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fs/fs_internal.c
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d41ce506b Initial Release, ... |
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/* * 2017 by Marek Behun <marek.behun@nic.cz> * * Derived from code in ext4/dev.c, which was based on reiserfs/dev.c * * SPDX-License-Identifier: GPL-2.0 */ #include <common.h> #include <compiler.h> #include <part.h> #include <memalign.h> int fs_devread(struct blk_desc *blk, disk_partition_t *partition, lbaint_t sector, int byte_offset, int byte_len, char *buf) { unsigned block_len; int log2blksz; ALLOC_CACHE_ALIGN_BUFFER(char, sec_buf, (blk ? blk->blksz : 0)); if (blk == NULL) { printf("** Invalid Block Device Descriptor (NULL) "); return 0; } log2blksz = blk->log2blksz; /* Check partition boundaries */ if ((sector + ((byte_offset + byte_len - 1) >> log2blksz)) >= partition->size) { printf("%s read outside partition " LBAFU " ", __func__, sector); return 0; } /* Get the read to the beginning of a partition */ sector += byte_offset >> log2blksz; byte_offset &= blk->blksz - 1; debug(" <" LBAFU ", %d, %d> ", sector, byte_offset, byte_len); if (byte_offset != 0) { int readlen; /* read first part which isn't aligned with start of sector */ if (blk_dread(blk, partition->start + sector, 1, (void *)sec_buf) != 1) { printf(" ** %s read error ** ", __func__); return 0; } readlen = min((int)blk->blksz - byte_offset, byte_len); memcpy(buf, sec_buf + byte_offset, readlen); buf += readlen; byte_len -= readlen; sector++; } if (byte_len == 0) return 1; /* read sector aligned part */ block_len = byte_len & ~(blk->blksz - 1); if (block_len == 0) { ALLOC_CACHE_ALIGN_BUFFER(u8, p, blk->blksz); block_len = blk->blksz; blk_dread(blk, partition->start + sector, 1, (void *)p); memcpy(buf, p, byte_len); return 1; } if (blk_dread(blk, partition->start + sector, block_len >> log2blksz, (void *)buf) != block_len >> log2blksz) { printf(" ** %s read error - block ", __func__); return 0; } block_len = byte_len & ~(blk->blksz - 1); buf += block_len; byte_len -= block_len; sector += block_len / blk->blksz; if (byte_len != 0) { /* read rest of data which are not in whole sector */ if (blk_dread(blk, partition->start + sector, 1, (void *)sec_buf) != 1) { printf("* %s read error - last part ", __func__); return 0; } memcpy(buf, sec_buf, byte_len); } return 1; } |