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author | NeilBrown <neilb@suse.de> | 2006-01-08 01:02:39 -0800 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-01-08 20:13:52 -0800 |
commit | 4a30131e7dbb17e5fec6958bfac9da9aff1fa29b (patch) | |
tree | 2ff6139b393a9a413e2ea4db4dd2d15eec2201f8 /fs | |
parent | 788540141f4549637e89aadca6e25cf25eb53383 (diff) | |
download | kernel_samsung_aries-4a30131e7dbb17e5fec6958bfac9da9aff1fa29b.zip kernel_samsung_aries-4a30131e7dbb17e5fec6958bfac9da9aff1fa29b.tar.gz kernel_samsung_aries-4a30131e7dbb17e5fec6958bfac9da9aff1fa29b.tar.bz2 |
[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')
-rw-r--r-- | fs/attr.c | 24 | ||||
-rw-r--r-- | fs/exec.c | 2 | ||||
-rw-r--r-- | fs/namei.c | 2 | ||||
-rw-r--r-- | fs/open.c | 9 |
4 files changed, 15 insertions, 22 deletions
@@ -67,20 +67,12 @@ EXPORT_SYMBOL(inode_change_ok); int inode_setattr(struct inode * inode, struct iattr * attr) { unsigned int ia_valid = attr->ia_valid; - int error = 0; - - if (ia_valid & ATTR_SIZE) { - if (attr->ia_size != i_size_read(inode)) { - error = vmtruncate(inode, attr->ia_size); - if (error || (ia_valid == ATTR_SIZE)) - goto out; - } else { - /* - * We skipped the truncate but must still update - * timestamps - */ - ia_valid |= ATTR_MTIME|ATTR_CTIME; - } + + if (ia_valid & ATTR_SIZE && + attr->ia_size != i_size_read(inode)) { + int error = vmtruncate(inode, attr->ia_size); + if (error) + return error; } if (ia_valid & ATTR_UID) @@ -104,8 +96,8 @@ int inode_setattr(struct inode * inode, struct iattr * attr) inode->i_mode = mode; } mark_inode_dirty(inode); -out: - return error; + + return 0; } EXPORT_SYMBOL(inode_setattr); @@ -1505,7 +1505,7 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs) goto close_fail; if (!file->f_op->write) goto close_fail; - if (do_truncate(file->f_dentry, 0, file) != 0) + if (do_truncate(file->f_dentry, 0, 0, file) != 0) goto close_fail; retval = binfmt->core_dump(signr, regs, file); @@ -1491,7 +1491,7 @@ int may_open(struct nameidata *nd, int acc_mode, int flag) if (!error) { DQUOT_INIT(inode); - error = do_truncate(dentry, 0, NULL); + error = do_truncate(dentry, 0, ATTR_MTIME|ATTR_CTIME, NULL); } put_write_access(inode); if (error) @@ -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: |