| Message ID | 87woh5pyqh.fsf@mail.parknet.co.jp (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] fat: Add nobarrier to workaround the strange behavior of device | expand |
On Fri, 28 Jun 2019 23:32:06 +0900 OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> wrote: > > v2: > Just cleanup, changed the place of options under comment of fat. > > --- Please be careful with the "^---$" - it denotes "end of changelog", so I ended up without a changelog! > There was the report of strange behavior of device with recent > blkdev_issue_flush() position change. A Reported-by: would be nice, but not necessary. > The following is simplified usbmon trace. > > 4203 9.160230 host -> 1.25.1 USBMS 95 SCSI: Synchronize Cache(10) LUN: 0x00 (LBA: 0x00000000, Len: 0) > 4206 9.164911 1.25.1 -> host USBMS 77 SCSI: Response LUN: 0x00 (Synchronize Cache(10)) (Good) > 4207 9.323927 host -> 1.25.1 USBMS 95 SCSI: Read(10) LUN: 0x00 (LBA: 0x00279950, Len: 240) > 4212 9.327138 1.25.1 -> host USBMS 77 SCSI: Response LUN: 0x00 (Read(10)) (Good) > > [...] > > 7323 10.202167 host -> 1.25.1 USBMS 95 SCSI: Synchronize Cache(10) LUN: 0x00 (LBA: 0x00000000, Len: 0) > 7326 10.432266 1.25.1 -> host USBMS 77 SCSI: Response LUN: 0x00 (Synchronize Cache(10)) (Good) > 7327 10.769092 host -> 1.25.1 USBMS 95 SCSI: Test Unit Ready LUN: 0x00 > 7330 10.769192 1.25.1 -> host USBMS 77 SCSI: Response LUN: 0x00 (Test Unit Ready) (Good) > 7335 12.849093 host -> 1.25.1 USBMS 95 SCSI: Test Unit Ready LUN: 0x00 > 7338 12.849206 1.25.1 -> host USBMS 77 SCSI: Response LUN: 0x00 (Test Unit Ready) (Check Condition) > 7339 12.849209 host -> 1.25.1 USBMS 95 SCSI: Request Sense LUN: 0x00 > > If "Synchronize Cache" command issued then there is idle time, the > device stop to process further commands, and behave as like no media. > (it returns NOT_READY [MEDIUM NOT PRESENT] for SENSE command, and this > happened on Kindle) [just a guess, the device is trying to detect the > "safe-unplug" operation of Windows or such?] > > To workaround those devices and provide flexibility, this adds > "barrier"/"nobarrier" mount options to fat driver. I think it would be helpful if the changelog were to at least describe the longer-term plan which hch described. > --- linux/fs/fat/fat.h~fat-nobarrier 2019-06-28 21:22:18.146191739 +0900 > +++ linux-hirofumi/fs/fat/fat.h 2019-06-28 23:26:04.881215721 +0900 > @@ -51,6 +51,7 @@ struct fat_mount_options { > tz_set:1, /* Filesystem timestamps' offset set */ > rodir:1, /* allow ATTR_RO for directory */ > discard:1, /* Issue discard requests on deletions */ > + barrier:1, /* Issue FLUSH command */ > dos1xfloppy:1; /* Assume default BPB for DOS 1.x floppies */ Documentation/filesystems/vfat.txt should be updated to describe this new option please. And perhaps to mention that a device-level quirk should be used in preference, if it is available.
diff -puN fs/fat/fat.h~fat-nobarrier fs/fat/fat.h --- linux/fs/fat/fat.h~fat-nobarrier 2019-06-28 21:22:18.146191739 +0900 +++ linux-hirofumi/fs/fat/fat.h 2019-06-28 23:26:04.881215721 +0900 @@ -51,6 +51,7 @@ struct fat_mount_options { tz_set:1, /* Filesystem timestamps' offset set */ rodir:1, /* allow ATTR_RO for directory */ discard:1, /* Issue discard requests on deletions */ + barrier:1, /* Issue FLUSH command */ dos1xfloppy:1; /* Assume default BPB for DOS 1.x floppies */ }; diff -puN fs/fat/file.c~fat-nobarrier fs/fat/file.c --- linux/fs/fat/file.c~fat-nobarrier 2019-06-28 21:22:18.147191734 +0900 +++ linux-hirofumi/fs/fat/file.c 2019-06-28 23:26:04.881215721 +0900 @@ -193,17 +193,21 @@ static int fat_file_release(struct inode int fat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync) { struct inode *inode = filp->f_mapping->host; + struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); int err; err = __generic_file_fsync(filp, start, end, datasync); if (err) return err; - err = sync_mapping_buffers(MSDOS_SB(inode->i_sb)->fat_inode->i_mapping); + err = sync_mapping_buffers(sbi->fat_inode->i_mapping); if (err) return err; - return blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL); + if (sbi->options.barrier) + err = blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL); + + return err; } diff -puN fs/fat/inode.c~fat-nobarrier fs/fat/inode.c --- linux/fs/fat/inode.c~fat-nobarrier 2019-06-28 21:22:18.148191730 +0900 +++ linux-hirofumi/fs/fat/inode.c 2019-06-28 23:26:28.029103863 +0900 @@ -1016,6 +1016,8 @@ static int fat_show_options(struct seq_f seq_puts(m, ",nfs=stale_rw"); if (opts->discard) seq_puts(m, ",discard"); + if (!opts->barrier) + seq_puts(m, ",nobarrier"); if (opts->dos1xfloppy) seq_puts(m, ",dos1xfloppy"); @@ -1031,8 +1033,9 @@ enum { Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes, Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes, Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont, - Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset, - Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy, + Opt_err_panic, Opt_err_ro, Opt_discard, Opt_barrier, Opt_nobarrier, + Opt_nfs, Opt_time_offset, Opt_nfs_stale_rw, Opt_nfs_nostale_ro, + Opt_err, Opt_dos1xfloppy, }; static const match_table_t fat_tokens = { @@ -1062,6 +1065,8 @@ static const match_table_t fat_tokens = {Opt_err_panic, "errors=panic"}, {Opt_err_ro, "errors=remount-ro"}, {Opt_discard, "discard"}, + {Opt_barrier, "barrier"}, + {Opt_nobarrier, "nobarrier"}, {Opt_nfs_stale_rw, "nfs"}, {Opt_nfs_stale_rw, "nfs=stale_rw"}, {Opt_nfs_nostale_ro, "nfs=nostale_ro"}, @@ -1146,6 +1151,7 @@ static int parse_options(struct super_bl opts->numtail = 1; opts->usefree = opts->nocase = 0; opts->tz_set = 0; + opts->barrier = 1; opts->nfs = 0; opts->errors = FAT_ERRORS_RO; *debug = 0; @@ -1269,6 +1275,15 @@ static int parse_options(struct super_bl case Opt_err_ro: opts->errors = FAT_ERRORS_RO; break; + case Opt_discard: + opts->discard = 1; + break; + case Opt_barrier: + opts->barrier = 1; + break; + case Opt_nobarrier: + opts->barrier = 0; + break; case Opt_nfs_stale_rw: opts->nfs = FAT_NFS_STALE_RW; break; @@ -1332,9 +1347,6 @@ static int parse_options(struct super_bl case Opt_rodir: opts->rodir = 1; break; - case Opt_discard: - opts->discard = 1; - break; /* obsolete mount options */ case Opt_obsolete:
v2: Just cleanup, changed the place of options under comment of fat. --- There was the report of strange behavior of device with recent blkdev_issue_flush() position change. The following is simplified usbmon trace. 4203 9.160230 host -> 1.25.1 USBMS 95 SCSI: Synchronize Cache(10) LUN: 0x00 (LBA: 0x00000000, Len: 0) 4206 9.164911 1.25.1 -> host USBMS 77 SCSI: Response LUN: 0x00 (Synchronize Cache(10)) (Good) 4207 9.323927 host -> 1.25.1 USBMS 95 SCSI: Read(10) LUN: 0x00 (LBA: 0x00279950, Len: 240) 4212 9.327138 1.25.1 -> host USBMS 77 SCSI: Response LUN: 0x00 (Read(10)) (Good) [...] 7323 10.202167 host -> 1.25.1 USBMS 95 SCSI: Synchronize Cache(10) LUN: 0x00 (LBA: 0x00000000, Len: 0) 7326 10.432266 1.25.1 -> host USBMS 77 SCSI: Response LUN: 0x00 (Synchronize Cache(10)) (Good) 7327 10.769092 host -> 1.25.1 USBMS 95 SCSI: Test Unit Ready LUN: 0x00 7330 10.769192 1.25.1 -> host USBMS 77 SCSI: Response LUN: 0x00 (Test Unit Ready) (Good) 7335 12.849093 host -> 1.25.1 USBMS 95 SCSI: Test Unit Ready LUN: 0x00 7338 12.849206 1.25.1 -> host USBMS 77 SCSI: Response LUN: 0x00 (Test Unit Ready) (Check Condition) 7339 12.849209 host -> 1.25.1 USBMS 95 SCSI: Request Sense LUN: 0x00 If "Synchronize Cache" command issued then there is idle time, the device stop to process further commands, and behave as like no media. (it returns NOT_READY [MEDIUM NOT PRESENT] for SENSE command, and this happened on Kindle) [just a guess, the device is trying to detect the "safe-unplug" operation of Windows or such?] To workaround those devices and provide flexibility, this adds "barrier"/"nobarrier" mount options to fat driver. Cc: <stable@vger.kernel.org> Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> --- fs/fat/fat.h | 1 + fs/fat/file.c | 8 ++++++-- fs/fat/inode.c | 22 +++++++++++++++++----- 3 files changed, 24 insertions(+), 7 deletions(-)