#include #include #include #include #include #define sblock sb_un.u_sblock /* * The super block. We allow enough room for * a complete disk block. */ union { struct fs u_sblock; char dummy[SBSIZE]; } sb_un; read_blocks(dp) struct dinode *dp; { int count; register int i, n; char dblock[MAXBSIZE]; count = dp->di_size; /* * For each direct block in the file (NDADDR indicates * the number of direct addresses stored)... */ for (i = 0; (i < NDADDR) && (count > 0); i++) { /* * Read in the block from disk. Read in count * bytes or a disk block, whichever is less. */ bread(fsbtodb(&sblock, dp->di_db[i]), dblock, n = min(count, sblock.fs_bsize)); count -= n; /* process data block ... */ } /* * Now start reading the indirect blocks. NIADDR is * the number of indirect addresses. Recall that * the first indirect address is singly indirect, * the second is doubly indirect, an so on. */ for (i = 0; (i < NIADDR) && (count > 0); i++) read_indirect (dp->di_ib[i], i, &count); } /* * read_indirect--read the indirect blocks of the file. The * level argument indicates our level of indirection; 0 is * singly indirect, 1 is doubly indirect, and so on. */ read_indirect (blkno, level, count) ino_t blkno; int *count; int level; { register int i, n; char dblock[MAXBSIZE]; daddr_t idblk[MAXBSIZE / sizeof(daddr_t)]; /* * Read in the block from disk. */ if (blkno) bread(fsbtodb(&sblock, blkno), idblk, sblock.fs_bsize); else bzero(idblk, sblock.fs_bsize); /* * If level is zero, then this block contains disk block * addresses, since blkno was a singly indirect address. * If level is non-zero, then this block contains addresses * of more indirect blocks. */ if (level <= 0) { /* * For each disk block (the NINDIR macro returns * the number of indirect addresses in a block)... */ for (i = 0; (i < NINDIR(&sblock)) && (*count > 0); i++) { /* * Read in the block from disk. */ bread(fsbtodb(&sblock, idblk[i]), dblock, n = min(*count, sblock.fs_bsize)); *count -= n; /* process data block ... */ } /* * Done processing. */ return; } /* * Decrement the level we're at. */ level--; /* * Handle the next level of indirection by calling * ourselves recursively with each address in this * block. */ for (i = 0; i < NINDIR(&sblock); i++) read_indirect(idblk[i], level, count); } vate-remove&id=b3c7ef0adadc5768e0baa786213c6bd1ce521a77'>root/net/ipv6/ip6_gre.c
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