Hi everyone,
The Linux Coda drivers and the ext3 patches don't seem to get along
very well, at least in Linux 2.4.7. I've got a stock 2.4.7 kernel with
a patch applied to the USB drivers (for a sony digital camera; see
http://www.sujal.net/tech/linux/ just a change in unusual_devs.h).
After I applied the ext3 patches from
http://www.uow.edu.au/~andrewm/linux/ext3/ . Basically, when an
application tries to write to a file system mounted via coda, the
application terminates with "Memory Fault" returned to the terminal.
THe file system still thinks it's busy (can't umount).
I'm using the ext3-2.4-0.9.5-247 patch. I have not yet tried a newer
kernel.
THe funny thing is that mounting/unmount works fine as long as I don't
try to write. Also, I can create files via touch or mkdir without
causing problems. The following log snippet shows me mounting then
immediately unmounting the filesystem, then remounting and trying a
write operation (using cp).
Just to let everyone know, I am running my own replacement for venus
(something similar to podfuk/uservfs), and I do have the NVidia drivers
loaded. I was able to recreate this bug without the NVdriver module
loaded, however. Also, I backed out the patches for ext3 and the
problem went away.
THe following messages appear in my syslog:
Sep 18 19:02:00 pcsshah kernel: Coda Kernel/Venus communications, v5.3.14,
coda@cs.cmu.edu
Sep 18 19:02:16 pcsshah kernel: coda_read_super: Bad mount version
Sep 18 19:02:16 pcsshah kernel: coda_read_super: device index: 0
Sep 18 19:02:16 pcsshah kernel: coda_read_super: rootfid is
(0x1234567,0xffffffff,0x1)
Sep 18 19:02:16 pcsshah kernel: coda_read_super: rootinode is 1450180609 dev 7
Sep 18 19:03:04 pcsshah kernel: Coda: Bye bye.
Sep 18 19:03:50 pcsshah gconfd (sujal-1184): 21 items remain in the cache after
cleaning already-synced items older than 300 seconds
Sep 18 19:04:34 pcsshah kernel: coda_read_super: Bad mount version
Sep 18 19:04:34 pcsshah kernel: coda_read_super: device index: 0
Sep 18 19:04:34 pcsshah kernel: coda_read_super: rootfid is
(0x1234567,0xffffffff,0x1)
Sep 18 19:04:34 pcsshah kernel: coda_read_super: rootinode is 1450180609 dev 7
Sep 18 19:05:02 pcsshah kernel: kernel BUG at file.c:45!
Sep 18 19:05:02 pcsshah kernel: invalid operand: 0000
Sep 18 19:05:02 pcsshah kernel: CPU: 0
Sep 18 19:05:02 pcsshah kernel: EIP: 0010:[<e59a73df>]
Sep 18 19:05:02 pcsshah kernel: EFLAGS: 00210282
Sep 18 19:05:02 pcsshah kernel: eax: 00000019 ebx: d403e1a0 ecx: 00000006
edx: 00000000
Sep 18 19:05:02 pcsshah kernel: esi: ffffffea edi: d3eaf240 ebp: d3f71de0
esp: d36f3f60
Sep 18 19:05:02 pcsshah kernel: ds: 0018 es: 0018 ss: 0018
Sep 18 19:05:02 pcsshah kernel: Process cp (pid: 1650, stackpage=d36f3000)
Sep 18 19:05:02 pcsshah kernel: Stack: e59acb2c e59acc83 0000002d d3f71de0
ffffffea 00000000 00000400 c0130f96
Sep 18 19:05:02 pcsshah kernel: d3f71de0 bfffef10 00000400 d3f71e00
00000000 0009bce9 00000000 d3a78b60
Sep 18 19:05:02 pcsshah kernel: d383ede0 00000000 d3f719c0 bffff308
d36f2000 00000400 bfffef10 bfffeef8
Sep 18 19:05:02 pcsshah kernel: Call Trace: [sys_write+150/208]
[system_call+51/56]
Sep 18 19:05:02 pcsshah kernel:
Sep 18 19:05:02 pcsshah kernel: Code: 0f 0b 83 c4 0c 8b 43 08 8b 70 08 8d 5e 5c
89 d9 ff 4e 5c 0f
Just FYI.
Thanks,
Sujal
--
---- Sujal Shah --- sujal@sujal.net ---
http://www.sujal.net
Now Playing: George Michael - Freedom 90
On Wed, Sep 19, 2001 at 10:23:36AM -0400, Sujal Shah wrote:> The Linux Coda drivers and the ext3 patches don't seem to get along > very well, at least in Linux 2.4.7. I've got a stock 2.4.7 kernel with > a patch applied to the USB drivers (for a sony digital camera; see > http://www.sujal.net/tech/linux/ just a change in unusual_devs.h). > > After I applied the ext3 patches from > http://www.uow.edu.au/~andrewm/linux/ext3/ . Basically, when an > application tries to write to a file system mounted via coda, the > application terminates with "Memory Fault" returned to the terminal. > THe file system still thinks it's busy (can't umount).Yeah, I know, and it will probably work when you don't enable data-journalling. Coda's kernelmodule currently uses generic_file_read and generic_file_write on it's containerfiles, which works for many filesystems. However, ext3fs (and tmpfs and several others) have a filesystem specific write implementation and don't really like being called with the generic functions. The patch is simple, but I haven't made it yet. Basically we need to wrap the read/write calls and call cii->c_cfile->f_op->file_write or something.> loaded, however. Also, I backed out the patches for ext3 and the > problem went away.ext2 uses the generic file read/write functions, so whenever ext2 is the underlying filesystem it all works fine. Jan
On Wed, Sep 19, 2001 at 10:23:36AM -0400, Sujal Shah wrote:> The Linux Coda drivers and the ext3 patches don't seem to get along > very well, at least in Linux 2.4.7. I've got a stock 2.4.7 kernel withThe attached patch should fix it. I haven't tested it against ext3, but with tmpfs which used to have the same problem, i.e. not using generic_file_ functions to access the container files. I'll pass it on to Linus and Alan once I get some feedback on whether this solves all problems. I believe this will fix the whole batch of problems that are have been reported with ext3fs, XFS, and tmpfs. It should apply fine for kernel versions 2.4.4 and higher (both the AC and the Linus trees). btw. my comment about disabling ext3 data journalling fixing it was bogus, there was a BUG() in Coda that got triggered because f_op->write wasn't generic_file_write. Jan diff -urN --exclude-from=dontdiff linux-2.4.10-pre9/fs/coda/file.c linux/fs/coda/file.c --- linux-2.4.10-pre9/fs/coda/file.c Thu Sep 6 20:02:24 2001 +++ linux/fs/coda/file.c Wed Sep 19 20:26:41 2001 @@ -31,28 +31,65 @@ int use_coda_close; static ssize_t -coda_file_write(struct file *file,const char *buf,size_t count,loff_t *ppos) +coda_file_read(struct file *file, char *buf, size_t count, loff_t *ppos) { + struct inode *inode = file->f_dentry->d_inode; + struct coda_inode_info *cii = ITOC(inode); struct file *cfile; + + cfile = cii->c_container; + if (!cfile) BUG(); + + if (!cfile->f_op || !cfile->f_op->read) + return -EINVAL; + + return cfile->f_op->read(cfile, buf, count, ppos); +} + +static ssize_t +coda_file_write(struct file *file,const char *buf,size_t count,loff_t *ppos) +{ struct inode *cinode, *inode = file->f_dentry->d_inode; struct coda_inode_info *cii = ITOC(inode); - ssize_t n; + struct file *cfile; + ssize_t ret; + int flags; cfile = cii->c_container; if (!cfile) BUG(); - if (!cfile->f_op || cfile->f_op->write != generic_file_write) - BUG(); + if (!cfile->f_op || !cfile->f_op->write) + return -EINVAL; cinode = cfile->f_dentry->d_inode; - down(&cinode->i_sem); + down(&inode->i_sem); + flags = cfile->f_flags; + cfile->f_flags |= file->f_flags & (O_APPEND | O_SYNC); + + ret = cfile->f_op->write(cfile, buf, count, ppos); - n = generic_file_write(file, buf, count, ppos); + cfile->f_flags = flags; inode->i_size = cinode->i_size; + up(&inode->i_sem); + + return ret; +} + +static int +coda_file_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct inode *inode = file->f_dentry->d_inode; + struct coda_inode_info *cii = ITOC(inode); + struct file *cfile; + + cfile = cii->c_container; + + if (!cfile) BUG(); - up(&cinode->i_sem); + if (!cfile->f_op || !cfile->f_op->mmap) + return -ENODEV; - return n; + return cfile->f_op->mmap(cfile, vma); } int coda_open(struct inode *i, struct file *f) @@ -237,9 +274,9 @@ struct file_operations coda_file_operations = { llseek: generic_file_llseek, - read: generic_file_read, + read: coda_file_read, write: coda_file_write, - mmap: generic_file_mmap, + mmap: coda_file_mmap, open: coda_open, flush: coda_flush, release: coda_release, diff -urN --exclude-from=dontdiff linux-2.4.10-pre9/fs/coda/psdev.c linux/fs/coda/psdev.c --- linux-2.4.10-pre9/fs/coda/psdev.c Wed Apr 25 19:18:54 2001 +++ linux/fs/coda/psdev.c Wed Sep 19 18:45:46 2001 @@ -414,7 +414,7 @@ static int __init init_coda(void) { int status; - printk(KERN_INFO "Coda Kernel/Venus communications, v5.3.14, coda@cs.cmu.edu\n"); + printk(KERN_INFO "Coda Kernel/Venus communications, v5.3.15, coda@cs.cmu.edu\n"); status = init_coda_psdev(); if ( status ) {