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When there are too many files in a directory, the generic_ci_match operation will be called repeatedly in large quantities. In extreme cases, the file creation speed will drop to three times per second. Use the following program to conduct a file-creation test in the private program directory(/data/media/0/Android/data/*) of Android. int main(int argc, char **argv) { size_t fcnt = 0; char path[PATH_MAX]; char buf[4096] = {0}; int i, fd; if (argc < 2) return - EINVAL; fcnt = atoi(argv[1]); for (i = 0; i < fcnt; i++) { snprintf(path, sizeof(path), "./%d", i); fd = open(path, O_RDWR | O_CREAT, 0600); if (fd < 0) return - 1; write(fd, buf, sizeof(buf)); close(fd); } return 0; } The test platform is Snapdragon 8s Gen4, with a kernel version of v6.6 and a userdebug version. Before this submission was merged, when creating 2000 files, the performance test results are as follows: $ time /data/file_creater 2000 0m14.83s real 0m00.00s user 0m14.30s system 0m15.61s real 0m00.00s user 0m15.04s system 0m14.72s real 0m00.01s user 0m14.18s system After this submission was merged, the performance is as follows: $ time /data/file_creater 2000 0m08.17s real 0m00.00s user 0m07.86s system 0m08.16s real 0m00.01s user 0m07.86s system 0m08.15s real 0m00.00s user 0m07.86s system It was observed through perf that the generic_ci_match function was called a large number of times, which led to most of the time being spent on memory allocation and release. Due to a flush_dcache operation in the implementation of cts_cbc_decrypt, this memory cannot be allocated on the stack. Signed-off-by: Yuwen Chen --- fs/f2fs/dir.c | 24 +++++++++++++++++------- fs/f2fs/f2fs.h | 3 ++- fs/f2fs/inline.c | 3 ++- 3 files changed, 21 insertions(+), 9 deletions(-) diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c index 4c6611fbd9574..ee0cbeb80debd 100644 --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -176,6 +176,7 @@ static struct f2fs_dir_entry *find_in_block(struct inode *dir, struct folio *dentry_folio, const struct f2fs_filename *fname, int *max_slots, + struct decrypted_name_prealloc *prealloc, bool use_hash) { struct f2fs_dentry_block *dentry_blk; @@ -184,12 +185,13 @@ static struct f2fs_dir_entry *find_in_block(struct inode *dir, dentry_blk = folio_address(dentry_folio); make_dentry_ptr_block(dir, &d, dentry_blk); - return f2fs_find_target_dentry(&d, fname, max_slots, use_hash); + return f2fs_find_target_dentry(&d, fname, max_slots, prealloc, use_hash); } static inline int f2fs_match_name(const struct inode *dir, const struct f2fs_filename *fname, - const u8 *de_name, u32 de_name_len) + const u8 *de_name, u32 de_name_len, + struct decrypted_name_prealloc *prealloc) { struct fscrypt_name f; @@ -197,7 +199,7 @@ static inline int f2fs_match_name(const struct inode *dir, if (fname->cf_name.name) return generic_ci_match(dir, fname->usr_fname, &fname->cf_name, - de_name, de_name_len, NULL); + de_name, de_name_len, prealloc); #endif f.usr_fname = fname->usr_fname; @@ -210,6 +212,7 @@ static inline int f2fs_match_name(const struct inode *dir, struct f2fs_dir_entry *f2fs_find_target_dentry(const struct f2fs_dentry_ptr *d, const struct f2fs_filename *fname, int *max_slots, + struct decrypted_name_prealloc *prealloc, bool use_hash) { struct f2fs_dir_entry *de; @@ -236,7 +239,8 @@ struct f2fs_dir_entry *f2fs_find_target_dentry(const struct f2fs_dentry_ptr *d, 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)); + le16_to_cpu(de->name_len), + prealloc); if (res < 0) return ERR_PTR(res); if (res) @@ -261,6 +265,7 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir, unsigned int level, const struct f2fs_filename *fname, struct folio **res_folio, + struct decrypted_name_prealloc *prealloc, bool use_hash) { int s = GET_DENTRY_SLOTS(fname->disk_name.len); @@ -296,7 +301,8 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir, } } - de = find_in_block(dir, dentry_folio, fname, &max_slots, use_hash); + de = find_in_block(dir, dentry_folio, fname, &max_slots, prealloc, + use_hash); if (IS_ERR(de)) { *res_folio = ERR_CAST(de); de = NULL; @@ -336,6 +342,7 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, unsigned int max_depth; unsigned int level; bool use_hash = true; + struct decrypted_name_prealloc prealloc = {0}; *res_folio = NULL; @@ -343,7 +350,8 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, start_find_entry: #endif if (f2fs_has_inline_dentry(dir)) { - de = f2fs_find_in_inline_dir(dir, fname, res_folio, use_hash); + de = f2fs_find_in_inline_dir(dir, fname, res_folio, &prealloc, + use_hash); goto out; } @@ -359,7 +367,8 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, } for (level = 0; level < max_depth; level++) { - de = find_in_level(dir, level, fname, res_folio, use_hash); + de = find_in_level(dir, level, fname, res_folio, &prealloc, + use_hash); if (de || IS_ERR(*res_folio)) break; } @@ -372,6 +381,7 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, goto start_find_entry; } #endif + kfree(prealloc.name); /* This is to increase the speed of f2fs_create */ if (!de) F2FS_I(dir)->task = current; diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 9333a22b9a01e..dfbd2215310fb 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -3673,6 +3673,7 @@ int f2fs_prepare_lookup(struct inode *dir, struct dentry *dentry, 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, + struct decrypted_name_prealloc *prealloc, bool use_hash); int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d, unsigned int start_pos, struct fscrypt_str *fstr); @@ -4316,7 +4317,7 @@ int f2fs_write_inline_data(struct inode *inode, struct folio *folio); int f2fs_recover_inline_data(struct inode *inode, struct folio *nfolio); struct f2fs_dir_entry *f2fs_find_in_inline_dir(struct inode *dir, const struct f2fs_filename *fname, struct folio **res_folio, - bool use_hash); + struct decrypted_name_prealloc *prealloc, bool use_hash); int f2fs_make_empty_inline_dir(struct inode *inode, struct inode *parent, struct folio *ifolio); int f2fs_add_inline_entry(struct inode *dir, const struct f2fs_filename *fname, diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c index 901c630685ced..d02ff6c26d70a 100644 --- a/fs/f2fs/inline.c +++ b/fs/f2fs/inline.c @@ -353,6 +353,7 @@ int f2fs_recover_inline_data(struct inode *inode, struct folio *nfolio) struct f2fs_dir_entry *f2fs_find_in_inline_dir(struct inode *dir, const struct f2fs_filename *fname, struct folio **res_folio, + struct decrypted_name_prealloc *prealloc, bool use_hash) { struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb); @@ -370,7 +371,7 @@ struct f2fs_dir_entry *f2fs_find_in_inline_dir(struct inode *dir, inline_dentry = inline_data_addr(dir, ifolio); make_dentry_ptr_inline(dir, &d, inline_dentry); - de = f2fs_find_target_dentry(&d, fname, NULL, use_hash); + de = f2fs_find_target_dentry(&d, fname, NULL, prealloc, use_hash); folio_unlock(ifolio); if (IS_ERR(de)) { *res_folio = ERR_CAST(de); -- 2.34.1