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author | 2006-01-08 01:02:39 -0800 | |
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committer | 2006-01-08 20:13:52 -0800 | |
commit | 4a30131e7dbb17e5fec6958bfac9da9aff1fa29b (patch) | |
tree | 2ff6139b393a9a413e2ea4db4dd2d15eec2201f8 /fs/open.c | |
parent | [PATCH] Permit multiple inclusion of linux/pagevec.h (diff) | |
download | linux-4a30131e7dbb17e5fec6958bfac9da9aff1fa29b.tar.gz linux-4a30131e7dbb17e5fec6958bfac9da9aff1fa29b.tar.bz2 linux-4a30131e7dbb17e5fec6958bfac9da9aff1fa29b.zip |
[PATCH] Fix some problems with truncate and mtime semantics.
SUS requires that when truncating a file to the size that it currently
is:
truncate and ftruncate should NOT modify ctime or mtime
O_TRUNC SHOULD modify ctime and mtime.
Currently mtime and ctime are always modified on most local
filesystems (side effect of ->truncate) or never modified (on NFS).
With this patch:
ATTR_CTIME|ATTR_MTIME are sent with ATTR_SIZE precisely when
an update of these times is required whether size changes or not
(via a new argument to do_truncate). This allows NFS to do
the right thing for O_TRUNC.
inode_setattr nolonger forces ATTR_MTIME|ATTR_CTIME when the ATTR_SIZE
sets the size to it's current value. This allows local filesystems
to do the right thing for f?truncate.
Also, the logic in inode_setattr is changed a bit so there are two return
points. One returns the error from vmtruncate if it failed, the other
returns 0 (there can be no other failure).
Finally, if vmtruncate succeeds, and ATTR_SIZE is the only change
requested, we now fall-through and mark_inode_dirty. If a filesystem did
not have a ->truncate function, then vmtruncate will have changed i_size,
without marking the inode as 'dirty', and I think this is wrong.
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs/open.c')
-rw-r--r-- | fs/open.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/fs/open.c b/fs/open.c index f53a5b9ffb7d..94968cb3afca 100644 --- a/fs/open.c +++ b/fs/open.c @@ -194,7 +194,8 @@ out: return error; } -int do_truncate(struct dentry *dentry, loff_t length, struct file *filp) +int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs, + struct file *filp) { int err; struct iattr newattrs; @@ -204,7 +205,7 @@ int do_truncate(struct dentry *dentry, loff_t length, struct file *filp) return -EINVAL; newattrs.ia_size = length; - newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME; + newattrs.ia_valid = ATTR_SIZE | time_attrs; if (filp) { newattrs.ia_file = filp; newattrs.ia_valid |= ATTR_FILE; @@ -266,7 +267,7 @@ static inline long do_sys_truncate(const char __user * path, loff_t length) error = locks_verify_truncate(inode, NULL, length); if (!error) { DQUOT_INIT(inode); - error = do_truncate(nd.dentry, length, NULL); + error = do_truncate(nd.dentry, length, 0, NULL); } put_write_access(inode); @@ -318,7 +319,7 @@ static inline long do_sys_ftruncate(unsigned int fd, loff_t length, int small) error = locks_verify_truncate(inode, file, length); if (!error) - error = do_truncate(dentry, length, file); + error = do_truncate(dentry, length, 0, file); out_putf: fput(file); out: |