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| author | David Howells <dhowells@redhat.com> | 2020-12-23 11:39:57 +0100 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2021-01-04 13:25:19 +0100 |
| commit | 366911cd762db02c2dd32fad1be96b72a66f205d (patch) | |
| tree | f09fdfc5d7c4d61dfb2fd936dc0f5a1a107db1fd /include/trace/events | |
| parent | afs: Work around strnlen() oops with CONFIG_FORTIFIED_SOURCE=y (diff) | |
| download | linux-366911cd762db02c2dd32fad1be96b72a66f205d.tar.xz linux-366911cd762db02c2dd32fad1be96b72a66f205d.zip | |
afs: Fix directory entry size calculation
The number of dirent records used by an AFS directory entry should be
calculated using the assumption that there is a 16-byte name field in the
first block, rather than a 20-byte name field (which is actually the case).
This miscalculation is historic and effectively standard, so we have to use
it.
The calculation we need to use is:
1 + (((strlen(name) + 1) + 15) >> 5)
where we are adding one to the strlen() result to account for the NUL
termination.
Fix this by the following means:
(1) Create an inline function to do the calculation for a given name
length.
(2) Use the function to calculate the number of records used for a dirent
in afs_dir_iterate_block().
Use this to move the over-end check out of the loop since it only
needs to be done once.
Further use this to only go through the loop for the 2nd+ records
composing an entry. The only test there now is for if the record is
allocated - and we already checked the first block at the top of the
outer loop.
(3) Add a max name length check in afs_dir_iterate_block().
(4) Make afs_edit_dir_add() and afs_edit_dir_remove() use the function
from (1) to calculate the number of blocks rather than doing it
incorrectly themselves.
Fixes: 63a4681ff39c ("afs: Locally edit directory data for mkdir/create/unlink/...")
Fixes: ^1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
Diffstat (limited to 'include/trace/events')
| -rw-r--r-- | include/trace/events/afs.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h index 4eef374d4413..4a5cc8c64be3 100644 --- a/include/trace/events/afs.h +++ b/include/trace/events/afs.h @@ -231,6 +231,7 @@ enum afs_file_error { afs_file_error_dir_bad_magic, afs_file_error_dir_big, afs_file_error_dir_missing_page, + afs_file_error_dir_name_too_long, afs_file_error_dir_over_end, afs_file_error_dir_small, afs_file_error_dir_unmarked_ext, @@ -488,6 +489,7 @@ enum afs_cb_break_reason { EM(afs_file_error_dir_bad_magic, "DIR_BAD_MAGIC") \ EM(afs_file_error_dir_big, "DIR_BIG") \ EM(afs_file_error_dir_missing_page, "DIR_MISSING_PAGE") \ + EM(afs_file_error_dir_name_too_long, "DIR_NAME_TOO_LONG") \ EM(afs_file_error_dir_over_end, "DIR_ENT_OVER_END") \ EM(afs_file_error_dir_small, "DIR_SMALL") \ EM(afs_file_error_dir_unmarked_ext, "DIR_UNMARKED_EXT") \ |