a1d312de7780e (Thomas Gleixner 2019-05-22 09:51:42 +0200 1) // SPDX-License-Identifier: GPL-2.0-or-later
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 2) /**
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 3) * compress.c - NTFS kernel compressed attributes handling.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 4) * Part of the Linux-NTFS project.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 5) *
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 6) * Copyright (c) 2001-2004 Anton Altaparmakov
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 7) * Copyright (c) 2002 Richard Russon
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 8) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 9)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 10) #include <linux/fs.h>
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 11) #include <linux/buffer_head.h>
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 12) #include <linux/blkdev.h>
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 13) #include <linux/vmalloc.h>
5a0e3ad6af866 (Tejun Heo 2010-03-24 17:04:11 +0900 14) #include <linux/slab.h>
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 15)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 16) #include "attrib.h"
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 17) #include "inode.h"
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 18) #include "debug.h"
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 19) #include "ntfs.h"
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 20)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 21) /**
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 22) * ntfs_compression_constants - enum of constants used in the compression code
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 23) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 24) typedef enum {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 25) /* Token types and access mask. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 26) NTFS_SYMBOL_TOKEN = 0,
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 27) NTFS_PHRASE_TOKEN = 1,
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 28) NTFS_TOKEN_MASK = 1,
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 29)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 30) /* Compression sub-block constants. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 31) NTFS_SB_SIZE_MASK = 0x0fff,
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 32) NTFS_SB_SIZE = 0x1000,
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 33) NTFS_SB_IS_COMPRESSED = 0x8000,
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 34)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 35) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 36) * The maximum compression block size is by definition 16 * the cluster
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 37) * size, with the maximum supported cluster size being 4kiB. Thus the
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 38) * maximum compression buffer size is 64kiB, so we use this when
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 39) * initializing the compression buffer.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 40) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 41) NTFS_MAX_CB_SIZE = 64 * 1024,
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 42) } ntfs_compression_constants;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 43)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 44) /**
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 45) * ntfs_compression_buffer - one buffer for the decompression engine
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 46) */
504e0e2f3dcac (Fabian Frederick 2014-06-04 16:05:50 -0700 47) static u8 *ntfs_compression_buffer;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 48)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 49) /**
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 50) * ntfs_cb_lock - spinlock which protects ntfs_compression_buffer
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 51) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 52) static DEFINE_SPINLOCK(ntfs_cb_lock);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 53)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 54) /**
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 55) * allocate_compression_buffers - allocate the decompression buffers
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 56) *
4e5e529ad684f (Ingo Molnar 2006-03-23 16:57:48 +0000 57) * Caller has to hold the ntfs_lock mutex.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 58) *
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 59) * Return 0 on success or -ENOMEM if the allocations failed.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 60) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 61) int allocate_compression_buffers(void)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 62) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 63) BUG_ON(ntfs_compression_buffer);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 64)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 65) ntfs_compression_buffer = vmalloc(NTFS_MAX_CB_SIZE);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 66) if (!ntfs_compression_buffer)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 67) return -ENOMEM;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 68) return 0;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 69) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 70)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 71) /**
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 72) * free_compression_buffers - free the decompression buffers
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 73) *
4e5e529ad684f (Ingo Molnar 2006-03-23 16:57:48 +0000 74) * Caller has to hold the ntfs_lock mutex.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 75) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 76) void free_compression_buffers(void)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 77) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 78) BUG_ON(!ntfs_compression_buffer);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 79) vfree(ntfs_compression_buffer);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 80) ntfs_compression_buffer = NULL;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 81) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 82)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 83) /**
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 84) * zero_partial_compressed_page - zero out of bounds compressed page region
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 85) */
367636772f094 (Anton Altaparmakov 2004-11-18 13:46:45 +0000 86) static void zero_partial_compressed_page(struct page *page,
367636772f094 (Anton Altaparmakov 2004-11-18 13:46:45 +0000 87) const s64 initialized_size)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 88) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 89) u8 *kp = page_address(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 90) unsigned int kp_ofs;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 91)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 92) ntfs_debug("Zeroing page region outside initialized size.");
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 93) if (((s64)page->index << PAGE_SHIFT) >= initialized_size) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 94) clear_page(kp);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 95) return;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 96) }
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 97) kp_ofs = initialized_size & ~PAGE_MASK;
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 98) memset(kp + kp_ofs, 0, PAGE_SIZE - kp_ofs);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 99) return;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 100) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 101)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 102) /**
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 103) * handle_bounds_compressed_page - test for&handle out of bounds compressed page
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 104) */
367636772f094 (Anton Altaparmakov 2004-11-18 13:46:45 +0000 105) static inline void handle_bounds_compressed_page(struct page *page,
367636772f094 (Anton Altaparmakov 2004-11-18 13:46:45 +0000 106) const loff_t i_size, const s64 initialized_size)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 107) {
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 108) if ((page->index >= (initialized_size >> PAGE_SHIFT)) &&
367636772f094 (Anton Altaparmakov 2004-11-18 13:46:45 +0000 109) (initialized_size < i_size))
367636772f094 (Anton Altaparmakov 2004-11-18 13:46:45 +0000 110) zero_partial_compressed_page(page, initialized_size);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 111) return;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 112) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 113)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 114) /**
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 115) * ntfs_decompress - decompress a compression block into an array of pages
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 116) * @dest_pages: destination array of pages
2c27ce915078a (Kees Cook 2018-08-17 15:44:11 -0700 117) * @completed_pages: scratch space to track completed pages
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 118) * @dest_index: current index into @dest_pages (IN/OUT)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 119) * @dest_ofs: current offset within @dest_pages[@dest_index] (IN/OUT)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 120) * @dest_max_index: maximum index into @dest_pages (IN)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 121) * @dest_max_ofs: maximum offset within @dest_pages[@dest_max_index] (IN)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 122) * @xpage: the target page (-1 if none) (IN)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 123) * @xpage_done: set to 1 if xpage was completed successfully (IN/OUT)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 124) * @cb_start: compression block to decompress (IN)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 125) * @cb_size: size of compression block @cb_start in bytes (IN)
367636772f094 (Anton Altaparmakov 2004-11-18 13:46:45 +0000 126) * @i_size: file size when we started the read (IN)
367636772f094 (Anton Altaparmakov 2004-11-18 13:46:45 +0000 127) * @initialized_size: initialized file size when we started the read (IN)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 128) *
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 129) * The caller must have disabled preemption. ntfs_decompress() reenables it when
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 130) * the critical section is finished.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 131) *
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 132) * This decompresses the compression block @cb_start into the array of
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 133) * destination pages @dest_pages starting at index @dest_index into @dest_pages
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 134) * and at offset @dest_pos into the page @dest_pages[@dest_index].
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 135) *
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 136) * When the page @dest_pages[@xpage] is completed, @xpage_done is set to 1.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 137) * If xpage is -1 or @xpage has not been completed, @xpage_done is not modified.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 138) *
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 139) * @cb_start is a pointer to the compression block which needs decompressing
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 140) * and @cb_size is the size of @cb_start in bytes (8-64kiB).
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 141) *
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 142) * Return 0 if success or -EOVERFLOW on error in the compressed stream.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 143) * @xpage_done indicates whether the target page (@dest_pages[@xpage]) was
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 144) * completed during the decompression of the compression block (@cb_start).
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 145) *
ea1754a084760 (Kirill A. Shutemov 2016-04-01 15:29:48 +0300 146) * Warning: This function *REQUIRES* PAGE_SIZE >= 4096 or it will blow up
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 147) * unpredicatbly! You have been warned!
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 148) *
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 149) * Note to hackers: This function may not sleep until it has finished accessing
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 150) * the compression block @cb_start as it is a per-CPU buffer.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 151) */
2c27ce915078a (Kees Cook 2018-08-17 15:44:11 -0700 152) static int ntfs_decompress(struct page *dest_pages[], int completed_pages[],
2c27ce915078a (Kees Cook 2018-08-17 15:44:11 -0700 153) int *dest_index, int *dest_ofs, const int dest_max_index,
2c27ce915078a (Kees Cook 2018-08-17 15:44:11 -0700 154) const int dest_max_ofs, const int xpage, char *xpage_done,
2c27ce915078a (Kees Cook 2018-08-17 15:44:11 -0700 155) u8 *const cb_start, const u32 cb_size, const loff_t i_size,
367636772f094 (Anton Altaparmakov 2004-11-18 13:46:45 +0000 156) const s64 initialized_size)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 157) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 158) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 159) * Pointers into the compressed data, i.e. the compression block (cb),
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 160) * and the therein contained sub-blocks (sb).
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 161) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 162) u8 *cb_end = cb_start + cb_size; /* End of cb. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 163) u8 *cb = cb_start; /* Current position in cb. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 164) u8 *cb_sb_start = cb; /* Beginning of the current sb in the cb. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 165) u8 *cb_sb_end; /* End of current sb / beginning of next sb. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 166)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 167) /* Variables for uncompressed data / destination. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 168) struct page *dp; /* Current destination page being worked on. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 169) u8 *dp_addr; /* Current pointer into dp. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 170) u8 *dp_sb_start; /* Start of current sub-block in dp. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 171) u8 *dp_sb_end; /* End of current sb in dp (dp_sb_start +
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 172) NTFS_SB_SIZE). */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 173) u16 do_sb_start; /* @dest_ofs when starting this sub-block. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 174) u16 do_sb_end; /* @dest_ofs of end of this sb (do_sb_start +
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 175) NTFS_SB_SIZE). */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 176)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 177) /* Variables for tag and token parsing. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 178) u8 tag; /* Current tag. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 179) int token; /* Loop counter for the eight tokens in tag. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 180) int nr_completed_pages = 0;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 181)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 182) /* Default error code. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 183) int err = -EOVERFLOW;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 184)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 185) ntfs_debug("Entering, cb_size = 0x%x.", cb_size);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 186) do_next_sb:
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 187) ntfs_debug("Beginning sub-block at offset = 0x%zx in the cb.",
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 188) cb - cb_start);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 189) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 190) * Have we reached the end of the compression block or the end of the
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 191) * decompressed data? The latter can happen for example if the current
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 192) * position in the compression block is one byte before its end so the
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 193) * first two checks do not detect it.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 194) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 195) if (cb == cb_end || !le16_to_cpup((le16*)cb) ||
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 196) (*dest_index == dest_max_index &&
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 197) *dest_ofs == dest_max_ofs)) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 198) int i;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 199)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 200) ntfs_debug("Completed. Returning success (0).");
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 201) err = 0;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 202) return_error:
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 203) /* We can sleep from now on, so we drop lock. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 204) spin_unlock(&ntfs_cb_lock);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 205) /* Second stage: finalize completed pages. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 206) if (nr_completed_pages > 0) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 207) for (i = 0; i < nr_completed_pages; i++) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 208) int di = completed_pages[i];
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 209)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 210) dp = dest_pages[di];
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 211) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 212) * If we are outside the initialized size, zero
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 213) * the out of bounds page range.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 214) */
367636772f094 (Anton Altaparmakov 2004-11-18 13:46:45 +0000 215) handle_bounds_compressed_page(dp, i_size,
367636772f094 (Anton Altaparmakov 2004-11-18 13:46:45 +0000 216) initialized_size);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 217) flush_dcache_page(dp);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 218) kunmap(dp);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 219) SetPageUptodate(dp);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 220) unlock_page(dp);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 221) if (di == xpage)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 222) *xpage_done = 1;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 223) else
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 224) put_page(dp);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 225) dest_pages[di] = NULL;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 226) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 227) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 228) return err;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 229) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 230)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 231) /* Setup offsets for the current sub-block destination. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 232) do_sb_start = *dest_ofs;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 233) do_sb_end = do_sb_start + NTFS_SB_SIZE;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 234)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 235) /* Check that we are still within allowed boundaries. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 236) if (*dest_index == dest_max_index && do_sb_end > dest_max_ofs)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 237) goto return_overflow;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 238)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 239) /* Does the minimum size of a compressed sb overflow valid range? */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 240) if (cb + 6 > cb_end)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 241) goto return_overflow;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 242)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 243) /* Setup the current sub-block source pointers and validate range. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 244) cb_sb_start = cb;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 245) cb_sb_end = cb_sb_start + (le16_to_cpup((le16*)cb) & NTFS_SB_SIZE_MASK)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 246) + 3;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 247) if (cb_sb_end > cb_end)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 248) goto return_overflow;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 249)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 250) /* Get the current destination page. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 251) dp = dest_pages[*dest_index];
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 252) if (!dp) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 253) /* No page present. Skip decompression of this sub-block. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 254) cb = cb_sb_end;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 255)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 256) /* Advance destination position to next sub-block. */
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 257) *dest_ofs = (*dest_ofs + NTFS_SB_SIZE) & ~PAGE_MASK;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 258) if (!*dest_ofs && (++*dest_index > dest_max_index))
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 259) goto return_overflow;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 260) goto do_next_sb;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 261) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 262)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 263) /* We have a valid destination page. Setup the destination pointers. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 264) dp_addr = (u8*)page_address(dp) + do_sb_start;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 265)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 266) /* Now, we are ready to process the current sub-block (sb). */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 267) if (!(le16_to_cpup((le16*)cb) & NTFS_SB_IS_COMPRESSED)) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 268) ntfs_debug("Found uncompressed sub-block.");
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 269) /* This sb is not compressed, just copy it into destination. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 270)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 271) /* Advance source position to first data byte. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 272) cb += 2;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 273)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 274) /* An uncompressed sb must be full size. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 275) if (cb_sb_end - cb != NTFS_SB_SIZE)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 276) goto return_overflow;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 277)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 278) /* Copy the block and advance the source position. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 279) memcpy(dp_addr, cb, NTFS_SB_SIZE);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 280) cb += NTFS_SB_SIZE;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 281)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 282) /* Advance destination position to next sub-block. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 283) *dest_ofs += NTFS_SB_SIZE;
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 284) if (!(*dest_ofs &= ~PAGE_MASK)) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 285) finalize_page:
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 286) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 287) * First stage: add current page index to array of
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 288) * completed pages.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 289) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 290) completed_pages[nr_completed_pages++] = *dest_index;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 291) if (++*dest_index > dest_max_index)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 292) goto return_overflow;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 293) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 294) goto do_next_sb;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 295) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 296) ntfs_debug("Found compressed sub-block.");
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 297) /* This sb is compressed, decompress it into destination. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 298)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 299) /* Setup destination pointers. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 300) dp_sb_start = dp_addr;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 301) dp_sb_end = dp_sb_start + NTFS_SB_SIZE;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 302)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 303) /* Forward to the first tag in the sub-block. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 304) cb += 2;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 305) do_next_tag:
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 306) if (cb == cb_sb_end) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 307) /* Check if the decompressed sub-block was not full-length. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 308) if (dp_addr < dp_sb_end) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 309) int nr_bytes = do_sb_end - *dest_ofs;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 310)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 311) ntfs_debug("Filling incomplete sub-block with "
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 312) "zeroes.");
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 313) /* Zero remainder and update destination position. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 314) memset(dp_addr, 0, nr_bytes);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 315) *dest_ofs += nr_bytes;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 316) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 317) /* We have finished the current sub-block. */
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 318) if (!(*dest_ofs &= ~PAGE_MASK))
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 319) goto finalize_page;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 320) goto do_next_sb;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 321) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 322)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 323) /* Check we are still in range. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 324) if (cb > cb_sb_end || dp_addr > dp_sb_end)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 325) goto return_overflow;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 326)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 327) /* Get the next tag and advance to first token. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 328) tag = *cb++;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 329)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 330) /* Parse the eight tokens described by the tag. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 331) for (token = 0; token < 8; token++, tag >>= 1) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 332) u16 lg, pt, length, max_non_overlap;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 333) register u16 i;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 334) u8 *dp_back_addr;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 335)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 336) /* Check if we are done / still in range. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 337) if (cb >= cb_sb_end || dp_addr > dp_sb_end)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 338) break;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 339)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 340) /* Determine token type and parse appropriately.*/
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 341) if ((tag & NTFS_TOKEN_MASK) == NTFS_SYMBOL_TOKEN) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 342) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 343) * We have a symbol token, copy the symbol across, and
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 344) * advance the source and destination positions.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 345) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 346) *dp_addr++ = *cb++;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 347) ++*dest_ofs;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 348)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 349) /* Continue with the next token. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 350) continue;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 351) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 352)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 353) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 354) * We have a phrase token. Make sure it is not the first tag in
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 355) * the sb as this is illegal and would confuse the code below.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 356) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 357) if (dp_addr == dp_sb_start)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 358) goto return_overflow;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 359)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 360) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 361) * Determine the number of bytes to go back (p) and the number
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 362) * of bytes to copy (l). We use an optimized algorithm in which
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 363) * we first calculate log2(current destination position in sb),
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 364) * which allows determination of l and p in O(1) rather than
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 365) * O(n). We just need an arch-optimized log2() function now.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 366) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 367) lg = 0;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 368) for (i = *dest_ofs - do_sb_start - 1; i >= 0x10; i >>= 1)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 369) lg++;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 370)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 371) /* Get the phrase token into i. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 372) pt = le16_to_cpup((le16*)cb);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 373)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 374) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 375) * Calculate starting position of the byte sequence in
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 376) * the destination using the fact that p = (pt >> (12 - lg)) + 1
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 377) * and make sure we don't go too far back.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 378) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 379) dp_back_addr = dp_addr - (pt >> (12 - lg)) - 1;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 380) if (dp_back_addr < dp_sb_start)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 381) goto return_overflow;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 382)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 383) /* Now calculate the length of the byte sequence. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 384) length = (pt & (0xfff >> lg)) + 3;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 385)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 386) /* Advance destination position and verify it is in range. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 387) *dest_ofs += length;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 388) if (*dest_ofs > do_sb_end)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 389) goto return_overflow;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 390)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 391) /* The number of non-overlapping bytes. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 392) max_non_overlap = dp_addr - dp_back_addr;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 393)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 394) if (length <= max_non_overlap) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 395) /* The byte sequence doesn't overlap, just copy it. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 396) memcpy(dp_addr, dp_back_addr, length);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 397)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 398) /* Advance destination pointer. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 399) dp_addr += length;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 400) } else {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 401) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 402) * The byte sequence does overlap, copy non-overlapping
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 403) * part and then do a slow byte by byte copy for the
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 404) * overlapping part. Also, advance the destination
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 405) * pointer.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 406) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 407) memcpy(dp_addr, dp_back_addr, max_non_overlap);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 408) dp_addr += max_non_overlap;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 409) dp_back_addr += max_non_overlap;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 410) length -= max_non_overlap;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 411) while (length--)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 412) *dp_addr++ = *dp_back_addr++;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 413) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 414)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 415) /* Advance source position and continue with the next token. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 416) cb += 2;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 417) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 418)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 419) /* No tokens left in the current tag. Continue with the next tag. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 420) goto do_next_tag;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 421)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 422) return_overflow:
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 423) ntfs_error(NULL, "Failed. Returning -EOVERFLOW.");
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 424) goto return_error;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 425) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 426)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 427) /**
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 428) * ntfs_read_compressed_block - read a compressed block into the page cache
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 429) * @page: locked page in the compression block(s) we need to read
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 430) *
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 431) * When we are called the page has already been verified to be locked and the
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 432) * attribute is known to be non-resident, not encrypted, but compressed.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 433) *
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 434) * 1. Determine which compression block(s) @page is in.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 435) * 2. Get hold of all pages corresponding to this/these compression block(s).
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 436) * 3. Read the (first) compression block.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 437) * 4. Decompress it into the corresponding pages.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 438) * 5. Throw the compressed data away and proceed to 3. for the next compression
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 439) * block or return success if no more compression blocks left.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 440) *
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 441) * Warning: We have to be careful what we do about existing pages. They might
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 442) * have been written to so that we would lose data if we were to just overwrite
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 443) * them with the out-of-date uncompressed data.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 444) *
ea1754a084760 (Kirill A. Shutemov 2016-04-01 15:29:48 +0300 445) * FIXME: For PAGE_SIZE > cb_size we are not doing the Right Thing(TM) at
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 446) * the end of the file I think. We need to detect this case and zero the out
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 447) * of bounds remainder of the page in question and mark it as handled. At the
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 448) * moment we would just return -EIO on such a page. This bug will only become
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 449) * apparent if pages are above 8kiB and the NTFS volume only uses 512 byte
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 450) * clusters so is probably not going to be seen by anyone. Still this should
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 451) * be fixed. (AIA)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 452) *
ea1754a084760 (Kirill A. Shutemov 2016-04-01 15:29:48 +0300 453) * FIXME: Again for PAGE_SIZE > cb_size we are screwing up both in
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 454) * handling sparse and compressed cbs. (AIA)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 455) *
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 456) * FIXME: At the moment we don't do any zeroing out in the case that
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 457) * initialized_size is less than data_size. This should be safe because of the
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 458) * nature of the compression algorithm used. Just in case we check and output
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 459) * an error message in read inode if the two sizes are not equal for a
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 460) * compressed file. (AIA)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 461) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 462) int ntfs_read_compressed_block(struct page *page)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 463) {
367636772f094 (Anton Altaparmakov 2004-11-18 13:46:45 +0000 464) loff_t i_size;
367636772f094 (Anton Altaparmakov 2004-11-18 13:46:45 +0000 465) s64 initialized_size;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 466) struct address_space *mapping = page->mapping;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 467) ntfs_inode *ni = NTFS_I(mapping->host);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 468) ntfs_volume *vol = ni->vol;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 469) struct super_block *sb = vol->sb;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 470) runlist_element *rl;
367636772f094 (Anton Altaparmakov 2004-11-18 13:46:45 +0000 471) unsigned long flags, block_size = sb->s_blocksize;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 472) unsigned char block_size_bits = sb->s_blocksize_bits;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 473) u8 *cb, *cb_pos, *cb_end;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 474) struct buffer_head **bhs;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 475) unsigned long offset, index = page->index;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 476) u32 cb_size = ni->itype.compressed.block_size;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 477) u64 cb_size_mask = cb_size - 1UL;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 478) VCN vcn;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 479) LCN lcn;
ea1754a084760 (Kirill A. Shutemov 2016-04-01 15:29:48 +0300 480) /* The first wanted vcn (minimum alignment is PAGE_SIZE). */
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 481) VCN start_vcn = (((s64)index << PAGE_SHIFT) & ~cb_size_mask) >>
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 482) vol->cluster_size_bits;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 483) /*
25985edcedea6 (Lucas De Marchi 2011-03-30 22:57:33 -0300 484) * The first vcn after the last wanted vcn (minimum alignment is again
ea1754a084760 (Kirill A. Shutemov 2016-04-01 15:29:48 +0300 485) * PAGE_SIZE.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 486) */
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 487) VCN end_vcn = ((((s64)(index + 1UL) << PAGE_SHIFT) + cb_size - 1)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 488) & ~cb_size_mask) >> vol->cluster_size_bits;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 489) /* Number of compression blocks (cbs) in the wanted vcn range. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 490) unsigned int nr_cbs = (end_vcn - start_vcn) << vol->cluster_size_bits
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 491) >> ni->itype.compressed.block_size_bits;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 492) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 493) * Number of pages required to store the uncompressed data from all
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 494) * compression blocks (cbs) overlapping @page. Due to alignment
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 495) * guarantees of start_vcn and end_vcn, no need to round up here.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 496) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 497) unsigned int nr_pages = (end_vcn - start_vcn) <<
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 498) vol->cluster_size_bits >> PAGE_SHIFT;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 499) unsigned int xpage, max_page, cur_page, cur_ofs, i;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 500) unsigned int cb_clusters, cb_max_ofs;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 501) int block, max_block, cb_max_page, bhs_size, nr_bhs, err = 0;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 502) struct page **pages;
2c27ce915078a (Kees Cook 2018-08-17 15:44:11 -0700 503) int *completed_pages;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 504) unsigned char xpage_done = 0;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 505)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 506) ntfs_debug("Entering, page->index = 0x%lx, cb_size = 0x%x, nr_pages = "
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 507) "%i.", index, cb_size, nr_pages);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 508) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 509) * Bad things happen if we get here for anything that is not an
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 510) * unnamed $DATA attribute.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 511) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 512) BUG_ON(ni->type != AT_DATA);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 513) BUG_ON(ni->name_len);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 514)
6da2ec56059c3 (Kees Cook 2018-06-12 13:55:00 -0700 515) pages = kmalloc_array(nr_pages, sizeof(struct page *), GFP_NOFS);
2c27ce915078a (Kees Cook 2018-08-17 15:44:11 -0700 516) completed_pages = kmalloc_array(nr_pages + 1, sizeof(int), GFP_NOFS);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 517)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 518) /* Allocate memory to store the buffer heads we need. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 519) bhs_size = cb_size / block_size * sizeof(struct buffer_head *);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 520) bhs = kmalloc(bhs_size, GFP_NOFS);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 521)
2c27ce915078a (Kees Cook 2018-08-17 15:44:11 -0700 522) if (unlikely(!pages || !bhs || !completed_pages)) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 523) kfree(bhs);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 524) kfree(pages);
2c27ce915078a (Kees Cook 2018-08-17 15:44:11 -0700 525) kfree(completed_pages);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 526) unlock_page(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 527) ntfs_error(vol->sb, "Failed to allocate internal buffers.");
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 528) return -ENOMEM;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 529) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 530)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 531) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 532) * We have already been given one page, this is the one we must do.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 533) * Once again, the alignment guarantees keep it simple.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 534) */
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 535) offset = start_vcn << vol->cluster_size_bits >> PAGE_SHIFT;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 536) xpage = index - offset;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 537) pages[xpage] = page;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 538) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 539) * The remaining pages need to be allocated and inserted into the page
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 540) * cache, alignment guarantees keep all the below much simpler. (-8
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 541) */
367636772f094 (Anton Altaparmakov 2004-11-18 13:46:45 +0000 542) read_lock_irqsave(&ni->size_lock, flags);
367636772f094 (Anton Altaparmakov 2004-11-18 13:46:45 +0000 543) i_size = i_size_read(VFS_I(ni));
367636772f094 (Anton Altaparmakov 2004-11-18 13:46:45 +0000 544) initialized_size = ni->initialized_size;
367636772f094 (Anton Altaparmakov 2004-11-18 13:46:45 +0000 545) read_unlock_irqrestore(&ni->size_lock, flags);
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 546) max_page = ((i_size + PAGE_SIZE - 1) >> PAGE_SHIFT) -
367636772f094 (Anton Altaparmakov 2004-11-18 13:46:45 +0000 547) offset;
ebab89909e0dc (Anton Altaparmakov 2007-11-03 07:38:59 +0000 548) /* Is the page fully outside i_size? (truncate in progress) */
ebab89909e0dc (Anton Altaparmakov 2007-11-03 07:38:59 +0000 549) if (xpage >= max_page) {
ebab89909e0dc (Anton Altaparmakov 2007-11-03 07:38:59 +0000 550) kfree(bhs);
ebab89909e0dc (Anton Altaparmakov 2007-11-03 07:38:59 +0000 551) kfree(pages);
2c27ce915078a (Kees Cook 2018-08-17 15:44:11 -0700 552) kfree(completed_pages);
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 553) zero_user(page, 0, PAGE_SIZE);
ebab89909e0dc (Anton Altaparmakov 2007-11-03 07:38:59 +0000 554) ntfs_debug("Compressed read outside i_size - truncated?");
ebab89909e0dc (Anton Altaparmakov 2007-11-03 07:38:59 +0000 555) SetPageUptodate(page);
ebab89909e0dc (Anton Altaparmakov 2007-11-03 07:38:59 +0000 556) unlock_page(page);
ebab89909e0dc (Anton Altaparmakov 2007-11-03 07:38:59 +0000 557) return 0;
ebab89909e0dc (Anton Altaparmakov 2007-11-03 07:38:59 +0000 558) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 559) if (nr_pages < max_page)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 560) max_page = nr_pages;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 561) for (i = 0; i < max_page; i++, offset++) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 562) if (i != xpage)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 563) pages[i] = grab_cache_page_nowait(mapping, offset);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 564) page = pages[i];
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 565) if (page) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 566) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 567) * We only (re)read the page if it isn't already read
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 568) * in and/or dirty or we would be losing data or at
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 569) * least wasting our time.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 570) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 571) if (!PageDirty(page) && (!PageUptodate(page) ||
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 572) PageError(page))) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 573) ClearPageError(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 574) kmap(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 575) continue;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 576) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 577) unlock_page(page);
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 578) put_page(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 579) pages[i] = NULL;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 580) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 581) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 582)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 583) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 584) * We have the runlist, and all the destination pages we need to fill.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 585) * Now read the first compression block.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 586) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 587) cur_page = 0;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 588) cur_ofs = 0;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 589) cb_clusters = ni->itype.compressed.block_clusters;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 590) do_next_cb:
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 591) nr_cbs--;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 592) nr_bhs = 0;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 593)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 594) /* Read all cb buffer heads one cluster at a time. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 595) rl = NULL;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 596) for (vcn = start_vcn, start_vcn += cb_clusters; vcn < start_vcn;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 597) vcn++) {
c49c31115067b (Richard Knutsson 2006-09-30 23:27:12 -0700 598) bool is_retry = false;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 599)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 600) if (!rl) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 601) lock_retry_remap:
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 602) down_read(&ni->runlist.lock);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 603) rl = ni->runlist.rl;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 604) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 605) if (likely(rl != NULL)) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 606) /* Seek to element containing target vcn. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 607) while (rl->length && rl[1].vcn <= vcn)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 608) rl++;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 609) lcn = ntfs_rl_vcn_to_lcn(rl, vcn);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 610) } else
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 611) lcn = LCN_RL_NOT_MAPPED;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 612) ntfs_debug("Reading vcn = 0x%llx, lcn = 0x%llx.",
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 613) (unsigned long long)vcn,
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 614) (unsigned long long)lcn);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 615) if (lcn < 0) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 616) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 617) * When we reach the first sparse cluster we have
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 618) * finished with the cb.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 619) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 620) if (lcn == LCN_HOLE)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 621) break;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 622) if (is_retry || lcn != LCN_RL_NOT_MAPPED)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 623) goto rl_err;
c49c31115067b (Richard Knutsson 2006-09-30 23:27:12 -0700 624) is_retry = true;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 625) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 626) * Attempt to map runlist, dropping lock for the
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 627) * duration.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 628) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 629) up_read(&ni->runlist.lock);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 630) if (!ntfs_map_runlist(ni, vcn))
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 631) goto lock_retry_remap;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 632) goto map_rl_err;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 633) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 634) block = lcn << vol->cluster_size_bits >> block_size_bits;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 635) /* Read the lcn from device in chunks of block_size bytes. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 636) max_block = block + (vol->cluster_size >> block_size_bits);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 637) do {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 638) ntfs_debug("block = 0x%x.", block);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 639) if (unlikely(!(bhs[nr_bhs] = sb_getblk(sb, block))))
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 640) goto getblk_err;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 641) nr_bhs++;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 642) } while (++block < max_block);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 643) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 644)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 645) /* Release the lock if we took it. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 646) if (rl)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 647) up_read(&ni->runlist.lock);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 648)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 649) /* Setup and initiate io on all buffer heads. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 650) for (i = 0; i < nr_bhs; i++) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 651) struct buffer_head *tbh = bhs[i];
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 652)
ca5de404ff036 (Nicholas Piggin 2008-08-02 12:02:13 +0200 653) if (!trylock_buffer(tbh))
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 654) continue;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 655) if (unlikely(buffer_uptodate(tbh))) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 656) unlock_buffer(tbh);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 657) continue;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 658) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 659) get_bh(tbh);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 660) tbh->b_end_io = end_buffer_read_sync;
2a222ca992c35 (Mike Christie 2016-06-05 14:31:43 -0500 661) submit_bh(REQ_OP_READ, 0, tbh);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 662) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 663)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 664) /* Wait for io completion on all buffer heads. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 665) for (i = 0; i < nr_bhs; i++) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 666) struct buffer_head *tbh = bhs[i];
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 667)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 668) if (buffer_uptodate(tbh))
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 669) continue;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 670) wait_on_buffer(tbh);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 671) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 672) * We need an optimization barrier here, otherwise we start
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 673) * hitting the below fixup code when accessing a loopback
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 674) * mounted ntfs partition. This indicates either there is a
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 675) * race condition in the loop driver or, more likely, gcc
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 676) * overoptimises the code without the barrier and it doesn't
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 677) * do the Right Thing(TM).
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 678) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 679) barrier();
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 680) if (unlikely(!buffer_uptodate(tbh))) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 681) ntfs_warning(vol->sb, "Buffer is unlocked but not "
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 682) "uptodate! Unplugging the disk queue "
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 683) "and rescheduling.");
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 684) get_bh(tbh);
7eaceaccab5f4 (Jens Axboe 2011-03-10 08:52:07 +0100 685) io_schedule();
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 686) put_bh(tbh);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 687) if (unlikely(!buffer_uptodate(tbh)))
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 688) goto read_err;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 689) ntfs_warning(vol->sb, "Buffer is now uptodate. Good.");
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 690) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 691) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 692)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 693) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 694) * Get the compression buffer. We must not sleep any more
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 695) * until we are finished with it.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 696) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 697) spin_lock(&ntfs_cb_lock);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 698) cb = ntfs_compression_buffer;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 699)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 700) BUG_ON(!cb);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 701)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 702) cb_pos = cb;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 703) cb_end = cb + cb_size;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 704)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 705) /* Copy the buffer heads into the contiguous buffer. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 706) for (i = 0; i < nr_bhs; i++) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 707) memcpy(cb_pos, bhs[i]->b_data, block_size);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 708) cb_pos += block_size;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 709) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 710)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 711) /* Just a precaution. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 712) if (cb_pos + 2 <= cb + cb_size)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 713) *(u16*)cb_pos = 0;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 714)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 715) /* Reset cb_pos back to the beginning. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 716) cb_pos = cb;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 717)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 718) /* We now have both source (if present) and destination. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 719) ntfs_debug("Successfully read the compression block.");
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 720)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 721) /* The last page and maximum offset within it for the current cb. */
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 722) cb_max_page = (cur_page << PAGE_SHIFT) + cur_ofs + cb_size;
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 723) cb_max_ofs = cb_max_page & ~PAGE_MASK;
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 724) cb_max_page >>= PAGE_SHIFT;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 725)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 726) /* Catch end of file inside a compression block. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 727) if (cb_max_page > max_page)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 728) cb_max_page = max_page;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 729)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 730) if (vcn == start_vcn - cb_clusters) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 731) /* Sparse cb, zero out page range overlapping the cb. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 732) ntfs_debug("Found sparse compression block.");
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 733) /* We can sleep from now on, so we drop lock. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 734) spin_unlock(&ntfs_cb_lock);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 735) if (cb_max_ofs)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 736) cb_max_page--;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 737) for (; cur_page < cb_max_page; cur_page++) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 738) page = pages[cur_page];
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 739) if (page) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 740) if (likely(!cur_ofs))
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 741) clear_page(page_address(page));
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 742) else
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 743) memset(page_address(page) + cur_ofs, 0,
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 744) PAGE_SIZE -
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 745) cur_ofs);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 746) flush_dcache_page(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 747) kunmap(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 748) SetPageUptodate(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 749) unlock_page(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 750) if (cur_page == xpage)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 751) xpage_done = 1;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 752) else
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 753) put_page(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 754) pages[cur_page] = NULL;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 755) }
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 756) cb_pos += PAGE_SIZE - cur_ofs;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 757) cur_ofs = 0;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 758) if (cb_pos >= cb_end)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 759) break;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 760) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 761) /* If we have a partial final page, deal with it now. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 762) if (cb_max_ofs && cb_pos < cb_end) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 763) page = pages[cur_page];
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 764) if (page)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 765) memset(page_address(page) + cur_ofs, 0,
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 766) cb_max_ofs - cur_ofs);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 767) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 768) * No need to update cb_pos at this stage:
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 769) * cb_pos += cb_max_ofs - cur_ofs;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 770) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 771) cur_ofs = cb_max_ofs;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 772) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 773) } else if (vcn == start_vcn) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 774) /* We can't sleep so we need two stages. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 775) unsigned int cur2_page = cur_page;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 776) unsigned int cur_ofs2 = cur_ofs;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 777) u8 *cb_pos2 = cb_pos;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 778)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 779) ntfs_debug("Found uncompressed compression block.");
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 780) /* Uncompressed cb, copy it to the destination pages. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 781) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 782) * TODO: As a big optimization, we could detect this case
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 783) * before we read all the pages and use block_read_full_page()
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 784) * on all full pages instead (we still have to treat partial
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 785) * pages especially but at least we are getting rid of the
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 786) * synchronous io for the majority of pages.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 787) * Or if we choose not to do the read-ahead/-behind stuff, we
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 788) * could just return block_read_full_page(pages[xpage]) as long
ea1754a084760 (Kirill A. Shutemov 2016-04-01 15:29:48 +0300 789) * as PAGE_SIZE <= cb_size.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 790) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 791) if (cb_max_ofs)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 792) cb_max_page--;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 793) /* First stage: copy data into destination pages. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 794) for (; cur_page < cb_max_page; cur_page++) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 795) page = pages[cur_page];
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 796) if (page)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 797) memcpy(page_address(page) + cur_ofs, cb_pos,
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 798) PAGE_SIZE - cur_ofs);
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 799) cb_pos += PAGE_SIZE - cur_ofs;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 800) cur_ofs = 0;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 801) if (cb_pos >= cb_end)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 802) break;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 803) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 804) /* If we have a partial final page, deal with it now. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 805) if (cb_max_ofs && cb_pos < cb_end) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 806) page = pages[cur_page];
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 807) if (page)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 808) memcpy(page_address(page) + cur_ofs, cb_pos,
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 809) cb_max_ofs - cur_ofs);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 810) cb_pos += cb_max_ofs - cur_ofs;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 811) cur_ofs = cb_max_ofs;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 812) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 813) /* We can sleep from now on, so drop lock. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 814) spin_unlock(&ntfs_cb_lock);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 815) /* Second stage: finalize pages. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 816) for (; cur2_page < cb_max_page; cur2_page++) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 817) page = pages[cur2_page];
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 818) if (page) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 819) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 820) * If we are outside the initialized size, zero
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 821) * the out of bounds page range.
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 822) */
367636772f094 (Anton Altaparmakov 2004-11-18 13:46:45 +0000 823) handle_bounds_compressed_page(page, i_size,
367636772f094 (Anton Altaparmakov 2004-11-18 13:46:45 +0000 824) initialized_size);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 825) flush_dcache_page(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 826) kunmap(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 827) SetPageUptodate(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 828) unlock_page(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 829) if (cur2_page == xpage)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 830) xpage_done = 1;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 831) else
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 832) put_page(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 833) pages[cur2_page] = NULL;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 834) }
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 835) cb_pos2 += PAGE_SIZE - cur_ofs2;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 836) cur_ofs2 = 0;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 837) if (cb_pos2 >= cb_end)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 838) break;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 839) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 840) } else {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 841) /* Compressed cb, decompress it into the destination page(s). */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 842) unsigned int prev_cur_page = cur_page;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 843)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 844) ntfs_debug("Found compressed compression block.");
2c27ce915078a (Kees Cook 2018-08-17 15:44:11 -0700 845) err = ntfs_decompress(pages, completed_pages, &cur_page,
2c27ce915078a (Kees Cook 2018-08-17 15:44:11 -0700 846) &cur_ofs, cb_max_page, cb_max_ofs, xpage,
2c27ce915078a (Kees Cook 2018-08-17 15:44:11 -0700 847) &xpage_done, cb_pos, cb_size - (cb_pos - cb),
2c27ce915078a (Kees Cook 2018-08-17 15:44:11 -0700 848) i_size, initialized_size);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 849) /*
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 850) * We can sleep from now on, lock already dropped by
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 851) * ntfs_decompress().
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 852) */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 853) if (err) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 854) ntfs_error(vol->sb, "ntfs_decompress() failed in inode "
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 855) "0x%lx with error code %i. Skipping "
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 856) "this compression block.",
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 857) ni->mft_no, -err);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 858) /* Release the unfinished pages. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 859) for (; prev_cur_page < cur_page; prev_cur_page++) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 860) page = pages[prev_cur_page];
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 861) if (page) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 862) flush_dcache_page(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 863) kunmap(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 864) unlock_page(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 865) if (prev_cur_page != xpage)
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 866) put_page(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 867) pages[prev_cur_page] = NULL;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 868) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 869) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 870) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 871) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 872)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 873) /* Release the buffer heads. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 874) for (i = 0; i < nr_bhs; i++)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 875) brelse(bhs[i]);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 876)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 877) /* Do we have more work to do? */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 878) if (nr_cbs)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 879) goto do_next_cb;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 880)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 881) /* We no longer need the list of buffer heads. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 882) kfree(bhs);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 883)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 884) /* Clean up if we have any pages left. Should never happen. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 885) for (cur_page = 0; cur_page < max_page; cur_page++) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 886) page = pages[cur_page];
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 887) if (page) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 888) ntfs_error(vol->sb, "Still have pages left! "
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 889) "Terminating them with extreme "
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 890) "prejudice. Inode 0x%lx, page index "
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 891) "0x%lx.", ni->mft_no, page->index);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 892) flush_dcache_page(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 893) kunmap(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 894) unlock_page(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 895) if (cur_page != xpage)
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 896) put_page(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 897) pages[cur_page] = NULL;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 898) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 899) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 900)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 901) /* We no longer need the list of pages. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 902) kfree(pages);
2c27ce915078a (Kees Cook 2018-08-17 15:44:11 -0700 903) kfree(completed_pages);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 904)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 905) /* If we have completed the requested page, we return success. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 906) if (likely(xpage_done))
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 907) return 0;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 908)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 909) ntfs_debug("Failed. Returning error code %s.", err == -EOVERFLOW ?
af901ca181d92 (André Goddard Rosa 2009-11-14 13:09:05 -0200 910) "EOVERFLOW" : (!err ? "EIO" : "unknown error"));
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 911) return err < 0 ? err : -EIO;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 912)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 913) read_err:
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 914) ntfs_error(vol->sb, "IO error while reading compressed data.");
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 915) /* Release the buffer heads. */
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 916) for (i = 0; i < nr_bhs; i++)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 917) brelse(bhs[i]);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 918) goto err_out;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 919)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 920) map_rl_err:
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 921) ntfs_error(vol->sb, "ntfs_map_runlist() failed. Cannot read "
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 922) "compression block.");
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 923) goto err_out;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 924)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 925) rl_err:
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 926) up_read(&ni->runlist.lock);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 927) ntfs_error(vol->sb, "ntfs_rl_vcn_to_lcn() failed. Cannot read "
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 928) "compression block.");
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 929) goto err_out;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 930)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 931) getblk_err:
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 932) up_read(&ni->runlist.lock);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 933) ntfs_error(vol->sb, "getblk() failed. Cannot read compression block.");
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 934)
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 935) err_out:
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 936) kfree(bhs);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 937) for (i = cur_page; i < max_page; i++) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 938) page = pages[i];
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 939) if (page) {
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 940) flush_dcache_page(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 941) kunmap(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 942) unlock_page(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 943) if (i != xpage)
09cbfeaf1a5a6 (Kirill A. Shutemov 2016-04-01 15:29:47 +0300 944) put_page(page);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 945) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 946) }
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 947) kfree(pages);
2c27ce915078a (Kees Cook 2018-08-17 15:44:11 -0700 948) kfree(completed_pages);
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 949) return -EIO;
^1da177e4c3f4 (Linus Torvalds 2005-04-16 15:20:36 -0700 950) }
VisionFive2 Linux kernel
StarFive Tech Linux Kernel for VisionFive (JH7110) boards (mirror)
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