Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * Copyright (C) 2017 Red Hat, Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  * Copyright (c) 2018 Christoph Hellwig.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) #include <linux/compiler.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include <linux/iomap.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include <linux/pagemap.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <linux/pagevec.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14)  * Seek for SEEK_DATA / SEEK_HOLE within @page, starting at @lastoff.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15)  * Returns true if found and updates @lastoff to the offset in file.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) static bool
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) page_seek_hole_data(struct inode *inode, struct page *page, loff_t *lastoff,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) 		int whence)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) 	const struct address_space_operations *ops = inode->i_mapping->a_ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) 	unsigned int bsize = i_blocksize(inode), off;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) 	bool seek_data = whence == SEEK_DATA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 	loff_t poff = page_offset(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 	if (WARN_ON_ONCE(*lastoff >= poff + PAGE_SIZE))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 		return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 	if (*lastoff < poff) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 		 * Last offset smaller than the start of the page means we found
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 		 * a hole:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 		if (whence == SEEK_HOLE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 			return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 		*lastoff = poff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 	 * Just check the page unless we can and should check block ranges:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 	if (bsize == PAGE_SIZE || !ops->is_partially_uptodate)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 		return PageUptodate(page) == seek_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 	lock_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 	if (unlikely(page->mapping != inode->i_mapping))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 		goto out_unlock_not_found;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 	for (off = 0; off < PAGE_SIZE; off += bsize) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 		if (offset_in_page(*lastoff) >= off + bsize)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 			continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 		if (ops->is_partially_uptodate(page, off, bsize) == seek_data) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 			unlock_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 			return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 		*lastoff = poff + off + bsize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) out_unlock_not_found:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	unlock_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65)  * Seek for SEEK_DATA / SEEK_HOLE in the page cache.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67)  * Within unwritten extents, the page cache determines which parts are holes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68)  * and which are data: uptodate buffer heads count as data; everything else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69)  * counts as a hole.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71)  * Returns the resulting offset on successs, and -ENOENT otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) static loff_t
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) page_cache_seek_hole_data(struct inode *inode, loff_t offset, loff_t length,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 		int whence)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	pgoff_t index = offset >> PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	pgoff_t end = DIV_ROUND_UP(offset + length, PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	loff_t lastoff = offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	struct pagevec pvec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 	if (length <= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 		return -ENOENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	pagevec_init(&pvec);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 		unsigned nr_pages, i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 		nr_pages = pagevec_lookup_range(&pvec, inode->i_mapping, &index,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 						end - 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 		if (nr_pages == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 		for (i = 0; i < nr_pages; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 			struct page *page = pvec.pages[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 			if (page_seek_hole_data(inode, page, &lastoff, whence))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 				goto check_range;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 			lastoff = page_offset(page) + PAGE_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 		pagevec_release(&pvec);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	} while (index < end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	/* When no page at lastoff and we are not done, we found a hole. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	if (whence != SEEK_HOLE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 		goto not_found;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) check_range:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 	if (lastoff < offset + length)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) not_found:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 	lastoff = -ENOENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 	pagevec_release(&pvec);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 	return lastoff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) static loff_t
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) iomap_seek_hole_actor(struct inode *inode, loff_t offset, loff_t length,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 		      void *data, struct iomap *iomap, struct iomap *srcmap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	switch (iomap->type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	case IOMAP_UNWRITTEN:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 		offset = page_cache_seek_hole_data(inode, offset, length,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 						   SEEK_HOLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 		if (offset < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 			return length;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 		fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 	case IOMAP_HOLE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 		*(loff_t *)data = offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 		return length;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) loff_t
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) iomap_seek_hole(struct inode *inode, loff_t offset, const struct iomap_ops *ops)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 	loff_t size = i_size_read(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	loff_t ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 	/* Nothing to be found before or beyond the end of the file. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	if (offset < 0 || offset >= size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 		return -ENXIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	while (offset < size) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 		ret = iomap_apply(inode, offset, size - offset, IOMAP_REPORT,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 				  ops, &offset, iomap_seek_hole_actor);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 		if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 			return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 		if (ret == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 		offset += ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	return offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) EXPORT_SYMBOL_GPL(iomap_seek_hole);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) static loff_t
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) iomap_seek_data_actor(struct inode *inode, loff_t offset, loff_t length,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 		      void *data, struct iomap *iomap, struct iomap *srcmap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	switch (iomap->type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	case IOMAP_HOLE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 		return length;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 	case IOMAP_UNWRITTEN:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 		offset = page_cache_seek_hole_data(inode, offset, length,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 						   SEEK_DATA);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 		if (offset < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 			return length;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 		fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 		*(loff_t *)data = offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) loff_t
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) iomap_seek_data(struct inode *inode, loff_t offset, const struct iomap_ops *ops)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 	loff_t size = i_size_read(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 	loff_t ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 	/* Nothing to be found before or beyond the end of the file. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	if (offset < 0 || offset >= size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 		return -ENXIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 	while (offset < size) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 		ret = iomap_apply(inode, offset, size - offset, IOMAP_REPORT,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 				  ops, &offset, iomap_seek_data_actor);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 		if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 			return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 		if (ret == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 			return offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 		offset += ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 	/* We've reached the end of the file without finding data */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 	return -ENXIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) EXPORT_SYMBOL_GPL(iomap_seek_data);