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Message-Id: <20200408215530.25649-10-harshads@google.com>
Date: Wed, 8 Apr 2020 14:55:20 -0700
From: Harshad Shirwadkar <harshadshirwadkar@...il.com>
To: linux-ext4@...r.kernel.org
Cc: tytso@....edu, Harshad Shirwadkar <harshadshirwadkar@...il.com>
Subject: [PATCH v6 10/20] ext4: break ext4_unlink() and ext4_link()
From: Harshad Shirwadkar <harshadshirwadkar@...il.com>
Break ext4_link() and ext4_unlink() each into 2 parts in order to make
them usable in recovery path as well.
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@...il.com>
---
fs/ext4/ext4.h | 4 ++
fs/ext4/namei.c | 139 +++++++++++++++++++++++++++++-------------------
2 files changed, 88 insertions(+), 55 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index e9c82f555b6d..c39966facf86 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -3365,6 +3365,10 @@ extern int ext4_handle_dirty_dirblock(handle_t *handle, struct inode *inode,
extern int ext4_ci_compare(const struct inode *parent,
const struct qstr *fname,
const struct qstr *entry, bool quick);
+extern int __ext4_unlink(struct inode *dir, const struct qstr *d_name,
+ struct inode *inode);
+extern int __ext4_link(struct inode *dir, struct inode *inode,
+ struct dentry *dentry);
#define S_SHIFT 12
static const unsigned char ext4_type_by_mode[(S_IFMT >> S_SHIFT) + 1] = {
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index a8aca4772aaa..77fc136fe718 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -3171,39 +3171,36 @@ static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
return retval;
}
-static int ext4_unlink(struct inode *dir, struct dentry *dentry)
+int __ext4_unlink(struct inode *dir, const struct qstr *d_name,
+ struct inode *inode)
{
- int retval;
- struct inode *inode;
struct buffer_head *bh;
struct ext4_dir_entry_2 *de;
handle_t *handle = NULL;
+ int retval = -ENOENT;
+ int skip_remove_dentry = 0;
- if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
- return -EIO;
-
- trace_ext4_unlink_enter(dir, dentry);
- /* Initialize quotas before so that eventual writes go
- * in separate transaction */
- retval = dquot_initialize(dir);
- if (retval)
- return retval;
- retval = dquot_initialize(d_inode(dentry));
- if (retval)
- return retval;
-
- retval = -ENOENT;
- bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
+ bh = ext4_find_entry(dir, d_name, &de, NULL);
if (IS_ERR(bh))
return PTR_ERR(bh);
- if (!bh)
- goto end_unlink;
- inode = d_inode(dentry);
+ if (!bh) {
+ retval = -ENOENT;
+ goto end_unlink;
+ }
retval = -EFSCORRUPTED;
- if (le32_to_cpu(de->inode) != inode->i_ino)
- goto end_unlink;
+ if (le32_to_cpu(de->inode) != inode->i_ino) {
+ /*
+ * It's okay if we find dont find dentry which matches
+ * the inode. That's because it might have gotten
+ * renamed to a different inode number
+ */
+ if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
+ skip_remove_dentry = 1;
+ else
+ goto end_unlink;
+ }
handle = ext4_journal_start(dir, EXT4_HT_DIR,
EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
@@ -3216,15 +3213,20 @@ static int ext4_unlink(struct inode *dir, struct dentry *dentry)
if (IS_DIRSYNC(dir))
ext4_handle_sync(handle);
- retval = ext4_delete_entry(handle, dir, de, bh);
- if (retval)
- goto end_unlink;
- dir->i_ctime = dir->i_mtime = current_time(dir);
- ext4_update_dx_flag(dir);
- ext4_mark_inode_dirty(handle, dir);
+ if (!skip_remove_dentry) {
+ retval = ext4_delete_entry(handle, dir, de, bh);
+ if (retval)
+ goto end_unlink;
+ dir->i_ctime = dir->i_mtime = current_time(dir);
+ ext4_update_dx_flag(dir);
+ ext4_mark_inode_dirty(handle, dir);
+ } else {
+ retval = 0;
+ }
+
if (inode->i_nlink == 0)
ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
- dentry->d_name.len, dentry->d_name.name);
+ d_name->len, d_name->name);
else
drop_nlink(inode);
if (!inode->i_nlink)
@@ -3232,6 +3234,33 @@ static int ext4_unlink(struct inode *dir, struct dentry *dentry)
inode->i_ctime = current_time(inode);
ext4_mark_inode_dirty(handle, inode);
+end_unlink:
+ brelse(bh);
+ if (handle)
+ ext4_journal_stop(handle);
+ return retval;
+}
+
+static int ext4_unlink(struct inode *dir, struct dentry *dentry)
+{
+ int retval;
+
+ if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
+ return -EIO;
+
+ trace_ext4_unlink_enter(dir, dentry);
+ /*
+ * Initialize quotas before so that eventual writes go
+ * in separate transaction
+ */
+ retval = dquot_initialize(dir);
+ if (retval)
+ return retval;
+ retval = dquot_initialize(d_inode(dentry));
+ if (retval)
+ return retval;
+
+ retval = __ext4_unlink(dir, &dentry->d_name, d_inode(dentry));
#ifdef CONFIG_UNICODE
/* VFS negative dentries are incompatible with Encoding and
* Case-insensitiveness. Eventually we'll want avoid
@@ -3242,11 +3271,6 @@ static int ext4_unlink(struct inode *dir, struct dentry *dentry)
if (IS_CASEFOLDED(dir))
d_invalidate(dentry);
#endif
-
-end_unlink:
- brelse(bh);
- if (handle)
- ext4_journal_stop(handle);
trace_ext4_unlink_exit(dentry, retval);
return retval;
}
@@ -3380,29 +3404,10 @@ static int ext4_symlink(struct inode *dir,
return err;
}
-static int ext4_link(struct dentry *old_dentry,
- struct inode *dir, struct dentry *dentry)
+int __ext4_link(struct inode *dir, struct inode *inode, struct dentry *dentry)
{
handle_t *handle;
- struct inode *inode = d_inode(old_dentry);
int err, retries = 0;
-
- if (inode->i_nlink >= EXT4_LINK_MAX)
- return -EMLINK;
-
- err = fscrypt_prepare_link(old_dentry, dir, dentry);
- if (err)
- return err;
-
- if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
- (!projid_eq(EXT4_I(dir)->i_projid,
- EXT4_I(old_dentry->d_inode)->i_projid)))
- return -EXDEV;
-
- err = dquot_initialize(dir);
- if (err)
- return err;
-
retry:
handle = ext4_journal_start(dir, EXT4_HT_DIR,
(EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
@@ -3436,6 +3441,30 @@ static int ext4_link(struct dentry *old_dentry,
return err;
}
+static int ext4_link(struct dentry *old_dentry,
+ struct inode *dir, struct dentry *dentry)
+{
+ struct inode *inode = d_inode(old_dentry);
+ int err;
+
+ if (inode->i_nlink >= EXT4_LINK_MAX)
+ return -EMLINK;
+
+ err = fscrypt_prepare_link(old_dentry, dir, dentry);
+ if (err)
+ return err;
+
+ if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
+ (!projid_eq(EXT4_I(dir)->i_projid,
+ EXT4_I(old_dentry->d_inode)->i_projid)))
+ return -EXDEV;
+
+ err = dquot_initialize(dir);
+ if (err)
+ return err;
+ return __ext4_link(dir, inode, dentry);
+}
+
/*
* Try to find buffer head where contains the parent block.
--
2.26.0.110.g2183baf09c-goog
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