5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Daniel Lee chullee@google.com
commit 91b587ba79e1b68bb718d12b0758dbcdab4e9cb7 upstream.
This patch addresses an issue where some files in case-insensitive directories become inaccessible due to changes in how the kernel function, utf8_casefold(), generates case-folded strings from the commit 5c26d2f1d3f5 ("unicode: Don't special case ignorable code points").
F2FS uses these case-folded names to calculate hash values for locating dentries and stores them on disk. Since utf8_casefold() can produce different output across kernel versions, stored hash values and newly calculated hash values may differ. This results in affected files no longer being found via the hash-based lookup.
To resolve this, the patch introduces a linear search fallback. If the initial hash-based search fails, F2FS will sequentially scan the directory entries.
Fixes: 5c26d2f1d3f5 ("unicode: Don't special case ignorable code points") Link: https://bugzilla.kernel.org/show_bug.cgi?id=219586 Signed-off-by: Daniel Lee chullee@google.com Reviewed-by: Chao Yu chao@kernel.org Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Cc: Daniel Rosenberg drosen@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/f2fs/dir.c | 53 ++++++++++++++++++++++++++++++++++++++--------------- fs/f2fs/f2fs.h | 6 ++++-- fs/f2fs/inline.c | 5 +++-- 3 files changed, 45 insertions(+), 19 deletions(-)
--- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -199,7 +199,8 @@ static unsigned long dir_block_index(uns static struct f2fs_dir_entry *find_in_block(struct inode *dir, struct page *dentry_page, const struct f2fs_filename *fname, - int *max_slots) + int *max_slots, + bool use_hash) { struct f2fs_dentry_block *dentry_blk; struct f2fs_dentry_ptr d; @@ -207,7 +208,7 @@ static struct f2fs_dir_entry *find_in_bl dentry_blk = (struct f2fs_dentry_block *)page_address(dentry_page);
make_dentry_ptr_block(dir, &d, dentry_blk); - return f2fs_find_target_dentry(&d, fname, max_slots); + return f2fs_find_target_dentry(&d, fname, max_slots, use_hash); }
#ifdef CONFIG_UNICODE @@ -284,7 +285,8 @@ static inline int f2fs_match_name(const }
struct f2fs_dir_entry *f2fs_find_target_dentry(const struct f2fs_dentry_ptr *d, - const struct f2fs_filename *fname, int *max_slots) + const struct f2fs_filename *fname, int *max_slots, + bool use_hash) { struct f2fs_dir_entry *de; unsigned long bit_pos = 0; @@ -307,7 +309,7 @@ struct f2fs_dir_entry *f2fs_find_target_ continue; }
- if (de->hash_code == fname->hash) { + if (!use_hash || de->hash_code == fname->hash) { res = f2fs_match_name(d->inode, fname, d->filename[bit_pos], le16_to_cpu(de->name_len)); @@ -334,11 +336,12 @@ found: static struct f2fs_dir_entry *find_in_level(struct inode *dir, unsigned int level, const struct f2fs_filename *fname, - struct page **res_page) + struct page **res_page, + bool use_hash) { int s = GET_DENTRY_SLOTS(fname->disk_name.len); unsigned int nbucket, nblock; - unsigned int bidx, end_block; + unsigned int bidx, end_block, bucket_no; struct page *dentry_page; struct f2fs_dir_entry *de = NULL; bool room = false; @@ -347,8 +350,11 @@ static struct f2fs_dir_entry *find_in_le nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level); nblock = bucket_blocks(level);
+ bucket_no = use_hash ? le32_to_cpu(fname->hash) % nbucket : 0; + +start_find_bucket: bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level, - le32_to_cpu(fname->hash) % nbucket); + bucket_no); end_block = bidx + nblock;
for (; bidx < end_block; bidx++) { @@ -364,7 +370,7 @@ static struct f2fs_dir_entry *find_in_le } }
- de = find_in_block(dir, dentry_page, fname, &max_slots); + de = find_in_block(dir, dentry_page, fname, &max_slots, use_hash); if (IS_ERR(de)) { *res_page = ERR_CAST(de); de = NULL; @@ -379,12 +385,18 @@ static struct f2fs_dir_entry *find_in_le f2fs_put_page(dentry_page, 0); }
- if (!de && room && F2FS_I(dir)->chash != fname->hash) { - F2FS_I(dir)->chash = fname->hash; - F2FS_I(dir)->clevel = level; - } + if (de) + return de;
- return de; + if (likely(use_hash)) { + if (room && F2FS_I(dir)->chash != fname->hash) { + F2FS_I(dir)->chash = fname->hash; + F2FS_I(dir)->clevel = level; + } + } else if (++bucket_no < nbucket) { + goto start_find_bucket; + } + return NULL; }
struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, @@ -395,11 +407,15 @@ struct f2fs_dir_entry *__f2fs_find_entry struct f2fs_dir_entry *de = NULL; unsigned int max_depth; unsigned int level; + bool use_hash = true;
*res_page = NULL;
+#if IS_ENABLED(CONFIG_UNICODE) +start_find_entry: +#endif if (f2fs_has_inline_dentry(dir)) { - de = f2fs_find_in_inline_dir(dir, fname, res_page); + de = f2fs_find_in_inline_dir(dir, fname, res_page, use_hash); goto out; }
@@ -415,11 +431,18 @@ struct f2fs_dir_entry *__f2fs_find_entry }
for (level = 0; level < max_depth; level++) { - de = find_in_level(dir, level, fname, res_page); + de = find_in_level(dir, level, fname, res_page, use_hash); if (de || IS_ERR(*res_page)) break; } + out: +#if IS_ENABLED(CONFIG_UNICODE) + if (IS_CASEFOLDED(dir) && !de && use_hash) { + use_hash = false; + goto start_find_entry; + } +#endif /* This is to increase the speed of f2fs_create */ if (!de) F2FS_I(dir)->task = current; --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -3325,7 +3325,8 @@ int f2fs_prepare_lookup(struct inode *di struct f2fs_filename *fname); void f2fs_free_filename(struct f2fs_filename *fname); struct f2fs_dir_entry *f2fs_find_target_dentry(const struct f2fs_dentry_ptr *d, - const struct f2fs_filename *fname, int *max_slots); + const struct f2fs_filename *fname, int *max_slots, + bool use_hash); int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d, unsigned int start_pos, struct fscrypt_str *fstr); void f2fs_do_make_empty_dir(struct inode *inode, struct inode *parent, @@ -3926,7 +3927,8 @@ int f2fs_write_inline_data(struct inode int f2fs_recover_inline_data(struct inode *inode, struct page *npage); struct f2fs_dir_entry *f2fs_find_in_inline_dir(struct inode *dir, const struct f2fs_filename *fname, - struct page **res_page); + struct page **res_page, + bool use_hash); int f2fs_make_empty_inline_dir(struct inode *inode, struct inode *parent, struct page *ipage); int f2fs_add_inline_entry(struct inode *dir, const struct f2fs_filename *fname, --- a/fs/f2fs/inline.c +++ b/fs/f2fs/inline.c @@ -335,7 +335,8 @@ process_inline:
struct f2fs_dir_entry *f2fs_find_in_inline_dir(struct inode *dir, const struct f2fs_filename *fname, - struct page **res_page) + struct page **res_page, + bool use_hash) { struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb); struct f2fs_dir_entry *de; @@ -352,7 +353,7 @@ struct f2fs_dir_entry *f2fs_find_in_inli inline_dentry = inline_data_addr(dir, ipage);
make_dentry_ptr_inline(dir, &d, inline_dentry); - de = f2fs_find_target_dentry(&d, fname, NULL); + de = f2fs_find_target_dentry(&d, fname, NULL, use_hash); unlock_page(ipage); if (IS_ERR(de)) { *res_page = ERR_CAST(de);