linux-toradex.git/fs/seq_file.c, branch v2.6.27.23

seq_file: properly cope with pread

2009-03-17T00:52:43+00:00

commit 8f19d472935c83d823fa4cf02bcc0a7b9952db30 upstream.

Currently seq_read assumes that the offset passed to it is always the
offset it passed to user space.  In the case pread this assumption is
broken and we do the wrong thing when presented with pread.

To solve this I introduce an offset cache inside of struct seq_file so we
know where our logical file position is.  Then in seq_read if we try to
read from another offset we reset our data structures and attempt to go to
the offset user space wanted.

[akpm@linux-foundation.org: restore FMODE_PWRITE]
[pjt@google.com: seq_open needs its fmode opened up to take advantage of this]
Signed-off-by: Eric Biederman 
Cc: Alexey Dobriyan 
Cc: Al Viro 
Cc: Paul Turner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

seq_file: fix big-enough lseek() + read()

2009-02-12T17:31:11+00:00

commit f01d1d546abb2f4028b5299092f529eefb01253a upstream.

lseek() further than length of the file will leave stale ->index
(second-to-last during iteration). Next seq_read() will not notice
that ->f_pos is big enough to return 0, but will print last item
as if ->f_pos is pointing to it.

Introduced in commit cb510b8172602a66467f3551b4be1911f5a7c8c2
aka "seq_file: more atomicity in traverse()".

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

seq_file: move traverse so it can be used from seq_read

2009-02-12T17:31:10+00:00

commit 33da8892a2f9e7d4b2d9a35fc80833ba2d2b1aa6 upstream.

In 2.6.25 some /proc files were converted to use the seq_file
infrastructure.  But seq_files do not correctly support pread(), which
broke some usersapce applications.

To handle pread correctly we can't assume that f_pos is where we left it
in seq_read.  So move traverse() so that we can eventually use it in
seq_read and do thus some day support pread().

Signed-off-by: Eric Biederman 
Cc: Paul Turner 
Cc: Alexey Dobriyan 
Cc: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

[PATCH] deal with the first call of ->show() generating no output

2008-08-25T05:18:10+00:00

seq_read() has a subtle bug - we want the first loop there to go
until at least one *non-empty* record had fit entirely into buffer.

Signed-off-by: Al Viro

seq_file: add seq_cpumask(), seq_nodemask()

2008-08-12T23:07:30+00:00

Short enough reads from /proc/irq/*/smp_affinity return -EINVAL for no
good reason.

This became noticed with NR_CPUS=4096 patches, when length of printed
representation of cpumask becase 1152, but cat(1) continued to read with
1024-byte chunks.  bitmap_scnprintf() in good faith fills buffer, returns
1023, check returns -EINVAL.

Fix it by switching to seq_file, so handler will just fill buffer and
doesn't care about offsets, length, filling EOF and all this crap.

For that add seq_bitmap(), and wrappers around it -- seq_cpumask() and
seq_nodemask().

Signed-off-by: Alexey Dobriyan 
Reviewed-by: Paul Jackson 
Cc: Mike Travis 
Cc: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[patch 2/7] vfs: mountinfo: add seq_file_root()

2008-04-23T04:04:38+00:00

Add a new function:

  seq_file_root()

This is similar to seq_path(), but calculates the path relative to the
given root, instead of current->fs->root.  If the path was unreachable
from root, then modify the root parameter to reflect this.

Signed-off-by: Miklos Szeredi 
Signed-off-by: Al Viro

[patch 1/7] vfs: mountinfo: add dentry_path()

2008-04-23T04:04:32+00:00

[mszeredi@suse.cz] split big patch into managable chunks

Add the following functions:

  dentry_path()
  seq_dentry()

These are similar to d_path() and seq_path().  But instead of
calculating the path within a mount namespace, they calculate the path
from the root of the filesystem to a given dentry, ignoring mounts
completely.

Signed-off-by: Ram Pai 
Signed-off-by: Miklos Szeredi 
Signed-off-by: Al Viro

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6

2008-04-23T01:28:34+00:00

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  [PATCH] get rid of __exit_files(), __exit_fs() and __put_fs_struct()
  [PATCH] proc_readfd_common() race fix
  [PATCH] double-free of inode on alloc_file() failure exit in create_write_pipe()
  [PATCH] teach seq_file to discard entries
  [PATCH] umount_tree() will unhash everything itself
  [PATCH] get rid of more nameidata passing in namespace.c
  [PATCH] switch a bunch of LSM hooks from nameidata to path
  [PATCH] lock exclusively in collect_mounts() and drop_collected_mounts()
  [PATCH] move a bunch of declarations to fs/internal.h

fs: use loff_t type instead of long long

2008-04-22T22:17:11+00:00

Use offset type consistently.

Signed-off-by: David Sterba 
Signed-off-by: Linus Torvalds

[PATCH] teach seq_file to discard entries

2008-04-22T03:14:02+00:00

Allow ->show() return SEQ_SKIP; that will discard all
output from that element and move on.

Signed-off-by: Al Viro