Re: [PATCH] exfat: limit log print for IO error

[Namjae Jeon]

On Fri, Aug 15, 2025 at 6:33 PM Chi Zhiling <chizhiling@xxxxxxx> wrote:
>
> From: Chi Zhiling <chizhiling@xxxxxxxxxx>
>
> For exFAT filesystems with 4MB read_ahead_size, removing the storage device
> when the read operation is in progress, which cause the last read syscall
> spent 150s [1]. The main reason is that exFAT generates excessive log
> messages [2].
>
> After applying this patch, approximately 300,000 lines of log messages
> were suppressed, and the delay of the last read() syscall was reduced
> to about 4 seconds.
>
> [1]:
> write(5, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 131072) = 131072 <0.000120>
> read(4, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 131072) = 131072 <0.000032>
> write(5, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 131072) = 131072 <0.000119>
> read(4, 0x7fccf28ae000, 131072)         = -1 EIO (Input/output error) <150.186215>
>
> [2]:
> [  333.696603] exFAT-fs (vdb): error, failed to access to FAT (entry 0x0000d780, err:-5)
> [  333.697378] exFAT-fs (vdb): error, failed to access to FAT (entry 0x0000d780, err:-5)
> [  333.698156] exFAT-fs (vdb): error, failed to access to FAT (entry 0x0000d780, err:-5)
>
> Signed-off-by: Chi Zhiling <chizhiling@xxxxxxxxxx>
Applied it to #dev.
Thanks!