reuse a flag only used for reclaim here. | |
100 | */ | |
101 | #define PG_tail PG_reclaim | |
102 | ||
f886ed44 AM |
103 | #if (BITS_PER_LONG > 32) |
104 | /* | |
105 | * 64-bit-only flags build down from bit 31 | |
106 | * | |
107 | * 32 bit -------------------------------| FIELDS | FLAGS | | |
108 | * 64 bit | FIELDS | ?????? FLAGS | | |
109 | * 63 32 0 | |
110 | */ | |
111 | #define PG_uncached 31 /* Page has been mapped as uncached */ | |
112 | #endif | |
1da177e4 | 113 | |
1da177e4 LT |
114 | /* |
115 | * Manipulation of page state flags | |
116 | */ | |
117 | #define PageLocked(page) \ | |
118 | test_bit(PG_locked, &(page)->flags) | |
119 | #define SetPageLocked(page) \ | |
120 | set_bit(PG_locked, &(page)->flags) | |
121 | #define TestSetPageLocked(page) \ | |
122 | test_and_set_bit(PG_locked, &(page)->flags) | |
123 | #define ClearPageLocked(page) \ | |
124 | clear_bit(PG_locked, &(page)->flags) | |
125 | #define TestClearPageLocked(page) \ | |
126 | test_and_clear_bit(PG_locked, &(page)->flags) | |
127 | ||
128 | #define PageError(page) test_bit(PG_error, &(page)->flags) | |
129 | #define SetPageError(page) set_bit(PG_error, &(page)->flags) | |
130 | #define ClearPageError(page) clear_bit(PG_error, &(page)->flags) | |
131 | ||
132 | #define PageReferenced(page) test_bit(PG_referenced, &(page)->flags) | |
133 | #define SetPageReferenced(page) set_bit(PG_referenced, &(page)->flags) | |
134 | #define ClearPageReferenced(page) clear_bit(PG_referenced, &(page)->flags) | |
135 | #define TestClearPageReferenced(page) test_and_clear_bit(PG_referenced, &(page)->flags) | |
136 | ||
137 | #define PageUptodate(page) test_bit(PG_uptodate, &(page)->flags) | |
f6ac2354 | 138 | #ifdef CONFIG_S390 |
2dcea57a HC |
139 | static inline void SetPageUptodate(struct page *page) |
140 | { | |
141 | if (!test_and_set_bit(PG_uptodate, &page->flags)) | |
6c210482 | 142 | page_clear_dirty(page); |
2dcea57a | 143 | } |
f6ac2354 | 144 | #else |
1da177e4 LT |
145 | #define SetPageUptodate(page) set_bit(PG_uptodate, &(page)->flags) |
146 | #endif | |
147 | #define ClearPageUptodate(page) clear_bit(PG_uptodate, &(page)->flags) | |
148 | ||
149 | #define PageDirty(page) test_bit(PG_dirty, &(page)->flags) | |
150 | #define SetPageDirty(page) set_bit(PG_dirty, &(page)->flags) | |
151 | #define TestSetPageDirty(page) test_and_set_bit(PG_dirty, &(page)->flags) | |
152 | #define ClearPageDirty(page) clear_bit(PG_dirty, &(page)->flags) | |
242e5468 | 153 | #define __ClearPageDirty(page) __clear_bit(PG_dirty, &(page)->flags) |
1da177e4 LT |
154 | #define TestClearPageDirty(page) test_and_clear_bit(PG_dirty, &(page)->flags) |
155 | ||
1da177e4 | 156 | #define PageLRU(page) test_bit(PG_lru, &(page)->flags) |
8d438f96 NP |
157 | #define SetPageLRU(page) set_bit(PG_lru, &(page)->flags) |
158 | #define ClearPageLRU(page) clear_bit(PG_lru, &(page)->flags) | |
67453911 | 159 | #define __ClearPageLRU(page) __clear_bit(PG_lru, &(page)->flags) |
1da177e4 LT |
160 | |
161 | #define PageActive(page) test_bit(PG_active, &(page)->flags) | |
162 | #define SetPageActive(page) set_bit(PG_active, &(page)->flags) | |
163 | #define ClearPageActive(page) clear_bit(PG_active, &(page)->flags) | |
67453911 | 164 | #define __ClearPageActive(page) __clear_bit(PG_active, &(page)->flags) |
1da177e4 LT |
165 | |
166 | #define PageSlab(page) test_bit(PG_slab, &(page)->flags) | |
f205b2fe NP |
167 | #define __SetPageSlab(page) __set_bit(PG_slab, &(page)->flags) |
168 | #define __ClearPageSlab(page) __clear_bit(PG_slab, &(page)->flags) | |
1da177e4 LT |
169 | |
170 | #ifdef CONFIG_HIGHMEM | |
cbe37d09 | 171 | #define PageHighMem(page) is_highmem(page_zone(page)) |
1da177e4 LT |
172 | #else |
173 | #define PageHighMem(page) 0 /* needed to optimize away at compile time */ | |
174 | #endif | |
175 | ||
176 | #define PageChecked(page) test_bit(PG_checked, &(page)->flags) | |
177 | #define SetPageChecked(page) set_bit(PG_checked, &(page)->flags) | |
178 | #define ClearPageChecked(page) clear_bit(PG_checked, &(page)->flags) | |
179 | ||
180 | #define PageReserved(page) test_bit(PG_reserved, &(page)->flags) | |
181 | #define SetPageReserved(page) set_bit(PG_reserved, &(page)->flags) | |
182 | #define ClearPageReserved(page) clear_bit(PG_reserved, &(page)->flags) | |
183 | #define __ClearPageReserved(page) __clear_bit(PG_reserved, &(page)->flags) | |
184 | ||
185 | #define SetPagePrivate(page) set_bit(PG_private, &(page)->flags) | |
186 | #define ClearPagePrivate(page) clear_bit(PG_private, &(page)->flags) | |
187 | #define PagePrivate(page) test_bit(PG_private, &(page)->flags) | |
188 | #define __SetPagePrivate(page) __set_bit(PG_private, &(page)->flags) | |
189 | #define __ClearPagePrivate(page) __clear_bit(PG_private, &(page)->flags) | |
190 | ||
191 | #define PageWriteback(page) test_bit(PG_writeback, &(page)->flags) | |
192 | #define SetPageWriteback(page) \ | |
193 | do { \ | |
194 | if (!test_and_set_bit(PG_writeback, \ | |
195 | &(page)->flags)) \ | |
ce866b34 | 196 | inc_zone_page_state(page, NR_WRITEBACK); \ |
1da177e4 LT |
197 | } while (0) |
198 | #define TestSetPageWriteback(page) \ | |
199 | ({ \ | |
200 | int ret; \ | |
201 | ret = test_and_set_bit(PG_writeback, \ | |
202 | &(page)->flags); \ | |
203 | if (!ret) \ | |
ce866b34 | 204 | inc_zone_page_state(page, NR_WRITEBACK); \ |
1da177e4 LT |
205 | ret; \ |
206 | }) | |
207 | #define ClearPageWriteback(page) \ | |
208 | do { \ | |
209 | if (test_and_clear_bit(PG_writeback, \ | |
210 | &(page)->flags)) \ | |
ce866b34 | 211 | dec_zone_page_state(page, NR_WRITEBACK); \ |
1da177e4 LT |
212 | } while (0) |
213 | #define TestClearPageWriteback(page) \ | |
214 | ({ \ | |
215 | int ret; \ | |
216 | ret = test_and_clear_bit(PG_writeback, \ | |
217 | &(page)->flags); \ | |
218 | if (ret) \ | |
ce866b34 | 219 | dec_zone_page_state(page, NR_WRITEBACK); \ |
1da177e4 LT |
220 | ret; \ |
221 | }) | |
222 | ||
223 | #define PageNosave(page) test_bit(PG_nosave, &(page)->flags) | |
224 | #define SetPageNosave(page) set_bit(PG_nosave, &(page)->flags) | |
225 | #define TestSetPageNosave(page) test_and_set_bit(PG_nosave, &(page)->flags) | |
226 | #define ClearPageNosave(page) clear_bit(PG_nosave, &(page)->flags) | |
227 | #define TestClearPageNosave(page) test_and_clear_bit(PG_nosave, &(page)->flags) | |
228 | ||
229 | #define PageNosaveFree(page) test_bit(PG_nosave_free, &(page)->flags) | |
230 | #define SetPageNosaveFree(page) set_bit(PG_nosave_free, &(page)->flags) | |
231 | #define ClearPageNosaveFree(page) clear_bit(PG_nosave_free, &(page)->flags) | |
232 | ||
676165a8 NP |
233 | #define PageBuddy(page) test_bit(PG_buddy, &(page)->flags) |
234 | #define __SetPageBuddy(page) __set_bit(PG_buddy, &(page)->flags) | |
235 | #define __ClearPageBuddy(page) __clear_bit(PG_buddy, &(page)->flags) | |
236 | ||
1da177e4 LT |
237 | #define PageMappedToDisk(page) test_bit(PG_mappedtodisk, &(page)->flags) |
238 | #define SetPageMappedToDisk(page) set_bit(PG_mappedtodisk, &(page)->flags) | |
239 | #define ClearPageMappedToDisk(page) clear_bit(PG_mappedtodisk, &(page)->flags) | |
240 | ||
241 | #define PageReclaim(page) test_bit(PG_reclaim, &(page)->flags) | |
242 | #define SetPageReclaim(page) set_bit(PG_reclaim, &(page)->flags) | |
243 | #define ClearPageReclaim(page) clear_bit(PG_reclaim, &(page)->flags) | |
244 | #define TestClearPageReclaim(page) test_and_clear_bit(PG_reclaim, &(page)->flags) | |
245 | ||
1da177e4 | 246 | #define PageCompound(page) test_bit(PG_compound, &(page)->flags) |
5e9dace8 NP |
247 | #define __SetPageCompound(page) __set_bit(PG_compound, &(page)->flags) |
248 | #define __ClearPageCompound(page) __clear_bit(PG_compound, &(page)->flags) | |
1da177e4 | 249 | |
d85f3385 CL |
250 | /* |
251 | * Note: PG_tail is an alias of another page flag. The result of PageTail() | |
252 | * is only valid if PageCompound(page) is true. | |
253 | */ | |
254 | #define PageTail(page) test_bit(PG_tail, &(page)->flags) | |
255 | #define __SetPageTail(page) __set_bit(PG_tail, &(page)->flags) | |
256 | #define __ClearPageTail(page) __clear_bit(PG_tail, &(page)->flags) | |
257 | ||
1da177e4 LT |
258 | #ifdef CONFIG_SWAP |
259 | #define PageSwapCache(page) test_bit(PG_swapcache, &(page)->flags) | |
260 | #define SetPageSwapCache(page) set_bit(PG_swapcache, &(page)->flags) | |
261 | #define ClearPageSwapCache(page) clear_bit(PG_swapcache, &(page)->flags) | |
262 | #else | |
263 | #define PageSwapCache(page) 0 | |
264 | #endif | |
265 | ||
266 | #define PageUncached(page) test_bit(PG_uncached, &(page)->flags) | |
267 | #define SetPageUncached(page) set_bit(PG_uncached, &(page)->flags) | |
268 | #define ClearPageUncached(page) clear_bit(PG_uncached, &(page)->flags) | |
269 | ||
270 | struct page; /* forward declaration */ | |
271 | ||
fba2591b LT |
272 | extern void cancel_dirty_page(struct page *page, unsigned int account_size); |
273 | ||
1da177e4 LT |
274 | int test_clear_page_writeback(struct page *page); |
275 | int test_set_page_writeback(struct page *page); | |
276 | ||
1da177e4 LT |
277 | static inline void set_page_writeback(struct page *page) |
278 | { | |
279 | test_set_page_writeback(page); | |
280 | } | |
281 | ||
282 | #endif /* PAGE_FLAGS_H */ |