4475da968a
The problem is caused by the incorrect handling of the parent inode's i_nlink count for the dentry to be RENAME_EXCHANGED. There are 3 cases to consider. Assume we want to RENAME_EXCHANGE struct dentry *a and struct dentry *b, and inode_a is pointed to by dentry_a, inode_b is pointed to by dentry_b: 1. If inode_a is a directory, but inode_b isn't, then we must decrease the i_nlink count of old_dir_i, and increase the i_nlink of new_dir_i. 2. If inode_a isn't a directory, but inode_b is a directory, then we must increase the i_nlink of old_dir_i, and decrease the i_nlink count of new_dir_i. 3. If the types of inode_a and inode_b are the same, we don't change the i_nlink for either old_dir_i or new_dir_i. Signed-off-by: Jing Qiu <aqiu0720@gmail.com> Signed-off-by: Felix Fietkau <nbd@nbd.name>
75 lines
2.5 KiB
Diff
75 lines
2.5 KiB
Diff
From: Felix Fietkau <nbd@nbd.name>
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Date: Sat, 25 Apr 2015 12:41:32 +0200
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Subject: [PATCH] jffs2: add RENAME_EXCHANGE support
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Signed-off-by: Felix Fietkau <nbd@nbd.name>
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---
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--- a/fs/jffs2/dir.c
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+++ b/fs/jffs2/dir.c
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@@ -781,18 +781,31 @@ static int jffs2_rename (struct inode *o
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int ret;
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struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dir_i->i_sb);
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struct jffs2_inode_info *victim_f = NULL;
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+ struct inode *fst_inode = d_inode(old_dentry);
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+ struct inode *snd_inode = d_inode(new_dentry);
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uint8_t type;
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uint32_t now;
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- if (flags & ~(RENAME_NOREPLACE|RENAME_WHITEOUT))
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+ if (flags & ~(RENAME_NOREPLACE|RENAME_WHITEOUT|RENAME_EXCHANGE))
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return -EINVAL;
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+ if ((flags & RENAME_EXCHANGE) && (old_dir_i != new_dir_i)) {
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+ if (S_ISDIR(fst_inode->i_mode) && !S_ISDIR(snd_inode->i_mode)) {
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+ inc_nlink(new_dir_i);
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+ drop_nlink(old_dir_i);
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+ }
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+ else if (!S_ISDIR(fst_inode->i_mode) && S_ISDIR(snd_inode->i_mode)) {
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+ drop_nlink(new_dir_i);
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+ inc_nlink(old_dir_i);
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+ }
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+ }
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+
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/* The VFS will check for us and prevent trying to rename a
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* file over a directory and vice versa, but if it's a directory,
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* the VFS can't check whether the victim is empty. The filesystem
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* needs to do that for itself.
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*/
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- if (d_really_is_positive(new_dentry)) {
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+ if (d_really_is_positive(new_dentry) && !(flags & RENAME_EXCHANGE)) {
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victim_f = JFFS2_INODE_INFO(d_inode(new_dentry));
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if (d_is_dir(new_dentry)) {
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struct jffs2_full_dirent *fd;
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@@ -827,7 +840,7 @@ static int jffs2_rename (struct inode *o
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if (ret)
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return ret;
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- if (victim_f) {
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+ if (victim_f && !(flags & RENAME_EXCHANGE)) {
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/* There was a victim. Kill it off nicely */
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if (d_is_dir(new_dentry))
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clear_nlink(d_inode(new_dentry));
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@@ -853,6 +866,12 @@ static int jffs2_rename (struct inode *o
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if (flags & RENAME_WHITEOUT)
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/* Replace with whiteout */
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ret = jffs2_whiteout(old_dir_i, old_dentry);
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+ else if (flags & RENAME_EXCHANGE)
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+ /* Replace the original */
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+ ret = jffs2_do_link(c, JFFS2_INODE_INFO(old_dir_i),
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+ d_inode(new_dentry)->i_ino, type,
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+ old_dentry->d_name.name, old_dentry->d_name.len,
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+ now);
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else
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/* Unlink the original */
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ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i),
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@@ -884,7 +903,7 @@ static int jffs2_rename (struct inode *o
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return ret;
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}
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- if (d_is_dir(old_dentry))
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+ if (d_is_dir(old_dentry) && !(flags & RENAME_EXCHANGE))
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drop_nlink(old_dir_i);
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new_dir_i->i_mtime = new_dir_i->i_ctime = old_dir_i->i_mtime = old_dir_i->i_ctime = ITIME(now);
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