From: Darrick J. Wong <djwong@xxxxxxxxxx> Add a debug function to dump an xfile's contents for debug purposes. Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx> --- fs/xfs/scrub/xfile.c | 98 ++++++++++++++++++++++++++++++++++++++++++++++++++ fs/xfs/scrub/xfile.h | 2 + 2 files changed, 100 insertions(+) diff --git a/fs/xfs/scrub/xfile.c b/fs/xfs/scrub/xfile.c index d3e678cd4a2f..851aeb244660 100644 --- a/fs/xfs/scrub/xfile.c +++ b/fs/xfs/scrub/xfile.c @@ -431,3 +431,101 @@ xfile_put_page( return -EIO; return 0; } + +/* Dump an xfile to dmesg. */ +int +xfile_dump( + struct xfile *xf) +{ + struct xfile_stat sb; + struct inode *inode = file_inode(xf->file); + struct address_space *mapping = inode->i_mapping; + loff_t holepos = 0; + loff_t datapos; + loff_t ret; + unsigned int pflags; + bool all_zeroes = true; + int error = 0; + + error = xfile_stat(xf, &sb); + if (error) + return error; + + printk(KERN_ALERT "xfile ino 0x%lx isize 0x%llx dump:", inode->i_ino, + sb.size); + pflags = memalloc_nofs_save(); + + while ((ret = vfs_llseek(xf->file, holepos, SEEK_DATA)) >= 0) { + datapos = rounddown_64(ret, PAGE_SIZE); + ret = vfs_llseek(xf->file, datapos, SEEK_HOLE); + if (ret < 0) + break; + holepos = min_t(loff_t, sb.size, roundup_64(ret, PAGE_SIZE)); + + while (datapos < holepos) { + struct page *page = NULL; + void *p, *kaddr; + u64 datalen = holepos - datapos; + unsigned int pagepos; + unsigned int pagelen; + + cond_resched(); + + if (fatal_signal_pending(current)) { + error = -EINTR; + goto out_pflags; + } + + pagelen = min_t(u64, datalen, PAGE_SIZE); + + page = shmem_read_mapping_page_gfp(mapping, + datapos >> PAGE_SHIFT, __GFP_NOWARN); + if (IS_ERR(page)) { + error = PTR_ERR(page); + if (error == -EIO) + printk(KERN_ALERT "%.8llx: poisoned", + datapos); + else if (error != -ENOMEM) + goto out_pflags; + + goto next_pgoff; + } + + if (!PageUptodate(page)) + goto next_page; + + kaddr = kmap_local_page(page); + p = kaddr; + + for (pagepos = 0; pagepos < pagelen; pagepos += 16) { + char prefix[16]; + unsigned int linelen; + + linelen = min_t(unsigned int, pagelen, 16); + + if (!memchr_inv(p + pagepos, 0, linelen)) + continue; + + snprintf(prefix, 16, "%.8llx: ", + datapos + pagepos); + + all_zeroes = false; + print_hex_dump(KERN_ALERT, prefix, + DUMP_PREFIX_NONE, 16, 1, + p + pagepos, linelen, true); + } + kunmap_local(kaddr); +next_page: + put_page(page); +next_pgoff: + datapos += PAGE_SIZE; + } + } + if (all_zeroes) + printk(KERN_ALERT "<all zeroes>"); + if (ret != -ENXIO) + error = ret; +out_pflags: + memalloc_nofs_restore(pflags); + return error; +} diff --git a/fs/xfs/scrub/xfile.h b/fs/xfs/scrub/xfile.h index 1aae2cd91720..adf5dbdc4c21 100644 --- a/fs/xfs/scrub/xfile.h +++ b/fs/xfs/scrub/xfile.h @@ -75,4 +75,6 @@ int xfile_get_page(struct xfile *xf, loff_t offset, unsigned int len, struct xfile_page *xbuf); int xfile_put_page(struct xfile *xf, struct xfile_page *xbuf); +int xfile_dump(struct xfile *xf); + #endif /* __XFS_SCRUB_XFILE_H__ */