s390utils/0067-cmsfs-fuse-Delete-old-file-if-renaming-to-an-existin.patch

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From f6494a1210439d591a1319498026ffcdd91a2ebf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dan=20Hor=C3=A1k?= <dan@danny.cz>
Date: Tue, 29 Mar 2011 10:49:25 +0200
Subject: [PATCH 67/70] cmsfs-fuse: Delete old file if renaming to an existing file
Description: cmsfs-fuse: Delete old file if renaming to an existing file.
Symptom: Stale old file if renaming a file to an existing file.
Problem: In case rename is used to overwrite an existing file the old
file entry was not deleted resulting in a duplicated file.
Solution: If the target of a rename operation exists delete the target
file before the rename operation.
---
cmsfs-fuse/cmsfs-fuse.c | 248 ++++++++++++++++++++++++-----------------------
1 files changed, 128 insertions(+), 120 deletions(-)
diff --git a/cmsfs-fuse/cmsfs-fuse.c b/cmsfs-fuse/cmsfs-fuse.c
index fd87774..9f1aa1a 100644
--- a/cmsfs-fuse/cmsfs-fuse.c
+++ b/cmsfs-fuse/cmsfs-fuse.c
@@ -2638,14 +2638,132 @@ static int cmsfs_utimens(const char *path, const struct timespec ts[2])
return 0;
}
+/*
+ * Get the address of the last directory entry.
+ */
+off_t find_last_fdir_entry(off_t addr, int level)
+{
+ struct fst_entry fst;
+ int left, rc;
+ off_t ptr;
+
+ if (level > 0) {
+ level--;
+ left = PTRS_PER_BLOCK;
+ while (left--) {
+ ptr = get_fixed_pointer(addr + left * PTR_SIZE);
+ BUG(ptr < 0);
+ if (ptr)
+ return find_last_fdir_entry(ptr, level);
+ }
+ DIE("Directory entry not found\n");
+ return 0;
+ }
+
+ left = cmsfs.blksize / sizeof(struct fst_entry);
+ while (left--) {
+ rc = _read(&fst, sizeof(fst),
+ addr + left * sizeof(struct fst_entry));
+ BUG(rc < 0);
+ if (is_file((unsigned long long *) fst.name,
+ (unsigned long long *) fst.type))
+ return addr + left * sizeof(struct fst_entry);
+ }
+ DIE("Directory entry not found\n");
+}
+
+static int delete_file(const char *path)
+{
+ off_t fst_kill, fst_last;
+ struct walk_file walk;
+ struct file *f_moved;
+ char file[MAX_FNAME];
+ struct fst_entry fst;
+ struct file *f;
+ int rc = 0, i;
+
+ if (cmsfs.readonly)
+ return -EROFS;
+
+ fst_kill = lookup_file(path + 1, &fst, SHOW_UNLINKED);
+ if (!fst_kill)
+ return -ENOENT;
+ f = create_file_object(&fst, &rc);
+ if (f == NULL)
+ return rc;
+
+ /* delete all data blocks */
+ for (i = 0; i < f->fst->nr_blocks; i++)
+ free_block(f->blist[i].disk_addr);
+
+ if (f->fst->fop) {
+ rc = f->fops->delete_pointers(f, f->fst->levels, ABS(f->fst->fop));
+ if (rc < 0)
+ goto error;
+ }
+
+ if (cmsfs.dir_levels)
+ fst_last = find_last_fdir_entry(get_fop(cmsfs.fdir), cmsfs.dir_levels);
+ else
+ fst_last = find_last_fdir_entry(cmsfs.fdir, cmsfs.dir_levels);
+
+ /* remove unlinked file from fcache */
+ strncpy(file, path + 1, MAX_FNAME);
+ str_toupper(file);
+ invalidate_htab_entry(file);
+
+ if (fst_last == fst_kill)
+ goto skip_copy;
+
+ /* copy last entry over unlinked entry */
+ rc = _read(&fst, sizeof(struct fst_entry), fst_last);
+ BUG(rc < 0);
+ rc = _write(&fst, sizeof(struct fst_entry), fst_kill);
+ BUG(rc < 0);
+
+ /* update moved fcache entry */
+ memset(file, 0, sizeof(file));
+ decode_edf_name(file, fst.name, fst.type);
+ update_htab_entry(fst_kill, file);
+ /* update cached address of moved FST */
+ f_moved = file_open(file);
+ if (f_moved != NULL)
+ f->fst_addr = fst_kill;
+
+skip_copy:
+ /* delete last entry */
+ rc = _zero(fst_last, sizeof(struct fst_entry));
+ BUG(rc < 0);
+
+ /* if the deleted entry was the first of a block, free the block */
+ if (fst_last % cmsfs.blksize == 0) {
+ cache_dblocks(&walk);
+ /* delete the last block from dlist */
+ walk.dlist_used--;
+ free_block(fst_last);
+ purge_dblock_ptrs(cmsfs.dir_levels, get_fop(cmsfs.fdir));
+ rewrite_dblock_ptrs(&walk);
+ free_dblocks(&walk);
+ }
+
+ destroy_file_object(f);
+ decrease_file_count();
+ update_block_count();
+ return 0;
+
+error:
+ destroy_file_object(f);
+ return rc;
+}
+
static int cmsfs_rename(const char *path, const char *new_path)
{
+ struct fst_entry fst, fst_new;
+ off_t fst_addr, fst_addr_new;
char uc_old_name[MAX_FNAME];
char fname[8], ftype[8];
- struct fst_entry fst;
char *uc_new_name;
struct file *f;
- off_t fst_addr;
int rc;
if (cmsfs.readonly)
@@ -2655,6 +2773,14 @@ static int cmsfs_rename(const char *path, const char *new_path)
if (!fst_addr)
return -ENOENT;
+ /* if new file already exists it must be overwritten so delete it */
+ fst_addr_new = lookup_file(new_path + 1, &fst_new, HIDE_UNLINKED);
+ if (fst_addr_new) {
+ delete_file(new_path);
+ /* fst_addr may have changed due to copy-up */
+ fst_addr = lookup_file(path + 1, &fst, HIDE_UNLINKED);
+ }
+
rc = edf_name_valid(new_path + 1);
if (rc)
return rc;
@@ -4042,124 +4168,6 @@ static int cmsfs_write(const char *path, const char *buf, size_t size,
return rc;
}
-/*
- * Get the address of the last directory entry.
- */
-off_t find_last_fdir_entry(off_t addr, int level)
-{
- struct fst_entry fst;
- int left, rc;
- off_t ptr;
-
- if (level > 0) {
- level--;
- left = PTRS_PER_BLOCK;
- while (left--) {
- ptr = get_fixed_pointer(addr + left * PTR_SIZE);
- BUG(ptr < 0);
- if (ptr)
- return find_last_fdir_entry(ptr, level);
- }
- DIE("Directory entry not found\n");
- return 0;
- }
-
- left = cmsfs.blksize / sizeof(struct fst_entry);
- while (left--) {
- rc = _read(&fst, sizeof(fst),
- addr + left * sizeof(struct fst_entry));
- BUG(rc < 0);
- if (is_file((unsigned long long *) fst.name,
- (unsigned long long *) fst.type))
- return addr + left * sizeof(struct fst_entry);
- }
- DIE("Directory entry not found\n");
-}
-
-static int delete_file(const char *path)
-{
- off_t fst_kill, fst_last;
- struct walk_file walk;
- struct file *f_moved;
- char file[MAX_FNAME];
- struct fst_entry fst;
- struct file *f;
- int rc = 0, i;
-
- if (cmsfs.readonly)
- return -EROFS;
-
- fst_kill = lookup_file(path + 1, &fst, SHOW_UNLINKED);
- if (!fst_kill)
- return -ENOENT;
- f = create_file_object(&fst, &rc);
- if (f == NULL)
- return rc;
-
- /* delete all data blocks */
- for (i = 0; i < f->fst->nr_blocks; i++)
- free_block(f->blist[i].disk_addr);
-
- if (f->fst->fop) {
- rc = f->fops->delete_pointers(f, f->fst->levels, ABS(f->fst->fop));
- if (rc < 0)
- goto error;
- }
-
- if (cmsfs.dir_levels)
- fst_last = find_last_fdir_entry(get_fop(cmsfs.fdir), cmsfs.dir_levels);
- else
- fst_last = find_last_fdir_entry(cmsfs.fdir, cmsfs.dir_levels);
-
- /* remove unlinked file from fcache */
- strncpy(file, path + 1, MAX_FNAME);
- str_toupper(file);
- invalidate_htab_entry(file);
-
- if (fst_last == fst_kill)
- goto skip_copy;
-
- /* copy last entry over unlinked entry */
- rc = _read(&fst, sizeof(struct fst_entry), fst_last);
- BUG(rc < 0);
- rc = _write(&fst, sizeof(struct fst_entry), fst_kill);
- BUG(rc < 0);
-
- /* update moved fcache entry */
- memset(file, 0, sizeof(file));
- decode_edf_name(file, fst.name, fst.type);
- update_htab_entry(fst_kill, file);
- /* update cached address of moved FST */
- f_moved = file_open(file);
- if (f_moved != NULL)
- f->fst_addr = fst_kill;
-
-skip_copy:
- /* delete last entry */
- rc = _zero(fst_last, sizeof(struct fst_entry));
- BUG(rc < 0);
-
- /* if the deleted entry was the first of a block, free the block */
- if (fst_last % cmsfs.blksize == 0) {
- cache_dblocks(&walk);
- /* delete the last block from dlist */
- walk.dlist_used--;
- free_block(fst_last);
- purge_dblock_ptrs(cmsfs.dir_levels, get_fop(cmsfs.fdir));
- rewrite_dblock_ptrs(&walk);
- free_dblocks(&walk);
- }
-
- destroy_file_object(f);
- decrease_file_count();
- update_block_count();
- return 0;
-
-error:
- destroy_file_object(f);
- return rc;
-}
-
static int cmsfs_unlink(const char *path)
{
struct fst_entry fst;
--
1.7.4