summaryrefslogtreecommitdiffstats
path: root/fs/freevxfs/vxfs_lookup.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /fs/freevxfs/vxfs_lookup.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/freevxfs/vxfs_lookup.c')
-rw-r--r--fs/freevxfs/vxfs_lookup.c272
1 files changed, 272 insertions, 0 deletions
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 <linux/fs.h>
+#include <linux/time.h>
+#include <linux/mm.h>
+#include <linux/highmem.h>
+#include <linux/kernel.h>
+#include <linux/pagemap.h>
+
+#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;
+}