From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- fs/freevxfs/vxfs_lookup.c | 272 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 272 insertions(+) create mode 100644 fs/freevxfs/vxfs_lookup.c (limited to 'fs/freevxfs/vxfs_lookup.c') diff --git a/fs/freevxfs/vxfs_lookup.c b/fs/freevxfs/vxfs_lookup.c new file mode 100644 index 000000000..f04ba2ed1 --- /dev/null +++ b/fs/freevxfs/vxfs_lookup.c @@ -0,0 +1,272 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2000-2001 Christoph Hellwig. + * Copyright (c) 2016 Krzysztof Blaszkowski + */ + +/* + * Veritas filesystem driver - lookup and other directory related code. + */ +#include +#include +#include +#include +#include +#include + +#include "vxfs.h" +#include "vxfs_dir.h" +#include "vxfs_inode.h" +#include "vxfs_extern.h" + +/* + * Number of VxFS blocks per page. + */ +#define VXFS_BLOCK_PER_PAGE(sbp) ((PAGE_SIZE / (sbp)->s_blocksize)) + + +static struct dentry * vxfs_lookup(struct inode *, struct dentry *, unsigned int); +static int vxfs_readdir(struct file *, struct dir_context *); + +const struct inode_operations vxfs_dir_inode_ops = { + .lookup = vxfs_lookup, +}; + +const struct file_operations vxfs_dir_operations = { + .llseek = generic_file_llseek, + .read = generic_read_dir, + .iterate_shared = vxfs_readdir, +}; + + +/** + * vxfs_find_entry - find a mathing directory entry for a dentry + * @ip: directory inode + * @dp: dentry for which we want to find a direct + * @ppp: gets filled with the page the return value sits in + * + * Description: + * vxfs_find_entry finds a &struct vxfs_direct for the VFS directory + * cache entry @dp. @ppp will be filled with the page the return + * value resides in. + * + * Returns: + * The wanted direct on success, else a NULL pointer. + */ +static struct vxfs_direct * +vxfs_find_entry(struct inode *ip, struct dentry *dp, struct page **ppp) +{ + u_long bsize = ip->i_sb->s_blocksize; + const char *name = dp->d_name.name; + int namelen = dp->d_name.len; + loff_t limit = VXFS_DIRROUND(ip->i_size); + struct vxfs_direct *de_exit = NULL; + loff_t pos = 0; + struct vxfs_sb_info *sbi = VXFS_SBI(ip->i_sb); + + while (pos < limit) { + struct page *pp; + char *kaddr; + int pg_ofs = pos & ~PAGE_MASK; + + pp = vxfs_get_page(ip->i_mapping, pos >> PAGE_SHIFT); + if (IS_ERR(pp)) + return NULL; + kaddr = (char *)page_address(pp); + + while (pg_ofs < PAGE_SIZE && pos < limit) { + struct vxfs_direct *de; + + if ((pos & (bsize - 1)) < 4) { + struct vxfs_dirblk *dbp = + (struct vxfs_dirblk *) + (kaddr + (pos & ~PAGE_MASK)); + int overhead = VXFS_DIRBLKOV(sbi, dbp); + + pos += overhead; + pg_ofs += overhead; + } + de = (struct vxfs_direct *)(kaddr + pg_ofs); + + if (!de->d_reclen) { + pos += bsize - 1; + pos &= ~(bsize - 1); + break; + } + + pg_ofs += fs16_to_cpu(sbi, de->d_reclen); + pos += fs16_to_cpu(sbi, de->d_reclen); + if (!de->d_ino) + continue; + + if (namelen != fs16_to_cpu(sbi, de->d_namelen)) + continue; + if (!memcmp(name, de->d_name, namelen)) { + *ppp = pp; + de_exit = de; + break; + } + } + if (!de_exit) + vxfs_put_page(pp); + else + break; + } + + return de_exit; +} + +/** + * vxfs_inode_by_name - find inode number for dentry + * @dip: directory to search in + * @dp: dentry we search for + * + * Description: + * vxfs_inode_by_name finds out the inode number of + * the path component described by @dp in @dip. + * + * Returns: + * The wanted inode number on success, else Zero. + */ +static ino_t +vxfs_inode_by_name(struct inode *dip, struct dentry *dp) +{ + struct vxfs_direct *de; + struct page *pp; + ino_t ino = 0; + + de = vxfs_find_entry(dip, dp, &pp); + if (de) { + ino = fs32_to_cpu(VXFS_SBI(dip->i_sb), de->d_ino); + kunmap(pp); + put_page(pp); + } + + return (ino); +} + +/** + * vxfs_lookup - lookup pathname component + * @dip: dir in which we lookup + * @dp: dentry we lookup + * @flags: lookup flags + * + * Description: + * vxfs_lookup tries to lookup the pathname component described + * by @dp in @dip. + * + * Returns: + * A NULL-pointer on success, else a negative error code encoded + * in the return pointer. + */ +static struct dentry * +vxfs_lookup(struct inode *dip, struct dentry *dp, unsigned int flags) +{ + struct inode *ip = NULL; + ino_t ino; + + if (dp->d_name.len > VXFS_NAMELEN) + return ERR_PTR(-ENAMETOOLONG); + + ino = vxfs_inode_by_name(dip, dp); + if (ino) + ip = vxfs_iget(dip->i_sb, ino); + return d_splice_alias(ip, dp); +} + +/** + * vxfs_readdir - read a directory + * @fp: the directory to read + * @retp: return buffer + * @filler: filldir callback + * + * Description: + * vxfs_readdir fills @retp with directory entries from @fp + * using the VFS supplied callback @filler. + * + * Returns: + * Zero. + */ +static int +vxfs_readdir(struct file *fp, struct dir_context *ctx) +{ + struct inode *ip = file_inode(fp); + struct super_block *sbp = ip->i_sb; + u_long bsize = sbp->s_blocksize; + loff_t pos, limit; + struct vxfs_sb_info *sbi = VXFS_SBI(sbp); + + if (ctx->pos == 0) { + if (!dir_emit_dot(fp, ctx)) + goto out; + ctx->pos++; + } + if (ctx->pos == 1) { + if (!dir_emit(ctx, "..", 2, VXFS_INO(ip)->vii_dotdot, DT_DIR)) + goto out; + ctx->pos++; + } + + limit = VXFS_DIRROUND(ip->i_size); + if (ctx->pos > limit) + goto out; + + pos = ctx->pos & ~3L; + + while (pos < limit) { + struct page *pp; + char *kaddr; + int pg_ofs = pos & ~PAGE_MASK; + int rc = 0; + + pp = vxfs_get_page(ip->i_mapping, pos >> PAGE_SHIFT); + if (IS_ERR(pp)) + return -ENOMEM; + + kaddr = (char *)page_address(pp); + + while (pg_ofs < PAGE_SIZE && pos < limit) { + struct vxfs_direct *de; + + if ((pos & (bsize - 1)) < 4) { + struct vxfs_dirblk *dbp = + (struct vxfs_dirblk *) + (kaddr + (pos & ~PAGE_MASK)); + int overhead = VXFS_DIRBLKOV(sbi, dbp); + + pos += overhead; + pg_ofs += overhead; + } + de = (struct vxfs_direct *)(kaddr + pg_ofs); + + if (!de->d_reclen) { + pos += bsize - 1; + pos &= ~(bsize - 1); + break; + } + + pg_ofs += fs16_to_cpu(sbi, de->d_reclen); + pos += fs16_to_cpu(sbi, de->d_reclen); + if (!de->d_ino) + continue; + + rc = dir_emit(ctx, de->d_name, + fs16_to_cpu(sbi, de->d_namelen), + fs32_to_cpu(sbi, de->d_ino), + DT_UNKNOWN); + if (!rc) { + /* the dir entry was not read, fix pos. */ + pos -= fs16_to_cpu(sbi, de->d_reclen); + break; + } + } + vxfs_put_page(pp); + if (!rc) + break; + } + + ctx->pos = pos | 2; + +out: + return 0; +} -- cgit v1.2.3