On 16 Jan 2021 at 06:54, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@xxxxxxxxxx>
>
> Add to xfs_db the ability to list a directory.
>
W.r.t logical correctness of the code,
Reviewed-by: Chandan Babu R <chandanrlinux@xxxxxxxxx>
> Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
> ---
> db/namei.c | 389 ++++++++++++++++++++++++++++++++++++++++++++++
> libxfs/libxfs_api_defs.h | 1
> man/man8/xfs_db.8 | 16 ++
> 3 files changed, 406 insertions(+)
>
>
> diff --git a/db/namei.c b/db/namei.c
> index eebebe15..e75b5ebd 100644
> --- a/db/namei.c
> +++ b/db/namei.c
> @@ -215,9 +215,398 @@ static struct cmdinfo path_cmd = {
> .help = path_help,
> };
>
> +/* List a directory's entries. */
> +
> +static const char *filetype_strings[XFS_DIR3_FT_MAX] = {
> + [XFS_DIR3_FT_UNKNOWN] = "unknown",
> + [XFS_DIR3_FT_REG_FILE] = "regular",
> + [XFS_DIR3_FT_DIR] = "directory",
> + [XFS_DIR3_FT_CHRDEV] = "chardev",
> + [XFS_DIR3_FT_BLKDEV] = "blkdev",
> + [XFS_DIR3_FT_FIFO] = "fifo",
> + [XFS_DIR3_FT_SOCK] = "socket",
> + [XFS_DIR3_FT_SYMLINK] = "symlink",
> + [XFS_DIR3_FT_WHT] = "whiteout",
> +};
> +
> +static const char *
> +get_dstr(
> + struct xfs_mount *mp,
> + uint8_t filetype)
> +{
> + if (!xfs_sb_version_hasftype(&mp->m_sb))
> + return filetype_strings[XFS_DIR3_FT_UNKNOWN];
> +
> + if (filetype >= XFS_DIR3_FT_MAX)
> + return filetype_strings[XFS_DIR3_FT_UNKNOWN];
> +
> + return filetype_strings[filetype];
> +}
> +
> +static void
> +dir_emit(
> + struct xfs_mount *mp,
> + xfs_dir2_dataptr_t off,
> + char *name,
> + ssize_t namelen,
> + xfs_ino_t ino,
> + uint8_t dtype)
> +{
> + char *display_name;
> + struct xfs_name xname = { .name = name };
> + const char *dstr = get_dstr(mp, dtype);
> + xfs_dahash_t hash;
> + bool good;
> +
> + if (namelen < 0) {
> + /* Negative length means that name is null-terminated. */
> + display_name = name;
> + xname.len = strlen(name);
> + good = true;
> + } else {
> + /*
> + * Otherwise, name came from a directory entry, so we have to
> + * copy the string to a buffer so that we can add the null
> + * terminator.
> + */
> + display_name = malloc(namelen + 1);
> + memcpy(display_name, name, namelen);
> + display_name[namelen] = 0;
> + xname.len = namelen;
> + good = libxfs_dir2_namecheck(name, namelen);
> + }
> + hash = libxfs_dir2_hashname(mp, &xname);
> +
> + dbprintf("%-10u %-18llu %-14s 0x%08llx %3d %s %s\n", off & 0xFFFFFFFF,
> + ino, dstr, hash, xname.len,
> + display_name, good ? _("(good)") : _("(corrupt)"));
> +
> + if (display_name != name)
> + free(display_name);
> +}
> +
> +static int
> +list_sfdir(
> + struct xfs_da_args *args)
> +{
> + struct xfs_inode *dp = args->dp;
> + struct xfs_mount *mp = dp->i_mount;
> + struct xfs_da_geometry *geo = args->geo;
> + struct xfs_dir2_sf_entry *sfep;
> + struct xfs_dir2_sf_hdr *sfp;
> + xfs_ino_t ino;
> + xfs_dir2_dataptr_t off;
> + unsigned int i;
> + uint8_t filetype;
> +
> + sfp = (struct xfs_dir2_sf_hdr *)dp->i_df.if_u1.if_data;
> +
> + /* . and .. entries */
> + off = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
> + geo->data_entry_offset);
> + dir_emit(args->dp->i_mount, off, ".", -1, dp->i_ino, XFS_DIR3_FT_DIR);
> +
> + ino = libxfs_dir2_sf_get_parent_ino(sfp);
> + off = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
> + geo->data_entry_offset +
> + libxfs_dir2_data_entsize(mp, sizeof(".") - 1));
> + dir_emit(args->dp->i_mount, off, "..", -1, ino, XFS_DIR3_FT_DIR);
> +
> + /* Walk everything else. */
> + sfep = xfs_dir2_sf_firstentry(sfp);
> + for (i = 0; i < sfp->count; i++) {
> + ino = libxfs_dir2_sf_get_ino(mp, sfp, sfep);
> + filetype = libxfs_dir2_sf_get_ftype(mp, sfep);
> + off = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
> + xfs_dir2_sf_get_offset(sfep));
> +
> + dir_emit(args->dp->i_mount, off, (char *)sfep->name,
> + sfep->namelen, ino, filetype);
> + sfep = libxfs_dir2_sf_nextentry(mp, sfp, sfep);
> + }
> +
> + return 0;
> +}
> +
> +/* List entries in block format directory. */
> +static int
> +list_blockdir(
> + struct xfs_da_args *args)
> +{
> + struct xfs_inode *dp = args->dp;
> + struct xfs_mount *mp = dp->i_mount;
> + struct xfs_buf *bp;
> + struct xfs_da_geometry *geo = mp->m_dir_geo;
> + xfs_dir2_dataptr_t diroff;
> + unsigned int offset;
> + unsigned int end;
> + int error;
> +
> + error = xfs_dir3_block_read(NULL, dp, &bp);
> + if (error)
> + return error;
> +
> + end = xfs_dir3_data_end_offset(geo, bp->b_addr);
> + for (offset = geo->data_entry_offset; offset < end;) {
> + struct xfs_dir2_data_unused *dup = bp->b_addr + offset;
> + struct xfs_dir2_data_entry *dep = bp->b_addr + offset;
> + uint8_t filetype;
> +
> + if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
> + /* Unused entry */
> + offset += be16_to_cpu(dup->length);
> + continue;
> + }
> +
> + /* Real entry */
> + diroff = xfs_dir2_db_off_to_dataptr(geo, geo->datablk, offset);
> + offset += libxfs_dir2_data_entsize(mp, dep->namelen);
> + filetype = libxfs_dir2_data_get_ftype(dp->i_mount, dep);
> + dir_emit(mp, diroff, (char *)dep->name, dep->namelen,
> + be64_to_cpu(dep->inumber), filetype);
> + }
> +
> + libxfs_trans_brelse(args->trans, bp);
> + return error;
> +}
> +
> +/* List entries in leaf format directory. */
> +static int
> +list_leafdir(
> + struct xfs_da_args *args)
> +{
> + struct xfs_bmbt_irec map;
> + struct xfs_iext_cursor icur;
> + struct xfs_inode *dp = args->dp;
> + struct xfs_mount *mp = dp->i_mount;
> + struct xfs_buf *bp = NULL;
> + struct xfs_ifork *ifp = XFS_IFORK_PTR(dp, XFS_DATA_FORK);
> + struct xfs_da_geometry *geo = mp->m_dir_geo;
> + xfs_dir2_off_t dirboff;
> + xfs_dablk_t dabno = 0;
> + int error = 0;
> +
> + /* Read extent map. */
> + if (!(ifp->if_flags & XFS_IFEXTENTS)) {
> + error = -libxfs_iread_extents(NULL, dp, XFS_DATA_FORK);
> + if (error)
> + return error;
> + }
> +
> + while (dabno < geo->leafblk) {
> + unsigned int offset;
> + unsigned int length;
> +
> + /* Find mapping for leaf block. */
> + if (!xfs_iext_lookup_extent(dp, ifp, dabno, &icur, &map))
> + break;
> + if (map.br_startoff >= geo->leafblk)
> + break;
> + libxfs_trim_extent(&map, dabno, geo->leafblk - dabno);
> +
> + /* Read the directory block of that first mapping. */
> + error = xfs_dir3_data_read(NULL, dp, map.br_startoff, 0, &bp);
> + if (error)
> + break;
> +
> + dirboff = xfs_dir2_da_to_byte(geo, map.br_startoff);
> + for (offset = geo->data_entry_offset; offset < geo->blksize;) {
> + struct xfs_dir2_data_entry *dep;
> + struct xfs_dir2_data_unused *dup;
> + uint8_t filetype;
> +
> + dup = bp->b_addr + offset;
> + dep = bp->b_addr + offset;
> +
> + if (be16_to_cpu(dup->freetag) ==
> + XFS_DIR2_DATA_FREE_TAG) {
> + /* Skip unused entry */
> + length = be16_to_cpu(dup->length);
> + offset += length;
> + continue;
> + }
> +
> + offset += libxfs_dir2_data_entsize(mp, dep->namelen);
> + filetype = libxfs_dir2_data_get_ftype(mp, dep);
> +
> + dir_emit(mp, xfs_dir2_byte_to_dataptr(dirboff + offset),
> + (char *)dep->name, dep->namelen,
> + be64_to_cpu(dep->inumber), filetype);
> + }
> +
> + dabno += XFS_DADDR_TO_FSB(mp, bp->b_length);
> + libxfs_buf_relse(bp);
> + bp = NULL;
> + }
> +
> + if (bp)
> + libxfs_buf_relse(bp);
> +
> + return error;
> +}
> +
> +/* Read the directory, display contents. */
> +int
> +listdir(
> + struct xfs_inode *dp)
> +{
> + struct xfs_da_args args = {
> + .dp = dp,
> + .geo = dp->i_mount->m_dir_geo,
> + };
> + int error;
> + int isblock;
> +
> + if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL)
> + return list_sfdir(&args);
> +
> + error = -libxfs_dir2_isblock(&args, &isblock);
> + if (error)
> + return error;
> +
> + if (isblock)
> + return list_blockdir(&args);
> + return list_leafdir(&args);
> +}
> +
> +/* List the inode number of the currently selected inode. */
> +static int
> +inum_cur(void)
> +{
> + if (iocur_top->typ != &typtab[TYP_INODE])
> + return ENOENT;
> +
> + dbprintf("%llu\n", iocur_top->ino);
> + return 0;
> +}
> +
> +/* If the io cursor points to a directory, list its contents. */
> +static int
> +ls_cur(
> + char *tag)
> +{
> + struct xfs_inode *dp;
> + int error = 0;
> +
> + if (iocur_top->typ != &typtab[TYP_INODE] ||
> + !S_ISDIR(iocur_top->mode))
> + return ENOTDIR;
> +
> + error = -libxfs_iget(mp, NULL, iocur_top->ino, 0, &dp);
> + if (error)
> + return error;
> +
> + if (!S_ISDIR(VFS_I(dp)->i_mode)) {
> + error = ENOTDIR;
> + goto rele;
> + }
> +
> + /* List the contents of a directory. */
> + if (tag)
> + dbprintf(_("%s:\n"), tag);
> +
> + error = listdir(dp);
> + if (error)
> + goto rele;
> +
> +rele:
> + libxfs_irele(dp);
> + return error;
> +}
> +
> +static void
> +ls_help(void)
> +{
> + dbprintf(_(
> +"\n"
> +" List the contents of the currently selected directory inode.\n"
> +"\n"
> +" Options:\n"
> +" -i -- Resolve the given paths to their corresponding inode numbers.\n"
> +" If no paths are given, display the current inode number.\n"
> +"\n"
> +" Directory contents will be listed in the format:\n"
> +" dir_cookie inode_number type hash name_length name\n"
> + ));
> +}
> +
> +static int
> +ls_f(
> + int argc,
> + char **argv)
> +{
> + bool inum_only = false;
> + int c;
> + int error = 0;
> +
> + while ((c = getopt(argc, argv, "i")) != -1) {
> + switch (c) {
> + case 'i':
> + inum_only = true;
> + break;
> + default:
> + ls_help();
> + return 0;
> + }
> + }
> +
> + if (optind == argc) {
> + if (inum_only)
> + error = inum_cur();
> + else
> + error = ls_cur(NULL);
> + if (error) {
> + dbprintf("%s\n", strerror(error));
> + exitcode = 1;
> + }
> +
> + return 0;
> + }
> +
> + for (c = optind; c < argc; c++) {
> + push_cur();
> +
> + error = path_walk(argv[c]);
> + if (error)
> + goto err_cur;
> +
> + if (inum_only)
> + error = inum_cur();
> + else
> + error = ls_cur(argv[c]);
> + if (error)
> + goto err_cur;
> +
> + pop_cur();
> + }
> +
> + return 0;
> +err_cur:
> + pop_cur();
> + if (error) {
> + dbprintf("%s: %s\n", argv[c], strerror(error));
> + exitcode = 1;
> + }
> + return 0;
> +}
> +
> +static struct cmdinfo ls_cmd = {
> + .name = "ls",
> + .altname = "l",
> + .cfunc = ls_f,
> + .argmin = 0,
> + .argmax = -1,
> + .canpush = 0,
> + .args = "[-i] [paths...]",
> + .help = ls_help,
> +};
> +
> void
> namei_init(void)
> {
> path_cmd.oneline = _("navigate to an inode by path");
> add_command(&path_cmd);
> +
> + ls_cmd.oneline = _("list directory contents");
> + add_command(&ls_cmd);
> }
> diff --git a/libxfs/libxfs_api_defs.h b/libxfs/libxfs_api_defs.h
> index 9492955d..9a00ce66 100644
> --- a/libxfs/libxfs_api_defs.h
> +++ b/libxfs/libxfs_api_defs.h
> @@ -190,6 +190,7 @@
> #define xfs_trans_resv_calc libxfs_trans_resv_calc
> #define xfs_trans_roll_inode libxfs_trans_roll_inode
> #define xfs_trans_roll libxfs_trans_roll
> +#define xfs_trim_extent libxfs_trim_extent
>
> #define xfs_verify_agbno libxfs_verify_agbno
> #define xfs_verify_agino libxfs_verify_agino
> diff --git a/man/man8/xfs_db.8 b/man/man8/xfs_db.8
> index 4df265ec..58727495 100644
> --- a/man/man8/xfs_db.8
> +++ b/man/man8/xfs_db.8
> @@ -806,6 +806,22 @@ This makes it easier to find discrepancies in the reservation calculations
> between xfsprogs and the kernel, which will help when diagnosing minimum
> log size calculation errors.
> .TP
> +.BI "ls [\-i] [" paths "]..."
> +List the contents of a directory.
> +If a path resolves to a directory, the directory will be listed.
> +If no paths are supplied and the IO cursor points at a directory inode,
> +the contents of that directory will be listed.
> +
> +The output format is:
> +directory cookie, inode number, file type, hash, name length, name.
> +.RS 1.0i
> +.TP 0.4i
> +.B \-i
> +Resolve each of the given paths to an inode number and print that number.
> +If no paths are given and the IO cursor points to an inode, print the inode
> +number.
> +.RE
> +.TP
> .BI "metadump [\-egow] " filename
> Dumps metadata to a file. See
> .BR xfs_metadump (8)
--
chandan
