kernel.git/fs/exfat/dir.c, branch linux-5.16.y

exfat: handle wrong stream entry size in exfat_readdir()

2021-07-04T00:33:00Z

The compatibility issue between linux exfat and exfat of some camera company was reported from Florian. In their exfat, if the number of files exceeds any limit, the DataLength in stream entry of the directory is no longer updated. So some files created from camera does not show in linux exfat. because linux exfat doesn't allow that cpos becomes larger than DataLength of stream entry. This patch check DataLength in stream entry only if the type is ALLOC_NO_FAT_CHAIN and add the check ensure that dentry offset does not exceed max dentries size(256 MB) to avoid the circular FAT chain issue. Fixes: ca06197382bd ("exfat: add directory operations") Cc: stable@vger.kernel.org # v5.9 Reported-by: Florian Cramer Reviewed-by: Sungjong Seo Tested-by: Chris Down Signed-off-by: Namjae Jeon

exfat: speed up iterate/lookup by fixing start point of traversing cluster chain

2021-04-27T11:45:07Z

When directory iterate and lookup is called, there's a buggy rewinding of start point for traversing cluster chain to the parent directory entry's first cluster. This caused repeated cluster chain traversing from the first entry of the parent directory that would show worse performance if huge amounts of files exist under the parent directory. Fix not to rewind, make continue from currently referenced cluster and dir entry. Tested with 50,000 files under single directory / 256GB sdcard, with command "time ls -l > /dev/null", Before : 0m08.69s real 0m00.27s user 0m05.91s system After : 0m07.01s real 0m00.25s user 0m04.34s system Signed-off-by: Hyeongseok Kim Reviewed-by: Sungjong Seo Signed-off-by: Namjae Jeon

exfat: improve write performance when dirsync enabled

2021-04-27T11:45:06Z

Degradation of write speed caused by frequent disk access for cluster bitmap update on every cluster allocation could be improved by selective syncing bitmap buffer. Change to flush bitmap buffer only for the directory related operations. Signed-off-by: Hyeongseok Kim Acked-by: Sungjong Seo Signed-off-by: Namjae Jeon

exfat: add support ioctl and FITRIM function

2021-04-27T11:45:06Z

Add FITRIM ioctl to enable discarding unused blocks while mounted. As current exFAT doesn't have generic ioctl handler, add empty ioctl function first, and add FITRIM handler. Signed-off-by: Hyeongseok Kim Reviewed-by: Chaitanya Kulkarni Acked-by: Sungjong Seo Signed-off-by: Namjae Jeon

exfat: remove 'rwoffset' in exfat_inode_info

2020-10-21T23:29:11Z

Remove 'rwoffset' in exfat_inode_info and replace it with the parameter of exfat_readdir(). Since rwoffset is referenced only by exfat_readdir(), it is not necessary a exfat_inode_info's member. Also, change cpos to point to the next of entry-set, and return the index of dir-entry via dir_entry->entry. Signed-off-by: Tetsuhiro Kohada Acked-by: Sungjong Seo Signed-off-by: Namjae Jeon

exfat: replace memcpy with structure assignment

2020-10-21T23:29:11Z

Use structure assignment instead of memcpy. Signed-off-by: Tetsuhiro Kohada Acked-by: Sungjong Seo Signed-off-by: Namjae Jeon

exfat: eliminate dead code in exfat_find()

2020-10-21T23:29:11Z

The exfat_find_dir_entry() called by exfat_find() doesn't return -EEXIST. Therefore, the root-dir information setting is never executed. Signed-off-by: Tetsuhiro Kohada Acked-by: Sungjong Seo Signed-off-by: Namjae Jeon

exfat: add error check when updating dir-entries

2020-08-11T23:31:12Z

Add error check when synchronously updating dir-entries. Suggested-by: Sungjong Seo Signed-off-by: Tetsuhiro Kohada Signed-off-by: Namjae Jeon

exfat: write multiple sectors at once

2020-08-11T23:31:11Z

Write multiple sectors at once when updating dir-entries. Add exfat_update_bhs() for that. It wait for write completion once instead of sector by sector. It's only effective if sync enabled. Signed-off-by: Tetsuhiro Kohada Signed-off-by: Namjae Jeon

exfat: remove EXFAT_SB_DIRTY flag

2020-08-11T23:31:10Z

This flag is set/reset in exfat_put_super()/exfat_sync_fs() to avoid sync_blockdev(). - exfat_put_super(): Before calling this, the VFS has already called sync_filesystem(), so sync is never performed here. - exfat_sync_fs(): After calling this, the VFS calls sync_blockdev(), so, it is meaningless to check EXFAT_SB_DIRTY or to bypass sync_blockdev() here. Remove the EXFAT_SB_DIRTY check to ensure synchronization. And remove the code related to the flag. Signed-off-by: Tetsuhiro Kohada Reviewed-by: Sungjong Seo Signed-off-by: Namjae Jeon