diff options
Diffstat (limited to 'sys/fs/ext2fs/ext2_bmap.c')
| -rw-r--r-- | sys/fs/ext2fs/ext2_bmap.c | 173 |
1 files changed, 145 insertions, 28 deletions
diff --git a/sys/fs/ext2fs/ext2_bmap.c b/sys/fs/ext2fs/ext2_bmap.c index a5e9a0258582..5d159b8ec152 100644 --- a/sys/fs/ext2fs/ext2_bmap.c +++ b/sys/fs/ext2fs/ext2_bmap.c @@ -139,6 +139,47 @@ ext4_bmapext(struct vnode *vp, int32_t bn, int64_t *bnp, int *runp, int *runb) return (error); } +static int +readindir(struct vnode *vp, e2fs_lbn_t lbn, e2fs_daddr_t daddr, struct buf **bpp) +{ + struct buf *bp; + struct mount *mp; + struct ext2mount *ump; + int error; + + mp = vp->v_mount; + ump = VFSTOEXT2(mp); + + bp = getblk(vp, lbn, mp->mnt_stat.f_iosize, 0, 0, 0); + if ((bp->b_flags & B_CACHE) == 0) { + KASSERT(daddr != 0, + ("readindir: indirect block not in cache")); + + bp->b_blkno = blkptrtodb(ump, daddr); + bp->b_iocmd = BIO_READ; + bp->b_flags &= ~B_INVAL; + bp->b_ioflags &= ~BIO_ERROR; + vfs_busy_pages(bp, 0); + bp->b_iooffset = dbtob(bp->b_blkno); + bstrategy(bp); +#ifdef RACCT + if (racct_enable) { + PROC_LOCK(curproc); + racct_add_buf(curproc, bp, 0); + PROC_UNLOCK(curproc); + } +#endif + curthread->td_ru.ru_inblock++; + error = bufwait(bp); + if (error != 0) { + brelse(bp); + return (error); + } + } + *bpp = bp; + return (0); +} + /* * Indirect blocks are now on the vnode for the file. They are given negative * logical block numbers. Indirect blocks are addressed by the negative @@ -228,34 +269,9 @@ ext2_bmaparray(struct vnode *vp, daddr_t bn, daddr_t *bnp, int *runp, int *runb) */ if (bp) bqrelse(bp); - - bp = getblk(vp, metalbn, bsize, 0, 0, 0); - if ((bp->b_flags & B_CACHE) == 0) { -#ifdef INVARIANTS - if (!daddr) - panic("ext2_bmaparray: indirect block not in cache"); -#endif - bp->b_blkno = blkptrtodb(ump, daddr); - bp->b_iocmd = BIO_READ; - bp->b_flags &= ~B_INVAL; - bp->b_ioflags &= ~BIO_ERROR; - vfs_busy_pages(bp, 0); - bp->b_iooffset = dbtob(bp->b_blkno); - bstrategy(bp); -#ifdef RACCT - if (racct_enable) { - PROC_LOCK(curproc); - racct_add_buf(curproc, bp, 0); - PROC_UNLOCK(curproc); - } -#endif - curthread->td_ru.ru_inblock++; - error = bufwait(bp); - if (error) { - brelse(bp); - return (error); - } - } + error = readindir(vp, metalbn, daddr, &bp); + if (error != 0) + return (error); daddr = ((e2fs_daddr_t *)bp->b_data)[ap->in_off]; if (num == 1 && daddr && runp) { @@ -296,6 +312,107 @@ ext2_bmaparray(struct vnode *vp, daddr_t bn, daddr_t *bnp, int *runp, int *runb) return (0); } +static e2fs_lbn_t +lbn_count(struct ext2mount *ump, int level) + +{ + e2fs_lbn_t blockcnt; + + for (blockcnt = 1; level > 0; level--) + blockcnt *= MNINDIR(ump); + return (blockcnt); +} + +int +ext2_bmap_seekdata(struct vnode *vp, off_t *offp) +{ + struct buf *bp; + struct indir a[EXT2_NIADDR + 1], *ap; + struct inode *ip; + struct mount *mp; + struct ext2mount *ump; + e2fs_daddr_t bn, daddr, nextbn; + uint64_t bsize; + off_t numblks; + int error, num, num1, off; + + bp = NULL; + error = 0; + ip = VTOI(vp); + mp = vp->v_mount; + ump = VFSTOEXT2(mp); + + if (vp->v_type != VREG || (ip->i_flags & SF_SNAPSHOT) != 0) + return (EINVAL); + if (*offp < 0 || *offp >= ip->i_size) + return (ENXIO); + + bsize = mp->mnt_stat.f_iosize; + for (bn = *offp / bsize, numblks = howmany(ip->i_size, bsize); + bn < numblks; bn = nextbn) { + if (bn < EXT2_NDADDR) { + daddr = ip->i_db[bn]; + if (daddr != 0) + break; + nextbn = bn + 1; + continue; + } + + ap = a; + error = ext2_getlbns(vp, bn, ap, &num); + if (error != 0) + break; + MPASS(num >= 2); + daddr = ip->i_ib[ap->in_off]; + ap++, num--; + for (nextbn = EXT2_NDADDR, num1 = num - 1; num1 > 0; num1--) + nextbn += lbn_count(ump, num1); + if (daddr == 0) { + nextbn += lbn_count(ump, num); + continue; + } + + for (; daddr != 0 && num > 0; ap++, num--) { + if (bp != NULL) + bqrelse(bp); + error = readindir(vp, ap->in_lbn, daddr, &bp); + if (error != 0) + return (error); + + /* + * Scan the indirect block until we find a non-zero + * pointer. + */ + off = ap->in_off; + do { + daddr = ((e2fs_daddr_t *)bp->b_data)[off]; + } while (daddr == 0 && ++off < MNINDIR(ump)); + nextbn += off * lbn_count(ump, num - 1); + + /* + * We need to recompute the LBNs of indirect + * blocks, so restart with the updated block offset. + */ + if (off != ap->in_off) + break; + } + if (num == 0) { + /* + * We found a data block. + */ + bn = nextbn; + break; + } + } + if (bp != NULL) + bqrelse(bp); + if (bn >= numblks) + error = ENXIO; + if (error == 0 && *offp < bn * bsize) + *offp = bn * bsize; + return (error); +} + /* * Create an array of logical block number/offset pairs which represent the * path of indirect blocks required to access a data block. The first "pair" |