]>
Commit | Line | Data |
---|---|---|
82094b55 AF |
1 | From: Jan Kara <jack@suse.cz> |
2 | Subject: [PATCH] zisofs: Implement reading of compressed files when PAGE_CACHE_SIZE > compress block size | |
3 | Patch-mainline: 2.6.33 | |
4 | References: bnc#540349 | |
5 | ||
6 | Also split and cleanup zisofs_readpage() when we are changing it anyway. | |
7 | ||
8 | Signed-off-by: Jan Kara <jack@suse.cz> | |
9 | --- | |
10 | fs/isofs/compress.c | 533 +++++++++++++++++++++++++++------------------------ | |
11 | fs/isofs/rock.c | 3 +- | |
12 | 2 files changed, 286 insertions(+), 250 deletions(-) | |
13 | ||
14 | diff --git a/fs/isofs/compress.c b/fs/isofs/compress.c | |
15 | index defb932..0b3fa79 100644 | |
16 | --- a/fs/isofs/compress.c | |
17 | +++ b/fs/isofs/compress.c | |
18 | @@ -36,286 +36,323 @@ static void *zisofs_zlib_workspace; | |
19 | static DEFINE_MUTEX(zisofs_zlib_lock); | |
20 | ||
21 | /* | |
22 | - * When decompressing, we typically obtain more than one page | |
23 | - * per reference. We inject the additional pages into the page | |
24 | - * cache as a form of readahead. | |
25 | + * Read data of @inode from @block_start to @block_end and uncompress | |
26 | + * to one zisofs block. Store the data in the @pages array with @pcount | |
27 | + * entries. Start storing at offset @poffset of the first page. | |
28 | */ | |
29 | -static int zisofs_readpage(struct file *file, struct page *page) | |
30 | +static loff_t zisofs_uncompress_block(struct inode *inode, loff_t block_start, | |
31 | + loff_t block_end, int pcount, | |
32 | + struct page **pages, unsigned poffset, | |
33 | + int *errp) | |
34 | { | |
35 | - struct inode *inode = file->f_path.dentry->d_inode; | |
36 | - struct address_space *mapping = inode->i_mapping; | |
37 | - unsigned int maxpage, xpage, fpage, blockindex; | |
38 | - unsigned long offset; | |
39 | - unsigned long blockptr, blockendptr, cstart, cend, csize; | |
40 | - struct buffer_head *bh, *ptrbh[2]; | |
41 | - unsigned long bufsize = ISOFS_BUFFER_SIZE(inode); | |
42 | - unsigned int bufshift = ISOFS_BUFFER_BITS(inode); | |
43 | - unsigned long bufmask = bufsize - 1; | |
44 | - int err = -EIO; | |
45 | - int i; | |
46 | - unsigned int header_size = ISOFS_I(inode)->i_format_parm[0]; | |
47 | unsigned int zisofs_block_shift = ISOFS_I(inode)->i_format_parm[1]; | |
48 | - /* unsigned long zisofs_block_size = 1UL << zisofs_block_shift; */ | |
49 | - unsigned int zisofs_block_page_shift = zisofs_block_shift-PAGE_CACHE_SHIFT; | |
50 | - unsigned long zisofs_block_pages = 1UL << zisofs_block_page_shift; | |
51 | - unsigned long zisofs_block_page_mask = zisofs_block_pages-1; | |
52 | - struct page *pages[zisofs_block_pages]; | |
53 | - unsigned long index = page->index; | |
54 | - int indexblocks; | |
55 | - | |
56 | - /* We have already been given one page, this is the one | |
57 | - we must do. */ | |
58 | - xpage = index & zisofs_block_page_mask; | |
59 | - pages[xpage] = page; | |
60 | - | |
61 | - /* The remaining pages need to be allocated and inserted */ | |
62 | - offset = index & ~zisofs_block_page_mask; | |
63 | - blockindex = offset >> zisofs_block_page_shift; | |
64 | - maxpage = (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | |
65 | - | |
66 | - /* | |
67 | - * If this page is wholly outside i_size we just return zero; | |
68 | - * do_generic_file_read() will handle this for us | |
69 | - */ | |
70 | - if (page->index >= maxpage) { | |
71 | - SetPageUptodate(page); | |
72 | - unlock_page(page); | |
73 | + unsigned int bufsize = ISOFS_BUFFER_SIZE(inode); | |
74 | + unsigned int bufshift = ISOFS_BUFFER_BITS(inode); | |
75 | + unsigned int bufmask = bufsize - 1; | |
76 | + int i, block_size = block_end - block_start; | |
77 | + z_stream stream = { .total_out = 0, | |
78 | + .avail_in = 0, | |
79 | + .avail_out = 0, }; | |
80 | + int zerr; | |
81 | + int needblocks = (block_size + (block_start & bufmask) + bufmask) | |
82 | + >> bufshift; | |
83 | + int haveblocks; | |
84 | + blkcnt_t blocknum; | |
85 | + struct buffer_head *bhs[needblocks + 1]; | |
86 | + int curbh, curpage; | |
87 | + | |
88 | + if (block_size > deflateBound(1UL << zisofs_block_shift)) { | |
89 | + *errp = -EIO; | |
90 | return 0; | |
91 | } | |
92 | - | |
93 | - maxpage = min(zisofs_block_pages, maxpage-offset); | |
94 | - | |
95 | - for ( i = 0 ; i < maxpage ; i++, offset++ ) { | |
96 | - if ( i != xpage ) { | |
97 | - pages[i] = grab_cache_page_nowait(mapping, offset); | |
98 | - } | |
99 | - page = pages[i]; | |
100 | - if ( page ) { | |
101 | - ClearPageError(page); | |
102 | - kmap(page); | |
103 | + /* Empty block? */ | |
104 | + if (block_size == 0) { | |
105 | + for ( i = 0 ; i < pcount ; i++ ) { | |
106 | + if (!pages[i]) | |
107 | + continue; | |
108 | + memset(page_address(pages[i]), 0, PAGE_CACHE_SIZE); | |
109 | + flush_dcache_page(pages[i]); | |
110 | + SetPageUptodate(pages[i]); | |
111 | } | |
112 | + return ((loff_t)pcount) << PAGE_CACHE_SHIFT; | |
113 | } | |
114 | ||
115 | - /* This is the last page filled, plus one; used in case of abort. */ | |
116 | - fpage = 0; | |
117 | + /* Because zlib is not thread-safe, do all the I/O at the top. */ | |
118 | + blocknum = block_start >> bufshift; | |
119 | + memset(bhs, 0, (needblocks + 1) * sizeof(struct buffer_head *)); | |
120 | + haveblocks = isofs_get_blocks(inode, blocknum, bhs, needblocks); | |
121 | + ll_rw_block(READ, haveblocks, bhs); | |
122 | ||
123 | - /* Find the pointer to this specific chunk */ | |
124 | - /* Note: we're not using isonum_731() here because the data is known aligned */ | |
125 | - /* Note: header_size is in 32-bit words (4 bytes) */ | |
126 | - blockptr = (header_size + blockindex) << 2; | |
127 | - blockendptr = blockptr + 4; | |
128 | + curbh = 0; | |
129 | + curpage = 0; | |
130 | + /* | |
131 | + * First block is special since it may be fractional. We also wait for | |
132 | + * it before grabbing the zlib mutex; odds are that the subsequent | |
133 | + * blocks are going to come in in short order so we don't hold the zlib | |
134 | + * mutex longer than necessary. | |
135 | + */ | |
136 | ||
137 | - indexblocks = ((blockptr^blockendptr) >> bufshift) ? 2 : 1; | |
138 | - ptrbh[0] = ptrbh[1] = NULL; | |
139 | + if (!bhs[0]) | |
140 | + goto b_eio; | |
141 | ||
142 | - if ( isofs_get_blocks(inode, blockptr >> bufshift, ptrbh, indexblocks) != indexblocks ) { | |
143 | - if ( ptrbh[0] ) brelse(ptrbh[0]); | |
144 | - printk(KERN_DEBUG "zisofs: Null buffer on reading block table, inode = %lu, block = %lu\n", | |
145 | - inode->i_ino, blockptr >> bufshift); | |
146 | - goto eio; | |
147 | - } | |
148 | - ll_rw_block(READ, indexblocks, ptrbh); | |
149 | - | |
150 | - bh = ptrbh[0]; | |
151 | - if ( !bh || (wait_on_buffer(bh), !buffer_uptodate(bh)) ) { | |
152 | - printk(KERN_DEBUG "zisofs: Failed to read block table, inode = %lu, block = %lu\n", | |
153 | - inode->i_ino, blockptr >> bufshift); | |
154 | - if ( ptrbh[1] ) | |
155 | - brelse(ptrbh[1]); | |
156 | - goto eio; | |
157 | - } | |
158 | - cstart = le32_to_cpu(*(__le32 *)(bh->b_data + (blockptr & bufmask))); | |
159 | - | |
160 | - if ( indexblocks == 2 ) { | |
161 | - /* We just crossed a block boundary. Switch to the next block */ | |
162 | - brelse(bh); | |
163 | - bh = ptrbh[1]; | |
164 | - if ( !bh || (wait_on_buffer(bh), !buffer_uptodate(bh)) ) { | |
165 | - printk(KERN_DEBUG "zisofs: Failed to read block table, inode = %lu, block = %lu\n", | |
166 | - inode->i_ino, blockendptr >> bufshift); | |
167 | - goto eio; | |
168 | - } | |
169 | + wait_on_buffer(bhs[0]); | |
170 | + if (!buffer_uptodate(bhs[0])) { | |
171 | + *errp = -EIO; | |
172 | + goto b_eio; | |
173 | } | |
174 | - cend = le32_to_cpu(*(__le32 *)(bh->b_data + (blockendptr & bufmask))); | |
175 | - brelse(bh); | |
176 | ||
177 | - if (cstart > cend) | |
178 | - goto eio; | |
179 | + stream.workspace = zisofs_zlib_workspace; | |
180 | + mutex_lock(&zisofs_zlib_lock); | |
181 | ||
182 | - csize = cend-cstart; | |
183 | - | |
184 | - if (csize > deflateBound(1UL << zisofs_block_shift)) | |
185 | - goto eio; | |
186 | - | |
187 | - /* Now page[] contains an array of pages, any of which can be NULL, | |
188 | - and the locks on which we hold. We should now read the data and | |
189 | - release the pages. If the pages are NULL the decompressed data | |
190 | - for that particular page should be discarded. */ | |
191 | - | |
192 | - if ( csize == 0 ) { | |
193 | - /* This data block is empty. */ | |
194 | - | |
195 | - for ( fpage = 0 ; fpage < maxpage ; fpage++ ) { | |
196 | - if ( (page = pages[fpage]) != NULL ) { | |
197 | - memset(page_address(page), 0, PAGE_CACHE_SIZE); | |
198 | - | |
199 | - flush_dcache_page(page); | |
200 | - SetPageUptodate(page); | |
201 | - kunmap(page); | |
202 | - unlock_page(page); | |
203 | - if ( fpage == xpage ) | |
204 | - err = 0; /* The critical page */ | |
205 | - else | |
206 | - page_cache_release(page); | |
207 | + zerr = zlib_inflateInit(&stream); | |
208 | + if (zerr != Z_OK) { | |
209 | + if (zerr == Z_MEM_ERROR) | |
210 | + *errp = -ENOMEM; | |
211 | + else | |
212 | + *errp = -EIO; | |
213 | + printk(KERN_DEBUG "zisofs: zisofs_inflateInit returned %d\n", | |
214 | + zerr); | |
215 | + goto z_eio; | |
216 | + } | |
217 | + | |
218 | + while (curpage < pcount && curbh < haveblocks && | |
219 | + zerr != Z_STREAM_END) { | |
220 | + if (!stream.avail_out) { | |
221 | + if (pages[curpage]) { | |
222 | + stream.next_out = page_address(pages[curpage]) | |
223 | + + poffset; | |
224 | + stream.avail_out = PAGE_CACHE_SIZE - poffset; | |
225 | + poffset = 0; | |
226 | + } else { | |
227 | + stream.next_out = (void *)&zisofs_sink_page; | |
228 | + stream.avail_out = PAGE_CACHE_SIZE; | |
229 | } | |
230 | } | |
231 | - } else { | |
232 | - /* This data block is compressed. */ | |
233 | - z_stream stream; | |
234 | - int bail = 0, left_out = -1; | |
235 | - int zerr; | |
236 | - int needblocks = (csize + (cstart & bufmask) + bufmask) >> bufshift; | |
237 | - int haveblocks; | |
238 | - struct buffer_head *bhs[needblocks+1]; | |
239 | - struct buffer_head **bhptr; | |
240 | - | |
241 | - /* Because zlib is not thread-safe, do all the I/O at the top. */ | |
242 | - | |
243 | - blockptr = cstart >> bufshift; | |
244 | - memset(bhs, 0, (needblocks+1)*sizeof(struct buffer_head *)); | |
245 | - haveblocks = isofs_get_blocks(inode, blockptr, bhs, needblocks); | |
246 | - ll_rw_block(READ, haveblocks, bhs); | |
247 | - | |
248 | - bhptr = &bhs[0]; | |
249 | - bh = *bhptr++; | |
250 | - | |
251 | - /* First block is special since it may be fractional. | |
252 | - We also wait for it before grabbing the zlib | |
253 | - mutex; odds are that the subsequent blocks are | |
254 | - going to come in in short order so we don't hold | |
255 | - the zlib mutex longer than necessary. */ | |
256 | - | |
257 | - if ( !bh || (wait_on_buffer(bh), !buffer_uptodate(bh)) ) { | |
258 | - printk(KERN_DEBUG "zisofs: Hit null buffer, fpage = %d, xpage = %d, csize = %ld\n", | |
259 | - fpage, xpage, csize); | |
260 | - goto b_eio; | |
261 | - } | |
262 | - stream.next_in = bh->b_data + (cstart & bufmask); | |
263 | - stream.avail_in = min(bufsize-(cstart & bufmask), csize); | |
264 | - csize -= stream.avail_in; | |
265 | - | |
266 | - stream.workspace = zisofs_zlib_workspace; | |
267 | - mutex_lock(&zisofs_zlib_lock); | |
268 | - | |
269 | - zerr = zlib_inflateInit(&stream); | |
270 | - if ( zerr != Z_OK ) { | |
271 | - if ( err && zerr == Z_MEM_ERROR ) | |
272 | - err = -ENOMEM; | |
273 | - printk(KERN_DEBUG "zisofs: zisofs_inflateInit returned %d\n", | |
274 | - zerr); | |
275 | - goto z_eio; | |
276 | + if (!stream.avail_in) { | |
277 | + wait_on_buffer(bhs[curbh]); | |
278 | + if (!buffer_uptodate(bhs[curbh])) { | |
279 | + *errp = -EIO; | |
280 | + break; | |
281 | + } | |
282 | + stream.next_in = bhs[curbh]->b_data + | |
283 | + (block_start & bufmask); | |
284 | + stream.avail_in = min_t(unsigned, bufsize - | |
285 | + (block_start & bufmask), | |
286 | + block_size); | |
287 | + block_size -= stream.avail_in; | |
288 | + block_start = 0; | |
289 | } | |
290 | ||
291 | - while ( !bail && fpage < maxpage ) { | |
292 | - page = pages[fpage]; | |
293 | - if ( page ) | |
294 | - stream.next_out = page_address(page); | |
295 | - else | |
296 | - stream.next_out = (void *)&zisofs_sink_page; | |
297 | - stream.avail_out = PAGE_CACHE_SIZE; | |
298 | - | |
299 | - while ( stream.avail_out ) { | |
300 | - int ao, ai; | |
301 | - if ( stream.avail_in == 0 && left_out ) { | |
302 | - if ( !csize ) { | |
303 | - printk(KERN_WARNING "zisofs: ZF read beyond end of input\n"); | |
304 | - bail = 1; | |
305 | - break; | |
306 | - } else { | |
307 | - bh = *bhptr++; | |
308 | - if ( !bh || | |
309 | - (wait_on_buffer(bh), !buffer_uptodate(bh)) ) { | |
310 | - /* Reached an EIO */ | |
311 | - printk(KERN_DEBUG "zisofs: Hit null buffer, fpage = %d, xpage = %d, csize = %ld\n", | |
312 | - fpage, xpage, csize); | |
313 | - | |
314 | - bail = 1; | |
315 | - break; | |
316 | - } | |
317 | - stream.next_in = bh->b_data; | |
318 | - stream.avail_in = min(csize,bufsize); | |
319 | - csize -= stream.avail_in; | |
320 | - } | |
321 | - } | |
322 | - ao = stream.avail_out; ai = stream.avail_in; | |
323 | - zerr = zlib_inflate(&stream, Z_SYNC_FLUSH); | |
324 | - left_out = stream.avail_out; | |
325 | - if ( zerr == Z_BUF_ERROR && stream.avail_in == 0 ) | |
326 | - continue; | |
327 | - if ( zerr != Z_OK ) { | |
328 | - /* EOF, error, or trying to read beyond end of input */ | |
329 | - if ( err && zerr == Z_MEM_ERROR ) | |
330 | - err = -ENOMEM; | |
331 | - if ( zerr != Z_STREAM_END ) | |
332 | - printk(KERN_DEBUG "zisofs: zisofs_inflate returned %d, inode = %lu, index = %lu, fpage = %d, xpage = %d, avail_in = %d, avail_out = %d, ai = %d, ao = %d\n", | |
333 | - zerr, inode->i_ino, index, | |
334 | - fpage, xpage, | |
335 | - stream.avail_in, stream.avail_out, | |
336 | - ai, ao); | |
337 | - bail = 1; | |
338 | - break; | |
339 | + while (stream.avail_out && stream.avail_in) { | |
340 | + zerr = zlib_inflate(&stream, Z_SYNC_FLUSH); | |
341 | + if (zerr == Z_BUF_ERROR && stream.avail_in == 0) | |
342 | + break; | |
343 | + if (zerr == Z_STREAM_END) | |
344 | + break; | |
345 | + if (zerr != Z_OK) { | |
346 | + /* EOF, error, or trying to read beyond end of input */ | |
347 | + if (zerr == Z_MEM_ERROR) | |
348 | + *errp = -ENOMEM; | |
349 | + else { | |
350 | + printk(KERN_DEBUG | |
351 | + "zisofs: zisofs_inflate returned" | |
352 | + " %d, inode = %lu," | |
353 | + " page idx = %d, bh idx = %d," | |
354 | + " avail_in = %d," | |
355 | + " avail_out = %d\n", | |
356 | + zerr, inode->i_ino, curpage, | |
357 | + curbh, stream.avail_in, | |
358 | + stream.avail_out); | |
359 | + *errp = -EIO; | |
360 | } | |
361 | + goto inflate_out; | |
362 | } | |
363 | + } | |
364 | ||
365 | - if ( stream.avail_out && zerr == Z_STREAM_END ) { | |
366 | - /* Fractional page written before EOF. This may | |
367 | - be the last page in the file. */ | |
368 | - memset(stream.next_out, 0, stream.avail_out); | |
369 | - stream.avail_out = 0; | |
370 | + if (!stream.avail_out) { | |
371 | + /* This page completed */ | |
372 | + if (pages[curpage]) { | |
373 | + flush_dcache_page(pages[curpage]); | |
374 | + SetPageUptodate(pages[curpage]); | |
375 | } | |
376 | + curpage++; | |
377 | + } | |
378 | + if (!stream.avail_in) | |
379 | + curbh++; | |
380 | + } | |
381 | +inflate_out: | |
382 | + zlib_inflateEnd(&stream); | |
383 | ||
384 | - if ( !stream.avail_out ) { | |
385 | - /* This page completed */ | |
386 | - if ( page ) { | |
387 | - flush_dcache_page(page); | |
388 | - SetPageUptodate(page); | |
389 | - kunmap(page); | |
390 | - unlock_page(page); | |
391 | - if ( fpage == xpage ) | |
392 | - err = 0; /* The critical page */ | |
393 | - else | |
394 | - page_cache_release(page); | |
395 | - } | |
396 | - fpage++; | |
397 | - } | |
398 | +z_eio: | |
399 | + mutex_unlock(&zisofs_zlib_lock); | |
400 | + | |
401 | +b_eio: | |
402 | + for (i = 0; i < haveblocks; i++) | |
403 | + brelse(bhs[i]); | |
404 | + return stream.total_out; | |
405 | +} | |
406 | + | |
407 | +/* | |
408 | + * Uncompress data so that pages[full_page] is fully uptodate and possibly | |
409 | + * fills in other pages if we have data for them. | |
410 | + */ | |
411 | +static int zisofs_fill_pages(struct inode *inode, int full_page, int pcount, | |
412 | + struct page **pages) | |
413 | +{ | |
414 | + loff_t start_off, end_off; | |
415 | + loff_t block_start, block_end; | |
416 | + unsigned int header_size = ISOFS_I(inode)->i_format_parm[0]; | |
417 | + unsigned int zisofs_block_shift = ISOFS_I(inode)->i_format_parm[1]; | |
418 | + unsigned int blockptr; | |
419 | + loff_t poffset = 0; | |
420 | + blkcnt_t cstart_block, cend_block; | |
421 | + struct buffer_head *bh; | |
422 | + unsigned int blkbits = ISOFS_BUFFER_BITS(inode); | |
423 | + unsigned int blksize = 1 << blkbits; | |
424 | + int err; | |
425 | + loff_t ret; | |
426 | + | |
427 | + BUG_ON(!pages[full_page]); | |
428 | + | |
429 | + /* | |
430 | + * We want to read at least 'full_page' page. Because we have to | |
431 | + * uncompress the whole compression block anyway, fill the surrounding | |
432 | + * pages with the data we have anyway... | |
433 | + */ | |
434 | + start_off = page_offset(pages[full_page]); | |
435 | + end_off = min_t(loff_t, start_off + PAGE_CACHE_SIZE, inode->i_size); | |
436 | + | |
437 | + cstart_block = start_off >> zisofs_block_shift; | |
438 | + cend_block = (end_off + (1 << zisofs_block_shift) - 1) | |
439 | + >> zisofs_block_shift; | |
440 | + | |
441 | + WARN_ON(start_off - (full_page << PAGE_CACHE_SHIFT) != | |
442 | + ((cstart_block << zisofs_block_shift) & PAGE_CACHE_MASK)); | |
443 | + | |
444 | + /* Find the pointer to this specific chunk */ | |
445 | + /* Note: we're not using isonum_731() here because the data is known aligned */ | |
446 | + /* Note: header_size is in 32-bit words (4 bytes) */ | |
447 | + blockptr = (header_size + cstart_block) << 2; | |
448 | + bh = isofs_bread(inode, blockptr >> blkbits); | |
449 | + if (!bh) | |
450 | + return -EIO; | |
451 | + block_start = le32_to_cpu(*(__le32 *) | |
452 | + (bh->b_data + (blockptr & (blksize - 1)))); | |
453 | + | |
454 | + while (cstart_block < cend_block && pcount > 0) { | |
455 | + /* Load end of the compressed block in the file */ | |
456 | + blockptr += 4; | |
457 | + /* Traversed to next block? */ | |
458 | + if (!(blockptr & (blksize - 1))) { | |
459 | + brelse(bh); | |
460 | + | |
461 | + bh = isofs_bread(inode, blockptr >> blkbits); | |
462 | + if (!bh) | |
463 | + return -EIO; | |
464 | + } | |
465 | + block_end = le32_to_cpu(*(__le32 *) | |
466 | + (bh->b_data + (blockptr & (blksize - 1)))); | |
467 | + if (block_start > block_end) { | |
468 | + brelse(bh); | |
469 | + return -EIO; | |
470 | + } | |
471 | + err = 0; | |
472 | + ret = zisofs_uncompress_block(inode, block_start, block_end, | |
473 | + pcount, pages, poffset, &err); | |
474 | + poffset += ret; | |
475 | + pages += poffset >> PAGE_CACHE_SHIFT; | |
476 | + pcount -= poffset >> PAGE_CACHE_SHIFT; | |
477 | + full_page -= poffset >> PAGE_CACHE_SHIFT; | |
478 | + poffset &= ~PAGE_CACHE_MASK; | |
479 | + | |
480 | + if (err) { | |
481 | + brelse(bh); | |
482 | + /* | |
483 | + * Did we finish reading the page we really wanted | |
484 | + * to read? | |
485 | + */ | |
486 | + if (full_page < 0) | |
487 | + return 0; | |
488 | + return err; | |
489 | } | |
490 | - zlib_inflateEnd(&stream); | |
491 | ||
492 | - z_eio: | |
493 | - mutex_unlock(&zisofs_zlib_lock); | |
494 | + block_start = block_end; | |
495 | + cstart_block++; | |
496 | + } | |
497 | + | |
498 | + if (poffset && *pages) { | |
499 | + memset(page_address(*pages) + poffset, 0, | |
500 | + PAGE_CACHE_SIZE - poffset); | |
501 | + flush_dcache_page(*pages); | |
502 | + SetPageUptodate(*pages); | |
503 | + } | |
504 | + return 0; | |
505 | +} | |
506 | ||
507 | - b_eio: | |
508 | - for ( i = 0 ; i < haveblocks ; i++ ) { | |
509 | - if ( bhs[i] ) | |
510 | - brelse(bhs[i]); | |
511 | +/* | |
512 | + * When decompressing, we typically obtain more than one page | |
513 | + * per reference. We inject the additional pages into the page | |
514 | + * cache as a form of readahead. | |
515 | + */ | |
516 | +static int zisofs_readpage(struct file *file, struct page *page) | |
517 | +{ | |
518 | + struct inode *inode = file->f_path.dentry->d_inode; | |
519 | + struct address_space *mapping = inode->i_mapping; | |
520 | + int err; | |
521 | + int i, pcount, full_page; | |
522 | + unsigned int zisofs_block_shift = ISOFS_I(inode)->i_format_parm[1]; | |
523 | + unsigned int zisofs_pages_per_cblock = | |
524 | + PAGE_CACHE_SHIFT <= zisofs_block_shift ? | |
525 | + (1 << (zisofs_block_shift - PAGE_CACHE_SHIFT)) : 0; | |
526 | + struct page *pages[max_t(unsigned, zisofs_pages_per_cblock, 1)]; | |
527 | + pgoff_t index = page->index, end_index; | |
528 | + | |
529 | + end_index = (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | |
530 | + /* | |
531 | + * If this page is wholly outside i_size we just return zero; | |
532 | + * do_generic_file_read() will handle this for us | |
533 | + */ | |
534 | + if (index >= end_index) { | |
535 | + SetPageUptodate(page); | |
536 | + unlock_page(page); | |
537 | + return 0; | |
538 | + } | |
539 | + | |
540 | + if (PAGE_CACHE_SHIFT <= zisofs_block_shift) { | |
541 | + /* We have already been given one page, this is the one | |
542 | + we must do. */ | |
543 | + full_page = index & (zisofs_pages_per_cblock - 1); | |
544 | + pcount = min_t(int, zisofs_pages_per_cblock, | |
545 | + end_index - (index & ~(zisofs_pages_per_cblock - 1))); | |
546 | + index -= full_page; | |
547 | + } else { | |
548 | + full_page = 0; | |
549 | + pcount = 1; | |
550 | + } | |
551 | + pages[full_page] = page; | |
552 | + | |
553 | + for (i = 0; i < pcount; i++, index++) { | |
554 | + if (i != full_page) | |
555 | + pages[i] = grab_cache_page_nowait(mapping, index); | |
556 | + if (pages[i]) { | |
557 | + ClearPageError(pages[i]); | |
558 | + kmap(pages[i]); | |
559 | } | |
560 | } | |
561 | ||
562 | -eio: | |
563 | + err = zisofs_fill_pages(inode, full_page, pcount, pages); | |
564 | ||
565 | /* Release any residual pages, do not SetPageUptodate */ | |
566 | - while ( fpage < maxpage ) { | |
567 | - page = pages[fpage]; | |
568 | - if ( page ) { | |
569 | - flush_dcache_page(page); | |
570 | - if ( fpage == xpage ) | |
571 | - SetPageError(page); | |
572 | - kunmap(page); | |
573 | - unlock_page(page); | |
574 | - if ( fpage != xpage ) | |
575 | - page_cache_release(page); | |
576 | + for (i = 0; i < pcount; i++) { | |
577 | + if (pages[i]) { | |
578 | + flush_dcache_page(pages[i]); | |
579 | + if (i == full_page && err) | |
580 | + SetPageError(pages[i]); | |
581 | + kunmap(pages[i]); | |
582 | + unlock_page(pages[i]); | |
583 | + if (i != full_page) | |
584 | + page_cache_release(pages[i]); | |
585 | } | |
586 | - fpage++; | |
587 | } | |
588 | ||
589 | /* At this point, err contains 0 or -EIO depending on the "critical" page */ | |
590 | diff --git a/fs/isofs/rock.c b/fs/isofs/rock.c | |
591 | index c2fb2dd..96a685c 100644 | |
592 | --- a/fs/isofs/rock.c | |
593 | +++ b/fs/isofs/rock.c | |
594 | @@ -518,8 +518,7 @@ repeat: | |
595 | if (algo == SIG('p', 'z')) { | |
596 | int block_shift = | |
597 | isonum_711(&rr->u.ZF.parms[1]); | |
598 | - if (block_shift < PAGE_CACHE_SHIFT | |
599 | - || block_shift > 17) { | |
600 | + if (block_shift > 17) { | |
601 | printk(KERN_WARNING "isofs: " | |
602 | "Can't handle ZF block " | |
603 | "size of 2^%d\n", | |
604 | -- | |
605 | 1.6.0.2 | |
606 |