diff options
Diffstat (limited to 'fs')
-rw-r--r-- | fs/xfs/linux-2.6/xfs_buf.c | 79 |
1 files changed, 76 insertions, 3 deletions
diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c index d71dc44e21ed..cb329edc925b 100644 --- a/fs/xfs/linux-2.6/xfs_buf.c +++ b/fs/xfs/linux-2.6/xfs_buf.c | |||
@@ -166,6 +166,75 @@ test_page_region( | |||
166 | } | 166 | } |
167 | 167 | ||
168 | /* | 168 | /* |
169 | * Mapping of multi-page buffers into contiguous virtual space | ||
170 | */ | ||
171 | |||
172 | typedef struct a_list { | ||
173 | void *vm_addr; | ||
174 | struct a_list *next; | ||
175 | } a_list_t; | ||
176 | |||
177 | static a_list_t *as_free_head; | ||
178 | static int as_list_len; | ||
179 | static DEFINE_SPINLOCK(as_lock); | ||
180 | |||
181 | /* | ||
182 | * Try to batch vunmaps because they are costly. | ||
183 | */ | ||
184 | STATIC void | ||
185 | free_address( | ||
186 | void *addr) | ||
187 | { | ||
188 | a_list_t *aentry; | ||
189 | |||
190 | #ifdef CONFIG_XEN | ||
191 | /* | ||
192 | * Xen needs to be able to make sure it can get an exclusive | ||
193 | * RO mapping of pages it wants to turn into a pagetable. If | ||
194 | * a newly allocated page is also still being vmap()ed by xfs, | ||
195 | * it will cause pagetable construction to fail. This is a | ||
196 | * quick workaround to always eagerly unmap pages so that Xen | ||
197 | * is happy. | ||
198 | */ | ||
199 | vunmap(addr); | ||
200 | return; | ||
201 | #endif | ||
202 | |||
203 | aentry = kmalloc(sizeof(a_list_t), GFP_NOWAIT); | ||
204 | if (likely(aentry)) { | ||
205 | spin_lock(&as_lock); | ||
206 | aentry->next = as_free_head; | ||
207 | aentry->vm_addr = addr; | ||
208 | as_free_head = aentry; | ||
209 | as_list_len++; | ||
210 | spin_unlock(&as_lock); | ||
211 | } else { | ||
212 | vunmap(addr); | ||
213 | } | ||
214 | } | ||
215 | |||
216 | STATIC void | ||
217 | purge_addresses(void) | ||
218 | { | ||
219 | a_list_t *aentry, *old; | ||
220 | |||
221 | if (as_free_head == NULL) | ||
222 | return; | ||
223 | |||
224 | spin_lock(&as_lock); | ||
225 | aentry = as_free_head; | ||
226 | as_free_head = NULL; | ||
227 | as_list_len = 0; | ||
228 | spin_unlock(&as_lock); | ||
229 | |||
230 | while ((old = aentry) != NULL) { | ||
231 | vunmap(aentry->vm_addr); | ||
232 | aentry = aentry->next; | ||
233 | kfree(old); | ||
234 | } | ||
235 | } | ||
236 | |||
237 | /* | ||
169 | * Internal xfs_buf_t object manipulation | 238 | * Internal xfs_buf_t object manipulation |
170 | */ | 239 | */ |
171 | 240 | ||
@@ -264,7 +333,7 @@ xfs_buf_free( | |||
264 | uint i; | 333 | uint i; |
265 | 334 | ||
266 | if ((bp->b_flags & XBF_MAPPED) && (bp->b_page_count > 1)) | 335 | if ((bp->b_flags & XBF_MAPPED) && (bp->b_page_count > 1)) |
267 | vm_unmap_ram(bp->b_addr - bp->b_offset, bp->b_page_count); | 336 | free_address(bp->b_addr - bp->b_offset); |
268 | 337 | ||
269 | for (i = 0; i < bp->b_page_count; i++) { | 338 | for (i = 0; i < bp->b_page_count; i++) { |
270 | struct page *page = bp->b_pages[i]; | 339 | struct page *page = bp->b_pages[i]; |
@@ -386,8 +455,10 @@ _xfs_buf_map_pages( | |||
386 | bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset; | 455 | bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset; |
387 | bp->b_flags |= XBF_MAPPED; | 456 | bp->b_flags |= XBF_MAPPED; |
388 | } else if (flags & XBF_MAPPED) { | 457 | } else if (flags & XBF_MAPPED) { |
389 | bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, | 458 | if (as_list_len > 64) |
390 | -1, PAGE_KERNEL); | 459 | purge_addresses(); |
460 | bp->b_addr = vmap(bp->b_pages, bp->b_page_count, | ||
461 | VM_MAP, PAGE_KERNEL); | ||
391 | if (unlikely(bp->b_addr == NULL)) | 462 | if (unlikely(bp->b_addr == NULL)) |
392 | return -ENOMEM; | 463 | return -ENOMEM; |
393 | bp->b_addr += bp->b_offset; | 464 | bp->b_addr += bp->b_offset; |
@@ -1672,6 +1743,8 @@ xfsbufd( | |||
1672 | count++; | 1743 | count++; |
1673 | } | 1744 | } |
1674 | 1745 | ||
1746 | if (as_list_len > 0) | ||
1747 | purge_addresses(); | ||
1675 | if (count) | 1748 | if (count) |
1676 | blk_run_address_space(target->bt_mapping); | 1749 | blk_run_address_space(target->bt_mapping); |
1677 | 1750 | ||