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path: root/fs/fat/namei_vfat.c
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Diffstat (limited to 'fs/fat/namei_vfat.c')
-rw-r--r--fs/fat/namei_vfat.c231
1 files changed, 192 insertions, 39 deletions
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
index c573314806cf..21620054e1c4 100644
--- a/fs/fat/namei_vfat.c
+++ b/fs/fat/namei_vfat.c
@@ -889,22 +889,57 @@ out:
return err;
}
-static int vfat_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
- struct dentry *old_dentry, struct inode *new_dir,
- struct dentry *new_dentry, unsigned int flags)
+static int vfat_get_dotdot_de(struct inode *inode, struct buffer_head **bh,
+ struct msdos_dir_entry **de)
+{
+ if (S_ISDIR(inode->i_mode)) {
+ if (fat_get_dotdot_entry(inode, bh, de))
+ return -EIO;
+ }
+ return 0;
+}
+
+static int vfat_sync_ipos(struct inode *dir, struct inode *inode)
+{
+ if (IS_DIRSYNC(dir))
+ return fat_sync_inode(inode);
+ mark_inode_dirty(inode);
+ return 0;
+}
+
+static int vfat_update_dotdot_de(struct inode *dir, struct inode *inode,
+ struct buffer_head *dotdot_bh,
+ struct msdos_dir_entry *dotdot_de)
+{
+ fat_set_start(dotdot_de, MSDOS_I(dir)->i_logstart);
+ mark_buffer_dirty_inode(dotdot_bh, inode);
+ if (IS_DIRSYNC(dir))
+ return sync_dirty_buffer(dotdot_bh);
+ return 0;
+}
+
+static void vfat_update_dir_metadata(struct inode *dir, struct timespec64 *ts)
+{
+ inode_inc_iversion(dir);
+ fat_truncate_time(dir, ts, S_CTIME | S_MTIME);
+ if (IS_DIRSYNC(dir))
+ (void)fat_sync_inode(dir);
+ else
+ mark_inode_dirty(dir);
+}
+
+static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry)
{
struct buffer_head *dotdot_bh;
- struct msdos_dir_entry *dotdot_de;
+ struct msdos_dir_entry *dotdot_de = NULL;
struct inode *old_inode, *new_inode;
struct fat_slot_info old_sinfo, sinfo;
struct timespec64 ts;
loff_t new_i_pos;
- int err, is_dir, update_dotdot, corrupt = 0;
+ int err, is_dir, corrupt = 0;
struct super_block *sb = old_dir->i_sb;
- if (flags & ~RENAME_NOREPLACE)
- return -EINVAL;
-
old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
old_inode = d_inode(old_dentry);
new_inode = d_inode(new_dentry);
@@ -913,15 +948,13 @@ static int vfat_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
if (err)
goto out;
- is_dir = S_ISDIR(old_inode->i_mode);
- update_dotdot = (is_dir && old_dir != new_dir);
- if (update_dotdot) {
- if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de)) {
- err = -EIO;
+ if (old_dir != new_dir) {
+ err = vfat_get_dotdot_de(old_inode, &dotdot_bh, &dotdot_de);
+ if (err)
goto out;
- }
}
+ is_dir = S_ISDIR(old_inode->i_mode);
ts = current_time(old_dir);
if (new_inode) {
if (is_dir) {
@@ -942,21 +975,15 @@ static int vfat_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
fat_detach(old_inode);
fat_attach(old_inode, new_i_pos);
- if (IS_DIRSYNC(new_dir)) {
- err = fat_sync_inode(old_inode);
- if (err)
- goto error_inode;
- } else
- mark_inode_dirty(old_inode);
+ err = vfat_sync_ipos(new_dir, old_inode);
+ if (err)
+ goto error_inode;
- if (update_dotdot) {
- fat_set_start(dotdot_de, MSDOS_I(new_dir)->i_logstart);
- mark_buffer_dirty_inode(dotdot_bh, old_inode);
- if (IS_DIRSYNC(new_dir)) {
- err = sync_dirty_buffer(dotdot_bh);
- if (err)
- goto error_dotdot;
- }
+ if (dotdot_de) {
+ err = vfat_update_dotdot_de(new_dir, old_inode, dotdot_bh,
+ dotdot_de);
+ if (err)
+ goto error_dotdot;
drop_nlink(old_dir);
if (!new_inode)
inc_nlink(new_dir);
@@ -966,12 +993,7 @@ static int vfat_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
old_sinfo.bh = NULL;
if (err)
goto error_dotdot;
- inode_inc_iversion(old_dir);
- fat_truncate_time(old_dir, &ts, S_CTIME|S_MTIME);
- if (IS_DIRSYNC(old_dir))
- (void)fat_sync_inode(old_dir);
- else
- mark_inode_dirty(old_dir);
+ vfat_update_dir_metadata(old_dir, &ts);
if (new_inode) {
drop_nlink(new_inode);
@@ -991,10 +1013,9 @@ error_dotdot:
/* data cluster is shared, serious corruption */
corrupt = 1;
- if (update_dotdot) {
- fat_set_start(dotdot_de, MSDOS_I(old_dir)->i_logstart);
- mark_buffer_dirty_inode(dotdot_bh, old_inode);
- corrupt |= sync_dirty_buffer(dotdot_bh);
+ if (dotdot_de) {
+ corrupt |= vfat_update_dotdot_de(old_dir, old_inode, dotdot_bh,
+ dotdot_de);
}
error_inode:
fat_detach(old_inode);
@@ -1021,13 +1042,145 @@ error_inode:
goto out;
}
+static void vfat_exchange_ipos(struct inode *old_inode, struct inode *new_inode,
+ loff_t old_i_pos, loff_t new_i_pos)
+{
+ fat_detach(old_inode);
+ fat_detach(new_inode);
+ fat_attach(old_inode, new_i_pos);
+ fat_attach(new_inode, old_i_pos);
+}
+
+static void vfat_move_nlink(struct inode *src, struct inode *dst)
+{
+ drop_nlink(src);
+ inc_nlink(dst);
+}
+
+static int vfat_rename_exchange(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry)
+{
+ struct buffer_head *old_dotdot_bh = NULL, *new_dotdot_bh = NULL;
+ struct msdos_dir_entry *old_dotdot_de = NULL, *new_dotdot_de = NULL;
+ struct inode *old_inode, *new_inode;
+ struct timespec64 ts = current_time(old_dir);
+ loff_t old_i_pos, new_i_pos;
+ int err, corrupt = 0;
+ struct super_block *sb = old_dir->i_sb;
+
+ old_inode = d_inode(old_dentry);
+ new_inode = d_inode(new_dentry);
+
+ /* Acquire super block lock for the operation to be atomic */
+ mutex_lock(&MSDOS_SB(sb)->s_lock);
+
+ /* if directories are not the same, get ".." info to update */
+ if (old_dir != new_dir) {
+ err = vfat_get_dotdot_de(old_inode, &old_dotdot_bh,
+ &old_dotdot_de);
+ if (err)
+ goto out;
+
+ err = vfat_get_dotdot_de(new_inode, &new_dotdot_bh,
+ &new_dotdot_de);
+ if (err)
+ goto out;
+ }
+
+ old_i_pos = MSDOS_I(old_inode)->i_pos;
+ new_i_pos = MSDOS_I(new_inode)->i_pos;
+
+ vfat_exchange_ipos(old_inode, new_inode, old_i_pos, new_i_pos);
+
+ err = vfat_sync_ipos(old_dir, new_inode);
+ if (err)
+ goto error_exchange;
+ err = vfat_sync_ipos(new_dir, old_inode);
+ if (err)
+ goto error_exchange;
+
+ /* update ".." directory entry info */
+ if (old_dotdot_de) {
+ err = vfat_update_dotdot_de(new_dir, old_inode, old_dotdot_bh,
+ old_dotdot_de);
+ if (err)
+ goto error_old_dotdot;
+ }
+ if (new_dotdot_de) {
+ err = vfat_update_dotdot_de(old_dir, new_inode, new_dotdot_bh,
+ new_dotdot_de);
+ if (err)
+ goto error_new_dotdot;
+ }
+
+ /* if cross directory and only one is a directory, adjust nlink */
+ if (!old_dotdot_de != !new_dotdot_de) {
+ if (old_dotdot_de)
+ vfat_move_nlink(old_dir, new_dir);
+ else
+ vfat_move_nlink(new_dir, old_dir);
+ }
+
+ vfat_update_dir_metadata(old_dir, &ts);
+ /* if directories are not the same, update new_dir as well */
+ if (old_dir != new_dir)
+ vfat_update_dir_metadata(new_dir, &ts);
+
+out:
+ brelse(old_dotdot_bh);
+ brelse(new_dotdot_bh);
+ mutex_unlock(&MSDOS_SB(sb)->s_lock);
+
+ return err;
+
+error_new_dotdot:
+ if (new_dotdot_de) {
+ corrupt |= vfat_update_dotdot_de(new_dir, new_inode,
+ new_dotdot_bh, new_dotdot_de);
+ }
+
+error_old_dotdot:
+ if (old_dotdot_de) {
+ corrupt |= vfat_update_dotdot_de(old_dir, old_inode,
+ old_dotdot_bh, old_dotdot_de);
+ }
+
+error_exchange:
+ vfat_exchange_ipos(old_inode, new_inode, new_i_pos, old_i_pos);
+ corrupt |= vfat_sync_ipos(new_dir, new_inode);
+ corrupt |= vfat_sync_ipos(old_dir, old_inode);
+
+ if (corrupt < 0) {
+ fat_fs_error(new_dir->i_sb,
+ "%s: Filesystem corrupted (i_pos %lld, %lld)",
+ __func__, old_i_pos, new_i_pos);
+ }
+ goto out;
+}
+
+static int vfat_rename2(struct user_namespace *mnt_userns, struct inode *old_dir,
+ struct dentry *old_dentry, struct inode *new_dir,
+ struct dentry *new_dentry, unsigned int flags)
+{
+ if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
+ return -EINVAL;
+
+ if (flags & RENAME_EXCHANGE) {
+ return vfat_rename_exchange(old_dir, old_dentry,
+ new_dir, new_dentry);
+ }
+
+ /* VFS already handled RENAME_NOREPLACE, handle it as a normal rename */
+ return vfat_rename(old_dir, old_dentry, new_dir, new_dentry);
+}
+
static const struct inode_operations vfat_dir_inode_operations = {
.create = vfat_create,
.lookup = vfat_lookup,
.unlink = vfat_unlink,
.mkdir = vfat_mkdir,
.rmdir = vfat_rmdir,
- .rename = vfat_rename,
+ .rename = vfat_rename2,
.setattr = fat_setattr,
.getattr = fat_getattr,
.update_time = fat_update_time,