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![Christoph Hellwig](/assets/img/avatar_default.png)
Both the data and attr fork have a format that is stored in the legacy idinode. Move it into the xfs_ifork structure instead, where it uses up padding. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
537 lines
13 KiB
C
537 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (c) 2000-2005 Silicon Graphics, Inc.
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* Copyright (c) 2013 Red Hat, Inc.
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* All Rights Reserved.
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*/
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#include "xfs.h"
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#include "xfs_fs.h"
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#include "xfs_shared.h"
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#include "xfs_format.h"
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#include "xfs_log_format.h"
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#include "xfs_trans_resv.h"
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#include "xfs_mount.h"
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#include "xfs_inode.h"
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#include "xfs_dir2.h"
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#include "xfs_dir2_priv.h"
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#include "xfs_trace.h"
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#include "xfs_bmap.h"
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#include "xfs_trans.h"
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#include "xfs_error.h"
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/*
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* Directory file type support functions
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*/
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static unsigned char xfs_dir3_filetype_table[] = {
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DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK,
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DT_FIFO, DT_SOCK, DT_LNK, DT_WHT,
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};
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unsigned char
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xfs_dir3_get_dtype(
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struct xfs_mount *mp,
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uint8_t filetype)
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{
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if (!xfs_sb_version_hasftype(&mp->m_sb))
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return DT_UNKNOWN;
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if (filetype >= XFS_DIR3_FT_MAX)
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return DT_UNKNOWN;
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return xfs_dir3_filetype_table[filetype];
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}
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STATIC int
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xfs_dir2_sf_getdents(
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struct xfs_da_args *args,
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struct dir_context *ctx)
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{
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int i; /* shortform entry number */
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struct xfs_inode *dp = args->dp; /* incore directory inode */
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struct xfs_mount *mp = dp->i_mount;
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xfs_dir2_dataptr_t off; /* current entry's offset */
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xfs_dir2_sf_entry_t *sfep; /* shortform directory entry */
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xfs_dir2_sf_hdr_t *sfp; /* shortform structure */
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xfs_dir2_dataptr_t dot_offset;
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xfs_dir2_dataptr_t dotdot_offset;
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xfs_ino_t ino;
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struct xfs_da_geometry *geo = args->geo;
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ASSERT(dp->i_df.if_flags & XFS_IFINLINE);
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ASSERT(dp->i_df.if_bytes == dp->i_d.di_size);
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ASSERT(dp->i_df.if_u1.if_data != NULL);
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sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
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/*
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* If the block number in the offset is out of range, we're done.
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*/
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if (xfs_dir2_dataptr_to_db(geo, ctx->pos) > geo->datablk)
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return 0;
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/*
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* Precalculate offsets for "." and ".." as we will always need them.
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* This relies on the fact that directories always start with the
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* entries for "." and "..".
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*/
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dot_offset = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
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geo->data_entry_offset);
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dotdot_offset = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
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geo->data_entry_offset +
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xfs_dir2_data_entsize(mp, sizeof(".") - 1));
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/*
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* Put . entry unless we're starting past it.
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*/
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if (ctx->pos <= dot_offset) {
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ctx->pos = dot_offset & 0x7fffffff;
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if (!dir_emit(ctx, ".", 1, dp->i_ino, DT_DIR))
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return 0;
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}
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/*
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* Put .. entry unless we're starting past it.
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*/
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if (ctx->pos <= dotdot_offset) {
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ino = xfs_dir2_sf_get_parent_ino(sfp);
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ctx->pos = dotdot_offset & 0x7fffffff;
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if (!dir_emit(ctx, "..", 2, ino, DT_DIR))
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return 0;
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}
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/*
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* Loop while there are more entries and put'ing works.
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*/
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sfep = xfs_dir2_sf_firstentry(sfp);
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for (i = 0; i < sfp->count; i++) {
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uint8_t filetype;
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off = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
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xfs_dir2_sf_get_offset(sfep));
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if (ctx->pos > off) {
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sfep = xfs_dir2_sf_nextentry(mp, sfp, sfep);
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continue;
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}
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ino = xfs_dir2_sf_get_ino(mp, sfp, sfep);
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filetype = xfs_dir2_sf_get_ftype(mp, sfep);
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ctx->pos = off & 0x7fffffff;
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if (XFS_IS_CORRUPT(dp->i_mount,
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!xfs_dir2_namecheck(sfep->name,
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sfep->namelen)))
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return -EFSCORRUPTED;
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if (!dir_emit(ctx, (char *)sfep->name, sfep->namelen, ino,
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xfs_dir3_get_dtype(mp, filetype)))
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return 0;
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sfep = xfs_dir2_sf_nextentry(mp, sfp, sfep);
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}
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ctx->pos = xfs_dir2_db_off_to_dataptr(geo, geo->datablk + 1, 0) &
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0x7fffffff;
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return 0;
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}
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/*
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* Readdir for block directories.
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*/
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STATIC int
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xfs_dir2_block_getdents(
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struct xfs_da_args *args,
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struct dir_context *ctx)
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{
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struct xfs_inode *dp = args->dp; /* incore directory inode */
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struct xfs_buf *bp; /* buffer for block */
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int error; /* error return value */
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int wantoff; /* starting block offset */
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xfs_off_t cook;
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struct xfs_da_geometry *geo = args->geo;
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int lock_mode;
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unsigned int offset, next_offset;
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unsigned int end;
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/*
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* If the block number in the offset is out of range, we're done.
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*/
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if (xfs_dir2_dataptr_to_db(geo, ctx->pos) > geo->datablk)
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return 0;
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lock_mode = xfs_ilock_data_map_shared(dp);
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error = xfs_dir3_block_read(args->trans, dp, &bp);
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xfs_iunlock(dp, lock_mode);
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if (error)
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return error;
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/*
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* Extract the byte offset we start at from the seek pointer.
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* We'll skip entries before this.
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*/
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wantoff = xfs_dir2_dataptr_to_off(geo, ctx->pos);
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xfs_dir3_data_check(dp, bp);
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/*
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* Loop over the data portion of the block.
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* Each object is a real entry (dep) or an unused one (dup).
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*/
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end = xfs_dir3_data_end_offset(geo, bp->b_addr);
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for (offset = geo->data_entry_offset;
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offset < end;
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offset = next_offset) {
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struct xfs_dir2_data_unused *dup = bp->b_addr + offset;
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struct xfs_dir2_data_entry *dep = bp->b_addr + offset;
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uint8_t filetype;
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/*
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* Unused, skip it.
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*/
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if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
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next_offset = offset + be16_to_cpu(dup->length);
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continue;
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}
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/*
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* Bump pointer for the next iteration.
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*/
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next_offset = offset +
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xfs_dir2_data_entsize(dp->i_mount, dep->namelen);
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/*
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* The entry is before the desired starting point, skip it.
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*/
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if (offset < wantoff)
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continue;
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cook = xfs_dir2_db_off_to_dataptr(geo, geo->datablk, offset);
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ctx->pos = cook & 0x7fffffff;
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filetype = xfs_dir2_data_get_ftype(dp->i_mount, dep);
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/*
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* If it didn't fit, set the final offset to here & return.
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*/
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if (XFS_IS_CORRUPT(dp->i_mount,
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!xfs_dir2_namecheck(dep->name,
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dep->namelen))) {
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error = -EFSCORRUPTED;
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goto out_rele;
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}
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if (!dir_emit(ctx, (char *)dep->name, dep->namelen,
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be64_to_cpu(dep->inumber),
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xfs_dir3_get_dtype(dp->i_mount, filetype)))
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goto out_rele;
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}
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/*
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* Reached the end of the block.
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* Set the offset to a non-existent block 1 and return.
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*/
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ctx->pos = xfs_dir2_db_off_to_dataptr(geo, geo->datablk + 1, 0) &
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0x7fffffff;
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out_rele:
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xfs_trans_brelse(args->trans, bp);
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return error;
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}
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/*
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* Read a directory block and initiate readahead for blocks beyond that.
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* We maintain a sliding readahead window of the remaining space in the
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* buffer rounded up to the nearest block.
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*/
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STATIC int
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xfs_dir2_leaf_readbuf(
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struct xfs_da_args *args,
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size_t bufsize,
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xfs_dir2_off_t *cur_off,
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xfs_dablk_t *ra_blk,
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struct xfs_buf **bpp)
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{
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struct xfs_inode *dp = args->dp;
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struct xfs_buf *bp = NULL;
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struct xfs_da_geometry *geo = args->geo;
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struct xfs_ifork *ifp = XFS_IFORK_PTR(dp, XFS_DATA_FORK);
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struct xfs_bmbt_irec map;
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struct blk_plug plug;
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xfs_dir2_off_t new_off;
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xfs_dablk_t next_ra;
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xfs_dablk_t map_off;
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xfs_dablk_t last_da;
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struct xfs_iext_cursor icur;
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int ra_want;
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int error = 0;
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if (!(ifp->if_flags & XFS_IFEXTENTS)) {
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error = xfs_iread_extents(args->trans, dp, XFS_DATA_FORK);
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if (error)
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goto out;
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}
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/*
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* Look for mapped directory blocks at or above the current offset.
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* Truncate down to the nearest directory block to start the scanning
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* operation.
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*/
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last_da = xfs_dir2_byte_to_da(geo, XFS_DIR2_LEAF_OFFSET);
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map_off = xfs_dir2_db_to_da(geo, xfs_dir2_byte_to_db(geo, *cur_off));
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if (!xfs_iext_lookup_extent(dp, ifp, map_off, &icur, &map))
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goto out;
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if (map.br_startoff >= last_da)
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goto out;
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xfs_trim_extent(&map, map_off, last_da - map_off);
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/* Read the directory block of that first mapping. */
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new_off = xfs_dir2_da_to_byte(geo, map.br_startoff);
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if (new_off > *cur_off)
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*cur_off = new_off;
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error = xfs_dir3_data_read(args->trans, dp, map.br_startoff, 0, &bp);
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if (error)
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goto out;
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/*
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* Start readahead for the next bufsize's worth of dir data blocks.
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* We may have already issued readahead for some of that range;
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* ra_blk tracks the last block we tried to read(ahead).
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*/
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ra_want = howmany(bufsize + geo->blksize, (1 << geo->fsblog));
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if (*ra_blk >= last_da)
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goto out;
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else if (*ra_blk == 0)
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*ra_blk = map.br_startoff;
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next_ra = map.br_startoff + geo->fsbcount;
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if (next_ra >= last_da)
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goto out_no_ra;
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if (map.br_blockcount < geo->fsbcount &&
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!xfs_iext_next_extent(ifp, &icur, &map))
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goto out_no_ra;
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if (map.br_startoff >= last_da)
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goto out_no_ra;
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xfs_trim_extent(&map, next_ra, last_da - next_ra);
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/* Start ra for each dir (not fs) block that has a mapping. */
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blk_start_plug(&plug);
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while (ra_want > 0) {
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next_ra = roundup((xfs_dablk_t)map.br_startoff, geo->fsbcount);
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while (ra_want > 0 &&
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next_ra < map.br_startoff + map.br_blockcount) {
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if (next_ra >= last_da) {
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*ra_blk = last_da;
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break;
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}
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if (next_ra > *ra_blk) {
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xfs_dir3_data_readahead(dp, next_ra,
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XFS_DABUF_MAP_HOLE_OK);
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*ra_blk = next_ra;
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}
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ra_want -= geo->fsbcount;
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next_ra += geo->fsbcount;
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}
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if (!xfs_iext_next_extent(ifp, &icur, &map)) {
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*ra_blk = last_da;
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break;
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}
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}
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blk_finish_plug(&plug);
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out:
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*bpp = bp;
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return error;
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out_no_ra:
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*ra_blk = last_da;
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goto out;
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}
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/*
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* Getdents (readdir) for leaf and node directories.
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* This reads the data blocks only, so is the same for both forms.
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*/
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STATIC int
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xfs_dir2_leaf_getdents(
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struct xfs_da_args *args,
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struct dir_context *ctx,
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size_t bufsize)
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{
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struct xfs_inode *dp = args->dp;
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struct xfs_mount *mp = dp->i_mount;
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struct xfs_buf *bp = NULL; /* data block buffer */
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xfs_dir2_data_entry_t *dep; /* data entry */
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xfs_dir2_data_unused_t *dup; /* unused entry */
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struct xfs_da_geometry *geo = args->geo;
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xfs_dablk_t rablk = 0; /* current readahead block */
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xfs_dir2_off_t curoff; /* current overall offset */
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int length; /* temporary length value */
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int byteoff; /* offset in current block */
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int lock_mode;
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unsigned int offset = 0;
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int error = 0; /* error return value */
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/*
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* If the offset is at or past the largest allowed value,
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* give up right away.
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*/
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if (ctx->pos >= XFS_DIR2_MAX_DATAPTR)
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return 0;
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/*
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* Inside the loop we keep the main offset value as a byte offset
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* in the directory file.
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*/
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curoff = xfs_dir2_dataptr_to_byte(ctx->pos);
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/*
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* Loop over directory entries until we reach the end offset.
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* Get more blocks and readahead as necessary.
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*/
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while (curoff < XFS_DIR2_LEAF_OFFSET) {
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uint8_t filetype;
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/*
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* If we have no buffer, or we're off the end of the
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* current buffer, need to get another one.
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*/
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if (!bp || offset >= geo->blksize) {
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if (bp) {
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xfs_trans_brelse(args->trans, bp);
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bp = NULL;
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}
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lock_mode = xfs_ilock_data_map_shared(dp);
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error = xfs_dir2_leaf_readbuf(args, bufsize, &curoff,
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&rablk, &bp);
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xfs_iunlock(dp, lock_mode);
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if (error || !bp)
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break;
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xfs_dir3_data_check(dp, bp);
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/*
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* Find our position in the block.
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*/
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offset = geo->data_entry_offset;
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byteoff = xfs_dir2_byte_to_off(geo, curoff);
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/*
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* Skip past the header.
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*/
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if (byteoff == 0)
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curoff += geo->data_entry_offset;
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/*
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* Skip past entries until we reach our offset.
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*/
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else {
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while (offset < byteoff) {
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dup = bp->b_addr + offset;
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if (be16_to_cpu(dup->freetag)
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== XFS_DIR2_DATA_FREE_TAG) {
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length = be16_to_cpu(dup->length);
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offset += length;
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continue;
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}
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dep = bp->b_addr + offset;
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length = xfs_dir2_data_entsize(mp,
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dep->namelen);
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offset += length;
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}
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/*
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* Now set our real offset.
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*/
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curoff =
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xfs_dir2_db_off_to_byte(geo,
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xfs_dir2_byte_to_db(geo, curoff),
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offset);
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if (offset >= geo->blksize)
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continue;
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}
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}
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/*
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* We have a pointer to an entry. Is it a live one?
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*/
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dup = bp->b_addr + offset;
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/*
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* No, it's unused, skip over it.
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*/
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if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
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length = be16_to_cpu(dup->length);
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offset += length;
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curoff += length;
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continue;
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}
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dep = bp->b_addr + offset;
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length = xfs_dir2_data_entsize(mp, dep->namelen);
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filetype = xfs_dir2_data_get_ftype(mp, dep);
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ctx->pos = xfs_dir2_byte_to_dataptr(curoff) & 0x7fffffff;
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if (XFS_IS_CORRUPT(dp->i_mount,
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!xfs_dir2_namecheck(dep->name,
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dep->namelen))) {
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error = -EFSCORRUPTED;
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break;
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}
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if (!dir_emit(ctx, (char *)dep->name, dep->namelen,
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be64_to_cpu(dep->inumber),
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xfs_dir3_get_dtype(dp->i_mount, filetype)))
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break;
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/*
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* Advance to next entry in the block.
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*/
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offset += length;
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|
curoff += length;
|
|
/* bufsize may have just been a guess; don't go negative */
|
|
bufsize = bufsize > length ? bufsize - length : 0;
|
|
}
|
|
|
|
/*
|
|
* All done. Set output offset value to current offset.
|
|
*/
|
|
if (curoff > xfs_dir2_dataptr_to_byte(XFS_DIR2_MAX_DATAPTR))
|
|
ctx->pos = XFS_DIR2_MAX_DATAPTR & 0x7fffffff;
|
|
else
|
|
ctx->pos = xfs_dir2_byte_to_dataptr(curoff) & 0x7fffffff;
|
|
if (bp)
|
|
xfs_trans_brelse(args->trans, bp);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Read a directory.
|
|
*
|
|
* If supplied, the transaction collects locked dir buffers to avoid
|
|
* nested buffer deadlocks. This function does not dirty the
|
|
* transaction. The caller should ensure that the inode is locked
|
|
* before calling this function.
|
|
*/
|
|
int
|
|
xfs_readdir(
|
|
struct xfs_trans *tp,
|
|
struct xfs_inode *dp,
|
|
struct dir_context *ctx,
|
|
size_t bufsize)
|
|
{
|
|
struct xfs_da_args args = { NULL };
|
|
int rval;
|
|
int v;
|
|
|
|
trace_xfs_readdir(dp);
|
|
|
|
if (XFS_FORCED_SHUTDOWN(dp->i_mount))
|
|
return -EIO;
|
|
|
|
ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
|
|
XFS_STATS_INC(dp->i_mount, xs_dir_getdents);
|
|
|
|
args.dp = dp;
|
|
args.geo = dp->i_mount->m_dir_geo;
|
|
args.trans = tp;
|
|
|
|
if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL)
|
|
rval = xfs_dir2_sf_getdents(&args, ctx);
|
|
else if ((rval = xfs_dir2_isblock(&args, &v)))
|
|
;
|
|
else if (v)
|
|
rval = xfs_dir2_block_getdents(&args, ctx);
|
|
else
|
|
rval = xfs_dir2_leaf_getdents(&args, ctx, bufsize);
|
|
|
|
return rval;
|
|
}
|